Chapter 10: Animal Adaptations Flashcards Preview

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Flashcards in Chapter 10: Animal Adaptations Deck (52)
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1
Q

Adaptations may be ___, ___, or ___.

A

Morphological, behavioral, or physiological.

2
Q

What happens if body temp goes outside of an acceptable range?

A

Enzymes in cells will not be able to perform chemical reactions. If the contents of the cell freeze, ice crystals can form inside cells which can damage cellular structures.

3
Q

Thermoregulation:

What is it?

A

The process that allows animals to maintain body temps.
Controlled by negative feedback system: if nerve cells detect shifts in body temps outside of the normal range, they send a message to the brain to initiate a corrective response.

4
Q

Thermoregulation:

What are ectotherms?

A

Animals that primarily regulate their temps using external sources of heat.
E.g. amphibians, reptiles, fish, and invertebrates.

5
Q

Thermoregulation:

What are endotherms?

A

Create most of their heat from metabolic processes. E.g. mammals and birds.

6
Q

Morphological adaptations:

Hair and feathers insulate animals by…?

A

Trapping a blanket of warm air near their skin, and hollow hairs or feathers can amplify this effect.

7
Q

Morphological adaptations:
Many alpine animals also have a lower surface area relative to their mass, to help retain body heat (stockier appearance). Give an ex.

A

E.g. Pikas are small lagomorphs that are closely related to rabbits and hares. Live high in the mountains of Asia and NA, and have very reduced ears and limbs compared to their low elevation cousins.

8
Q

Morphological adaptations:

For some smaller alpine dwelling animals, it may be advantageous to have an increased SA. Give an example.

A

E.g. the wing size of flying insects is often proportionately greater in high altitude populations so that they can cope with the thinner air encountered during flight.
For actively flying insects, wing loading will be higher at greater elevations, so these populations are subjected to stronger selection for wings with increased SA.
E.g. in males of fly, Drosophila flavopilosa, in Chile, both wing length and breadth are increased with elevation.

9
Q

Morphological adaptations:
Some alpine animals have darker colouration at higher elevations in order to absorb more radiative heat. For ectothermic insects it can be advantageous to adjust body temps through thermal basking (and by selection of specific spectral reflectants and absorbance properties of the body surface. These species are reducing their albedo). Give an ex.

A

E.g. Alpine butterflies in the genus Colias, or the Sulphur butterflies. In Colias, wing melanisation is essential for thermoregulation because darker wings absorb more sunlight. (warms flight muscles.)
In one species of Colias, from the Rockies of Colorodo, the degree of wing melonisation increase tenfold between 1800 and 3000 m.
Similar altitude related colour polymorphism or morphological variation is seen in other insects as well, inc. leaf hoppers, ladybugs, and grasshoppers.

10
Q

Dr. Felix Sperling, Curator of E.H. Strickland Entomological Museum at Ualberta:

A

On butterflies and morphological adaptations.

11
Q

Behavioural adaptations:

What is it?

A

Behavioural adaptations concerns hour to hour, day to day and even seasonal choices made by animals that actively contribute to thermoregulation.

12
Q

Behavioural adaptations:
Ectotherms are capable of living in lots of environments. However, they rely on external production of heat, so they often have periods of inactivity that are correlated with cooler temps. When their internal temp drops…?

A

Their enzymes become less effective and their metabolism decreases.
Smaller ectotherms that are susceptible to heat loss due to greater SA rely heavily on microclimates to survive harsh alpine conditions.

13
Q

Behavioural adaptations:

Give an example.

A

E.g. A species of rock-dwelling lizard in the genus Phymaturus, that thrives at elevations above 4000 m in the Andes Mountains burrows underground at night, where the soil provides insulations from the cold nights. In the morning, the lizard emerges from its burrow and generates heat by basking in the sun, which can increase its internal temp to 30 degrees, even if ambient temps are freezing.

14
Q

Behavioural adaptations:

Extreme low temps during winter are also hard on endothermic organisms. Give examples.

A

Large mammals, such as bighorn sheep, migrate to lower elevations during the winters, while birds migrate to lower latitudes. Smaller alpine animals, such as collared Pikas (Mountains of Yukon and Alaska) minimize their exposure to extreme temps by seeking shelter in piles of boulders that provide protection. In bot summer and winter, Pikas use these sheltered places to help maintain their own thermal equilibrium.

15
Q

Physiological adaptations:

What are they?

