Exam 3- Mammals Final Flashcards
behavioral response of predators to different prey densities (feeding rate)
functional response of predators
there is generally a ___ relationship between feeding rate and prey density with an ___
positive, asymptote
asymptote on graph of the functional response of predators
handling constraints, gut capacity limitations
the response of a predator population to prey density
numerical response
alterations in fertility rate, survival, and dispersal as a result of changing prey density
population response
asymptote on graph of the numerical response of predators
determined by interference competition between predators
combines functional and numerical response of predators
total response
total response expresses the percent of the ______ as a function of _____
prey population eaten, prey density
without predators, the prey population size = _____
carrying capacity (K)
if abiotic factors reduce prey, predators maintain them
predator pit
mortality rate declining as prey density is increasing, often referred to as ___
depensatory response
area with a large amount of waterfowl and important breeding
North American prairie pothole region
nest success is declining at _____% per year
0.5
effects of predator exclusion on waterfowl
- improvement in islands and exclusion plots
- removal not significant in improving success
- nest success kept declining over time
- suggesting that factors other than predation could be important for duck population
why may the duck populations have continued to decrease?
predator removal may not have taken smaller predators, functional response from these smaller predators can lead to higher mortality of nests
wolves and ungulates in Yukon
- decline in caribou, moose, Dall sheep
- reduction of wolves over 5 years
- wolf predation was reducing caribou/moose calf recruitment and reducing adult moose survival
- no effect on dall sheep
____ are very efficient vole predators
weasels
weasel subnivean hunting
killed 1/2 voles in the population over 3 years
Russian Crop Ticks and weasels resulted in….
59% fewer voles
in many instances ___ combines with _____ to limit prey populations
predation, competition
hare population fluctuation
1-2 orders of magnitude every 10 years, lynx primary predator
during peak hare year…
- predation increase 1.6 fold
- starvation increase 9 fold
- predation made up 58% of deaths
- population limited by predation and food
predation-sensitive food hypothesis
joint limitation of prey abundance by predation and food
predator regulation hypothesis
prey density regulated at some low density (predator pit) by a predator population
surplus prey hypothesis
predators only take animals that would have died from competition and population size at K
wildebeest and lions/hyenas bone marrow predictions
- PRH: predated and live samples similar bone marrow
- SPH: predated and non-predation deaths similar bone marrow
-PSFH: predated samples poorer condition than live, predated better condition than non-predated samples, predated better condition when food is limiting than when abundant
the effect of one species on another is mediated through a third
indirect effect
Rabbit density/predation in absence of lynx
5-10 fold increase in predation, 2-4 fold lower density
the substitution of mortality agents akin to the SPH where predators consume prey that would otherwise starve
compensatory mortality
effect of removal of bobcats/coyotes on deer Texas deer populations
fawn:doe ratio 3-4 times higher (density dependent inc. in winter mortality compensated for reduced mortality rates due to predation) in the short-term (6 years)
intense predation on normally food limited prey increases _____, allowing prey to compensate by ______
mortality rate, increasing other vital rates
result of industrial whaling on orca diet
increase in predation of seals, sea lions, sea otters
microparasite
anything a cell big: virus, bacteria, fungi
macroparasites
arthropods (ixodes scapularis) , nematodes (baylisascaris procyonis), cestodes (taenia solium)
parasite effect on victims is dependent on…
host health, parasite load and virulence, environmental conditions
____ increases the condition of the surviving population, while ____ lowers the condition of the surviving population
predation, parasitism
Southeast Cooperative Wildlife Disease Unit
uses counts of parasites in deer abomasums as an index of herd health
black-footed ferret and canine distemper
federally endangered, 1970s captive breeding program, 2 litters produced where both died from canine distemper (even vaccinated), 1981 new colony of 128 was found but dropped to 16 in 4 years from distemper and human-introduced influenza
common dolphins and Crassicauda
nematode parasite (roundworm), causing brain lesions, dolphins strand on beach, natural mortality 8% yearly and this is >10% of that mortality
wolves and canine parvo
first reported in dogs in 1970, kills dogs 1-12 weeks, effects nutritionally stressed animals, survivors have antibodies, prevalence increased at 4%/yr in MN wolves 79-93 until 87% exposure, >80% parvo caused population decline, 3 shot vax
brucellosis
bacterial disease of ungulates, not lethal but causes decrease in milk production, females lose first fetus (50-70% abortion in highly infected herds), can lead to sterility, spreads through aborted placentas
Wyoming Elk vaccination
vaccinated against brucellosis via bio-bullet, reducing abortions by 70%
mice and Heligmosomoides nematodes
