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Lecture 13

ANSC 3180 Lecture 13: Food Habits
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by OneClass2439092 , Winter 2017
13 Pages
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Winter 2017

Department
Animal Science
Course Code
ANSC 3180
Professor
Esther Finegan
Lecture
13

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How much energy to animals need to survive, grow and reproduce?
(lectures 3a-3g)
What do animals eat? Daily, annually? (lectures 4a-4f)
What nutrients and toxins do foods contain and what use do animals
make of food eaten? (lecture 5 series)
Carnivores -eat animal material
Omnivore -eat both animal and plant material
Herbivores -eat plant material
Generalists, eat a wide variety of different foods/ food species
E.g. ruffed grouse: eats 300+ plant species, 100+ small mammal
species
Polyphages:
E.g. snail kite: single fresh water snail genus -apple snails
Monophages:
Consume only one category of food all adult life
eat vertebrate animal species
eat little/no plant food compared to canids
eat vertebrate species but may also eat plant material
Felids,
Obligate:
May change category of food eaten
Through seasons of the year or during periods of food scarcity
Facultative:
Not a plant, bacteria, fungus, virus or prion
Means a vertebrate animal -mammal, bird, reptile, amphibian, fish
Means an invertebrate animal: sea anemones, oysters, spiders,
milipeeds, mussels
'Animal'
All animal products, not only muscle meat
Catch live prey
E.g. bobcat, mountain lion, coyote, weasel, hawks, owls,
dragonflies
Predators:
Find dead prey
E.g. vulture
Scavengers:
Eat plankton
!
E.g. Caribbean flamingo, baleen whale
!
Planktonivores
Eat sponges
!
E.g. green sea turtle (silica spikes need mucous in gut)
!
Spongivores
Eat shrimp, crabs (chitin exoskeleton)
!
E.g. oyster catcher (crabs and shellfish), some penguins
(chitinase)
!
Crustacivores:
Eat insects (chitin exoskeleton)
!
Many insects are seasonal (migration, facultative
insectivory), insects in wood/crevices
!
Eat 10+/min
1/2 of bats weight insects/night
Body weight in insects/night in nursing females
Scoop up insects with tail membrane
E.g. little brown vat
!
Probe under bark for insect eggs, larvae, pupae &
adults, spiders
E.g. brown creeper
!
Makes rows of holes in birch and aspen trees, and
eats the insects which are attracted to sweet sap
E.g. yellow bellied sapsucker
!
90% diet is flying insects (almost constantly in
flight)
E.g. tree swallows
!
Some egest exoskeletons (kestrels, flycatchers,
swallows)
!
Some remove part of exoskeleton (grasshopper
sparrows -remove wings)
!
Some have chitinase
!
Insectivores:
Eat ants, termites
!
E.g. echidnas, numbat, tamanduas, pangolins, aardwolf,
aardvark, silky & giant anteaters
!
Myrmecophages:
Eat snails, clams, mussels, oysters, squid and slugs
!
E.g. limpkin and snail kite (apple snails), oystercatches
(also shellfish and crabs)
!
Molluscivores:
Eat fish
!
Seasonal changes fat composition
!
E.g. river otter, common loon, belted kingfisher, brown
pelican, gray seal, osprey
!
Piscivores:
Eat blood
!
Vampire bats, sharp-beaked ground finch (takes blood
from other birds)
!
Sanquivores:
Eat reptiles, amphibians, mammals, birds
!
E.g. milk (fish, frogs, muskrats, mice, voles, hares,
rabbits, garter snakes, salamanders, crayfish)
!
E.g. wolf (beavers, hares, groundhogs, deer, rabbits)
!
E.g. great blue heron (fish, frogs, snakes)
!
Birds of prey (hawks, owls, eagles, vultures)
!
Carnivores:
Types of Food:
Food Habits: Carnivores
Opportunistic feeders, seasonal foods
Should obtain wide variety of nutrients
Summer/Fall: mushrooms, berries, nuts, acorns
!
Winter: lichens, conifer seeds
!
Spring: maple sap, buds, beetles, moths, eggs, nestlings,
carrion
!
E.g. flying squirrel
Seeds, berries, insects, snakes, young birds, eggs, frogs,
squirrels, carrion, human food waste
!
E.g. crow
Small fish, crayfish, mice, insects, berries, carrion,
human food waste
!
E.g. ring-billed gull
Crayfish, frogs, clams, turtle/bird eggs, snakes, berries,
nuts, carrion
!
E.g. raccoon & striped skunk
Fruit, spiders, scorpions, crabs, centipedes, millipeeds
!
E.g. coati mundi
Eat a wide variety of feed stuffs, both animal and plant
Food Habits: Omnivores
Omnivore
Feeds on fruit, honey, insects, small vertebrates and carrion
Tayra
4C)When do animals eat?
