Lesson 10 Flashcards
What is the process by which animals are able to maintain their internal temperature, despite dramatic changed in ambient temperature?
Thermoregulation
Contrast ectotherms and endotherms.
Ectotherms primarily regulate body temperature using external sources of heat.
Endotherms generate most of their heat through metabolic processes.
What morphological adaptations can be found in animals that live in the mountainous alpine?
1 - hair and feathers insulate animals (hollow hairs amplify this effect).
2 - Lower surface area relative to mass which help to retain body heat (short appendages)
3 - increased wing span (to cope with thinner air for insects)
4 - darker colouration (absorb more heat)
What are the morphological adaptations of Pikas that live in the mountains of Asia and North America?
Smaller appendages, such as ears and legs, allowing them to retain more body heat.
Why might insects that live in mountains have longer and wider wings?
Because the air is thinner at higher elevations, therefore wing-loading is higher.
What effect allows sulphur butterflies to partake in thermal basking at higher elevations?
Melanization - giving them darker wings and allowing them to warm in the sun
Melanization increases with altitude and can be seen in many different types of insects.
What types of adaptations do ectotherms rely on to keep their body temperatures within their normal range?
Behavioural.
Small ectotherms rely on specific microclimates to help maintain their body temperature. What is an example of on of these microclimates found in the alpine?
The interior of cushion plants are often favourable microclimates (often housing pollinators).
Describe the behavioural responses of the Phymaturus lizard that allow it to adapt to living in cold temperatures. (This lizard thrives at elevations above 4000 m in the Andes mountains).
The phymaturus lizard burrows at night when temperatures cool, allowing it to be insulated by the earth. In the morning its leaves its den and basks in the sun. This allows it to increase its body temperature to 30 degrees, even if ambient temperatures are around freezing.
What behavioural adaptations of big horn sheep allow them to survive the winter?
The migrate to lower elevation valleys.
Define physiological adaptations.
Physiological adaptations are involuntary, passive responses that are internally regulated.
What are the two categories of physiological adaptations?
1 - Heat conservation
2 - Heat generation
What are three heat conservation physiological adaptations of alpine animals?
1 - piloerection (increasing the barrier warm air within their fur that provides insulation)
2 - Vasoconstriction (reducing the amount of heat lost from the surface of their skin)
3 - Countercurrent heat exchange between arteries and veins (heat is transferred from arteries to veins before reaching extremities, which decreases the amount of heat lost to the environment).
By which process are endotherms able to amplify their internal heat production under cold conditions?
Thermogenesis (shivering)
How does non-shivering thermogenesis work?
Hormone release increases metabolic rate and the activation of brown fat.
What is Torpor? What is an example of this?
Torpor is a state of low metabolic rate and decreased body temperature. An example of this is hibernation.
By how much does a marmots heart rate and breathing rate decrease during hibernation?
Heart rate decreases from 200bpm to 30bpm
Breathing rate decreases from 60breaths per minute to 1-2 breaths per minute
Describe how insects adapt to live at high elevations throughout the winter?
Supercooling - allowing the water within their cells to cool to as much as negative 40 degrees before forming into a solid.
What is a cryoprotectant?
Animals that live in extreme environments produce this (glycopropalene/antifreeze) to protect their tissues from freezing.
What is meant by a species that is freezing-tolerant? What species is an example of this?
A species that can tolerate ice-formation within their tissues. The New Zealand alpine cockroach is an example of this type of species.
What type of appendage in animals may be considered a heat-exchange surface, facilitating heat loss in the summers?
Their ears - high SA and low insulation.
What is the difference between sweating and panting as a means to thermoregulate?
Sweating is a passive process, which panting is an active process.
What adaptations do mountain ungulates have that allows them to cope with sparse food sources?
Multi chambered stomachs that allow them to extract as much nutrients as possible from their food sources.
What adaptation do Lamas in the Andes have that make them highly suitable to live at high elevations?
They have the highest relative concentration of red blood cells, making them extremely efficient at transporting oxygen when the partial pressures of air is low.
What is the smallest grouse in North America?
White Tailed Ptarmigan
What is the only bird in North America to reside exclusively in the alpine zone?
White-tailed ptarmigan.
How are white-tailed ptarmigan able to camouflage themselves from predators year-round?
They change the colour of their feathers - from white in the winter to a speckled grey in the summer.
What body temperature can be maintained by ptarmigan throughout the winters despite cold temperatures?
40 degrees Celsius!
How many species of marmots are there in the world?
14 species. 6 in North America and 8 in Eurasia.
How long do marmots spend in hibernation yearly?
Around 200 days
What is a hybernacula?
