1. BIOL 4120: Principles of Ecology Lecture 7: Animal adaptations to the Environment Dafeng Hui Office: Harned Hall 320 Phone: 963-5777 Email: dhui@tnstate.edu

2. Topics 7.1 Animals have various ways to acquire energy and nutrients 7.2 Animals have various nutritional needs 7.3 Animal require oxygen to release energy contained in food 7.4 Regulation of internal conditions involves homeostasis and feedback 7.5 Animals have different methods of maintaining their body temperatures 7.6 Poikilotherms depend on environmental temperatures 7.7 Homeotherms escape the thermal restraints of the environment 7.8 Endothermy and Ectothermy involve trade-offs 7.9 Heterotherms take on characteristics of ectotherms and endotherms 7.10 Torpor helps some animals conserve energy 7.11 Some animals use unique physiological means for thermal balance 7.12 Maintenance of water balance 7.13 Biological clocks influence animal activity

3. Animals are heterotrophs and derive their energy and most nutrients from consuming organic compounds contained in other plants and animals Animals are heterotrophs and derive their energy and most nutrients from consuming organic compounds contained in other plants and animals Key processes common to all animals Key processes common to all animals Acquire and digest foodAcquire and digest food Absorb oxygenAbsorb oxygen Maintain body temperature and water balanceMaintain body temperature and water balance Adapt to light and temperature variationsAdapt to light and temperature variations Animals encounter different constraints in aquatic versus terrestrial environments Animals encounter different constraints in aquatic versus terrestrial environments Chapter 7 Animal Adaptations to the Environment

4. 7.1 Animals have various ways of acquiring energy and nutrients Energy sources for plants and animals Energy sources for plants and animals Three Feeding Methods of Heterotrophs: Three Feeding Methods of Heterotrophs: Herbivores: Feed on plants.Herbivores: Feed on plants. Carnivores: Feed on animal flesh.Carnivores: Feed on animal flesh. Omnivores: Feed on both plants and animalsOmnivores: Feed on both plants and animals Detritivores: Feed on non-living organic matter (earthworm, dung beetle).Detritivores: Feed on non-living organic matter (earthworm, dung beetle).

5. Animals have various ways of acquiring energy and nutrients Mouthparts reflect how organisms obtain their food. Mouthparts reflect how organisms obtain their food.

6. Herbivores Herbivores Grazers (cattle, dear, sheep, grasshopper)Grazers (cattle, dear, sheep, grasshopper) Leafy material (Ruminants chew the cud; Non ruminants are less efficient) Leafy material (Ruminants chew the cud; Non ruminants are less efficient) High in cellulose and some lignin (C:N ratio) High in cellulose and some lignin (C:N ratio) Use specialized microorganisms in gut to help digest the difficult carbohydrate molecules in ruman or cecum or redigestion (Fermentation)Use specialized microorganisms in gut to help digest the difficult carbohydrate molecules in ruman or cecum or redigestion (Fermentation) Microorganisms produce proteins, lipids etcMicroorganisms produce proteins, lipids etc BrowsersBrowsers Woody material (Termites) Woody material (Termites) High in lignin and celluloseHigh in lignin and cellulose Use specialized microorganisms in gut to help digest the difficult carbohydrate moleculesUse specialized microorganisms in gut to help digest the difficult carbohydrate molecules Microorganisms produce proteins, lipids etcMicroorganisms produce proteins, lipids etc Granivores (birds)Granivores (birds) Seeds Seeds Crop with specialized enzymesCrop with specialized enzymes Gizzard for grindingGizzard for grinding Frugivores (monkey etc.)Frugivores (monkey etc.) Fruit Fruit

7. Carnivores Carnivores First level feed directly on herbivoresFirst level feed directly on herbivores No cellulose No cellulose Rapid digestion and easy assimilation Rapid digestion and easy assimilation Hunting is energy consuming Hunting is energy consuming Second level feed on first level carnivoresSecond level feed on first level carnivores Omnivores Omnivores Food eating habits vary with season, life cycle and their sizesFood eating habits vary with season, life cycle and their sizes Fox Fox Preferential carnivorePreferential carnivore Insects, small mammals and birds Insects, small mammals and birds but eats berries, fruit, grass but eats berries, fruit, grass Bear Bear Preferential herbivorePreferential herbivore Buds, leaves, berries, fruit, etc Buds, leaves, berries, fruit, etc Supplemented by insects, fish and small to medium mammals Supplemented by insects, fish and small to medium mammals