A

Involuntary passive responses that are internally regulated and can be categorized into two groups:

  1. Heat conservation
  2. Heat generation
16
Q

Physiological adaptations:

What are the ways in which animals can conserve heat?

A
  1. Piloerection (involuntary reflex caused by muscle contractions near the surface of the skin; goosebumps): raising their fur to increase the barrier of warm air that provides insulation.
  2. Vasoconstriction (At low temps, blood vessels decrease diameter; people appear pale when cold): restricts heat transfer to environment.
  3. Countercurrent heat exchange (arteries that carry warm blood to extremities run parallel, and close, to veins that return blood to the trunk of the body): temp gradient causes heat in arterial blood to be progressively transferred to cooler venous blood, so that it is cooler when it reaches extremities.
17
Q

What is thermogenesis?

A

Process whereby endotherms have adaptations that amplify their internal heat production under cold conditions.

18
Q

Give an example of thermogenesis.

A

E.g. shivering, produced by small, involuntary contractions of skeletal muscles. Common in birds and mammals.
Non-shivering version involves the release of a hormone that increases an animal’s metabolic rate, and is mostly in mammals.

19
Q

Although non-shivering thermogenesis can take place throughout the body, alpine species, especially those that hibernate…

A

Have a tissue called brown fat that is specialized for heat generation.

20
Q

Special adaptations: winter:

What is hibernation?

A

An adaptations that saves animals energy by reducing their activity levels.
Insulation through fat reserves, more hair, or burrows.
Hibernation is a type of long-term torpor, which is a state of low metabolic rate and decreased body temp.
Hibernation determines new temp set point.

21
Q

Special adaptations: winter:

During hibernations, the hears rate and breathing is substantially reduced. Give an ex.

A

E.g. A marmot’s heart rate drops from 180-200 beats per min to only 28-38, and their respiratory rate decreases from 60 breaths per min to 1-2.

22
Q

Special adaptations: winter:
Ectotherms can’t hibernate in the same way, but many species are capable of overwintering under extreme conditions. Give an ex.

A

E.g. Some insects that live at high elevations adapt to cold temps using supercooling, a process where water cools below its freezing point without changing phases into a solid. Without a source for nucleation or forming crystals, water can cool to below -40 without freezing.

23
Q

Special adaptations: winter:

Give another example of overwintering.

A

Some other species produce unique carbs and amino acids before winter which help prevent their cells from freezing. These cryoprotectants protect tissues from freezing and can prevent some of the adverse effects of extreme low temps. One of those carbs, propylene glycol, is the same chemical used in automotive antifreeze.

24
Q

Special adaptations: winter:

Other species are considered freezing tolerant and can survive ice formation within their tissues. Give an example.

A

E.g. New Zealand Alpine Cockroach, can survive freezing to -6.

25
Q

Special adaptations: summer:

Animals can dissipate heat through heat exchange surfaces and evaporative cooling. Describe heat exchange surfaces.

A

Heat exchange surfaces accelerate heat loss through specialized appendages, like ears. Facilitate the transfer of heat from the animal to the environment because they have high surface areas, with many blood vessels close to the surface that are only lightly insulated with a thin cuticle.

26
Q

Special adaptations: summer:

Describe evaporative cooling.

A

Evaporative cooling can help animals keep cool through evaporation of water from the body by sweating or panting. Sweating is a passive process (air removes water secreted by sweat glands), panting is an active process (create air currents to remove water across respirator system surface).

27
Q

Other adaptations:
Many mountain-dwelling animals, including mountain goats and yak, have specialized hooves that allow them to safely and effectively navigate steep and rocky mountain terrain. Describe.

A

Hooves combine hard outer edge with soft inner pad that provides cushioning for jumping between rocks. Helps grip rocks and resist slipping.

28
Q

Other adaptations:

Some mountain animals, mountain sheep and yak, like other ungulates, have adapted to the unproductive food supply. How?

A

Multiple-chambered stomach that allows them to increase the amount of nutrients extracted from the hard, dry vegetation.

29
Q

Other adaptations:

Many alpine animals also have larger hearts and lungs, and more blood cells to carry oxygen. Give an example.

A

E.g. Llamas in the Andes have the highest concentration of red blood cells of all mammals, and the process of binding and transporting O2 in their blood using haemoglobin is also highly efficient.

30
Q

White-tailed Ptarmigan:

What are they?

