Midterm 2 Flashcards
Gause’s law of competitive exclusion
Two species competing for the exact same limiting resource/s cannot coexist
• one will outcompete the other (can’t overlap in all dimensions)
Is migratory coupling likely or unlikely to happen in this population?
- Low landscape productivity
- Ectotherms
- Predators are sessile, swimming, or walking
low likelihood
Arctic ground squirrels hibernate. How do they prepare for this?
- Seasonal phenomenon
- Pre-hibernation hyperphagia • Gain up to 40% of body mass • Need polyunsaturated fats
- Find hibernaculum: dark, near 0°C
How do hibernating animals know when to hibernate? What influences the timing? 2 things (very brief).
influenced by circannual and environmental cues
Why does the incidence of population cycles increase with latitude only in mammals?
Many fish, birds and insects can mitigate the effects of seasonality by migration or diapause (insects), but few mammals (from this study) do.
sustained state of hypothermia with behavioural inactivity, entry to and exit from which is governed by internal signals together with exclusively seasonal external cues.
hibernation
How does blubber benefit arctic animals?
- Insulation
- Helps deal with fasting that can occur in winter (energy stores)
Describe this consequence of freezing in the body of an organism:
Freezing of intracellular fluids.
Freezing intracellular fluids:
• Increases osmolality (solute concentration) in
unfrozen portions (extracellular)
• Can cause osmotic swelling & rupture
What are pros and cons of geolocators vs. satellite locators (ICARUS) or use on birds?
- Smaller; can go on small birds
- Cheaper
BUT
- Cannot transmit data (must be retrieved)
- Low location accuracy – average 185km
T or F - eliminating plant chemical defences (toxicity) for lemmings prevented population cycles
false
T or F - costs of migration increase with distance migrated
true
- predation increases diversity by reducing interspecific competition among prey species
- E.g., presence of herbivores creates more niches for plants
- remove predators and prey start competing • One (or a few) may dominate
- E.g. conifers in Boreal forest
Cropping principle:
Do duck and geese use the same flyways or do they change routes during migration?
- Ducks & Geese
- Use particular flyways
- Narrow & well defined paths
- Hunter band (on foot) returns
- Useful conservation info
T or F - species richness increases with increasing latitude
FALSE -
The number of species increases from high (cold-temperate) to low (warm) latitudes
- highest at approx. latitude 0
What can cause osteoporosis in moose teeth/jaw?
if a twig gets caught in teeth they can get an infection and have permanent damage or die
List some major migrators in the boreal forest
- salmon
- whooping crane
- caribou
- white winged scoter
- palm warbler
T or F - metabolism and foraging behaviour are linked. Describe this.
- TRUE.
- In the ocean, mammal and bird richness generally peak in colder, temperate waters
- Ectothermic fish and reptiles that rely on ambient heat
to regulate their body temperature show the highest diversity in tropical and subtropical habitats
In order to keep an insect in check, ___ of offspring must die.
- 90%
- 92.5%
- 95 %
- 97.5%
- 99%
- 99.9%
97.5%
T or F - there is no latitudinal gradient in population cycle periods.
TRUE.
Also, the occurrence of cycles increases with latitude, but only in mammals.
Describe this Extrinsic hypothesis of lemming population cycling: sun/weather (abiotic) hypothesis.
Sun spots (11 yr cycle) & weather - influences weather patterns (correlated with net snow accumulation), can correlate with cycles of lemmings
Is boreal forest precipitation increasing or decreasing? Does it differ from east to west, or in winter or summer?
Increasing everywhere.
More precipitation in winter, but less precipitation in summer (north, ex. northern Alberta).
Thermal conductance and conductivity can be reduced by insulation. How do arctic foxes change their fur to accomplish this?
Shed new fur or grow new fur.
Conductance:
• In Arctic fox, fur conductance 114% higher in the summer than the winter
• Fur thickness increased 200% summer to winter
There are 2 ways animals can reduce heat loss in their peripheries in winter.
Describe: Allowing peripheral tissues to be cooler, in huskies.
- Huskies maintain foot temperature at 0C even if the ground is -50C.
- Cutaneous vascular plexus regulates footpad temp to within a degree of freezing
• _____: low production, high diversity
• deserts: low production, high diversity
What may cause erosion of moose teeth?
Cadium is very high in west MB soils - moose eat aspen which accumulates cadmium 10x more than other trees. The cadmium ruins their teeth.
By how many degrees did the Yukon warm from 1950-2000?
1.5C
Why might moose rip bark off trees?
Low nutritional value but done in severe winters
Describe how these 3 allow organisms to survive freezing (each is different).
- Ice nucleating proteins –
- Antifreeze proteins –
- Cryoprotectants –
- Ice nucleating proteins – allow formation of ice crystals, slow and controlled.
- Antifreeze proteins – prevent ice crystals getting too large.
- Cryoprotectants – Prevent cell shrinkage, promote supercooling.
T or F - young cows (female moose) have more offspring than older ones.
FALSE - young cows have 1 offspring, older ones have more, 2-4.
Describe the migration of pattern/path soaring birds may take (eagles, hawks, seabirds like sooty shearwaters, wandering albatross).
- Use updrafts & thermals
- Only fly in daytime
- Stay over land
What type of species are particular abundant in the arctic diversity wise?
Primitive species are particularly abundant
There are more species of primitive taxa (i.e., mosses, liverworts, lichens & algae) in the Arctic than of vascular plants
Is the boreal forest vulnerable? Why or why not? What would be a risk?
- Boreal trees: high fecundity, large genetic diversity, large populations create high adaptive potential
- Boreal forest vulnerable to climate change because of the homogeneity of the boreal landscape and the pace of change
- Vulnerable to loss of permafrost
- Drought and fire will move Prairies northward
- Invasive shrub species may interrupt the traditional recovery from forest fires
T or F - These are intracellular protectants from freezing:
•Ice Nucleating
Proteins (INP)
•Antifreeze Proteins (AFP)
•Polyols
False - extracellular
___ regions along the Woodland/Shrubland border are browning; the rest of the boreal forest is greening.
(east, west, north, south).
Strongest warming is along the Tundra/Boreal forest boundary.
Western regions along the Woodland/Shrubland border are browning; the rest of the boreal forest is greening.
Strongest warming is along the Tundra/Boreal forest boundary.
Lemming body size during pop. cycle?
* in terms of population cycles
•animals often largest during the peak phase (controlling for age, sex, reproductive stage). The ‘Chitty effect’ (selection favors different genotypes at different densities, behavioural polymorphism).
Adaption
Adaptation = inheritable characteristic that gives the individual an advantage (reproductively) over others with different inherited abilities
What insect stage is most cold tolerant?
Late larval instars are the most cold tolerant. They can withstand temperatures approaching -40° for extended periods. If the beetle enters winter as a young larvae, or any other life stage, significant mortality may occur.
T or F - Abiotic factors influence the northern borders of geographic distribution of animals.
TRUE - Often, it’s temperatures lower than species-specific tolerance limits.
T or F - foot size decreases with latitude within species.
FALSE - it increases with latitude within species
- Exam
What determines the southern borders of the geographic distribution of terrestrial Arctic animals?
Often it’s biotic factors such as competitors and natural enemies.
What can cause birds to get lost during migration?
Storms – weather
• blown off course, get lost
What are proximate vs ultimate explanations?
Proximate explanations refer to causal mechanism or developmental questions
Ultimate explanations refer to the functional or evolutionary history questions
What age moose are hunters killing and why is this a problem?
Most kills 0-7 years old (esp. 1.5 to 2.5) - they’re removing the prime breeders and the ones that would be breeders soon so the population isn’t increasing much.
Describe the process of cryoprotectant formation in wood frogs. What else do they do?
- Blood glucose rises from ~5 mM to 200-400 mM
- Glucose triggered by ice formation
- Made from liver glycogen
- Liver is ~12% of body mass
In summary, they…
• Alter metabolism to synthesize cryoprotectants (polyols, sugars)
• Defend against intracellular desiccation
• Suppress metabolic rate
When do moose shed antlers, and who sheds first?
- Shed in 1st week of December
- Older bulls first
What’s an ultimate explanation for migration?
must increase fitness somehow
T or F - Biotic factors influence the northern borders of geographic distribution of animals.
FALSE - Often, it’s temperatures lower than species-specific tolerance limits.
Describe this (1/2) hypothesis of why migration evolved/ started: Climate change.
- Climate change
• Species lived in the north all year during periods when the climate was warm
• The climate gradually changedeventually the winters grew too cold, forcing the species to head south each year.
Wood frogs freeze solid in winter, how is this possible?
Ice nucleating agents:
- Form in extracellular regions
- Initiate ice crystals formation
- Prevent crystals from getting big
- Extracellular freezing only
- Up to 70% of body water frozen
Biotelemetry is the measurement of behavioural, energetic status and movements of animals in their natural environment.
Why is it beneficial?