8. Red Fox is an example of an omnivore Red Fox is an example of an omnivore

9. 7.2 Animals have various nutritional needs Animals need amino acids and specific minerals such as sodium, calcium, magnesium, etc Animals need amino acids and specific minerals such as sodium, calcium, magnesium, etc High quality and quantity of plants are very important to animal survival High quality and quantity of plants are very important to animal survival Herbivores show certain preference on high N plants (Taste and odor) Herbivores show certain preference on high N plants (Taste and odor) Deficiency in minerals influences distribution, behavior, and physiology of animals Deficiency in minerals influences distribution, behavior, and physiology of animals Sodium can be hard to obtain and can be a problem Sodium can be hard to obtain and can be a problem Kangaroos, Rabbits in AustraliaKangaroos, Rabbits in Australia Overgrazing of sodium rich plants can cause population collapse (plants died) Overgrazing of sodium rich plants can cause population collapse (plants died) ElephantsElephants See preference for sodium rich water hole in Wankie National Park, Zimbabwe See preference for sodium rich water hole in Wankie National Park, Zimbabwe Dear: eating mineral-rich soil in spring Dear: eating mineral-rich soil in spring High potassium in spring vegetation may cause calcium, magnesium deficiency in goats, cattle and sheep (influence hormone balance) High potassium in spring vegetation may cause calcium, magnesium deficiency in goats, cattle and sheep (influence hormone balance) Nutrient conditions influence growth and reproduction. Nutrient conditions influence growth and reproduction.

10. Deer need lots of calcium, phosphorus and protein to grow antlers, which are needed for reproductive success Deer need lots of calcium, phosphorus and protein to grow antlers, which are needed for reproductive success Deficiency results in stunted antlersDeficiency results in stunted antlers

11. 7.3 Animals require oxygen Energy from organic compounds in the food they eat Energy from organic compounds in the food they eat Release energy primarily through aerobic respiration Release energy primarily through aerobic respiration O2 is required (could be an issue for aquatic animals) O2 is required (could be an issue for aquatic animals) Methods to acquire O2 Methods to acquire O2 Body surface: insects, tracheal tubesBody surface: insects, tracheal tubes Lungs: mammals, birds, reptilesLungs: mammals, birds, reptiles Lung and air sacs: birdsLung and air sacs: birds Lungs: whales and sharksLungs: whales and sharks Gills: FishGills: Fish

12. Respiration systems Animals need to use aerobic respiration Therefore need to have excellent oxygen uptake system Therefore need to have excellent oxygen uptake system Small animals Small animals DiffusionDiffusion Insects Insects Diffusion and spiraclesDiffusion and spiracles Amphibians Amphibians Vascularised skinVascularised skin Simple lungsSimple lungs Mammals Mammals LungsLungs Birds Birds LungsLungs Anterior and posterior air sacsAnterior and posterior air sacs Fish Fish GillsGills Aquatic mammals Aquatic mammals LungsLungs Special haemoglobin oxygen storage systemsSpecial haemoglobin oxygen storage systems O2 countercurrent exchange

13. BIOL 4120: Principles of Ecology Lecture 7: Animal adaptations to the Environment Dafeng Hui Office: Harned Hall 320 Phone: 963-5777 Email: dhui@tnstate.edu

14. 7.4 Regulation of internal conditions involves homeostasis and feedback Homeostasis: The maintenance of a relatively constant internal environment in a varying external environment. Homeostasis depends on negative feedback Negative feedback: when a system deviates from the normal or desired state, mechanisms function to restore the system back to that state. Example: room temperature setting

15. Homeostasis To stay alive, animals need to keep their body within certain limits To stay alive, animals need to keep their body within certain limits TemperatureTemperature Water balanceWater balance pHpH Salt balanceSalt balance Feedback systems to help to keep within specific limits Feedback systems to help to keep within specific limits Outside limits – Outside limits – DehydrationDehydration Heat shockHeat shock Salt imbalanceSalt imbalance DeathDeath

16. Negative feedback (thermoregulation)

17. Body structure influences the T exchange Body structure influences the T exchange Temperature (Tb, Ts, Ta) Temperature (Tb, Ts, Ta) Tb Ts conduction Tb Ts conduction Boundary layer (a thin layer of air surround the body) Core temperature Tb Surface temperature Ts Ears Fingers Toes Ts Ta: conduction, convection, radiation, evaporation Ts Ta: conduction, convection, radiation, evaporation Insulation (air, body covering) influences energy exchanges Insulation (air, body covering) influences energy exchanges Animals exchange energy with their surrounding environment

