Exam 3 Flashcards

Question

Food Sharing: Vampire Bats

Answer 1

Groups are mostly female, low coefficient of relatedness (not very genetically related) Frequent blood meals critical for survival Females will regurgitate blood meal to feed group members that have not fed recently Hungry bat will be more likely to get a shared meal of she has fed the satiated bat sometime in the past

Answer 2

•  Cooperation is a ‘byproduct’ of a situation in which an individual would suffer a cost by not cooperating •  Differs from reciprocity: 1)  No temptation to ‘cheat’ or not cooperate 2)  Past behavior is not relevant (no scorekeeping) because cooperating is in the best interest of all parties Examples: 1)  Female yuhina jays & harsh environments 2)  House sparrows & large food source

Answer 3

Two or more individuals that cooperate to act against another individual or group Commonly involves intervening in an aggressive interaction with one individual Long-lasting coalitions are called alliances

Answer 4

Cooperation between 2 different species •  Imperial blue butterfly and Iridomyrmex ants have a mutualistic relationship •  Butterfly larvae and pupae cannot survive without ants •  Ants gain significant nutrition from nectar produced by larvae and pupae

Answer 5

searching for and consuming food includes agriculture, hunting

Answer 6

Agriculture can be considered a form of symbiosis (close, long-term interaction between 2 species) •  Agriculture-practicing animals: 1)  Humans 2)  Bark beetles 3)  Termites 4)  Ants

Answer 7

Hypothesis: evolution of complex ant-fungus relationship includes protection of fungus from destruction •  Supporting evidence: 1) At least 20 species of fungus-growing ants have Streptomyces bacteria, which produces antibiotics 2) Bacteria passed from parent to offspring 3) Only female reproductive ants ‘cultivate’ fungus gardens and carry bacteria 4) Bacteria’s antibiotics kill only specific parasites of the fungus

Answer 8

Fungal garden chambers: plant material incorporated into fungal mats Detritus chambers: storage of waste materials

Answer 9

refers to a type of mathematically-based models used to predict different aspects of foraging behavior

Answer 10

Supported by an early laboratory experiment by Krebs (1978) •  Great tit foraging studied using a conveyor belt presenting 2 different-sized pieces of mealworms for birds to choose (large = most profitable, small = least profitable) •  Encounter rate, energy content, and handling time required were measured and controlled •  Model accurately predicted when birds would take more profitable prey vs. both prey types \*Encounter rate of most profitable (and NOT least profitable) that determines whether least profitable prey chosen

Answer 11

Patch = clump of food that can be depleted (eaten) by a forager •  Once feeding in a patch starts, rate of feeding slows because food is disappearing •  Other less depleted patches available but will require a travel cost (energy, time, predation risk) Key question addressed by this model: How long should an animal forage in a patch it is depleting before moving on to the next patch?

Answer 12

Many animals have specific nutritional needs such as zinc and sodium; foraging for these nutrients can be costly Example: Moose require sodium (found in aquatic but not terrestrial plants) Model accounted for: 1) Minimum daily food requirement 2) Speed of digestion 3) Energy values of aquatic & terrestrial plants 4) Sodium constraint \*Model accurately predicted that a moose needs to spend 18% of its summer foraging time on aquatic plants to meet yearly sodium needs

Answer 13

Risk = variability in prey/food availability •  Hunger state of an animal influences preferences for risktaking Satiated animal: Risk-averse = animal prefers less variance Starving animal: Risk-prone = animal prefers variance Hungry but not starving/satiated: Risk-insensitive = animal is indifferent

Answer 14

Caching/hoarding = saving food for later consumption; sooner as in the case of an animal carcass or later (e.g. months) Hoarding 1)  Scatter – large number of caches of food (squirrels, birds) 2)  Larder – usually one large cache of food kept in nest (hamsters)

Answer 15

Recall: hippocampus (yellow circle) is important for spatial learning in mammals In birds, hippocampus (blue bracket) is associated with food retrieval

Answer 16

•  Relationship between food-storing behavior and hippocampal volume studied in 7 bird species with different food-storing behaviors •  Species that rarely store food: alpine chough (A) and jackdaw (B) •  Species that show moderate levels of food storage: rook and crow (C), red-billed blue magpie (D) and magpie (E) •  Species that shows high levels of food storage: European jay (F) MORE

Answer 17

Largest relative hippocampal volume compared to other birds •  Food-storage/retrieval is very important to this species •  Stores 6,000 to 11,000 seeds and remembers locations for 9 months

Answer 18

Hypothesis: Birds from food-poor areas should be better at caching and retrieval and have a larger hippocampus compared to birds from food-rich areas Experiment: Black-capped chickadees captured from 2 separate locations and allowed to cache & retrieve seeds 1) Alaska – food-poor 2) Colorado – food-rich Results: Compared to Colorado birds, Alaskan birds 1)  Cached more seeds 2)  Found more of them efficiently 3)  Had larger hippocampi with more neurons

Answer 19

•  Many learning-related processes involve the forebrain •  Perhaps larger forebrain size is predictive of better learning ability? •  Relative forebrain size measured as ratio of forebrain:brain stem