What is one major con of biotelemetry?
- Provides insight into a species’ ecological role and biotic/abiotic interactions in the ecosystem.
- Can acquire a large amount of data quickly - depth, temperature, movement, GPS, salinity, [phytoplankton], etc. depending on method.
Con: Expensive!
What 3 things limit the northern growth of Aspen trees?
- moisture
- long growing season
- temperature
T or F - predators lag behind prey in population
true
What animal has this?
Cutaneous vascular plexusregulate footpad temp to within a degree of freezing.
Husky
Describe this 1 of 7 latitudinal gradient hypotheses: Productivity
+ exceptions
- tropics support a greater number of species because more resources are available, allowing for more specialization
- larger input of solar energy = more primary production
- in general: ↑ production → ↑ diversity
exceptions:
• marshes: high production, relatively low diversity
• deserts: low production, high diversity
No correlation between productivity and vertebrate biodiversity
How can tracking arctic cod give us new data? What is measured with these monitoring techniques?
- 85 tagged arctic cod gave over 1 million detections
- GLMM to examine daily presence and absence throughout the year
- Fixed effects: ice cover, salinity, dissolved oxygen, water temperature, toothed whale presence
- Discovered new movements and behaviour, like how they expanded residence during open water and ice cover
- Many depart from the same area en masse
Selection favors different genotypes at different densities (behavioural polymorphism).
Chitty hypothesis
How can sublethal effects of predation risk could affect hare reproduction?
Fecal cortisol metabolite concentrations were 7x higher in captive hares exposed to predators (a trained dog) during gestation
Offspring of stressed hares were smaller
Litter size decreased
Maternal inheritance of stress hormones (may explain lag of population recovery)
Describe vertical migration in copepods or zooplankton.
- Deep waters during the day (avoid visual predators)
- Surface at night to feed, predators again don’t find them as much
- Depth ranges from 40 m at noon, up to the surface at dusk and returning again to the same depth just before dawn.
____ birds lay smaller clutches, less frequently – offset by higher survival
Tropical birds lay smaller clutches, less frequently – offset by higher survival
Did migration originate from the north or the south? Explain this.
- NORTH!
• Analyzed an evolutionary tree showing the lineages of some 800 species of songbirds
• Developed a model that used the evolutionary tree for these many species to predict the ancestry of their seasonal migrations
• reconstructed changes in the breeding and nonbreeding distribution of these birds throughout their evolutionary history
** • Found that long-distance migration had most often evolved through species shifting their wintering ranges toward the tropics.
** • Taken together, the evidence suggests that migration evolved most commonly in birds that originally were found in the north, the “northern home” idea.
What is the metabolic and overall response in this situation:
Endothermic predator, ectothermic prey
- Can be asymmetric in metabolic response to water temperature
- Higher capture efficiency in colder waters – prey more sluggish
T or F - lemmings are keystone species
True - Lemmings are keystone -herbivores in many tundra areas
T or F - the incidence of population cycles increased with latitude in fish.
FALSE - in mammals.
- Many fish, birds and insects can mitigate the effects of seasonality by migration or diapause (insects), but few mammals (from this study) do
When is the lemming reproduction rate lowest? When is winter reproduction common?
- in terms of population cycles
•reproductive rate is lowest at peak densities
(maturation rate, pregnancy rate, breeding season
length)
•winter reproduction is common in years prior to the peak
•litter sizes are generally smaller in winter – however,
population growth is more rapid
What is the mechanism of moose antler shedding?
Erosion at the point of adhesion, around the edges.
What are benefits of wintering in the south for caribou?
• Winter in areas in south:
-regions with less snow
- feed on lichens primarily
• Move north to calving areas in spring:
- on tundra, minimize encounters with predators
- good foraging during lactation
- winds keep insects away
• Caribou can lose up to 300ml of blood per day from insects
What part of the moose falls off, and how?
The bell with rope (the patch of fur like stuff hanging below face) freezes and falls off.
List 4 major environmental drivers of habitat use.
- Migration (latitude)
- Environment presence interactions (ex. chlorophyll A concentration, estimating niche dynamics, thermal habitat use, shark and fishery overlap)
- Animal density
- Residence/foraging areas
T or F - These are intracellular protectants from freezing:
High ‘polyols’
• Glucose
• Glycerol
• Sorbitol
true
What are some control measures for insect outbreaks? There are 9, list 5 or 6.
pheromone traps cut and burn cold weather predators (woodpeckers) forest fires nematodes fungi tree defences (pitch) thinner stands
What 2 things can change the insulation of fur (or feathers)?
- Structure of hair (ex. reindeer hair is hollow).
* Increased density & thickness of fur.
Recent hypotheses have speculated that the jet stream flow will become more meridional as the temperature contrast between Arctic and Sub-tropical zones declines.
What could this cause?
- This leads to prolonged spells of anomalous weather, though the overall global average will continue to rise
- These spells of unusual weather could trigger events that tip ecosystems into a new state
- Forest fires, extreme permafrost melt, winter rain or freezing rain, droughts, floods
Ecology of fear
Non-consumptive (are not eaten) predator effects:
• Altered foraging patterns
• Chronic stress under risk of predation
Describe this technology: BRUV video.
- Lasers take measurements of creature
- Video recording (can put go pro on this instrument)
- Can catch animals with bait, ex shark
In the ocean, what might be the biggest driver of diversity?
SST - sea surface temp!
A link between food & predator hypotheses: why do populations cycle in the North?
• simple food webs: specialist predators tightly coupled to prey
• length of winter: long winters mean food supply is not replenished
** key: Delayed density dependance in stronger in long winters (can be top-down or bottom-up, as long as winter is long)
4 ways animals can survive in the cold.
- Migrate (leave)
- Habitat selection (hide)
•Underground
•Deep water (fresh or salt) – not always •Under snow - Adjust life cycle (overwinter as eggs)
- Adjust body temperature
•Increase metabolism (produce heat)
•Reduce heat loss (insulate)
Environmental drivers of habitat use, describe how shark-fishery overlaps were found
- Found shark hotspots and found fishing hotspots, overlap of high density sharks and fishing vessels = bycadch
Removing 13 black bears from a moose range will change the population from 40/100 calves to __/100 surviving calves.
80
What rule describes why many arctic animals white?
Gloger’s Rule
Pigmentation (melanin) declines as one approaches the poles
Can animals use freeze avoidance if they’re in physical contact with ice?
Freeze tolerance often seen in animals that can’t avoid coming into contact with ice (freeze avoidance doesn’t work).
Endotherms stay warm to survive the cold.
Describe torpor.
Torpor - entry of animal into hypothermia with behavioural inactivity.
Torpor conserves energy; less expended at a given temperature.
Do migratory shorebirds
experience reduced nest predation the farther north they travel?
Yes - 6 fold higher survival at higher latitudes, so higher chance of chick survival/ fitness if you go more north.
- Nest survival increased with
latitude - Thus, higher egg survival is a benefit of longer migration
This latitudinal decline in Arctic species is associated with an increase in super-dominant species that occupy a wide range of habitats.
Give a few examples of these super dominant species
- Mosses
- Sedges
- Willow
- Lemmings
** Exam
T or F - In warmer waters (closer to equator), trophic control is due to resource control.
TRUE (bottom-up control, so nutrient supply of primary producers determines abundance of higher levels)
What happens when prey is at low density for specialist vs generalist predators? What is the result?
- Specialist predators – efficient even at low prey densities
- Generalist predators – may switch to alternative prey (stabilizes dynamics)
Thus, predation patterns affect prey population dynamics
Describe the 3rd stage in the evolution of migration: Migration.
- only migrant population remains. Gradual elimination of the resident population
** Exam
T or F - In warmer waters (closer to equator), trophic control is due to consumer control.
FALSE - resource control
Foxes can survive __ days of starvation before beginning to use fat deposits
Foxes can survive 7 days of starvation before beginning to use fat deposits
In migration: Quality of wintering grounds can affect ____ and _____
Quality of wintering grounds can affect survival and breeding success
When do moose antlers grow, are full size, and harden?
- New growth 1st week of April
- Full size mid July
- Harden by Sept
(shed velvet early Sept, lose antlers in 1st week of December).
T or F - specialist predators drive lemming population cycles
TRUE - Specialist predators appear to drive the cycle (predator will hunt lemmings even at low abundance)
Describe this consequence of freezing in the body of an organism:
Increased concentrations of inorganic salts due to freezing.
Freezing increases concentrations of inorganic
salts:
• Can change structure of proteins, inhibit functioning
(enzymes)
T or F - castrated bulls (moose) stop shedding their antlers.
true
Describe this intrinsic hypothesis of lemming population cycling: Chitty hypothesis.
Chitty hypothesis: behavioral & genetic factors
- selection favors different genotypes at different densities
- behavioral polymorphism
- Populations consist of ‘docile’ and ‘aggressive’ types whose fitness varies with population density.