A

The smallest grouse in NA and the only bird in NA to reside permanently in the alpine zone.

31
Q

White-tailed Ptarmigan:

What are some of the adaptations?

A
  • change the colour of their feathers seasonally, from while in winter to speckled brown in summer, camouflage
  • during winter, plumage extends to cover feet, insulating extremities
  • feathers on feet also act as snowshoes
  • insulation from feathers and fat accumulated during summer allows thermoregulation
  • sedentary lifestyle conserves energy in winter, avoid flight and sit still for long period
  • Ptarmigan can maintain body temps at +40 throughout winter despite temps. Even have feathers around nostrils to warm air prior to entry into respiratory tract
  • eat snow, roost into snow during winter to keep warm, bath in snow during summer to keep cool
32
Q

Marmots:

There are 14 species of marmots in the world, 6 in NA and 6 in Eurasia. What are they?

A

Large rodents in the squirrel family, and they are expert hibernators, spending about 200 days a yr in hibernation.

33
Q

Marmots:

Describe their hibernation.

A

During hibernation, marmots cycle through long periods of torpor that are briefly interrupted by bouts of wakefulness. When torpor is induced, marmots decrease their set pt temp from around 40 to less than 5, almost matching ambient temp in burrow. Marmots rely entirely on their fat store to survive.
Enter burrows, called hibernaculum, as early as September, and don’t emerge until April or may. Insulate burrow with dried plant material.

34
Q

Marmots:

When they emerge, they reproduce and then eat. Often ___ their mass in preparation of another hibernation.

A

Double.

35
Q

Marmots:
The social behaviour of marmots is a useful adaptation that helps them keep warm during winter and avoid predation during summer. What do they do?

A

Huddling together in social family groups while they overwinter, reduces heat loss and increases their survival. Signal each other.

36
Q

Marmots:
Their unique adaptations to the alpine make marmots useful sentinel species for understanding environmental impacts in mountains. Give an ex.

A

E.g. the most endangered mammal in Canada is Vancouver Island marmot. Census in 2003, only 21 wild marmots on Vancouver Island. Due to increased predation as. With habitat changes caused by clearcutting followed by rapid forest regeneration. Over past 15 yrs marmots have been released into wild and the population has recovered to over 400.

37
Q

Marmots:
In Europe, Alpine marmots, Marmota marmot, were introduced in the Pyrenees in 1948 (borders Spain and France), where the alpine marmot had disappeared at the end of the Pleistocene, some 10,000 yrs ago. What happened?

A

They were first released by French hunters from the Alps as food source for brown bears and golden eagles to reduce predation on chamois (goat antelope genus native to the mountains in Europe).
Population exploded to over 10,000 from an initial release of 400. Questions about damage and unbalancing the ecosystem.
Negatives: impacts on flora, compete against other herbivores, carry disease such as plague.

38
Q

Marmots:

Dr. Isabel Barrio, Uiceland:

A

Spoke on Marmots in Pyrenees.

39
Q

Yak:

What is it?

A

A long-haired bovid found throughout the Himalayan region of S-C Asia.

40
Q

Yak:

What are their adaptations?

A
  • thick fleece of course outer hair and an undercoat of fine down
  • accumulate a layer of subcutaneous fat prior to winter
  • skin is relatively thick and their sweat glands are mostly not functional
  • large chest, with 14-15 pairs of thoracic ribs which is more than any other cattle, large lungs, and large heart
  • large rumen, useful for alpine grazing on a mixed diet of grasses and sedges, and shrubs
  • Yak do best when the annual mean temp is below 5, and the average in the hottest month doesn’t exceed 15
41
Q

Yak:

Domesticated yaks have been kept by mountain people for thousands of yrs for…?

A

Meat, milk, fibre, droppings as fuel, and as beasts of burden for transportation across mountain passes.

42
Q

Bar-headed Geese:

Birds have a considerable advantage over mammals at high altitudes. What are they?

A

The SA of their lungs is almost 10 times greater than in humans and the barrier between the lung and the capillaries is 2-8 times thinner, leading to greater diffusion of O2.
So they are capable of breathing rapidly and taking in large amounts of air.
In birds, air travels in one direction through the lungs opposite to the blood flow in the surrounding capillaries. This uni-directional flow means that the air has a high concentration of oxygen that diffuses more readily.