During the day
Light -see food but also can be seen by predators
Diurnal:
During the night
Ex. Tarsier -biggest eyes relative to body weight
Dark -cannot see food easily (need enhanced sight or hearing) but
cannot be seen by predators
Cooler in hot environments (deserts)
Nocturnal:
Dawn and dusk (cooler in hot climates)
Includes many grazers and browsers
Crepuscular:
Sun is above the horizon for 24 hours continuously at least once a
year (midnight sun)
24 hours continuously dark (polar night)
Arctic/Antarctic Circle:
Northernmost place where sun is directly overhead
Tropic of Cancer:
Daylight = night; throughout the year
Equator:
Southernmost place where the sun is directly overhead
Tropic of Capricorn:
Vernal Equinox (March 20) -12 hours
Summer solstice (June 21) -max 17 hours
Autumnal Equinox (Sep 22) -12 hours
Winter solstice (Dec 21) - 7-12 hours
Variation in Daylight Hours:
Singapore -fairly constant throughout year
New York -large increase in summer months
Antarctica -large increase in winter months
Daily Solar Radiation:
*see slide
Direct (from sun) --> shadow
Diffused (through clouds)
Reflected (from Earth's surface)
Solar/short-wave radiation:
Black -~90%
White -~50%
Amount absorbed depends on the colour of the animal:
Direct solar radiation intensity changes with time of day/year:
Twilight -before sunrise, after sunset
The sun is just below horizon ~1.5 hrs
Civil twilight -sun is 6 degrees below horizon
Nautical twilight -sun is 12 degrees below horizon
Astronomical twilight -sun is 18 degrees below horizon
Twilight Zones:
Solar Radiation: Twilight
No solar radiation
No visible light
Solar Radiation: Darkness
Limited solar radiation reflected from the moon
Limited vision in animals
Solar Radiation: Moonlight
Monotremata (echidna, platypus)
Tubulidentata (aardvark)
Pholidota (pangolins)
Macroscelidea (elephant shrews)
*NOT carnivora or insectivora
Mammalian orders that eat only animal food:
Lagomorpha (rabbits, hares)
Perissodactyla (horses, rhinos, tapirs)
Proboscidea (elephants)
Sirenia (manatees, dugongs)
Hyracoidea (hyraxes)
*NOT Cetartiodactyla (camels and deer are herbivores; pigs
are omnivores; whales and dolphins are carnivores)
Mammalian orders which eat only plant food:
Food Habits: Animal Taxonomy
Coyote, wolf -facultative carnivore
Arctic fox -opportunistic omnivore (garbage, caribou
droppings)
Red/grey fox -substantial plant material in diet -->
opportunistic feeders
Canidae (canids)
Polar bear -obligate carnivore (pre-formed vitamin A)
Black bear -frugivore
Grizzly bear -omnivore (fish)
Giant panda -herbivore (bamboo)
Ursidae (ursids)
Raccoon -omnivore
Procyonidae
Lesser (red) panda -herbivore (bamboo shoots and other
vegetation)
Ailuridae:
Long-tailed weasel, lesser weasel, black-footed ferret, mink,
badger, river otter, sea otter -carnivores
Marten, fisher, wolverine -carnivore
Striped skunk, western spotted skunk -omnivores
Mutelida (mustelids)
Common palm civet -rats, insects, coffee beans, mangos
(omnivore)
Fossa -carnivore
Viverridae:
Brown hyaena -scavenging carnivore: invertebrates, eggs
(fruit)
Striped hyaena -omnivore
Spotted hyaena -carnivore (vertebrate prey)
Aardwolf -carnivore (ants, termites)
Hyaenidae:
Forced to be carnivores by nutrient requirement (taurine,
arachidonic acid, pre-formed vitamin A)
!
Cougar, lynx, bobcat, lions, tigers, leopards, jaguars..etc -
obligate carnivores
Felidae (felids):
Order: Carnivora
Solenodons (DR, Haiti) -omnivore (ants, insects, grubs, small
reptiles, fruit, vegetation)
Solenodontidae:
Tenrecs (Madagascar) -carnivore (earthworms, grubs,
grasshoppers, small vertebrates)
Tenrecidae:
Golden moles -carnivore (earthworms, small invertebrates)
Chrysochloridae:
Hedgheogs, moonrats (Asia) -earthworms, beetles, roaches,
insect larvae, millipedes, centipedes, spiders, scorpions, snails,
small vertebrates, fruit
Erinaceidae:
Shrews -insects, worms, sowbugs, snails, salamanders, young
mice, vegetation, frogs, fish, fungus, spiders
Soricidae:
Moles -snails, worms, insecs, fish, frogs, water plants,
crustaceans,
Talpidae:
Order: Insectivora
Gut of herbivorous prey will contain vegetation
Felids may eat grass by choice
Do all carnivores eat only animal material?
Invertebrates may be eaten with plant material
Grubs in apples (protein), snails of pasture grass (Ca),
catepillars on leaves
Do all herbivores only eat plant material?
Are these exceptions purposeful, accidental or inevitable?
Exclusive carnivores/herbivores:
How many species of mammals have well described food habits? (let
alone clearly understood nutritional requirements)
Order Carnivora -not all carnivores
Order Insectivora -no species eats only insects (some are
omnivores)
Animals in a given order may have similar gut structure but not
always similar food habits
When food habits are poorly known it may be necessary to extrapolate to a
closely related animal species
4d) Food Chains & Food Webs
Spines, thorns and toxins prevent predation
Easily accessible nectar -white and yellow flowers
Concealed nectar -red, blue and purple flowers
Encourages pollination
Nectar in coloured flowers
Fleshy fruits -encourage seed dispersal
Plants:
Speed and agility -escape predation
Large groups -distract against predation
Camouflage, burrowing, crepuscular, nocturnal feeding -avoid
detection
Ex. Eastern coral snake (venomous) and scarlet king snake
(non-venonmous)
Toxins (or false toxin-colouration) -deter predators
Herbivores:
Claws, talons, beaks, horns, teeth, poisonous bite/sting -defend &
catch prey
Ex. Javan slow loris -only mammals to have venomous bite
Carnivores:
Include: algae, mosses, liverworts, ferns, lichens (symbiosis
between fungi and algae), conifers, monocots/grasses,
dicots/forbs, bushes, trees
Does NOT include fungi
Contain chlorophyll
!
Manufacture organic compounds from water, CO2, and
minerals, using solar energy by photosynthesis
!
Green plants independent of external sources of organic
carbon compounds (don’t need food; make their own)
!
Autotrophs:
Green plants are not only eaten but also used as shade or
shelter
Producers (green plants)1.
Organisms (animals, fungi) dependent on external
sources of organic carbon compounds
!
Heterotrophs:
Need to consume food
Only 5-20% of food energy is stored in animal tissues, rest
used in life processes (maintenance) or lost as heat
Primary consumers (herbivores)2.
Heterotrophs (see above)
Secondary consumers (omnivores/carnivores which eat herbivores)3.
Heterotrophs (see above)
Tertiary consumers (omnivores/carnivores which eat
omnivores/carnivores)
4.
Trophic Levels:
Direct Observation1.
Enclosurea)
Exclosure b)
Cafeteria c)
'Utilization' Techniques (before and after studies)2.
In vivo a)
Post mortemb)
Digesta Sampling3.
Faecal Analysis4.
Stable isotopesa)
Radioisotopesb)
Isotope Studies5.
Adipose Tissue Composition 6.
Methodology -how to find out what wild animals are eating is a major
issue
Endangered species --> equally welfare all species?