- At high density, selection favors aggressive types that are good survivors but poor breeders. Population decreases.
- At low density, selection favors docile type that are good breeders. Population increases.
Ice management is key to survive freezing (or to avoid it).
What is a category of intracellular compounds that can be used? Give 3 examples.
•Intracellularly: High ‘polyols’
- Glucose
- Glycerol
- Sorbitol
What are implications for sedges with climate change? What has been their response?
Their initial responses to climatic warming are likely to be increased productivity and abundance
• followed by probable later movement farther to the north.
There are 3 subpoints of the vegetation herbivore interaction hypothesis lemming population cycling:
a. Food abundance
b. Nutrient recovery hypothesis (food quality)
c. Plant chemical defence
Describe: Nutrient recovery hypothesis (food quality).
- was this proven right or wrong?
high lemming populations reduced plant cover and the insulation provided by dead vegetation, thereby increasing the depth of thaw and diluting the soil nutrient pool
Test: add fertilizer.
Did not prevent decline
Why are northern ecosystems less diverse (2)?
• Low prey diversity promotes unstable population dynamics (cycles)
• Less species redundancy lowers ecosystem
resilience
Describe insect freeze tolerance or avoidance in boreal regions.
- Many insects freeze tolerant
- Some can tolerate -85C
- Very low super cooling point, extremely high cyroprotectants
- When freezing, glycerol binds to water; water is not lost during this, avoids dehydration.
What can be used to identify female vs male moose?
Vulva patch - females have white patch in this area. They also have a smaller bell and lighter nose.
Which 3 trees may be most affected by insect outbreaks? All are pines.
- Lodgepole pine
- Jack pine
- Whitebark pine
Describe this 1 of 7 latitudinal gradient hypotheses: Disturbance
• if community disturbance frequency is very high →
local extinction of species → ↓ species diversity
• if community disturbance frequency is very low → competitive exclusion by dominant species → ↓ species diversity
Intermediate disturbance hypothesis:
• moderate disturbance maximizes diversity
• leads to patches at local level
What are the predicted fire impacts of climate change in terms of: frequency, severity, changes in trees, carbon.
- More frequent and severe fires
- Shorter growth periods between fires
- Proportionally younger stands
- Change in forest structure
- Decrease in carbon storage (may become carbon source)
When is moose antler velvet shed and what do they do with it?
- Shed early September
- Moose shakes head or sometimes rubs against stuff to try to grab it, and eats it.
T or F - Antlers are the fastest growing tissue we know of
TRUE
Why might animals move to a new location?
- Acquire food (or energy)
- Avoid predation
- Avoid adverse conditions
- Locate suitable mates
- Locate spawning or nursery habitats
Population cycle
a pattern of periodic fluctuations in population size with rather constant period (amplitude may vary highly)
Influenced by food, predators, disease, climate
The shape is not necessarily symmetrical; tends to be a rapid explosion after 2 or more low years
- Not seasonal
changes, or irregular
irruptions, but regular,
multi-annual cycles
Approx how many km is a round trip for the arctic tern?
How long is it’s lifespan, and how many km does this result in? How many round trips to the moon?
- Average round trip was 70,900 km (range 59,500 - 81,600 km)
- Lifespan > 30 years: total distance flown in a lifetime may be >2.4 million km ( ~3 return journeys to the Moon)
T or F - female moose have smaller bells than males and lighter noses.
True.
Scale of prey + predators together
- Migrant prey induces migration in predators to feed on this prey
migratory coupling
Migratory coupling
- Scale of prey + predators together
- Migrant prey induces migration in predators to feed on this prey
Do moose have antlers or horns?
Antlers! Horns are retained, antlers are not
What are some major dangers for moose?
- Hunting
- Motor vehicle accidents
- Railroads
- Other accidents (drowning)
- Brain worm
- Ticks
- hydatid cysts in lungs (from wolves)
- Calves being hunted by wolves, and bears (*huge)
Intermediate disturbance hypothesis:
Intermediate disturbance hypothesis:
• moderate disturbance maximizes diversity
• leads to patches at local level
T or F - zooplankton migrate
True! But within the water column (vertical migration)
What is “upper level flow”, aka zonal and meridional flow? (in terms of location and what it actually is).
- Zonal: Atmospheric circulation that following (generally) latitudinal lines.
- Meridional: Same, but more longitudinal (north to south).
- Can be thought of as rivers of air (wind). Fastest winds are found where the lines are packed, and the core of the high speed winds is the jet stream.
Pigmentation (melanin) declines as one approaches the poles
Gloger’s rule
Less biodiverse systems in colder waters = ____ controlled
- productivity
- resource
- consumer
- temperature
Less biodiverse systems in colder waters = consumer controlled
Traveling from a central place to a patch containing food and then returning to that central place (typically a nest)
• No spatio-temporal restrictions here
• Longer distance better have higher payoff
central place foraging
Define biotelemetry
Measurement of behavioural, energetic status and movements of animals in their natural environment.
T or F - Rising ocean temperatures may alter the balance of marine endotherms and ectotherms across the globe
true! Affect predator prey relationships between endos and ectos, and endos may become less efficient at consuming prey over time.
What’s a proximate explanation for migration?
perception of day length, hormonal triggers
- Prevent cell shrinkage
* Promote supercooling
Cryoprotectants
T or F - supplemental food for lemmings prevented population cycles
false
__% of moose breed between September 22nd-30th
65%
____ = longest and largest insect migration in North America, traveling up to 8,000 km/yr
monarch butterfly
T or F - the reason pinnipeds are most diverse at the poles may be related due to low shark diversity/numbers at the poles. This means that sharks are competitors to seals.
False - most likely they’re predators to the seals
Rapoport’s Rule:
Rapoport’s Rule: taxa have larger latitudinal ranges in polar regions
Describe this 1 of 7 latitudinal gradient hypotheses: Predation
• increased species diversity in tropics is function of increased number of predators that regulate the prey species at low densities
• decreases competition among prey species (due to high predation)
• allows coexistence of prey species and potential for
new additions
• Stronger selective pressure on avoiding predation than
becoming better competitors
***** not required for card but key:
Cropping principle:
• predation increases diversity by reducing interspecific competition among prey species
• E.g., presence of herbivores creates more niches for plants
• remove predators and prey start competing • One (or a few) may dominate
• E.g. conifers in Boreal forest
___% of species exhibit population cycles
29% (could say 30)
- predation increases diversity by reducing interspecific competition among prey species
- E.g., presence of herbivores creates more niches for plants
- remove predators and prey start competing
- One (or a few) may dominate
- E.g. conifers in Boreal forest
Cropping principle:
What is the mechanism of reindeer conchae (reduce heat loss when breathing)?
Animal inhales:
• Air passes over warm mucosa, saturated with water
• Mucosa are cooled & warm wet air goes to lungs
Animal exhales:
• Air passing back over cooler mucosa is warm, wet from lungs
• Water condenses & mucosa are warmed
• Animal exhales cool “dry” air
What 2 things is insulation by fur decreased by? Give an example for each.
Water:
• Fur does not work as well when wet
• Polar bear fur sheds water very efficiently
Wind:
• Destroys air layering = heat loss by convection
• Muskoxen very long fur is not affected by high winds
Describe this consequence of freezing in the body of an organism:
Extracellular freezing.
Extracellular freezing:
- Can cause cells to shrink too much (desiccation)
- Leads to stress on membranes
- Stops cell functioning
Describe this form of biotelemetry: Satellite telemetry (data loggers), which were used in the 70’s.
- Basic mechanism (2 types).
- Pros and cons of both.
- Animals it may be used for.
- What kind of things it can measure.
- Mechanism: Sends a signal when a satellite passes by a tagged animal. More satellite pings give better location estimates. Signal is transmitted to receiving stations then processed in France or Washington DC.
- ARGOS uses Doppler effect to estimate location – high error, can give a wide range (estimated) of location.
- GPS (Global position system) – high spatial accuracy, smaller range estimation.
- First placed on large terrestrial animals (black bear and elk) but can be used for diving animals too.
- Can track things like location, time, depth, temp, salinity, fluorometry.
Measurement of behavioural, energetic status and movements of animals in their natural environment.
biotelemetry
Describe 2 strategies birds can use when flying to ensure they’ll have enough energy stories during migration.
- Get really fat & then long flight (lipid stores)
2. Not so fat, short flights, stopover & feed to refuel
If you saw moose antlers each with 2 spikes, what would you know about the moose?
It’s younger, they have smaller and simpler antlers - antlers are offensive/ for fighting and are simple, and pointed.
How are polar bears caught and tagged?
- Tranquilize bear from helicopter
- Take measurements
- Can put on collar or ear tag
entry of animal into hypothermia with behavioural inactivity.
torpor
This latitudinal decline in Arctic species is associated with an increase in super-dominant species that occupy a wide range of habitats.
Why are they able to live in a wide range of habitats?
