Food Chains and Research Studies Flashcards Preview

ANSC*3180- Wildlife Nutrition > Food Chains and Research Studies > Flashcards

Flashcards in Food Chains and Research Studies Deck (15)
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1
Q

Producers –> autotrophs

A

plants, algae, phytoplankton (photosynthesis)
make their own food
create chemical energy from solar energy
photosynthesis= H2O +CO2 –light–> sugars + O2

2
Q

Primary Consumers –> heterotrophs

A

herbivores (eat plants and algae)

eat their food

3
Q

Secondary consumer

A

omnivores/ carnivores (eat herbivores)

4
Q

Tertiary consumers

A

omnivores/carnivores (eat omnivores/ carnivores)

5
Q

Apex Predators

A

tertiary consumer with no predators

often vital to ecosystem (keystone species)

6
Q

Decomposers

A

bacteria and fungi
break down decomposing plants/animals
release inorganic nutrients back into the environment

7
Q

Direct Observation

A

Pros- generally inexpensive

Cons-

  • difficult wit crepuscular/ nocturnal/ fossorial species
  • difficult with aquatic animals
  • difficult in certain environment
  • no indication as to what the animal is doing when not observed
  • very time consuming

potenial issues
- animals do not always eat the whole food item

8
Q

Utilization studies- Enclosure

A

pros

  • relatively simple to perform
  • gives indication of which plant species/ parts were eaten

cons

  • only useful for herbivores
  • other animals may have eaten from the enclosure
9
Q

Utilization studies- cafeteria- captive animals

A

pros

  • relatively simple to perform
  • gives indication of which plant species/ part were eaten
  • gives indication of plant species/ part preference

Cons

  • animals are captive and cannot range/forage freely
  • may not capture all plant parts (roots, stems)
10
Q

Digesta Sampling: Fistulation

A

pros

  • more accurate than utilization techniques
  • can identify proportion/types of feed

Cons

  • only works with captive (and tame) animals
  • may not be a true representation of a wild diet
  • surgical procedure required to implant fistula
11
Q

Digesta Sampling: pellets

A

pros

  • more accurate than utilization techniques
  • non-invasive

cons

  • some food components are poorly represented or absent
  • only useful for birds
  • some bird species do not necessarily eat whole prey

pellets contains only indigestible components of foods eaten:

  • bones: provide species, size , age of prey
  • feathers: provide species and age of prey
  • scales: provide age and class of prey
12
Q

Digesta Sampling: Postmortem

A

pros

  • more accurate than utilization techniques
  • no animals killed specifically for the procedure/study

cons

  • time of last meal unknown
  • degree of digestion unknown
13
Q

Fecal Analysis

A

pros
- may provide information not attained via utilization techniques
- non-invasive
cons
- only poorly digested food components are represented
- may be difficult to ID the species the produced the faces

14
Q

Stable Isotope Studies

A

every biologically active element exists in various isotopic forms;

  • isotopes differ based on # of neutrons in the nucleus
  • two or more isotopes of each element are stable
15
Q

Adipose Tissue composition

A

fats stored as adipose tissue reflect fats consumed by the animal
except in ruminants/ foregut fermenters who can hydrogenate fatty acids
microbes in fermentation may produce unusual fatty pics