Aquatic species -faecal analysis is difficult
Crepuscular/nocturnal/fossorial species -direct observation is
difficult
How to choose what method to use:
Little expensive equipment needed (binoculars and time)
Advantages:
Difficult in crepuscular/nocturnal/fossorial species
Difficult in aquatic environment
Difficult in areas with high vegetation
Difficult in open areas to watch unnoticed
Does not indicate what animal eats while not being observed
Time consuming
Disadvantages:
Chimpanzees/gorillas -observer needs to be within a few feet
to see which food items and parts are being consumed
If vegetation is heterogeneous mix of many different
plant species, it can be difficult to determine exactly
what is eaten (always difficult to determine which part of
plant is eaten)
!
Herbivores on grassland savannah -if vegetation in
homogenous or in large homogeneous patches observation
may be useful
Different members of group may eat different parts of
carcass
!
Carnivores -observer watches hunt and visits site later to see
which part of carcass remains
Bald Eagle -observe bird returning to nest/roost with prey (do
not bring complete prey back to nest though)
Examples:
Direct Observation:
Survey vegetation first (quadrats, quantity, species, plant parts)
Let animals into enclosure for set time
Re-survey after animals have left
Estimate which plant species and parts have been eaten
!
Advantages:
Other animal (slugs, snails, rabbits) may also have been
eating in enclosure
!
Disadvantages:
E.g. herbivores, rabbits, equids, bovids
Enclosure
Survey vegetation both inside and outside exclosure area and
compare
Estimate which plant species and parts have been eaten
!
Advantages:
Other animals may have been eating inside and outside
exclosure
!
Disadvantages:
Exclosure
Range of plant material (species, parts, ages) offered to captive
animals
Determine amount of each plant material offered and amount
left after feeding
Estimate which plant species/parts have been eaten and
which are preferred
!
Advantages:
Animals are captive and cannot range freely
!
Plant material is usually cut, not growing -animals may
eat different plant parts
!
Disadvantages:
Cafeteria
Utilization:
Esophageal fistula / rumen fistula
Collect samples through fistula (tube)
Sort, identify (microscope), weigh food
More accurate than utilization techniques
!
Advantages:
Work with captive, tame animals
!
Surgical procedures to implant fistulas
!
Disadvantages:
Ex. Herbivores, grazers, browsers
Fistulas
Pellets cast by birds of prey
Bone -gives species, size and age of prey
!
Feathers -gives species and age of prey
!
Hair -hair atlas
!
Scales -gives age class of prey
!
Otoliths (from fish skull) -gives species of prey
!
Contain only indigestible components of food:
Collect pellets, sort contens and identify
Owls -usually eat prey whole --> more remains
!
Hawks -tear pieces from prey --> more acid digestion
(less remains, further digested)
!
Difficult to find
Some insectivorous birds (kestrels, swallows,
flycatchers) egest insect exoskeletons
!
Examples;
More accurate than utilization techniques
!
Non-invasive
!
Advantages:
Some food components poorly represented or absent
!
Disadvantages
Pellets
Regurgitation (with or without emetics)
Disadvantages: invasive, welfare, captive
Irrigate/stomach pump for birds (that do not produce pellets)
Digesta Sampling -In Vivo
Collect GITs from hunters/ road kills
Sort and identify stomach contents
Knowing the average segment/worms --> number of worms
eaten
E.g. count worm chaetae
More accurate than utilization techniques
No animal specifically killed for study
Advantages:
Time of last mean and degree of digestion unknown
Some easily digested food components poorly represented or
absent
Disadvantages:
Digesta Sampling -Post Mortem
Collect faeces/scats
Sort and identify faecal contents
No animal killed
May provide information not provided by utilization
techniques
Advantages:
Highly digestible food components under represented or absent
(soft-bodied invertebrates, fungi)
May not know which individual (species/M/F) produced faeces
Observe defecation, dunging sites, territorial markers
Morphological characteristics, shape, size and consistency may
help identify but diet will affect morphology
pH reflects lower end of GIT -may distinguish hind-gut
fermenters
Parasites may be species specific
Some bile acid residue may be present, may be species specific
(e.g. bear -ursodeoxycholic acid)
Molecular scatology, DNA analysis may be used to identify
cellular debris in faecas
Faecal steroids, may distinguish M/F and stages in
reproductive cycle
Disadvantages:
Faecal Analysis
Food Habits
Friday,*March*3,*2017
12:30*PM
How much energy to animals need to survive, grow and reproduce?
(lectures 3a-3g)
What do animals eat? Daily, annually? (lectures 4a-4f)
What nutrients and toxins do foods contain and what use do animals
make of food eaten? (lecture 5 series)
Carnivores -eat animal material
Omnivore -eat both animal and plant material
Herbivores -eat plant material
Generalists, eat a wide variety of different foods/ food species
E.g. ruffed grouse: eats 300+ plant species, 100+ small mammal
species
Polyphages:
Specialists, eat only one kind of food/ food species
E.g. snail kite: single fresh water snail genus -apple snails
Monophages:
Consume only one category of food all adult life
eat vertebrate animal species
eat little/no plant food compared to canids
eat vertebrate species but may also eat plant material
Felids,
Obligate:
May change category of food eaten
Through seasons of the year or during periods of food scarcity
Facultative:
Not a plant, bacteria, fungus, virus or prion
Means a vertebrate animal -mammal, bird, reptile, amphibian, fish
Means an invertebrate animal: sea anemones, oysters, spiders,
milipeeds, mussels
'Animal'
All animal products, not only muscle meat
Catch live prey
E.g. bobcat, mountain lion, coyote, weasel, hawks, owls,
dragonflies
Predators:
Find dead prey
E.g. vulture
Scavengers:
Eat plankton
!
E.g. Caribbean flamingo, baleen whale
!
Planktonivores
Eat sponges
!
E.g. green sea turtle (silica spikes need mucous in gut)
!
Spongivores
Eat shrimp, crabs (chitin exoskeleton)
!
E.g. oyster catcher (crabs and shellfish), some penguins
(chitinase)
!
Crustacivores:
Eat insects (chitin exoskeleton)
!
Many insects are seasonal (migration, facultative
insectivory), insects in wood/crevices
!
Eat 10+/min
1/2 of bats weight insects/night
Body weight in insects/night in nursing females
Scoop up insects with tail membrane
E.g. little brown vat
!