These “super-dominant” species are generally highly plastic, occupy a wide range of habitats, and generally have large effects on ecosystem processes
- Must be generalists, specialization isn’t ideal
In the ocean, mammal and bird richness generally peak in ___, ____ waters.
In the ocean, mammal and bird richness generally peak in colder, temperate waters,
Would this bird have high, moderate, or low juvenile survival rates?
- Temperate resident:
- Migrant:
- Tropical resident:
- Temperate resident: low
- Migrant: moderate
- Tropical resident: moderate to high
Describe this 1 of 7 latitudinal gradient hypotheses: History (time)
- also give support and arguments against this theory
History (time) hypothesis:
• tropical habitats are older, more stable, less disturbed
• Time for adaptation & speciation
Support for theory:
• geological past of boreal less constant than tropics due
to glaciation
• all communities diversify with time
Argument against it:
• as glaciers moved in, species moved south to escape
• history hypothesis can not be tested
How did moose come to Canada?
Bering land bridge
Central place foraging
Traveling from a central place to a patch containing food and then returning to that central place (typically a nest)
• No spatio-temporal restrictions here
• Longer distance better have higher payoff
Density mediated vs trait mediate effects of predators on prey.
+ Where is density more common?
Density-mediated: predators reduce prey numbers
• may be more common in aquatic systems
Trait-mediated: predators affect prey phenotype (e.g., behavior)
• effect of the risk of predation
T or F - birds or animals migrate from every location on earth.
False - it’s Primarily a non-tropical phenomenon BUT altitudinal migration can occur in the tropics so it’s also kind of true.
Gloger’s rule states: Pigmentation (melanin) declines as one approaches the poles.
What are 4 reasons why this is beneficial?
- Camouflage - dark soil, vegetation
- Photoprotection - from UV light
- Protection versus parasites
- Pleiotropy - the production by a single gene of two or more apparently unrelated effects
Describe hydatid cysts in moose lungs.
- Moose to wolf to moose to wolf cycle
- It’s a tapeworm that causes cysts in lung and can kill moose
Is tree growth of needleleaf species negatively or positively influenced by warm summers?
What about late summer precipitation? Winter precipitation?
- Growth of all needleleaf species (fir, spruce, pine, except white pine) was negatively influenced by warm summers in the previous year(s).
- Growth positively correlated with late summer precipitation (but not with winter precipitation), and with current temperatures.
T or F - moose can be aged by their teeth.
true
Should episodic or integrated events be studied for climate change? What do these both mean?
- Episodic: Looking at only one factor that has changed.
- Integrated: Many. Better to study.
___% of species exhibit population cycles. Which ones mostly?
29% (could say 30). Mainly in mammal and fish populations
Describe this Extrinsic hypothesis of lemming population cycling: Predation hypothesis.
- Latitudinal gradient in population cycles… in northern populations: Found increase in amplitude and cycle length.
- Specialist predators exist in the north (least weasel, stoat) and more generalist and nomadic predators in the south.
- Specialist predators appear to drive the cycle (predator will hunt lemmings even at low abundance)
T or F - there is competition for resources in the arctic.
Not so much, competitive species aren’t common in the arctic
Humans have anthropogenic impacts on animal movement/migration that cause displacement, what does this influence in animals?
Decreases in displacements influences: • key ecological traits of that species • Population persistence • Ecosystem processes like.... - Predator-prey interactions and nutrient cycling - Disease transmission
List the 4 atmospheric gasses that have been increasing.
- CO2
- CH4 (methane)
- N2O (nitrous oxide)
- Water vapour
T or F - the moose breeding season has shortened.
True, it used to be 12 weeks and is now 6.
Describe this Extrinsic hypothesis of lemming population cycling: vegetation herbivore interaction hypothesis.
*there are 3 subpoints, just list them.
a. Food abundance
b. Nutrient recovery hypothesis (food quality)
c. Plant chemical defence
There are 2 ways animals can reduce heat loss in their peripheries in winter.
Describe: Allowing peripheral tissues to be cooler, in terms of vasoconstriction (birds).
- Close a shunt to stop blood flow, reduces heat loss from feet by lowering their temperature.
- Do this in addition to counter current exchange.
There are 2 major triggers for insect outbreaks. List and describe them briefly.
- Warm winters with no sustained temperatures
below -40C:
- Northern range is dictated by short summers that are too short to complete insect life cycle
- In southern regions, warm fall causes energy reserve exhaustion
- Cold spells can kill larval instars if long enough - Drought
- Weakens trees and makes them more susceptible to insect attack
Describe this newer telemetry tool: Stomach temperature pills.
- Measure temperature in stomach
* Feeding events can be measured and depth they fed at, etc.
An example of migratory coupling where the predator follows prey a long distance
- Red knot (bird) follows horseshoe crab eggs 1000-10,000km+
Describe this newer telemetry tool: ICARUS.
- Uses new technology and antennae system on the ISS (international space stations).
- Can track insects and other tiny things.
- Can use dispersion/behaviour of tagged animals to predict natural disasters
Describe this mechanism migrating animals may use to know where to go: Geomagnetic cues
- Magnetic cues from earth
- Tested by gluing magnets on pigeons’ heads; modifies the magnetic cues. Birds oriented in wrong direction.
List 3 major costs/risks of migration
- Energy
- Predation
- Getting lost
Some plants moose eat are ____.
Aspen, red osier dogwood, thistle, balsam fir (up to 50% of diet)
taxa have larger latitudinal ranges in polar regions
Rapoport’s Rule: taxa have larger latitudinal ranges in polar regions
T or F - There is a latitudinal decrease in predation (low predation at the arctic, higher predation a bit more south, like Churchill) .
true
How do insects (like mosquitos) accomplish freeze avoidance?
- Use supercooling: system remains unfrozen below melting point (0°C)
- Water-impermeable exoskeleton: Keeps soft tissues away from environmental ice, may involve cocoon or wax coating. Body removes ice nucleators (particles that could form ice).
- Supercooling chemicals: antifreeze proteins or cryoprotectants (glycerol, polyols).
relationship between per capita consumption and prey density
Functional response
T or F - haws, eagles, albatross fly at night.
False, soaring birds don’t fly at night ever. Flapping birds like songbirds fly at night.
In terms of “upper level flow”, aka zonal and meridional flow, what happens when these “waves” bulge northward and southward?
ex. a ridge or trough is formed? what temp of air would be found in each?
- When the flow bulges northward, a ridge is formed; ridges have warm air.
- Southward bulges are troughs; they have cold air.
Evaporative heat loss from breathing is a problem in the arctic. How do reindeers deal with this?
Describe how this is accomplished, not the mechanism.
- Reindeerelaborate nasal cavities (called conchae):
- Increase surface area (for heat exchange)
- Divide air flow
- Have thick mucosal layer
There are 3 subpoints of the vegetation herbivore interaction hypothesis lemming population cycling:
a. Food abundance
b. Nutrient recovery hypothesis (food quality)
c. Plant chemical defence
Describe: Plant chemical defence.
- was this proven right or wrong?
Possible issues with plants…
•decrease digestibility
•toxic
No relationship to rodent cycles found.
There are 2 categories of supercooling chemicals; antifreeze proteins and cryoprotectants.
What are cryoprotectants? Animals in what kind of habitat would use it?
- Glycerol (alcohol produced from fat) or other polyols are found in animals in exposed habitats
- Reduce the nucleation potential of seed crystals
- Accumulate high concentrations in body fluids
Describe the 2nd stage in the evolution of migration: Split. Give an example.
Split; migratory & resident populations.
- Fox sparrow had a breeding range (resident population) and a winter range for the migratory population.
What are some constraints on the boreal forest’s ability to respond to climate change? 2 main ones.
- Forests species often align along moisture gradients because of their differing abilities to tolerate drought. Boreal forest is water limited
in the west. - Growth is nitrogen limited and species vary with their nitrogen uptake ability. The availability is partly controlled by carbon (N comes from decaying vegetation)
What telemetry mechanism can be used for fish that don’t surface?
- Pop off tags (PSATs); good for organisms that migrate and can record temperature and depth.
- Put on fish (multiple tags) and can be programmed to pop off at a certain time, which is when the signal is transmitted. You need multiple tags popping off so you can track the animal (a connect the dots map is made).
Natural selection
the process of differential survival and reproduction of alternative genetic variants within a population.
Why do flapping birds like songbirds fly at night?
- Avoid predators & can feed during the day
- Less turbulence caused by thermals and updrafts
- Cooler, thus avoid overheatingflight muscles generate lots of heat
- Convective & evaporative cooling…no sweat glands but can secrete water through their skin & respiratory tract
- Night is more humid so less moisture loss
prevent ice crystals getting too large
Antifreeze proteins
Why are arctic animals white? How does it relate to heat?
*Not the 4 reasons why Gloger’s rule benefits the organisms.