18. 7.5 Animals have different methods of maintaining their body temperatures Three groups of animals Endothermy resulting in homeothermy Endothermy resulting in homeothermy Use of internal heat source (metabolically)Use of internal heat source (metabolically) Mammals and birds Mammals and birds Maintain a fairly constant temperature (warm-blooded) Maintain a fairly constant temperature (warm-blooded) Ectothermy resulting in poikilothermy Ectothermy resulting in poikilothermy Use of external heat sourcesUse of external heat sources Reptiles, amphibians, fish, insects and invertebrates Reptiles, amphibians, fish, insects and invertebrates Results in a variable body temperature (cold-blooded) Results in a variable body temperature (cold-blooded) Heterotherm Heterotherm Uses both endothermy and ectothermyUses both endothermy and ectothermy Bats, bees and hummingbirds Bats, bees and hummingbirds Depends on environmental situations and metabolic needs. Depends on environmental situations and metabolic needs.

19. As the temperature increases, so does the metabolic rate Therefore these animals are more active during the day Every 10 o C doubles metabolic rate Naturally low metabolic rate and high conductivity Activities also control temperature Upper and lower limits vary Lizards and snakes have a 5 o C Amphibians have a 10 o C 7.6 Poikilotherms depend on environmental temperatures Operative T range: range of body T at which poikilotherms can carry out their daily activities (next slide).

20. During the day, the snake can maintain a fairly constant temperature by adjusting it ’ s environment (bask in sun to raise T, seek shade to cool, submerge in water etc) During the day, the snake can maintain a fairly constant temperature by adjusting it ’ s environment (bask in sun to raise T, seek shade to cool, submerge in water etc) During the night, it has few options During the night, it has few options Temperature drops 10- 15 degrees Become torpid (slow moving) Restricted by environment Limited to Maximum size due to need for surface area to gather heat No minimum size

21. Poikilotherms in water Poikilotherms in water No insulationNo insulation Match of body temperature to water temperatureMatch of body temperature to water temperature Water temperature normally only changes slowly with seasonWater temperature normally only changes slowly with season Poikilotherms can adjust slowly to a wide range of temperatures than land poikilotherms (acclimation)Poikilotherms can adjust slowly to a wide range of temperatures than land poikilotherms (acclimation) Stressed by rapid temperature changesStressed by rapid temperature changes

22. 7.7 Homeotherms escape the thermal restraints of the environment Homeotherms can escape the thermal restraints of the environments, thus Homeotherms can escape the thermal restraints of the environments, thus can exploit a wide range of thermal environments But needs energy to maintain relative constant T But needs energy to maintain relative constant T Therefore homeotherms use large amounts of glucose etc to maintain temperature (aerobic respiration) Therefore homeotherms use large amounts of glucose etc to maintain temperature (aerobic respiration) O2 is consumed during respiration O2 is consumed during respiration Rate of O2 consumption is used to measure metabolic rate Rate of O2 consumption is used to measure metabolic rate

24. Resting metabolic rate and ambient temperature Thermoneutral zone: a range of environmental temperatures within which the metabolic rates are minimal. Critical T: lower and upper critical T

25. Homeotherms can escape the thermal constraints of the environments Ways to keep body warm: 1. Insulation to reduce the convection: fur, feather, or body fat Mammals: fur, change fur in the winter Mammals: fur, change fur in the winter Fur can keep body heat in and the heat out Birds: feather Birds: feather Insects: a dense fur-like coat (moths, bees) Insects: a dense fur-like coat (moths, bees) 2. When insulation fails: shivering (a form of involuntary muscular activity that increase heat production. 3. Small mammals: burn brown fat (bats) without shivering. Ways to keep body Cool: 1. birds and mammals: evaporation of moisture from skin 2. mammals: sweat glands (horse, human), panting 3. birds: gular fluttering

26. 7.8 Endothermy and Ectothermy involve trade-offs New Scientist, 2009

27. 7.8 Endothermy and Ectothermy involve trade-offs Endotherms can survive in large range of T, why not all animals are endotherms? EndothermsEctotherms EndothermsEctotherms Activity: under all environments limited to environmental T Energy: high low Food: most for respiration, less less for respiration to growth more to growth to growth more to growth Limits on size: limit on minimum size limit on maximum size limit on minimum size limit on maximum size

28. Limited in size Warm-blooded animals: body mass (volume) produce heat, lost through surface area, the ratio of surface to volume is key factor too. Small animals have larger ratio and greater relative heat loss to environment, require higher mass-specific metabolic rate to maintain and consume more food energy per unit body weight. Too small Need too much energy to keep temperature stable 2 gm limit Shrew (Solex spp) eats own body weight in food every day to maintain temperature Cold-blooded animals absorb heat through surface, thus the surface area to volume is also a key factor. Large animals limited to warm areas.