reduces exploratory activities
Marilyn Scott
experimentally demonstrated a parasite can regulate a mammal population: in lab introduced parasite, population crashed and stabilized low, treat parasite population recovers
cottontails and Tularemia
vectors are ticks and deer flies, outbreaks in squirrels and beavers, caused by bacterium, fatal (affect liver/spleen/lymphatic, necrosis), lethargic/spasmodic behavior, dead in a week, transmitted to humans with ectoparasites and contaminated tissue
grooming as macroparasite avoidance
rats spend 1/3 of time grooming, preventing this caused 30 fold increase in lice infestation, impala and gazelle self groom > 1000 times / 12 hours
rove beetles
mutualism, 10% of length of host rodents, Bob Timm showed they attach to rodents during nocturnal movements and drop off in nests during the day, prey on lice/ticks/fleas
stress as an indication factor
stress should cause latent infections to become visible through stress and food deprivation (monkeys keeping new members in the periphery, quarantine)
licking wounds
cleanses (saliva is bactericidal) and promotes closure (epithelial and nerve growth factors in saliva)
fever response
increased body temperature to enhance immunological response, reduce blood plasma iron to starve bacteria
how to elevate body temperature
vasoconstriction, seek warm sites, shivering
fever response energetic costs
4-5 degree increase causes 25% increase in metabolism
fever response is linked with _____ strategy
energy conservation
fever energy conservation strategies
anorexia, depression, lethargy (iron concentrations, heat loss)
Parasites evolve ____ might jump hosts by ____ (common with ____)
rapidly, mutating, viruses
cycles
multiannual fluctuations that occur with some regularity (periodicity)
regional synchrony in fluctuations of ____ species
coexisting (think rabbit/lynx or animals that share food)
cycles frequently have ____ crashes in abundance
summer
cycles most occur in _____ latitudes
northern
biological cycle times scale ____ as W^0.25
allometrically (nerve conduction time, cardiac cycle time, respiratory cycle time, generation time)
periodicity is about…
twice the average age to maturity, generation length times 4/5
vole/lemming period cycles
- period of 3-5 years
- amplitude of 50-200 fold increase/decrease
- meadow and prairie vole cycles in Indiana
- pine voles and lemmings do not cycle
hare period cycles
- period 9-10 years
- amplitude 15-200 fold
- Hudson bay Co. provides data for 150 years
Hare coincident cyclic species
lynx, mink, long tailed weasel, GH owls, goshawks, ruffed grouse
Archbishop Olaus Magnus
Sweden, mid 1500s noted lemming ~3 year cycles
intrinsic factors
genetics, physiology (cycles occur over large areas and include many species)
extrinsic factors
sunspots, stress (best evidence is for >1 extrinsic factor)
increase phase
high fertility, low mortality, population dominated by the youth, large litters, early age at first reproduction, few predators
peak phase
fertility rates decline
hares:
- no territoriality, considerable home range overlap
- fertility declines due to lower food quality/quantity
voles:
- females territorial, social factors
- high density dispersal reduced and young females forgo breeding
- subordinate females who do breed risk losing offspring to infanticide
decline phase
low fertility rates, high mortality, increase in older individuals, many factors important in causing decline (food availability, predators catch up)
food quality as a player in population cycling
proteinase inhibitors (inducible defense)
- most common plant toxin that reduces herbivory
- causes pancreatic enlargement
- build up during peak phase and year 1 of decline phase
- can cause dramatic declines in herbivore density
- cause changes in body size and organ mass
- can cause high degree of synchrony in fluctuations
extensive herbivory causes plants to revert to a ___ stage, as ___ plants produce more toxins
juvenile, juvenile
indirect effects of predators
field voles delay reproduction when weasels are highly active, increase survival because females in estrous are more likely detected, in high density wait for crash before breeding
_____ is greatest when in the presence of a specialist predator
antipredator response
an interacting assemblage occupying a particular area
community
a community, but also including abiotic components
environment
a major terrestrial community that recurs on >1 continent characterized by dominant form of vegetation
biome
____ biomes of North America
5
arctic tundra
- circumpolar distribution south of polar ice and north of tree line
- permafrost (2’ deep), low precip (8”), swampy
- lichens, grasses, sedges, annual forbs
- subnivean environment, hibernation, migration
boreal forest (taiga)
- bordered by tundra to north, deciduous forest to south
- goes across continent through Adirondacks, down Appalachians, Rockies and Sierras
- severe winters, 15-40 inches
- spruce, balsam fir
- paper birch and aspen in burned sites
deciduous forest
- best developed in eastern US
- temperate climate, 30-50 inches
- soil has deep rich humus layer with rich clay lower horizons
- plants have deciduous leaves and hard mast (oak, hickory, walnut, beech)
- granivores
grasslands
- west of the edge of deciduous forests to foothills of rockies
- east-west gradient in precip. 40-10 inches (rain shadow)
- topography flat and undulating
- tallgrass prairie eastern portion dominated by bluegrass, Indian grass, switch grass