Black objects absorb and radiate more heat than white objects
• White objects lose less heat
• Fur has insulative properties
However, radiant heat loss is largely a function of an
object’s temperature
• Since endotherms same core temp, radiate approximately same amount of heat over time
What is the main driving force behind the presence or absence of cod that we found out using tracking gear?
Presence and absence driven by several environmental variables but mainly sea ice
Describe this form of biotelemetry: Acoustic/ultrasonic telemetry, which was used in the 60’s/70’s.
- Basic mechanism.
- How it was used historically vs now.
- Uses lower frequency pings (kHz), for tracking aquatic animals.
- Used in ocean tracking network.
Previously had to track with a hydrophone from boat, which meant the organisms had to be followed. Now you can set up receiver stations.
** Exam
T or F - In colder waters (further from equator), trophic control is due to consumer control.
TRUE (top-down control, top predator abundance controls prey abundance)
T or F - Some species may have both cyclic and non-cyclic populations.
true
What makes the arctic tern able to migrate such huge distances (considered the ultimate migrator)?
• Ultimate sun follower
• Fairly small bird (<125 g)
• Long-lived …up to 34 years
• Opportunistic feeder of small fish, crustaceans on top surface (50 cm) of ocean
- Pause in areas of high productivity
• Used archival loggers placed on birds to follow them
T or F - Lemmings can consume up to 100 times more vegetation than caribou or muskox in Alaska
True
Within species, foot size ____ with
latitude.
increases or decreases
Within species, foot size increases with
latitude.
Ice management is key to survive freezing (or to avoid it).
What are 3 categories of extracellular compounds that can be used?
Extracellularly:
- Ice Nucleating Proteins (INP)
- Antifreeze Proteins (AFP)
- Polyols
Endotherms stay warm to survive the cold.
Describe hibernation. What size animals hibernate?
Hibernation - sustained state of torpor, entry to and exit from which is governed by internal signals together with exclusively seasonal external cues.
Done by small mammals.
Why do moose like fires?
Fires burn off limited soil, new (nutritious) vegetation grows for the moose to eat. Also tree knockdowns mean more vegetation to eat.
Describe this 1 of 7 latitudinal gradient hypotheses: Competition
Competition hypothesis:
• less competition in boreal environments compared to
tropics
• Northern populations are more regulated by extreme environmental conditions than by biological factors
• since population sizes small, decreased competition for resources
• major sources of mortality are abiotic – populations maintained
For how long was the arctic tern found to stop in the mid-Atlantic ocean, and why?
- Hot-spot in mid-Atlantic ocean –> spent 25 days at this spot
- Using NASA data, identified areas of high marine productivity (chlorophyll)
- coincided with areas of stop-over points
How can we distinguish between dispersal and migration?
Long-term tracking studies used to discriminate the two (to see if animals return, then it’s migration)
What are expected and currently underway changes in the boreal forest in terms of temp, precipitation, productivity, species, etc.
- greater precipitation but a drier forest
- higher temperatures
- disruption of landscape from melting, fire
- changes in hydrology
- declining net primary productivity (changed in 2003)
- changes in plant phenology (timing of biological events) - changes in species mix (forest to grassland/mixed forest)
Allen’s rule.
Describe foxes to illustrate this concept.
• A reduction of the Arctic fox’s ears, muzzle, legs, and tail allows it to conserve heat.
- In the instance of arctic foxes: • Short appendages • Blunt snout • Short rounded ears • Dense winter fur • Furry feet
Do humpback whales migrate? If so, to where/why?
Humpback whale migration – tropics to poles
- Feed in Alaska (lipid rich prey)
- Calves had in Hawaii or Baja (breed and nurse)
What is the metabolic and overall response in this situation: Ectothermic predator and prey
- invariant along thermal gradients
* Similar metabolic rates at same temp
T or F - endotherms will become less efficient at consuming prey over time due to warming ocean temperatures.
true
When might animals leave hibernation (arousal)? What do they use to assist?
Arousal is the period when metabolic rate will rise.
- Can occur if temps in burrow go too low
- Can occur spontaneously
- Some species have food caches and will feed during this time
- Use BAT for arousal
Evaporative heat loss from breathing is a problem in the arctic. How much energy is lost daily by breathing in humans?
In humans on cold days, 20% energy lost by breathing
2 intrinsic and 3 extrinsic hypotheses for why lemming populations cycle (list only)
Intrinsic:
1. density-dependent selection
(Chitty hypothesis)
2. social stress
Extrinsic:
- abiotic (sun spots, weather)
- vegetation-herbivore interactions
- predator-prey interactions
__% of bird species from the boreal that migrate south.
> 80% of all bird species breeding in the boreal region of Canada winter farther south
When are warm bodies predators favoured?
warm-bodied predators are favored where prey are slow, stupid, and cold
What physiological things occur during hibernation?
Metabolic rate falls to fraction of normal.
- MR inhibited as Tb falls (small animals cool faster)
- decreased body temperature
- decreased heart rate
- periods of torpor lasting weeks
- non-REM sleep
- all of this reverses in arousal.
Which of these male and females are most productive/ prime breeders?
- Age 0-1 (calfs)
- Age 2-3 (juniors)
- Age 4-12 (adults)
- Age 13-18 (seniors)
adults, age 4-12
_____ marks the boundary between warm and cold air.
Jet stream marks the boundary between warm and cold air.
Environmental drivers of habitat use, describe niche dynamics
Can estimate niche dynamics by species by finding thermal habitat use (graph colour shows density of population of a species)
What’s the adaptationist program (theory)?
all traits have positive and negative effects on an individual’s reproductive success.
• i.e., costs & benefits.
• To be selected for, a trait must confer more
+ than –
(benefit > cost – Cost/benefit approach)
2 reasons why caribou would migrate north (summer), and 3 reasons why they would want to have babies more south.
In the north…
• Maximize access to abundant & high quality forage
• Minimize interactions with predators and insects
South…
• Fewer predators + insects
• Cool breezes
• Good grazing
How can extreme weather cause a tipping point to be reached in the boreal forest?
What are some things that can change due to this (lakes, species, permafrost).
- Extreme weather can cause a large die off of one or more animal species (ex. after a large fire)
- The spread of a new pest species
- The physical character of the terrain changes
- A change in permafrost that becomes permanent
- Lakes disappear, merge, or become part of a drainage
T or F - keystone species are usually at the bottom of the food web (primary producers)
false - usually in the middle
How can metabolic asymmetries influence predator prey interactions? Have some animals developed solutions?
Metabolic asymmetries also drive asymmetries in sensory and information-processing rates
• flicker fusion rates, saccadic eye movement, and cerebral neural firing
• Mesothermic billfish can channel heat production in eyes and brain – increase neurosensory
What is this?
A large area of low pressure and cold air over earth’s north and south poles. When the jet stream weakens, it becomes wavier, allowing the cold air to dip southward in places while warmer air pushes northward elsewhere.
Polar vortex
Describe this mechanism migrating animals may use to know where to go: Solar compass
- Circadian rhythm/ Internal clock, hard to orient themselves if it’s changed
- Homing pigeons will use the direction of the sun, not the height in the sky
- Resets in captivity
*exam
T or F - Seals use/live in the subnivian layer.
True
Nearly 30% of populations are cyclic (mainly in mammal and fish populations).
The occurence of cycles increases with
latitude, but only in ____.
• No latitudinal gradient in cycle period.
mammals
- exam
What determines the northern borders of the geographic distribution of animals?
- Often, it’s temperatures lower than species-specific tolerance limits.
More biodiverse systems in warmer waters = ______ constrained
- productivity
- resource
- consumer
- temperature
More biodiverse systems in warmer waters = resource constrained
Functional response =
Functional response = relationship between per capita consumption and prey density
How are fish caught and tagged?
- Fish them
- Take weight/measurement
- Cut open and put tag in, then suture (uses MS222 anesthetic)
- Called arctic chair surgery
Beetles have ways to survive cold (ex. antifreeze). To have the biggest impact on mortality, when should the cold come and does it need to be sustained?
As winter temperatures decline, the beetle develops antifreeze in its blood. For cold temperatures to have their biggest impact on mortality, they have to come early or late in the season, when the beetle is least tolerant. Also, the cold temperatures must persist for several days because, with insulating bark and snow, it can take considerable time before under-bark temperatures decline to lethal levels.
80% of boreal birds from Canada migrate south.
~ __% winter in tropical or subtropical regions.
During winter, __% of birds in Mexico are migrants
~ 50% winter in tropical or subtropical regions
During winter, 50% of birds in Mexico are migrants.
Cropping principle:
- predation increases diversity by reducing interspecific competition among prey species
- E.g., presence of herbivores creates more niches for plants
- remove predators and prey start competing
- One (or a few) may dominate
- E.g. conifers in Boreal forest
Ex. in lakes:
• top predators (fish) feed on zooplankton
• if fish are removed → community diversity decreases, becomes dominated by a few species of large, grazing zooplankton
• Trophic cascade (Food web lectures)
• add fish → diversity of small zooplankton and their invertebrate predators increases
T or F - In the ocean, mammal and bird richness generally peak in colder, temperate waters.