Probe under bark for insect eggs, larvae, pupae &
adults, spiders
E.g. brown creeper
!
Makes rows of holes in birch and aspen trees, and
eats the insects which are attracted to sweet sap
E.g. yellow bellied sapsucker
!
90% diet is flying insects (almost constantly in
flight)
E.g. tree swallows
!
Some egest exoskeletons (kestrels, flycatchers,
swallows)
!
Some remove part of exoskeleton (grasshopper
sparrows -remove wings)
!
Some have chitinase
!
Insectivores:
Eat ants, termites
!
E.g. echidnas, numbat, tamanduas, pangolins, aardwolf,
aardvark, silky & giant anteaters
!
Myrmecophages:
Eat snails, clams, mussels, oysters, squid and slugs
!
E.g. limpkin and snail kite (apple snails), oystercatches
(also shellfish and crabs)
!
Molluscivores:
Eat fish
!
Seasonal changes fat composition
!
E.g. river otter, common loon, belted kingfisher, brown
pelican, gray seal, osprey
!
Piscivores:
Eat blood
!
Vampire bats, sharp-beaked ground finch (takes blood
from other birds)
!
Sanquivores:
Eat reptiles, amphibians, mammals, birds
!
E.g. milk (fish, frogs, muskrats, mice, voles, hares,
rabbits, garter snakes, salamanders, crayfish)
!
E.g. wolf (beavers, hares, groundhogs, deer, rabbits)
!
E.g. great blue heron (fish, frogs, snakes)
!
Birds of prey (hawks, owls, eagles, vultures)
!
Carnivores:
Types of Food:
Food Habits: Carnivores
Opportunistic feeders, seasonal foods
Should obtain wide variety of nutrients
Summer/Fall: mushrooms, berries, nuts, acorns
!
Winter: lichens, conifer seeds
!
Spring: maple sap, buds, beetles, moths, eggs, nestlings,
carrion
!
E.g. flying squirrel
Seeds, berries, insects, snakes, young birds, eggs, frogs,
squirrels, carrion, human food waste
!
E.g. crow
Small fish, crayfish, mice, insects, berries, carrion,
human food waste
!
E.g. ring-billed gull
Crayfish, frogs, clams, turtle/bird eggs, snakes, berries,
nuts, carrion
!
E.g. raccoon & striped skunk
Fruit, spiders, scorpions, crabs, centipedes, millipeeds
!
E.g. coati mundi
Eat a wide variety of feed stuffs, both animal and plant
Food Habits: Omnivores
Omnivore
Feeds on fruit, honey, insects, small vertebrates and carrion
Tayra
4C)When do animals eat?
During the day
Light -see food but also can be seen by predators
Diurnal:
During the night
Ex. Tarsier -biggest eyes relative to body weight
Dark -cannot see food easily (need enhanced sight or hearing) but
cannot be seen by predators
Cooler in hot environments (deserts)
Nocturnal:
Dawn and dusk (cooler in hot climates)
Includes many grazers and browsers
Crepuscular:
Sun is above the horizon for 24 hours continuously at least once a
year (midnight sun)
24 hours continuously dark (polar night)
Arctic/Antarctic Circle:
Northernmost place where sun is directly overhead
Tropic of Cancer:
Daylight = night; throughout the year
Equator:
Southernmost place where the sun is directly overhead
Tropic of Capricorn:
Vernal Equinox (March 20) -12 hours
Summer solstice (June 21) -max 17 hours
Autumnal Equinox (Sep 22) -12 hours
Winter solstice (Dec 21) - 7-12 hours
Variation in Daylight Hours:
Singapore -fairly constant throughout year
New York -large increase in summer months
Antarctica -large increase in winter months
Daily Solar Radiation:
*see slide
Direct (from sun) --> shadow
Diffused (through clouds)
Reflected (from Earth's surface)
Solar/short-wave radiation:
Black -~90%
White -~50%
Amount absorbed depends on the colour of the animal:
Direct solar radiation intensity changes with time of day/year:
Twilight -before sunrise, after sunset
The sun is just below horizon ~1.5 hrs
Civil twilight -sun is 6 degrees below horizon
Nautical twilight -sun is 12 degrees below horizon
Astronomical twilight -sun is 18 degrees below horizon
Twilight Zones:
Solar Radiation: Twilight
No solar radiation
No visible light
Solar Radiation: Darkness
Limited solar radiation reflected from the moon
Limited vision in animals
Solar Radiation: Moonlight
Monotremata (echidna, platypus)
Tubulidentata (aardvark)
Pholidota (pangolins)
Macroscelidea (elephant shrews)
*NOT carnivora or insectivora
Mammalian orders that eat only animal food:
Lagomorpha (rabbits, hares)
Perissodactyla (horses, rhinos, tapirs)
Proboscidea (elephants)
Sirenia (manatees, dugongs)
Hyracoidea (hyraxes)
*NOT Cetartiodactyla (camels and deer are herbivores; pigs
are omnivores; whales and dolphins are carnivores)
Mammalian orders which eat only plant food:
Food Habits: Animal Taxonomy
Coyote, wolf -facultative carnivore
Arctic fox -opportunistic omnivore (garbage, caribou
droppings)
Red/grey fox -substantial plant material in diet -->
opportunistic feeders
Canidae (canids)
Polar bear -obligate carnivore (pre-formed vitamin A)
Black bear -frugivore
Grizzly bear -omnivore (fish)
Giant panda -herbivore (bamboo)
Ursidae (ursids)
Raccoon -omnivore
Procyonidae
Lesser (red) panda -herbivore (bamboo shoots and other
vegetation)
Ailuridae:
Long-tailed weasel, lesser weasel, black-footed ferret, mink,
badger, river otter, sea otter -carnivores
Marten, fisher, wolverine -carnivore
Striped skunk, western spotted skunk -omnivores
Mutelida (mustelids)
Common palm civet -rats, insects, coffee beans, mangos
(omnivore)
Fossa -carnivore
Viverridae:
Brown hyaena -scavenging carnivore: invertebrates, eggs
(fruit)
Striped hyaena -omnivore
Spotted hyaena -carnivore (vertebrate prey)
Aardwolf -carnivore (ants, termites)
Hyaenidae:
Forced to be carnivores by nutrient requirement (taurine,
arachidonic acid, pre-formed vitamin A)
!