- shortgrass prairie western characterized by bunch grasses
- cursorial, fossorial, herbivorous
desert
- very dry (5 inches)
- extreme temperatures, great fluctuation
- plants adapted to conserve water and reproduce rapidly when favorable conditions arise
- small, nocturnal granivores, efficient kidneys
species richness
of species in a community without considering relative abundance
(20 indiv. for 5 species = 5, 2 indiv. for 50 species = 50)
evenness
distribution of individuals among species
diversity
combination of richness and evenness, common approach Shannon-Wiener index, Simpson’s index
trophic structure
feeding relations of species in a community with the flow of energy
guild
group of species exploiting a resource in a common way (ex. granivorous rodents)
interspecific competition
competition between two species
principle of competitive exclusion
Gause, 2 ecologically identical species cannot coexist in the same community indefinitely
fox competition
- red fox 60% heavier
- arctic fox crit temp -40, red 9
- Red North limit = prey productivity
- Acrtic South limit = red fox competition
SE AZ removals of rodents/ants
rodent: ant colonies > 71%
ant: rodent biomass > 29%
neither: seed density >4x, plant density 2x
keystone species
a species whose presence is key to the stability of a community
mycophagy
consuming fungi
ectomycorrhizal fungi
common associates with woody plants, fix N, critical to establishment/success, two types
Epigeous fungi
wind dispersed (puff balls)
Hypogeous fungi
dispersed by rodents, marsupials, dung beetles bury feces close to roots
Zoogeography
branch of biogeography that is the study of animal distributions, typically reliant on historical and ecological influences
Theodor Lilienthal
noted that the facing coasts of many countries may be separated by the sea but have congruent shape
Wegener
proposed continents have drifted over the earth
DuToit
based upon jigsaw puzzle, fit east coast on new world and west coast on old world, proposed modern view of continental drift originating from a single great land mass
lithosphere
earth’s crust, 45 miles thick
plate tectonics
the system of movement of the earth’s crust slowly changing plates by adding molten rock on upwelling borders and destroying rock on plunging borders
pangaea
a single land mass, 200 MyBP
Cretaceous period
66 MyBP, Laurasia had nearly split from Gondwana
convergent evolution
functional duplication of types in separate species, most common on southern hemisphere (continents separated longer?)
examples of convergent evolution
myrmecophagous animals, cursorial herbivores, fossorial or burrowing mammals found on most continents
Paleocene era (net cooling trend)
65 MyBP, trees in Iceland, alligators in Alaska, Denver had Mexico’s current 68F annual isotherm
the average life span for a species is….
2 million years
Milankovitch cycles
periodic (100k years) cycles in warming/cooling during the Cenozoic era, regarding changes in orbit (100 ky), tilt (40 ky), wobble (19-23 ky), triggering glaciations
island biogeography supporting isolation
S (richness) of non-volant mammals on islands in great lakes declines as isolation increase and island area decreases
corridor example
Europe, Asia
filter route example
Beringia for cold adapted species
sweepstakes route
route used rarely by few species (swimming from Africa to Madagascar, bats and Hawaii)
Cope’s rule
generalization that animal taxa evolve toward larger body size, implying larger body size is advantageous (intermediate size of 1kg optimum for energy acquisition)
species diversity is limited in the north and south by…
- abiotic factors (N, northern species have larger ranges)
- biotic factors (S)
___ species at risk
___ mammalian extinctions since 1500
___ data deficient species
___ % of mammals at risk
1340
85
839
20-26
rare species are at risk due to…
environmental, demographic (age ratio, sex ratio), and genetic stochasticity
habitat restriction
proboscis monkeys and mangrove swamp
range restriction
golden-lion tamarins and the loss of Atlantic forests for agriculture
body size and home range size restrictions
maned wolf, require 8 sq mile, low density populations
humans have caused ____% of extinctions since 1600
75
beaver exploitation
trapped for hats in the 1600s, saved by nutria and silk
Steller’s sea cow
Vitus Bering, extinction 27 years post discovery
wolf overexploitation
today occupies 5% of former range outside of Alaska
___% of extinctions since 1600 due to overexploitation
60
rhinoceros overexploitation
90% of adult mortality from poaching
horns good as dagger handles, aphrodisiac, fever suppressant
mammals in savannas of Ghana
41 species, 6 reserves
78 local extinctions over last 30 years
more likely extinctions if reserve is isolated and the species is monogamous
neotropical mammals
biomass of nonprimate game species reduced 80-94%
biomass primates reduced 94%
frugivores and seed dispersal problems?
exotics have caused ___% of extinctions since 1600
20
feral horses
wild free-roaming horses and burro act 1971
destroy habitat and exclude native wildlife
expensive maintenance (50 mil)
difficult to manage (BLM)
illegal to cull
domestic cats on native wildlife
Wisconsin: 50 mil songbirds, 140k game birds
UK: 50 mil small mammals
Australia: endangerment of eastern barred bandicoot
human population size
8 bil
stabilize 8-14 bil
40% of NPP taken/destroyed by us
habitat destruction/disturbance