TRUE
T or F - concurrent heat exchange is used in the extremities of arctic animals to create a small gradient that reduces heat loss.
FALSE - it’s countercurrent (concurrent has larger gradient, heat lost)
- moderate disturbance maximizes diversity
* leads to patches at local level
Intermediate disturbance hypothesis:
______ is the environmental variable that best predicts plant diversity, nesting bird species, ground beetle species, and butterfly species in the Arctic
Summer temperature
Humpback whales spend time in the south in the winter (breed, nurse) and spend summers farther north where they increase their lipid stores. This is ecosystem connectance, they bring energy to the south region.
Is this central place foraging?
C.P.F. = Traveling from a central place to a patch containing food and then returning to that central place (typically a nest)
• Longer distance better have higher payoff
Yes, just a longer term version of it.
When would a moose have it’s prime antlers?
Early sept (fully grown, nearly fully hardened, has velvet/may be shedding it)
T or F - supplemental nutrients (better food quality) for lemmings prevented population cycles
false
What would happen if ice crystals form near a fish using supercooling proteins? What’s this called?
• Called ‘seeding’
(a) fish remains at −1.5° C, blood is supercooled
(b) Ice at −1.9° C put near fish, destroys supercooling in the fish
(c) fish freezes and dies
Describe this mechanism migrating animals may use to know where to go: Stellar compass
- Stars guide them
- Important for birds that migrate at night
How do aspen trees influence humidity?
Aspen forests release twice as much water and half as much heat as boreal forests – atmospheric humidifiers
Do song birds use the same flyways or do they change routes during migration?
– Less is know about flyways
– More variability
– Appear to use weather fronts
We can study animal movement with direct observations (ex. binoculars). What are pros and cons of this?
Pros: Able to directly observe animal behaviour/interactions.
Cons: 1) Difficult to follow animal 2) Presence may influence results 3) Incredible amount of hours 4) Subjective behavioural classifications
What 2 types of fur do caribou have, and how do they differ?
- Outer coat of long ‘guard hairs’ 775 hairs/cm2
- Fine ‘woolly’ underfur of >2000 follicles/cm2
- undercoat functions as an efficient air trap
How do wind turbines potentially harm bat migration?
- Migrating bats possibly hit by blades
- Undetectable pressure drop near wind turbines can damage their respiratory system = internal haemorrhaging and death
T or F - there is latitudinal gradient in population cycle periods.
false - there is not!
Also, the occurrence of cycles increases with latitude, but only in mammals.
List 3 major cases of troubling issues with biotelemetry.
- Tagged sharks used as warning systems at beaches
• Permitting agency had access to the tagging data
• These data were then used to locate and kill tagged animals to allegedly
reduce human–wildlife conflict - In India, attempts were made to hack GPS collar information from endangered Bengal tigers in a case of “cyber poaching”
- Hunters may target tagged wolves from Yellowstone National Park to interfere with research
So across a wide diversity of taxa, it’s established that more biodiversity in tropical than polar latitudes in terrestrial and marine environments.
What are some potential drivers? (Just general).
- More area, more species
- Precipitation
- Warmer summer temperature
List the 3 basic stages of the evolution of migration.
- Partial migration - Some individuals of a population migrate.
- Split - migratory and resident populations.
- Migrants only.
How long does the arctic tern take to make it’s trop down south? north? Why does it differ?
- Northbound corresponded with wind patterns (averaged 40 days)
- Southbound journey always longer & less direct than northbound (averaged 93 days). Birds stop for a bit in some areas
Where does energy come from that maintains the jet stream? Can it change?
- Energy comes from the temperature contrast across the jet.
- Strongest temperature contrast in winter.
- Strong contrasts “lock” the jet stream in place.
Arctic foxes can adjust their LCT in summer and winter, how does it vary? Is their core body temperature different?
- Lower Critical Temperatures of BMR:
• -7 C in winter
• 5 C in summer - Average body core temperature:
• 39.8 C in summer
• 39.3 C in winter
• Even starved foxes for 8 days in winter when body mass already in decline – no change in BMR
Explain how the impact of climate change is most obvious in the increased frequency and intensity of extreme events.
– Not increasing amount of forest fires, but more large and hot forest fires
– Not increasing temperature averages, but incidences of extreme heat
– Not dry spells, but unprecedented season-long droughts (and for wet spells too)
- Extended periods of above-freezing temperatures in January and also sustained freezing rain storms in the cold season, unusually cold weather, huge clusters of storms and tornados
______ is the environmental variable that best predicts plant diversity in the Arctic
Summer temperature is the environmental variable that best predicts plant diversity in the Arctic
• A reduction of the animal’s ears, muzzle, legs, and tail allows it to conserve heat.
- In the instance of arctic foxes: • Short appendages • Blunt snout • Short rounded ears • Dense winter fur • Furry feet
Allen’s rule
T or F: The advantages of hibernation (energy savings) decrease with increasing body size.
True.
• ____: high production, relatively low diversity
• marshes: high production, relatively low diversity
Describe this (1/2) hypothesis of why migration evolved/ started: Living in a warm place.
- Lived in warm place
• Competition for resources & range expansion
• During warm months, some members of the species began living in more northern areas
• winter came, food grew scarce, so they temporarily relocated to warmer latitudes
T or F - In terms of global warming, the most vulnerable species are those that are most abundant in the northernmost part of the tundra zone or in polar deserts.
True - distribution will contract until they’re out competed.
These groups of species are best adapted to the climate conditions of the high Arctic, where more competitive species are absent
How can stable isotopes be used to track migration in birds?
•Deuterium in feathers reflects rainfall in areas where feathers were grown
•Used feathers of overwintering birds in south to map where they came from (where breeding occurred)
- sample at multiple locations to find where they overwintered based on deuterium levels
There are 2 ways animals can reduce heat loss in their peripheries in winter.
Describe: insulating extremities (caribou, bears, birds)
- Caribou have hairy hooves
- Polar bears have hairy feet
- Birds have knobbly feet (like little bubbles that reduce contact with cold ground)
How does warming affect lemmings and their survival?
Warming affects snow cover, depth, and quality
• Higher juvenile mortality (melt-frost events in the spring)
• Exposed to predators earlier in summer
T or F - there has been no increase in number of fires nationally.
true
What is the most common tree in the boreal forest?
aspen
Describe brown adipose tissue.
- How does it work/when is it used?
- Where is it located?
- Do all animals have it? Do they lose it?
- Used in arousal from hibernation.
- Highly vascular, well innervated, contains many mitochondria. Near blood vessels and vital organs (heart, brain, kidneys).
- Burned to produce heat, not energy.
Brown Adipose Tissue (BAT) is found in almost all mammals in at least one stage of their life.
- Normally present during infancy.
- Often lost after infancy (including humans).
- Remains in hibernators through their entire life.
Population cycle
a pattern of periodic fluctuations in population size with rather constant period (amplitude may vary highly)
Influenced by food, predators, disease, climate
Are lemmings docile or aggressive at the peak of the pop. cycle?
- in terms of population cycles
•More aggressive at peak (especially the Norwegian
lemming), more docile otherwise
By how many degrees has the global land-ocean temperature index increased since 1940?
a. -0.5
b. 0
c. +0.5
d. +1.0
e. +1.5
d. +1.0
Arctic warming will lead to specialization or generalization? Explain this.
- At the southern limits of the tundra, there is greater specialization among microhabitats. Warming is therefore likely to lead to more pronounced habitat and niche specialization.
- Species most likely to expand into tundra are taiga species that currently exist as outlier populations in the Arctic.
Describe this form of biotelemetry: Radio telemetry (VHF)’s, which was used in the 60’s.
- Basic mechanism.
- Pros and cons.
- Animals it may be used for and animals it wouldn’t work for.
VHF transmitters attached to fish (FW), or large terrestrial mammals like mountain lions and tigers to determine migrations and home ranges.
Pros: Less expensive.
Cons: Must follow up or set up receiving stations, and it doesn’t work well in salt water (signals absorbed quicker).
*Dave’s research
What area did ringed seals have the most displacement from over the year and why?
- High arctic most displacement/ most movement, the seals follow the food
T or F: Brown adipose tissue is burned for energy.
FALSE - it’s burned for heat.
If you saw the typical large, palmed and spiky moose antlers, what would you know about the moose?
Adult, middle-aged, prime of its life. Antlers are both defensive (palm) mostly, but also offensive (spikes). Bigger antlers are intimidating and smaller antlered moose will likely avoid them.
a pattern of periodic fluctuations in population size with rather constant period (amplitude may vary highly)
Influenced by food, predators, disease, climate
population cycle
core temperature drops below that required for normal metabolism and body functions
hypothermia
How does a hibernaculum act as a thermal barrier?