Cougar, lynx, bobcat, lions, tigers, leopards, jaguars..etc -
obligate carnivores
Felidae (felids):
Order: Carnivora
Solenodons (DR, Haiti) -omnivore (ants, insects, grubs, small
reptiles, fruit, vegetation)
Solenodontidae:
Tenrecs (Madagascar) -carnivore (earthworms, grubs,
grasshoppers, small vertebrates)
Tenrecidae:
Golden moles -carnivore (earthworms, small invertebrates)
Chrysochloridae:
Hedgheogs, moonrats (Asia) -earthworms, beetles, roaches,
insect larvae, millipedes, centipedes, spiders, scorpions, snails,
small vertebrates, fruit
Erinaceidae:
Shrews -insects, worms, sowbugs, snails, salamanders, young
mice, vegetation, frogs, fish, fungus, spiders
Soricidae:
Moles -snails, worms, insecs, fish, frogs, water plants,
crustaceans,
Talpidae:
Order: Insectivora
Gut of herbivorous prey will contain vegetation
Felids may eat grass by choice
Do all carnivores eat only animal material?
Invertebrates may be eaten with plant material
Grubs in apples (protein), snails of pasture grass (Ca),
catepillars on leaves
Do all herbivores only eat plant material?
Are these exceptions purposeful, accidental or inevitable?
Exclusive carnivores/herbivores:
How many species of mammals have well described food habits? (let
alone clearly understood nutritional requirements)
Order Carnivora -not all carnivores
Order Insectivora -no species eats only insects (some are
omnivores)
Animals in a given order may have similar gut structure but not
always similar food habits
When food habits are poorly known it may be necessary to extrapolate to a
closely related animal species
4d) Food Chains & Food Webs
Spines, thorns and toxins prevent predation
Easily accessible nectar -white and yellow flowers
Concealed nectar -red, blue and purple flowers
Encourages pollination
Nectar in coloured flowers
Fleshy fruits -encourage seed dispersal
Plants:
Speed and agility -escape predation
Large groups -distract against predation
Camouflage, burrowing, crepuscular, nocturnal feeding -avoid
detection
Ex. Eastern coral snake (venomous) and scarlet king snake
(non-venonmous)
Toxins (or false toxin-colouration) -deter predators
Herbivores:
Claws, talons, beaks, horns, teeth, poisonous bite/sting -defend &
catch prey
Ex. Javan slow loris -only mammals to have venomous bite
Carnivores:
Include: algae, mosses, liverworts, ferns, lichens (symbiosis
between fungi and algae), conifers, monocots/grasses,
dicots/forbs, bushes, trees
Does NOT include fungi
Contain chlorophyll
!
Manufacture organic compounds from water, CO2, and
minerals, using solar energy by photosynthesis
!
Green plants independent of external sources of organic
carbon compounds (don’t need food; make their own)
!
Autotrophs:
Green plants are not only eaten but also used as shade or
shelter
Producers (green plants)1.
Organisms (animals, fungi) dependent on external
sources of organic carbon compounds
!
Heterotrophs:
Need to consume food
Only 5-20% of food energy is stored in animal tissues, rest
used in life processes (maintenance) or lost as heat
Primary consumers (herbivores)2.
Heterotrophs (see above)
Secondary consumers (omnivores/carnivores which eat herbivores)3.
Heterotrophs (see above)
Tertiary consumers (omnivores/carnivores which eat
omnivores/carnivores)
4.
Trophic Levels:
Direct Observation1.
Enclosurea)
Exclosure b)
Cafeteria c)
'Utilization' Techniques (before and after studies)2.
In vivo a)
Post mortemb)
Digesta Sampling3.
Faecal Analysis4.
Stable isotopesa)
Radioisotopesb)
Isotope Studies5.
Adipose Tissue Composition 6.
Methodology -how to find out what wild animals are eating is a major
issue
Endangered species --> equally welfare all species?
Aquatic species -faecal analysis is difficult
Crepuscular/nocturnal/fossorial species -direct observation is
difficult
How to choose what method to use:
Little expensive equipment needed (binoculars and time)
Advantages:
Difficult in crepuscular/nocturnal/fossorial species
Difficult in aquatic environment
Difficult in areas with high vegetation
Difficult in open areas to watch unnoticed
Does not indicate what animal eats while not being observed
Time consuming
Disadvantages:
Chimpanzees/gorillas -observer needs to be within a few feet
to see which food items and parts are being consumed
If vegetation is heterogeneous mix of many different
plant species, it can be difficult to determine exactly
what is eaten (always difficult to determine which part of
plant is eaten)
!
Herbivores on grassland savannah -if vegetation in
homogenous or in large homogeneous patches observation
may be useful
Different members of group may eat different parts of
carcass
!
Carnivores -observer watches hunt and visits site later to see
which part of carcass remains
Bald Eagle -observe bird returning to nest/roost with prey (do
not bring complete prey back to nest though)
Examples:
Direct Observation:
Survey vegetation first (quadrats, quantity, species, plant parts)
Let animals into enclosure for set time
Re-survey after animals have left
Estimate which plant species and parts have been eaten
!
Advantages:
Other animal (slugs, snails, rabbits) may also have been
eating in enclosure
!
Disadvantages:
E.g. herbivores, rabbits, equids, bovids
Enclosure
Survey vegetation both inside and outside exclosure area and
compare
Estimate which plant species and parts have been eaten
!
Advantages:
Other animals may have been eating inside and outside
exclosure
!
Disadvantages:
Exclosure
Range of plant material (species, parts, ages) offered to captive
animals
Determine amount of each plant material offered and amount
left after feeding
Estimate which plant species/parts have been eaten and
which are preferred
!
Advantages:
Animals are captive and cannot range freely
!
Plant material is usually cut, not growing -animals may
eat different plant parts
!
Disadvantages:
Cafeteria
Utilization:
Esophageal fistula / rumen fistula
Collect samples through fistula (tube)
Sort, identify (microscope), weigh food
More accurate than utilization techniques
!
Advantages:
Work with captive, tame animals
!
Surgical procedures to implant fistulas
!