Answer 20

•  Lefebrve and colleagues came up with a potential indicator of learning ability: Foraging innovation = “either the ingestion of a new food or type of the use of a new foraging technique” •  Data were gathered for 322 foraging innovations in 318 bird species from North America and the British Isles •  Frequency of innovations was plotted against relative forebrain size

Answer 21

•  Is there a fitness advantage to having larger brains? •  Invasion potential = survival in a new environment •  Larger brain size à greater invasion potential •  Higher innovation frequency à greater invasion potential

Answer 22

Can animals other than humans plan for the future? Two requirements needed to support existence of this ability: 1)  Behavior must be novel, not innate 2)  Behavior cannot be tied to current motivational state of animal but to an anticipated state in the future

Answer 23

4 hr trial: Bird chooses worm (worm is still fresh after 4 hrs) 124 hr trial: Bird chooses peanuts (worm is rotten after 124 hrs) Birds knew what (worm/peanut), where (side of tray), and when (how long ago food cached)!

Answer 24

1) Deep-sea worms: release of bioluminescent “bombs” 2) Ground squirrels: tail waving, dirt throwing

Answer 25

•  Deep sea worms (genus Swima) release glowing green fluidfiled sacs or “bombs” to scare off predators •  “Bombs” are actually detachable gills that glow for several seconds after release •  These worms live about 2 miles down from the ocean surface

Answer 26

•  California ground squirrels and gopher snakes have been prey-predator for about 1 million years •  Antipredator behaviors include: 1)  Group mobbing, including biting & harrassment, until snake leaves 2)  Throwing dirt, pebbles, etc. 3)  Specific snake alarm calls California ground squirrels will mount similar antipredator behaviors against rattlesnakes A: Snakes are recognized as predators B: Confrontations are common C: Squirrels have defensive responses including throwing items

Answer 27

Two general types: 1) Avoid detection by predator 2) Predator encounter

Answer 28

1) Blending into the environment 2) Being quiet 3) Choosing safe habitats

Answer 29

•  Commonly known as becoming camouflaged or cryptic •  Reduces likelihood of detection by predators •  This strategy of matching backgrounds is not necessarily based on behavior •  Natural selection can act to favor variants of certain traits that facilitate “blending in” Example: Coat color in oldfield mouse (also known as beach mouse) \*Mice living on the beach are lighter than mice living more inland

Answer 30

Cuttlefish and related cephalopods (octopus, squid) use 3 forms of active camouflage: 1)  Uniform: single color adopted from background 2)  Mottled: mixture of small dark and light splotches resembling background 3)  Disruptive: mixture of large dark and light resembling background

Answer 31

•  Reducing sound production in response to particular predator sounds Examples: 1) Gulf toadfish: avoiding bottlenose dolphins 2) Wax moths: avoiding bats

Answer 32

•  Make up about 13% of bottlenose dolphin diet •  Dolphins orient towards “boat whistle” sounds made by males during the breeding season Question: Do toadfish listen for sounds of dolphin foraging and then decrease their “boat whistling”? •  Dolphin vocalizations include: 1)  High-frequency whistles used for social communication 2)  Clicks and low-frequency “pops”, used for foraging •  For toadfish, low-frequency sounds are easy to hear Experiment: •  Male toadfish captured during breeding season •  Whistling males exposed to one of the following sounds: 1)  Pops associated with dolphin foraging 2)  High-frequency whistles involved in social communication 3)  “Snapping” sounds of snapping shrimp = control sound •  Whistling activity of male toadfish measured for 5 min before, during, and after test or control sounds

Answer 33

•  Similar to Gulf toadfish, greater wax moths also become quiet when a predator is detected •  Wax moth predator = bat •  Bats emit echolocation calls during foraging Female moths face 2 problems: 1)  Male mating calls sound very similar to bat calls 2)  Female “wing-fanning” response attracts bats as well as males

Answer 34

Avoid predators by selecting predator-free habitats Examples: 1) Nesting site choice in parrots 2) Conservation concerns in relocating animals to new environments and new predators

Answer 35

Brightsmith and colleagues compared Australian and Amazonian parrot species 1)  DNA sequences 2)  Nesting behavior: Tree cavity (TC) or other cavity (OC) nesters \*Ancestral state of nesting site choice = tree cavity \*Other cavity nesting preference evolved independently Question: What forces of natural selection drove nesting site choices from tree cavity to other cavity?

Answer 36

•  Co-evolution = changes in traits of species 1 results in changes in traits of species 2; these change feed back in turn on traits of species 1 etc. etc. •  Can result in an “arms race” such that as prey evolve behaviors to defend against predators, predators evolve behaviors that increase prey detection

Answer 37

•  Rabbits are an introduced species in Australia •  Co-evolved with ferrets, cats, and foxes in Europe Exposure to scents of predators with shared evolutionary history à decreased use of scented areas Exposure to scent of native Australian predator (spotted quoll) à no decrease

Exam 3 Flashcards

(61 cards)