- While the temperature outside fluctuates, the hibernacula temperature stays relatively constant.
- Whether the temerpature is +20 or -40, the hibernacula stays around 0 to -5 in the case of arctic ground squirrels.
____ trade-off between survival & reproduction in birds
latitudinal or longitudinal
latitudinal
How much browner is non-arctic Canada getting according to the vegetation index trend (% per decade)?
+2.5%
- 0%
- 2.5%
- 5%
- 7.5%
-2.5% or so, some areas up to -5%.
inheritable characteristic that gives the individual an advantage (reproductively) over others with different inherited abilities
adaption
he process of differential survival and reproduction of alternative genetic variants within a population.
natural selection
What is the difference between migration and dispersal?
Dispersal – movement away from a particular area
Migration – Movement away from and then subsequent return to the same location on a regular basis (usually annual).
Recent hypotheses have speculated that the jet stream flow will become more ____ as the temperature contrast between Arctic and Sub-tropical zones declines.
- meridinal or zonal
Recent hypotheses have speculated that the jet stream flow will become more meridional as the temperature contrast between Arctic and Sub-tropical zones declines.
In terms of “upper level flow”, aka zonal and meridional flow, which of these brings “normal” weather, and which can bring more extreme weather? Describe this.
- Zonal flows bring “normal” changeable weather.
- Meridional flows bring warm/dry/cold/wet spells that often persist, sometimes for weeks.
As populations grow, there is a time lag until
negative feedback mechanisms brings the
population back down
Delayed density dependence
____ ____ has extremely high biodiversity amongst all taxa
western pacific or Indonesian area (around but mostly above Australia)
T or F - There are more species of primitive taxa (i.e., mosses, liverworts, lichens & algae) in the Arctic than of vascular plants.
TRUE
T or F - Summer rain is most important for boreal forest growth in response to climate disturbances, and is important for the ability to take up excess carbon.
True
allow formation of ice crystals, slow and controlled
Ice nucleating proteins
Describe this mechanism migrating animals may use to know where to go: Olfaction
- Sense of smell
- If olfactory nerve cut, the birds will go to the wrong place (can’t find home)
Describe this 1 of 7 latitudinal gradient hypotheses: Environmental stability (climate)
Environmental stability (climatic) hypothesis:
• annual climate in tropics more stable than temperate
or polar climates (less seasonality)
• constant climate → finer specializations and adaptations, shallower niches
• tropical species ↑ number of broods / year • ↑ potential for evolutionary change
• ↑ rate of speciation
• high diversity habitats generally found in stable climates; low diversity habitats associated with severe and/or unpredictable climates
So across a wide diversity of taxa, it’s established that more biodiversity in tropical than polar latitudes in terrestrial and marine environments.
What is 1 exception, that’s more diverse at higher latitudes?
pinnipeds (they’re concentrated at the poles)
List 5 benefits of breeding in the north (migrating, then returning home to breed).
- Greater habitat available for breeding
- Long periods of daylight for foraging
- Superabundance of food in spring (higher resources)
- Fewer competitors
- Fewer predators
T or F - the amount of permafrost in all parts of the boreal forest is decreasing.
False. It is decreasing in many/most areas, but it’s staying the same and even increasing in some areas.
T or F - lemmings represent 48% of vertebrate biomass and 41% of energy flow in the boreal forest of the southwest Yukon
false - snowshoe hares do!
How are the polar vortex and jet stream related?
Polar vortex = A large area of low pressure and cold air over earth’s north and south poles. When the jet stream weakens, it becomes wavier, allowing the cold air to dip southward in places while warmer air pushes northward elsewhere.
A weak jet stream is “wobblier” and allows cold arctic air to move southward, where a large pressure difference/strong jet stream keeps a straighter path that keeps cold air over the arctic.
Describe the migration of pattern/path flapping birds may take (songbirds).
- can fly over the ocean
- Creates fewer updrafts, less turbulence
- Mostly fly at night (avoid predators, cooler, convective and evaporating cooling, more on another card).
T or F - bull’s fight each other
they might, and can be very violent. will die if antlers lock
What 2 hypotheses may explain what drives the lynx-hare cycle? Are these bottom up or top down?
- Hares use up food when population densities are high = starve, decline in sync population.
- hares limit lynx (bottom-up regulation) - Lynx reach high density in response to increases in hare density; at high density, eat all the hares & hare population crashes
- lynx limit hares (top-down regulation)
Which of these would be used for fish or marine mammals mostly?
- Acoustic
- Satellite
- Acoustic for fish
- Satellite for mammals
Define permafrost.
Permafrost: any rock or soil remaining below freezing for two or more years.
Is migratory coupling likely or unlikely to happen in this population?
- Variable system productivity
- High connectively
- Endotherms
highly likely
the temperature when spontaneous freezing occurs in supercooled system
super cooling point
Describe this newer telemetry tool: 3D accelerometers (90’s).
- Reconstruct animal behavior.
- Measure feeding events (can get data on tilt, rotation, force of animal movement).
- Must be retrieved.
What do geolocators record?
Geolocators - Record ambient light intensity, reveal information on sunrise & sunset (can be put on bird leg)
T or F - These are extracellular protectants from freezing:
•Ice Nucleating
Proteins (INP)
•Antifreeze Proteins (AFP)
•Polyols
true
Largest increases in mean annual temperature in ___ and ___ zones of boreal forest.
north
south
east
west
northern and eastern zones
Describe this newer telemetry tool: Predation tags.
- Tag ID changes code 3-5 hours after ingestion; stomach acid digests a polymer.
- Lets you see if the fish you’re tracking was eaten, and then you’re tracking the predator instead of prey.
- First tested in ponds in Windsor, ON.
How might wind affect metabolic heat production?
- Increased wind displaces the warm air layer under fur (convection heat loss).
- Must increase heat production to compensate.
How was biotelemetry used for figuring out habitat use of manta rays and conservation in Sudan’s Red Sea?
- Mantas have high association within marine reserve boundary
- Resort development could pose negative implications for Manta feeding areas (filter feeders so dredging increases turbidity + pollution and run off)
- Found that manta’s live in proposed area of development
Gloger’s Rule
Pigmentation (melanin) declines as one approaches the poles
List and briefly describe 5 key characteristics of population cycles.
1. periodic • fluctuations recur repeatably 2. regular intervals • arvicolines: 3 – 5 years • hare & lynx: 8 – 11 years 3. large amplitude • fur records; mark – recapture studies 4. northern distribution • northern populations cycle more frequently than southern 5. synchronous • broadly synchronous within and among species
Predation is a risk with migration. What’s an example of a bird that preys on migrants?
Eleonora’s Falcon
• preys on migrants
• Delayed breeding season (late summer, early fall), which is during migration
T or F: The arctic is getting greener according to the vegetation index trend.
True.
T or F - bowhead whales migrate
true
There are 2 ways animals can reduce heat loss in their peripheries in winter.
Describe: Allowing peripheral tissues to be cooler, in terms of counter current vs concurrent flow.
Countercurrent flow: Veins and arteries in close proximity, heat is exchanged (small gradients are maintained), less heat lost.
Concurrent flow: Large space between veins and arteries, large gradients cause heat to disappear quickly.
Fur works well in terrestrial environments – what about aquatic? Why do pinnipeds (seals) have fur, and how is it modified?
External fur can serve as the first thermal barrier in water.
- Different characteristics than terrestrial mammals -some otariids have an elongated scale pattern
- Shorter length and flatter hair
Thick guard hairs become flattened - maintain the air layer trapped by the fine underhairs.
• Protects by preventing penetration by water (waterproof barrier)
• protect the insulating air layer
• Facilitates movement through the water by reducing pressure drag
65% of moose breed between _____ and ____
__% of moose breed between September 22nd-30th
Current studies suggest that the western parts of the Boreal forest will transform to a landscape of ____ and ___ forest.
Current studies suggest that the western parts of the Boreal forest will transform to a landscape of grasslands and mixed forest.
Define: super cooling point
Super cooling point (SCP) is the temperature when spontaneous freezing occurs in supercooled system
T or F: Southern/non arctic Canada is getting greener according to the vegetation index trend.
False.
What are 3 reasons why despite low latitudes having the most species diversity, pinnipeds are much more diverse at the poles. Which one is most likely?
1) sharks as predators to seals 2) sharks as competitors to seals
3) sharks as prey to seals
most likely #1
T or F - snowshoe hares represent 48% of vertebrate biomass and 41% of energy flow in the boreal forest of the southwest Yukon
true
Why do moose have a hump on their back?
where ligaments attach
Would this bird have high, moderate, or low reproductive rates?
- Temperate resident:
- Migrant:
- Tropical resident:
- Temperate resident: high
- Migrant: moderate
- Tropical resident: low
T or F - Abiotic factors influence the southern borders of geographic distribution of animals.