Disadvantages:
Ex. Herbivores, grazers, browsers
Fistulas
Pellets cast by birds of prey
Bone -gives species, size and age of prey
!
Feathers -gives species and age of prey
!
Hair -hair atlas
!
Scales -gives age class of prey
!
Otoliths (from fish skull) -gives species of prey
!
Contain only indigestible components of food:
Collect pellets, sort contens and identify
Owls -usually eat prey whole --> more remains
!
Hawks -tear pieces from prey --> more acid digestion
(less remains, further digested)
!
Difficult to find
Some insectivorous birds (kestrels, swallows,
flycatchers) egest insect exoskeletons
!
Examples;
More accurate than utilization techniques
!
Non-invasive
!
Advantages:
Some food components poorly represented or absent
!
Disadvantages
Pellets
Regurgitation (with or without emetics)
Disadvantages: invasive, welfare, captive
Irrigate/stomach pump for birds (that do not produce pellets)
Digesta Sampling -In Vivo
Collect GITs from hunters/ road kills
Sort and identify stomach contents
Knowing the average segment/worms --> number of worms
eaten
E.g. count worm chaetae
More accurate than utilization techniques
No animal specifically killed for study
Advantages:
Time of last mean and degree of digestion unknown
Some easily digested food components poorly represented or
absent
Disadvantages:
Digesta Sampling -Post Mortem
Collect faeces/scats
Sort and identify faecal contents
No animal killed
May provide information not provided by utilization
techniques
Advantages:
Highly digestible food components under represented or absent
(soft-bodied invertebrates, fungi)
May not know which individual (species/M/F) produced faeces
Observe defecation, dunging sites, territorial markers
Morphological characteristics, shape, size and consistency may
help identify but diet will affect morphology
pH reflects lower end of GIT -may distinguish hind-gut
fermenters
Parasites may be species specific
Some bile acid residue may be present, may be species specific
(e.g. bear -ursodeoxycholic acid)
Molecular scatology, DNA analysis may be used to identify
cellular debris in faecas
Faecal steroids, may distinguish M/F and stages in
reproductive cycle
Disadvantages:
Faecal Analysis
Food Habits
Friday,*March*3,*2017 12:30*PM
How much energy to animals need to survive, grow and reproduce?
(lectures 3a-3g)
What do animals eat? Daily, annually? (lectures 4a-4f)
What nutrients and toxins do foods contain and what use do animals
make of food eaten? (lecture 5 series)
Carnivores -eat animal material
Omnivore -eat both animal and plant material
Herbivores -eat plant material
Generalists, eat a wide variety of different foods/ food species
E.g. ruffed grouse: eats 300+ plant species, 100+ small mammal
species
Polyphages:
Specialists, eat only one kind of food/ food species
E.g. snail kite: single fresh water snail genus -apple snails
Monophages:
Consume only one category of food all adult life
eat vertebrate animal species
eat little/no plant food compared to canids
eat vertebrate species but may also eat plant material
Felids,
Obligate:
May change category of food eaten
Through seasons of the year or during periods of food scarcity
Facultative:
Not a plant, bacteria, fungus, virus or prion
Means a vertebrate animal -mammal, bird, reptile, amphibian, fish
Means an invertebrate animal: sea anemones, oysters, spiders,
milipeeds, mussels
'Animal'
All animal products, not only muscle meat
Catch live prey
E.g. bobcat, mountain lion, coyote, weasel, hawks, owls,
dragonflies
Predators:
Find dead prey
E.g. vulture
Scavengers:
Eat plankton
!
E.g. Caribbean flamingo, baleen whale
!
Planktonivores
Eat sponges
!
E.g. green sea turtle (silica spikes need mucous in gut)
!
Spongivores
Eat shrimp, crabs (chitin exoskeleton)
!
E.g. oyster catcher (crabs and shellfish), some penguins
(chitinase)
!
Crustacivores:
Eat insects (chitin exoskeleton)
!
Many insects are seasonal (migration, facultative
insectivory), insects in wood/crevices
!
Eat 10+/min
1/2 of bats weight insects/night
Body weight in insects/night in nursing females
Scoop up insects with tail membrane
E.g. little brown vat
!
Probe under bark for insect eggs, larvae, pupae &
adults, spiders
E.g. brown creeper
!
Makes rows of holes in birch and aspen trees, and
eats the insects which are attracted to sweet sap
E.g. yellow bellied sapsucker
!
90% diet is flying insects (almost constantly in
flight)
E.g. tree swallows
!
Some egest exoskeletons (kestrels, flycatchers,
swallows)
!
Some remove part of exoskeleton (grasshopper
sparrows -remove wings)
!
Some have chitinase
!
Insectivores:
Eat ants, termites
!
E.g. echidnas, numbat, tamanduas, pangolins, aardwolf,
aardvark, silky & giant anteaters
!
Myrmecophages:
Eat snails, clams, mussels, oysters, squid and slugs
!
E.g. limpkin and snail kite (apple snails), oystercatches
(also shellfish and crabs)
!
Molluscivores:
Eat fish
!
Seasonal changes fat composition
!
E.g. river otter, common loon, belted kingfisher, brown
pelican, gray seal, osprey
!
Piscivores:
Eat blood
!
Vampire bats, sharp-beaked ground finch (takes blood
from other birds)
!
Sanquivores:
Eat reptiles, amphibians, mammals, birds
!
E.g. milk (fish, frogs, muskrats, mice, voles, hares,
rabbits, garter snakes, salamanders, crayfish)
!
E.g. wolf (beavers, hares, groundhogs, deer, rabbits)
!
E.g. great blue heron (fish, frogs, snakes)
!
Birds of prey (hawks, owls, eagles, vultures)
!
Carnivores:
Types of Food:
Food Habits: Carnivores
Opportunistic feeders, seasonal foods
Should obtain wide variety of nutrients
Summer/Fall: mushrooms, berries, nuts, acorns
!
Winter: lichens, conifer seeds
!
Spring: maple sap, buds, beetles, moths, eggs, nestlings,
carrion
!
E.g. flying squirrel
Seeds, berries, insects, snakes, young birds, eggs, frogs,
squirrels, carrion, human food waste
!
E.g. crow
Small fish, crayfish, mice, insects, berries, carrion,
human food waste
!