43
Q

Bar-headed Geese:
Common birds native to S-C Asia and every fall, these geese migrate from their breeding grounds in Mongolia to India, returning again in the spring. This journey takes them across the Tibetan Plateau and over the Himalayas. Flying is most costly and exhausting form of locomotion, migrate over 1000 km at altitude that averages over 4500 m. How?

A
  • Compared with other geese, their lungs are 25% bigger, meaning that the volume of O2 inhaled with each breath is larger. During high intensity flight they breathe deeper instead of faster, which reduced dead-space ventilation and maximizes O2 diffusion in lung.
  • Hemoglobin has high affinity for O2 ( amount of O2 in blood is greater) and they have more capillaries in their heart and muscles, which means that the diffusion of O2 at the tissue is higher.
44
Q

Bar-headed Geese:

Lawrence Swan:

A

Recounts bar-headed geese over Barun Glacier, Mount Makailu (5th highest).

45
Q

Bar-headed Geese:

Dr. Bill Milson, Zoologist UBC:

A

Adaptations at every step from environment to mitochondria where ATP are produced. 1. O2 into lung (respiratory), 2. Oxygen into blood (ability to bind and transport O2), 3. Heart to move O2 from lung to tissues, 4. Tissue, moving O2 capillaries in tissue into mito.

46
Q

Organisms living in mountain lakes experience different environmental constraints relative to those living on land. What are some?

A
  • water has a high specific heat capacity, which means that aquatic environments lose and gain heat less rapidly
  • cold water and sediment that originates from glaciers, as well as extended seasonal ice cover, limit primary productivity
  • most are naturally fishless, often dominated by large, often endemic, zooplankton (many have bright red or black pigments that protect them from high UV radiation)
47
Q

Most of the lakes in the mountain national parks in Canada were fishless before 1900, but have been stocked since then. Explain.

A
  • A survey of 1464 lakes in Jasper, Banff, Yoho, Waterton, Revelstoke, and Glacier national parks found that over 90% of the lakes did not contain fish until they were stocked in the 20th century.
  • The few that did, consisted of small communities, with 1-4 species, depending on size, altitude, and exposure of the lake.
48
Q

Bull trout (part of Char family, which includes Brook trout and lake trout) was once the most widespread native trout in the mountain parks and require water temperatures generally below 13, as well as clean gravel beds, deep pools, and large systems of interconnected waterways to accommodate spawning migrations (favoured deep pools of cold lakes and large rivers as well as high, cold mountain headwaters). What has happened in recent times?

A

Bull trout has disappeared from much of its former range due to damaged habitat, over-fishing and the introduction of fish species which has displaced it.

49
Q

During the last century, Rocky Mountains lakes were extensively stocked with sport fish to promote recreational fishing. What happened?

A
  • Contributed to loss of over 90% of Mountain Yellow-Legged Frog pop.
  • Lake Minnewanka: stocked with fish from 1901-1972, estimated that over 17 mil eggs and fry of lake trout, atlantic salmon, sisco, brook trout, cutthroat trout, smallmouth basks, lakewhite fish, and rainbow trout were introduced.
  • Mark Taylor, Aquatic ecologist, Parks Canada: Cave and Basin, mosquito fish, predominant non-native eastern brook trout and rainbow trout, lots of conservation on westloat cutthroat trout (species at risk)
50
Q
Tech Tip (Matt Peter):
Food and water.
A
  • Backcountry cooking: Equation… Calories vs. weight to carry vs. ease of preparation.
  • Simple, one pot to prepare, high in calories, light
  • Boost calories with spoonful of butter, cream cheese, smooth peanut butter.
  • 4 things to treat in water: protozoa, bacteria, viruses, particulate
  • Treat options are heat, chemicals, filtering, purifying
51
Q

Guest lecture:

Alpine Limnology by Laura Redmond. (Refer to video for examples)

A
1. What are the main stressors that act on lakes and ponds in mountains
High UV (pigmentation: melanin, carotenoid; increased enzymatic repair; behavioral), low terrestrial inputs (oligotrophic, low DOC), cold temps (metabolic constrains, behavioural), high temp variation (up to 20 degrees in day), short growing season (ice-off from weeks to months, ephippia), low connectivity/gene flow (low propagule pressure)
  1. How have species adapted to these stressors
  2. What are the predicted forecasts for these cold-adapted communities

Fish stocking, Anthropogenic nutrient deposition, toxin deposition, bioaccumulation

52
Q

Define Limnology.

A

The study of inland waters.