FALSE - Often it’s biotic factors such as competitors and natural enemies.
predators affect prey phenotype (e.g., behavior)
• effect of the risk of predation
Trait-mediated:
How do migrating animals know where to go? List 5 potential mechanisms.
Cues to direction • Visual landmarks • Solar compass • Stellar compass • Geomagnetism • Olfaction
T or F - Biotic factors influence the southern borders of geographic distribution of animals.
TRUE - Often it’s biotic factors such as competitors and natural enemies.
What are 4 main causes for insect outbreaks?
- A series of mild winters
- Good weather during the dispersal and attack periods
- Abundance of pine of susceptible age and size
- Strong winds blowing from the west
T or F - In the ocean, fish richness generally peak in colder, temperate waters.
FALSE - they’re ectotherms so most diverse in tropics
- exam
____ ____ use the subnivean space.
ring seals
What’s a moose wallow?
- A moose wallow is a pit the bull moose creates during the mating season (digs it).
- May make 7 holes and only pee in the last one.
- Will pee in it, and cover himself in as much pee as possible. The scent attracts females who will wait there for him, he will come back to check if he’s attracted mates.
- Possibly detected by Jacobson’s organ
- Urine may help to synchronize ovulation (If all moose ovulating same time and giving birth at the same time, less predation on young).
Describe this newer telemetry tool: Crittercams (80’s).
- Animal borne video cameras that attach with suction cups (last 24-48 hours), then float to surface and must be retrieved.
What is most likely influencing diversity globally?
Rank the 5 most likely things from most to least important.
- Consumer trophic level (predators)
- Shark diversity
- Phytoplankton cell diameter
- Primary producer turnover
- Temperature
- Temperature
- Shark diversity
- Phytoplankton cell diameter
- Primary producer turnover
- Consumer trophic level (predators)
List 2 hypotheses for why migration evolved/started.
- Live in a warm place (competition, relocation but had to come back in winter).
- Climate change (winters too cold, had to migrate back and forth).
*explanation not required for card
There has been a __% decrease in moose numbers in the 17 year time span from 1993 - 2010.
There has been a 58% decrease in moose numbers in the 17 year time span from 1993 - 2010.
How much greener is the arctic getting according to the vegetation index trend (% per decade)?
-2.5% 0% \+2.5% \+5% \+7.5%
A large range, but around +5-+7.5 in many areas.
Describe how warming temps or a warm summer + warm winter can permanently change the permafrost table due to changes in the active layer.
- The maximum depth of refreezing permafrost over winter is 80cm, so if summer melt causes more than 80cm of thawing, there will be a liquid layer left above the permafrost table called a talik.
- Climate change (increasing winter temps and/or increasing snowfall will bring a thinning of the active layer.
- The talik passes energy upward and downward and further accelerates permafrost thawing.
- A single warm summer followed by a warm or snowy winter can trigger talik development over a wide area that will continually erode the underlying permafrost table.
Shorter summary: If active layer thaws enough, the lower part can stay liquid over winter. Liquid generates heat, next summer this spreads outward and there’s even less permafrost.
** Exam
T or F - In colder waters (further from equator), trophic control is due to resource control.
FALSE - consumer control
Give a few examples of freeze tolerant animals.
• Many terrestrial insects • Intertidal molluscs & barnacles • Amphibians & reptiles: - frogs (6 species) - hatchling painted turtles - garter snakes - lizards (some)
Is it better to use mean annual temperature or extreme temperatures to study climate change?
extremes
There are 2 ways animals can reduce heat loss in their peripheries in winter.
Describe: Allowing peripheral tissues to be cooler, in terms of counter current flow.
Countercurrent flow: Veins and arteries in close proximity, heat is exchanged (small gradients are maintained), less heat lost.
How can light sensitive loggers/ geolomggers be used to track the arctic tern?
Geolocators - Record ambient light intensity, reveal information on sunrise & sunset
Combine light data with time recordings
• 2 daily geographical positions can be
calculated
• migration routes can be mapped
Describe the 1st stage in the evolution of migration: Partial migration.
Some individuals of a population migrate
predators reduce prey numbers
• may be more common in aquatic systems
Density-mediated:
T or F - Delayed density dependance in weaker in long winters.
False - Delayed density dependance in stronger in long winters (can be top-down or bottom-up, as long as winter is long).
T or F - These are extracellular protectants from freezing:
High ‘polyols’
• Glucose
• Glycerol
• Sorbitol
False - intracellular
Guard hairs vs underfur.
- Guard hairs: longer, coarser – protection.
* Underfur: short, dense, function is thermal insulation.
Would this bird have high, moderate, or low adult survival rates?
- Temperate resident:
- Migrant:
- Tropical resident:
- Temperate resident: low
- Migrant: moderate
- Tropical resident: high
What is the cause of climate change? What is a symptom of it?
- Cause: Population growth.
- Symptom: Increased CO2.
To determine:
hares limit lynx (bottom-up regulation)
or
lynx limit hares (top-down regulation)
an experiment at Kluane national park in the boreal forest was done. Treaments were: add food, exclude predators, or both. What was the result?
- Exclude predators: hares increase 2x.
- Increase food: hares increase 3x.
- Both: hares increase 11x.
Food availability and predation have synergistic effect
Describe this 1 of 7 latitudinal gradient hypotheses: Spatial heterogeneity
Spatial heterogeneity hypothesis:
• higher diversity in tropics due to increase in number of
potential habitats + habitat types of species
• A broader diversity of habitats can harbor a broader diversity
• ↓ environmental complexity moving away from equator (topographic features, vegetation complexity)
The more heterogeneous and complex the physical environment, the more diverse the plant and animal communities
T or F - lemmings use subnivean space
true
Describe an example of how birds can reduce energy expenditure in migration?
- V formation: reduces drag by up to 65%
- Birds at front and outer edges work much harder, but they all rotate
List 7 possible latitudinal gradient hypotheses.
- History (time)
- Spatial heterogeneity
- Competition
- Predation
- Productivity
- Environmental stability (climate)
- Disturbance
- not mutually exclusive, all are related.
Describe these 2 possible tropic controls;
- Resource supply
- Consumer pressure
are these top-down or bottom-up control? Positive or negative correlation?
1) Resource supply (bottom-up control – strong positive correlation)
2) Consumer pressure (top-down control – strong negative correlation)
Hypothermia
Hypothermia: core temperature drops below that required for normal metabolism and body functions
What is the active layer of permafrost and what does the size of it depend on?
- Part that thaws and freezes with temperature changes.
- Depth of active layer depends on vegetation, snow cover, organic material (peat is an especially good insulator), summer temperatures.
What does a dark line on a moose tooth tell you?
winter growth
What 3 things can happen if the body of an organism freezes? List only.
- Freezing of intracellular fluids.
- Extracellular freezing.
- Increased concentrations of inorganic salts due to freezing.
When do lemmings bread? Breeding capacity and timeline?
- not important maybe
- Active summer & winter and breed year-round
- Under snow in winter, in subnivean space
- Tremendous reproductive capacity
- Average 4-6 young per litter
- Gestation 3 weeks, weaned at 3 weeks of age, can mature at 4 weeks of age
- Breed post-partum (on the day they give birth); simultaneously pregnant and lactating!
- Thus, generation time is 7 weeks (time from mom giving birth to offspring giving birth)
What bird species is considered the ultimate migrant?
the Arctic tern
T or F - moose nose lightens in summer.
FALSE - it darkens in summer.
There are 2 categories of supercooling chemicals; antifreeze proteins and cryoprotectants.
What are antifreeze proteins? Animals in what kind of habitat would use it?
AFPs in plasma – decreases the freezing point.
•Antifreeze proteins are found in animals in subnivean habitats
T or F - forest growth northward is faster than grassland spread from south - which will increase carbon uptake.
FALSE! forest growth northward is SLOWER than grassland spread from south - which will REDUCE carbon uptake.
Delayed density dependence
+ 2 things that may influence it
As populations grow, there is a time lag until
negative feedback mechanisms brings the
population back down
Could be in terms of:
- Reproduction (food shortage)
- Mortality (predation)
Describe this intrinsic hypothesis of lemming population cycling: Social stress hypothesis.
Social stress hypothesis: behavioral & physiological factors
• high population densities lead to chronic stress, long-term glucocorticoid exposure, may lead to:
• immune suppression
• growth inhibition
• reproductive failure
• neuron death
• decline in reproduction, survival
Lemmings are keystone -herbivores in many tundra areas.
What do they eat (+ quantity), and how do they contribute to other species?
- Eat green vegetation
- Consume much more vegetation than caribou or muskoxen (3-100x more)
- Primary prey for many Arctic predators
- Play key role in the food web
T or F - younger bulls (male moose) have the best/most productive sperm.
FALSE - sperm isn’t as good in younger bulls, may have bad tails, etc. Older bulls have much better sperm
3 major growth factors for aspen at the northern limit of growth:
- Moisture
- Long growing season
- Temperature