E.g. ring-billed gull
Crayfish, frogs, clams, turtle/bird eggs, snakes, berries,
nuts, carrion
!
E.g. raccoon & striped skunk
Fruit, spiders, scorpions, crabs, centipedes, millipeeds
!
E.g. coati mundi
Eat a wide variety of feed stuffs, both animal and plant
Food Habits: Omnivores
Omnivore
Feeds on fruit, honey, insects, small vertebrates and carrion
Tayra
4C)When do animals eat?
During the day
Light -see food but also can be seen by predators
Diurnal:
During the night
Ex. Tarsier -biggest eyes relative to body weight
Dark -cannot see food easily (need enhanced sight or hearing) but
cannot be seen by predators
Cooler in hot environments (deserts)
Nocturnal:
Dawn and dusk (cooler in hot climates)
Includes many grazers and browsers
Crepuscular:
Sun is above the horizon for 24 hours continuously at least once a
year (midnight sun)
24 hours continuously dark (polar night)
Arctic/Antarctic Circle:
Northernmost place where sun is directly overhead
Tropic of Cancer:
Daylight = night; throughout the year
Equator:
Southernmost place where the sun is directly overhead
Tropic of Capricorn:
Vernal Equinox (March 20) -12 hours
Summer solstice (June 21) -max 17 hours
Autumnal Equinox (Sep 22) -12 hours
Winter solstice (Dec 21) - 7-12 hours
Variation in Daylight Hours:
Singapore -fairly constant throughout year
New York -large increase in summer months
Antarctica -large increase in winter months
Daily Solar Radiation:
*see slide
Direct (from sun) --> shadow
Diffused (through clouds)
Reflected (from Earth's surface)
Solar/short-wave radiation:
Black -~90%
White -~50%
Amount absorbed depends on the colour of the animal:
Direct solar radiation intensity changes with time of day/year:
Twilight -before sunrise, after sunset
The sun is just below horizon ~1.5 hrs
Civil twilight -sun is 6 degrees below horizon
Nautical twilight -sun is 12 degrees below horizon
Astronomical twilight -sun is 18 degrees below horizon
Twilight Zones:
Solar Radiation: Twilight
No solar radiation
No visible light
Solar Radiation: Darkness
Limited solar radiation reflected from the moon
Limited vision in animals
Solar Radiation: Moonlight
Monotremata (echidna, platypus)
Tubulidentata (aardvark)
Pholidota (pangolins)
Macroscelidea (elephant shrews)
*NOT carnivora or insectivora
Mammalian orders that eat only animal food:
Lagomorpha (rabbits, hares)
Perissodactyla (horses, rhinos, tapirs)
Proboscidea (elephants)
Sirenia (manatees, dugongs)
Hyracoidea (hyraxes)
*NOT Cetartiodactyla (camels and deer are herbivores; pigs
are omnivores; whales and dolphins are carnivores)
Mammalian orders which eat only plant food:
Food Habits: Animal Taxonomy
Coyote, wolf -facultative carnivore
Arctic fox -opportunistic omnivore (garbage, caribou
droppings)
Red/grey fox -substantial plant material in diet -->
opportunistic feeders
Canidae (canids)
Polar bear -obligate carnivore (pre-formed vitamin A)
Black bear -frugivore
Grizzly bear -omnivore (fish)
Giant panda -herbivore (bamboo)
Ursidae (ursids)
Raccoon -omnivore
Procyonidae
Lesser (red) panda -herbivore (bamboo shoots and other
vegetation)
Ailuridae:
Long-tailed weasel, lesser weasel, black-footed ferret, mink,
badger, river otter, sea otter -carnivores
Marten, fisher, wolverine -carnivore
Striped skunk, western spotted skunk -omnivores
Mutelida (mustelids)
Common palm civet -rats, insects, coffee beans, mangos
(omnivore)
Fossa -carnivore
Viverridae:
Brown hyaena -scavenging carnivore: invertebrates, eggs
(fruit)
Striped hyaena -omnivore
Spotted hyaena -carnivore (vertebrate prey)
Aardwolf -carnivore (ants, termites)
Hyaenidae:
Forced to be carnivores by nutrient requirement (taurine,
arachidonic acid, pre-formed vitamin A)
!
Cougar, lynx, bobcat, lions, tigers, leopards, jaguars..etc -
obligate carnivores
Felidae (felids):
Order: Carnivora
Solenodons (DR, Haiti) -omnivore (ants, insects, grubs, small
reptiles, fruit, vegetation)
Solenodontidae:
Tenrecs (Madagascar) -carnivore (earthworms, grubs,
grasshoppers, small vertebrates)
Tenrecidae:
Golden moles -carnivore (earthworms, small invertebrates)
Chrysochloridae:
Hedgheogs, moonrats (Asia) -earthworms, beetles, roaches,
insect larvae, millipedes, centipedes, spiders, scorpions, snails,
small vertebrates, fruit
Erinaceidae:
Shrews -insects, worms, sowbugs, snails, salamanders, young
mice, vegetation, frogs, fish, fungus, spiders
Soricidae:
Moles -snails, worms, insecs, fish, frogs, water plants,
crustaceans,
Talpidae:
Order: Insectivora
Gut of herbivorous prey will contain vegetation
Felids may eat grass by choice
Do all carnivores eat only animal material?
Invertebrates may be eaten with plant material
Grubs in apples (protein), snails of pasture grass (Ca),
catepillars on leaves
Do all herbivores only eat plant material?
Are these exceptions purposeful, accidental or inevitable?
Exclusive carnivores/herbivores:
How many species of mammals have well described food habits? (let
alone clearly understood nutritional requirements)
Order Carnivora -not all carnivores
Order Insectivora -no species eats only insects (some are
omnivores)
Animals in a given order may have similar gut structure but not
always similar food habits
When food habits are poorly known it may be necessary to extrapolate to a
closely related animal species
4d) Food Chains & Food Webs
Spines, thorns and toxins prevent predation
Easily accessible nectar -white and yellow flowers
Concealed nectar -red, blue and purple flowers
Encourages pollination
Nectar in coloured flowers
Fleshy fruits -encourage seed dispersal
Plants:
Speed and agility -escape predation
Large groups -distract against predation
Camouflage, burrowing, crepuscular, nocturnal feeding -avoid
detection
Ex. Eastern coral snake (venomous) and scarlet king snake
(non-venonmous)
Toxins (or false toxin-colouration) -deter predators
Herbivores:
Claws, talons, beaks, horns, teeth, poisonous bite/sting -defend &
catch prey
Ex. Javan slow loris -only mammals to have venomous bite
Carnivores:
Include: algae, mosses, liverworts, ferns, lichens (symbiosis
between fungi and algae), conifers, monocots/grasses,
dicots/forbs, bushes, trees
Does NOT include fungi
Contain chlorophyll
!