29. Metabolic rate and body mass

30. 7.9 Heterotherms take on characteristics of ectotherms and endotherms Temporal heterotherms: species that sometimes regulate their body T and sometimes they do not. Insects, bats, bees, hummingbirds Adult insects can be ectothermic and endothermic: T limits on flight: 30oC for take off, and no more than 40oC for flight Need warm-up to take off: ectothermic Flight: burn energy, endothermic

31. 7.10 Torpor helps some animals conserve energy 7.10 Torpor helps some animals conserve energy Torpor Torpor Small homeothemic animalsSmall homeothemic animals Become heterothermic Become heterothermic Body temperature drops to ambient at night Body temperature drops to ambient at night Inactive Inactive Bats, Some mice, kangaroosBats, Some mice, kangaroos Hibernation Hibernation Many poikilotherms and some mammals have winter torpor to save energyMany poikilotherms and some mammals have winter torpor to save energy Selective advantage when resources are fewSelective advantage when resources are few MammalsMammals Heart rate, respiration fall Heart rate, respiration fall Temperature drops to ambient Temperature drops to ambient Groundhogs, chipmonks Groundhogs, chipmonks Not bears Not bears No temperature changeNo temperature change Just long sleep with no eating, drinking, defecating or urinatingJust long sleep with no eating, drinking, defecating or urinating Females give birth and feed young in this periodFemales give birth and feed young in this period Can wake up easilyCan wake up easily Do not visit a bear cave in winter!Do not visit a bear cave in winter!

32. 7.11 Some animals use unique physiological means for thermal balance Storing body heat: Camel, oryx and some gazelles Body T change from 34oc to 41oC for camel (morning to afternoon) Reduce need for evaporative cooling and save water and energy Reduce need for evaporative cooling and save water and energySupercooling: many ectothermic animals of temperate and Arctic regions When the body T below freezing points without actually freezing The presence of certain solute (glycerol) in the body lower the freezing points The presence of certain solute (glycerol) in the body lower the freezing points Wood frog, grey tree frog, spring peeper Countercurrent heat exchange: to conserve heat in a cold environment and to cool vital part of body during heat stress.

33. Countcurrent heat exchange happens in homeotherms (porpoise, whale) as well as in certain poikilotherms (tuna, mackerel shark) Countcurrent heat exchange happens in homeotherms (porpoise, whale) as well as in certain poikilotherms (tuna, mackerel shark) To preserve heat in cold water, and get ride of heat in warm water To cool brain, reduce T by 2-3oC

34. 7.12 Maintenance of water balance Terrestrial Terrestrial InputInput Drinking Drinking Eating Eating Produced by metabolism (respiration) Produced by metabolism (respiration) Output – Need to control in extreme environmentsOutput – Need to control in extreme environments Urine Urine Concentrated to avoid water lossConcentrated to avoid water loss Feces Feces Evaporation Evaporation No sweat glands in some mammalsNo sweat glands in some mammals Breathing Breathing

35. What happens to ungulates in a hot dry climate like Africa No pants, no sweating to save water, store heat in body (T up to 46oC at daytime, release heat at night 36oC) Countcurrent heat exchange to lower head T Eat at nighttime, more water in plants Respiration to produce water

36. Maintenance of water balance Aquatic Aquatic Freshwater (hyperosmotic, high salt in body)Freshwater (hyperosmotic, high salt in body) Prevent excess uptake of waterPrevent excess uptake of water Remove excess water Remove excess water Retain salt in special cells (gills)Retain salt in special cells (gills) Large amounts of very dilute urineLarge amounts of very dilute urine Saltwater (hypoosmotic, low salt in body)Saltwater (hypoosmotic, low salt in body) If salt concentration is higher than in body, dehydrate If salt concentration is higher than in body, dehydrate Ion pumps, gill (fish)Ion pumps, gill (fish) Kidneys (eliminate salts, marine mammals)Kidneys (eliminate salts, marine mammals) Salt secreting glands in birdsSalt secreting glands in birds