A burrow in which animals hibernate.
By how much is the internal set point temperature of marmots reduced when torpor is induced?
From around 40 degrees celcius to around 5 degrees
How do social behaviour adaptions help increase survival rates of marmots?
They can huddle together during hibernation, which keeps them warmer. And in the summer, they’ll produce a high-pitched warning for other marmots, when predators are nearby.
What is a sentinel species?
One that can help us to understand environmental changes, by observing how the species responds.
What is the most endangered mammal in Canada?
The Vancouver island marmot.
Only 21 in 2003 (as a consequence of clear-cutting forests)
The population is now at almost 400 individuals - meaning they are able to adapt to different environments.
At what temperatures do Yak do best?
When the annual mean temperature is below 5 degrees and the average in the hottest month doesn’t exceed 13 degrees.
How do Yak cope with cold?
Mostly by conserving heat.
Facilitated by coarse putter hair and an under coat of fine down. They also accumulate a layer of subcutaneous fat prior to the winter. Their skin is thick and their sweat glands are mostly non functional.
What adaptations do Yak have that help them cope to low oxygen environments?
They have a large chest (14-15 pairs of thoracic ribs), large lungs and a large heart.
What adaptations do Yak have that allow them to forage various food sources?
Their Rumen which facilitates digestion of various food sources.
What mountain range do bar-headed geese migrate over every year?
The Himalayas.
What advantages do bar-headed geese have over other other animals for withstanding high altitudes?
1 - lungs that are 25% bigger than other gees
2 - higher affinity for oxygen and more efficient diffusion
3 - more capillaries in their heart and muscles
True or false: water has a high specific heat capacity relative to air.
True! - meaning aquatic environments lose and gain heat less rapidly
How are mountain lakes different form lower aquatic systems?
Most mountain lakes are naturally fishless!
What species dominates mountain lakes?
Large, endemic, zooplankton! - usually bright red or black pigments.
When were mountain lakes stocked with fish in North America?
Began in the 20th century.
What was once the most widespread native trout in the mountain parks?
Bull trout (part of the char family). They require water temps below 13 degrees Celsius. However, bull trout, have been displaced from introduced fish populations, and overfishing.
Describe the impact of introduced fish population into alpine lakes in the 20th century.
These fish populations displaced native fish populations (such as bull trout) as well as decreased the number of zooplankton and tadpoles, which contributed to the loss of over 90 percent of mountain yellow-legged frog populations.
What four things may you need to treat for when consuming water from the mountains?
What are the four treatment options for these?
1 - Protozoa
2 - bacteria
3 - viruses
4 - particulate
Treatment options:
1 - heat
2 - chemicals
3 - filtering
4 - purifying
Define Limnology
The study of inland waters
Define adaptation according to Laura Redmond
The development of a feature that increases Darwinian fitness relative to alternative features.
What 6 main stressors act on alpine lakes?
1 - High UV stress (increases with elevation, risks DNA damage)
2 - low terrestrial inputs (less organic matter being put into the system, less food and more UV - clearer water)
3 - cold temperature
4 - high temperature variation (diurnal fluctuations in temperature - up to 20 degree changes)
5 - short growing season (lower time for plankton to photosynthesize)
6 - low connectivity/gene flow (genetic variation is low because communities are isolated)
How have organisms in alpine lakes adapted to protect themselves from UV radiation? What are the costs of these adaptations?
1 - pigmentation/melanin - acts as a protective layer
*decreased growth rate as well as increased predation by introduced fish
2 - Increased enzymatic repair - increasing DNA damage as it’s happening
3 - behavioural adaptation - when temperatures are highest, organisms hide out at the bottom of the lake
What is watermelon snow?
When you see red pigmentation in alpine snow.
- this is caused from green algae that contains carotenoid pigment (the same pigment that causes leaves to change colour in the fall)
Define Oliogotrophic
When there are low nutrient inputs into an ecosystem - like alpine lakes (aka low dissolved organic carbon (DOC))
How do alpine lake species adapt to cold temperature?
1 - metabolic constraints (metabolism slows down)
2 - behavioural (low mobility to conserve energy)
Define ephippia
RESTING EGGS
When organisms create resting eggs that allow them to survive in a dry lake basin, making them desiccation tolerant. (For when alpine lake dry up in the fall).
What is anthropogenic nutrient deposition?
Phytoplankton need both nitrogen and phosphorus to grow
Increases in nitrogen can cause plankton to be phosphorus limited, causing algae blooms.
Define bio accumulation
The gradual buildup of pollutants as you move up the food chain. - contamination levels increase with levels of the food chain, and especially at higher elevations.