Manufacture organic compounds from water, CO2, and
minerals, using solar energy by photosynthesis
!
Green plants independent of external sources of organic
carbon compounds (don’t need food; make their own)
!
Autotrophs:
Green plants are not only eaten but also used as shade or
shelter
Producers (green plants)1.
Organisms (animals, fungi) dependent on external
sources of organic carbon compounds
!
Heterotrophs:
Need to consume food
Only 5-20% of food energy is stored in animal tissues, rest
used in life processes (maintenance) or lost as heat
Primary consumers (herbivores)2.
Heterotrophs (see above)
Secondary consumers (omnivores/carnivores which eat herbivores)3.
Heterotrophs (see above)
Tertiary consumers (omnivores/carnivores which eat
omnivores/carnivores)
4.
Trophic Levels:
Direct Observation1.
Enclosurea)
Exclosure b)
Cafeteria c)
'Utilization' Techniques (before and after studies)2.
In vivo a)
Post mortemb)
Digesta Sampling3.
Faecal Analysis4.
Stable isotopesa)
Radioisotopesb)
Isotope Studies5.
Adipose Tissue Composition 6.
Methodology -how to find out what wild animals are eating is a major
issue
Endangered species --> equally welfare all species?
Aquatic species -faecal analysis is difficult
Crepuscular/nocturnal/fossorial species -direct observation is
difficult
How to choose what method to use:
Little expensive equipment needed (binoculars and time)
Advantages:
Difficult in crepuscular/nocturnal/fossorial species
Difficult in aquatic environment
Difficult in areas with high vegetation
Difficult in open areas to watch unnoticed
Does not indicate what animal eats while not being observed
Time consuming
Disadvantages:
Chimpanzees/gorillas -observer needs to be within a few feet
to see which food items and parts are being consumed
If vegetation is heterogeneous mix of many different
plant species, it can be difficult to determine exactly
what is eaten (always difficult to determine which part of
plant is eaten)
!
Herbivores on grassland savannah -if vegetation in
homogenous or in large homogeneous patches observation
may be useful
Different members of group may eat different parts of
carcass
!
Carnivores -observer watches hunt and visits site later to see
which part of carcass remains
Bald Eagle -observe bird returning to nest/roost with prey (do
not bring complete prey back to nest though)
Examples:
Direct Observation:
Survey vegetation first (quadrats, quantity, species, plant parts)
Let animals into enclosure for set time
Re-survey after animals have left
Estimate which plant species and parts have been eaten
!
Advantages:
Other animal (slugs, snails, rabbits) may also have been
eating in enclosure
!
Disadvantages:
E.g. herbivores, rabbits, equids, bovids
Enclosure
Survey vegetation both inside and outside exclosure area and
compare
Estimate which plant species and parts have been eaten
!
Advantages:
Other animals may have been eating inside and outside
exclosure
!
Disadvantages:
Exclosure
Range of plant material (species, parts, ages) offered to captive
animals
Determine amount of each plant material offered and amount
left after feeding
Estimate which plant species/parts have been eaten and
which are preferred
!
Advantages:
Animals are captive and cannot range freely
!
Plant material is usually cut, not growing -animals may
eat different plant parts
!
Disadvantages:
Cafeteria
Utilization:
Esophageal fistula / rumen fistula
Collect samples through fistula (tube)
Sort, identify (microscope), weigh food
More accurate than utilization techniques
!
Advantages:
Work with captive, tame animals
!
Surgical procedures to implant fistulas
!
Disadvantages:
Ex. Herbivores, grazers, browsers
Fistulas
Pellets cast by birds of prey
Bone -gives species, size and age of prey
!
Feathers -gives species and age of prey
!
Hair -hair atlas
!
Scales -gives age class of prey
!
Otoliths (from fish skull) -gives species of prey
!
Contain only indigestible components of food:
Collect pellets, sort contens and identify
Owls -usually eat prey whole --> more remains
!
Hawks -tear pieces from prey --> more acid digestion
(less remains, further digested)
!
Difficult to find
Some insectivorous birds (kestrels, swallows,
flycatchers) egest insect exoskeletons
!
Examples;
More accurate than utilization techniques
!
Non-invasive
!
Advantages:
Some food components poorly represented or absent
!
Disadvantages
Pellets
Regurgitation (with or without emetics)
Disadvantages: invasive, welfare, captive
Irrigate/stomach pump for birds (that do not produce pellets)
Digesta Sampling -In Vivo
Collect GITs from hunters/ road kills
Sort and identify stomach contents
Knowing the average segment/worms --> number of worms
eaten
E.g. count worm chaetae
More accurate than utilization techniques
No animal specifically killed for study
Advantages:
Time of last mean and degree of digestion unknown
Some easily digested food components poorly represented or
absent
Disadvantages:
Digesta Sampling -Post Mortem
Collect faeces/scats
Sort and identify faecal contents
No animal killed
May provide information not provided by utilization
techniques
Advantages:
Highly digestible food components under represented or absent
(soft-bodied invertebrates, fungi)
May not know which individual (species/M/F) produced faeces
Observe defecation, dunging sites, territorial markers
Morphological characteristics, shape, size and consistency may
help identify but diet will affect morphology
pH reflects lower end of GIT -may distinguish hind-gut
fermenters
Parasites may be species specific
Some bile acid residue may be present, may be species specific
(e.g. bear -ursodeoxycholic acid)
Molecular scatology, DNA analysis may be used to identify
cellular debris in faecas
Faecal steroids, may distinguish M/F and stages in
reproductive cycle
Disadvantages:
Faecal Analysis
Food Habits
Friday,*March*3,*2017 12:30*PM

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