37. Buoyancy aids aquatic organisms to stay afloat Gas or swim bladder (most fish) Gas or swim bladder (most fish) 5-10% body volume5-10% body volume Lungs in air-breathing animals Lungs in air-breathing animals Replace heavy chemical ions in the body fluids with lighter ones Replace heavy chemical ions in the body fluids with lighter ones Squid (ammonium ions to replace sodium ions)Squid (ammonium ions to replace sodium ions) Shark, mackerels, bluefish: store lipids (less dense than seawater)Shark, mackerels, bluefish: store lipids (less dense than seawater)

38. Aquatic animals need to move up and down in water Aquatic animals need to move up and down in water Buoyancy aids Buoyancy aids Shark Shark Large fatty liver Must swim to not sink Fish Fish Gas bladder Used to move up and down Seal Seal Blubber Can float on surface with air in lungs

39. 7.13 Biological clocks influence animal activity Daily and seasonal light and dark cycles Daily and seasonal light and dark cycles Critical daylengths trigger seasonal responses Critical daylengths trigger seasonal responses Activity rhythms of intertidal organisms follow tidal cycles Activity rhythms of intertidal organisms follow tidal cycles

40. Animals react to changing light through internal biological clocks Animals react to changing light through internal biological clocks Internal Biological Clocks have adaptive value Internal Biological Clocks have adaptive value Used to change behavior: feeding, food storage, reproduction, migration.Used to change behavior: feeding, food storage, reproduction, migration. Daily (Circadian rhythm): sleep, metabolic rate, temperature Daily (Circadian rhythm): sleep, metabolic rate, temperature Predators must match their feeding activity with prey. Seasonal: food storage, migration

41. Seasonal Changes for male deer Seasonal Changes for male deer Only needed during mating season Only needed during mating season Can be damaged and need replacing Can be damaged and need replacing

42. Critical daylengths trigger seasonal responses Squirrels start activity when the day starts, regardless of the season

43. Daylengths influence organisms activity Critical daylength Critical daylength Duration of light or dark reaches a certain proportion of the 24-hour day, it inhibits or promotes a photoperiodic response.Duration of light or dark reaches a certain proportion of the 24-hour day, it inhibits or promotes a photoperiodic response. Normally 10-14 hoursNormally 10-14 hours Day-neutral organisms: not controlled by daylength Day-neutral organisms: not controlled by daylength Short-day organisms: reproduction (or other activity) is stimulated by daylength shorter than critical daylength Short-day organisms: reproduction (or other activity) is stimulated by daylength shorter than critical daylength Long-day organisms: ~longer~ Long-day organisms: ~longer~ Diapause: a stage of arrested growth over winter in insects of the temperate regions controlled by photoperiod. Diapause: a stage of arrested growth over winter in insects of the temperate regions controlled by photoperiod. Requirement: 12-13 hours of lightRequirement: 12-13 hours of light A quarter-hour difference can determine diapause or notA quarter-hour difference can determine diapause or not

44. Crabs from a tidal estuary retain timed activities in a fixed environment Crabs from a tidal estuary retain timed activities in a fixed environment Color change (day and night) Activity (tides) Two clocks Tidal Solar Activity rhythms of intertidal organisms follow tidal cycles

45. The END

46. Circadian (24 hr) rhythm is very important to most living organisms Circadian (24 hr) rhythm is very important to most living organisms Timing measures Timing measures LightLight TemperatureTemperature MoistureMoisture Temperate zone Temperate zone Light cycleLight cycle Arctic and subarctic zones Arctic and subarctic zones TemperatureTemperature Tropical and subtropical zones Tropical and subtropical zones MoistureMoisture

47. Water Movement in Aquatic Environment Isomotic (isotonic): Body fluids and external fluid are at the same concentration. Isomotic (isotonic): Body fluids and external fluid are at the same concentration. Hypoosmotic (hypotonic): Body fluids are at a lower concentration of salt than the external environment. Hypoosmotic (hypotonic): Body fluids are at a lower concentration of salt than the external environment. Hyperosmotic (hypertonic): Body fluids are at a higher salt concentration than the external environment. (freshwater) Hyperosmotic (hypertonic): Body fluids are at a higher salt concentration than the external environment. (freshwater)

48. Fig. 5.4

50. Digestive systems are different for these different type of animals Stomach Caecum: Intestine Colon