Feeding and Foraging behaviours

Question 1

Definition of generalists?

Answer 1

• will eat practically anything

- e.g. fox

Question 2

Definition of specialists?

Answer 2

• can only eat certain things
• has evolutionary benefits as there isn’t as much competition
• e.g. panda

Question 3

How does the volume of food consumed differ in animals?

Answer 3

• depending on needs, habitat, how it collects food
• those that select specific parts of food that’s chosen for highly nutritious content
• those that bulk feed and choose to eat large quantity of food rather than quality
• if species has high BMR and needs to meet that demand regularly they’ll consume little but often throughout the day
• if the species doesn’t have high energy requirement and hence lower BMR so they feed about once a year

Question 4

How does food consumed differ based on whether they conform to environment of not?

Answer 4

• some species conform to prevailing environmental conditions (e.g. frogs are ectothermic, rely on prevailing external temperature conditions to regulate internal metabolism)
• some species are regulators and have precise control over internal physiology (e.g. brown bear has control and is endothermic, relies on energy from diet to produce heat for cellular respiration)

Question 5

Example of animal changing physiology based on the food that’s available to them?

Answer 5

• Andean hillstar, hummingbird from South America
• have high metabolism so need to constantly eat throughout the day to have energy to fly between flowers where they gather nectar from
• perform a behaviour called torpor where they shut down physiology down to baseline levels to survive cold periods at night when flowers are closed

Question 6

What decisions does an animal have to make?

Answer 6

• what to eat
• what not to eat
• how big the food item should be
• where they should search for the food

Question 7

How might animals choose food by colour?

Answer 7

• red and black fruits are common colours and highly conspicuous
• colour doesn’t indicate nutritional content as they may contain sugars which will provide energy but not many useful vitamins/minerals
• less common fruit colours indicate nutritional content

Question 8

How might animals choose food based on medicinal value?

Answer 8

• some organic compounds can be broken down in the gut to help them self-medicate or break down other food items
• e.g. garlic and onion

Question 9

What are foraging cues?

Answer 9

-can be neophobic (afraid of trying new things) when alone but when in a group with shared experiences they’re more likely to try unfamiliar foods

Question 10

How do animals choose what not to eat?

Answer 10

• will avoid those that induce sickness as a warning mechanism was passed down to them
• generalists may encounter many different foods and pay attention to sickness inducing cues
• specialists have no facultative (choice/amount of different things to encounter) response

Question 11

How do animals decide where they should search for food?

Answer 11

• which habitat is most profitable
• where everyone else is feeding
• where everyone else is not feeding
• whether there’s local information centre available

Question 12

What is marginal value theorem?

Answer 12

• need to ask themselves at what point they should leave current feeding patch to go and find a new one
• they’re debating: potential energy available at current patch, energy expenditure when travelling to new site, energy expended searching for food in increasingly diminished feeding site, energy available in new foraging areas