ZOO4480: Topic 6: Modes of Feeding

Mammalian herbivores are typically broken up into what two groups?

1. Browsers and Grazers 2. Gnawers

Modifications to herbivore

1. Canines are reduced/lost 2. Molariform teeth are broad and shaped to crush plant, high crowned, hypsodont 3. Chewing is side to side 4. Pterygoideus and masseter have increased in size 5. Temporalis is reduced 6. Dentary has a deeper angle 7. Stomach may be simple/multichambered 8. Longer intestines with a well developed cecum

Adaptations of granivores?

1. Cheek pouches

Common features of omnivores?

1. Complete dentition .2. Bunodont molariform teeth

Types of terrestrial carnivores

1. Dasyuridae (marsupials - catlike quolls, Tasmanian devil) 2. Felids (obligate carnivores - cats, binocular vision, sensitive vibrate, parakeratinized papillae on tongue) 3. Mustelids (obligate - weasels) 5. Canids (facultative - form packs)

Frugivore adaptations

1. Decreased number of molars 2. Sharp canines 3. Some primates can see in color to find ripe fruit

Adaptations of carnivorous mammals?

1. Digestive tracts are fairly unspecialized 2. Canines become long and pointed 3. Premolars and molars modified to process meat ( some have molars designed to crush bone) 4. Powerful jaw muscles 5. Well developed sensory systems to better find and capture prey

Nectarivore adaptations?

1. Elongated tongue and muzzle 2. Reduction in the number and size of teeth

The ruminant stomach has four chambers that are separated into what two divisions?

1. Fermentation division 2. True stomach

Herbivorous mammals must use fomentation to break down cellulose. What are the two basic strategies of doing this?

1. Foregut fermentation 2. Hindgut fermentation

Aquatic carnivores can be divided into what two groups?

1. Freshwater 2. Marine

Adaptations for Odontoceti

1. Homodontic dentition (uniform sharp teeth) 2. Echolocation

Adaptations in graminivores

1. Hypsodont molariform teeth with complex patterns on the occlusal surface to prevent wear from silicates 2. Wider months on the anterior portion 3. Long digestive tracts 4. Symbiotic bacteria to aid in digestion

What factors affect an animal's ability to forage and acquire highly profitable resources?

1. Learning 2. Genetics

Pinnipeds are primarily piscivorous and have adaptations

1. Leopard seals have massive teeth and jaws 2. Crabeater seals have specialized teeth that allow them to filter feed 3. Fairly short digestive tracts (Southern Elephant seal = 202m)

Adaptations in folivores

1. Long digestive tracts 2. Symbiotic bacteria to aid in digestion 3. Flexible upper lip/flexible long tongue

The main muscles for jaw adduction in carnivorous mammals are?

1. Masseter 2. Temporalis 3. Pterygoideus

Cetacea have split into two Parvorders based on different feeding strategies and evolution

1. Odontoceti 2. Mysticeti

What are the two portions that make up the true stomach division of a ruminant stomach?

1. Omasum 2. Abomasum

How many chambers does the pseudoruminant stomach have and what are they?

1. Omasum 2. Abomasum 3. Reticulum

Animals do not eat only the most profitable food types

1. Other prey types may be easier to find 2. Toxins may be present in prey types 3. There are other essential nutrients in all organism's diets

What are the two portions that make up the fermentation division of a ruminant stomach?

1. Rumen 2. Reticulum

Gnawing mammals have what adaptations?

1. Simple small intestine 2. Complex large intestine with a cecum 3. Incisors that grow throughout life and are self-sharpening 4. Some have cheek pouches for storing food

A number of adaptations have evolved to exploit the rich food source of insects, they are?

1. Some insectivores produce a venom in their saliva (proteolytic enzymatic compounds that causes paralysis) 2. Myrmecophagus 3. Special sensory system to more easily find and capture prey

Some insectivores have developed special sensory system to more easily find and capture prey

1. The bill of the platypus is highly innervated for tactile perception and electroreception 2.. The snouts of moles and desmans have Eimer organs

Dietary specializations that show anatomical and physiological specialization of the digestive system include

1. Tooth shape and distribution 2. Glandular secretions 3. Stomach shape and degree of compartmentalization 4. Length and regional specialization of small/large intestines

Some insectivores have become very specialized and have lost their teeth, instead they use?

A long sticky tongue

Insectivorous mammals have what kind of digestive tract?

A relatively short digestive tract lacking a cecum

Aerial insectivores feed on?

A wide variety of arthropods, primarily insects, crayfish, and centipedes

This portion of the true stomach is the final gastric compartment and is the glandular portion that will secrete enzymes for chemical digestion

Abomasum

The ruminant stomach involved what to break down cellulose?

Animals swallows food, stores it in first chamber of stomach, regurgitates it to chew it, then swallows once more

Mysticeti are the?

Baleen whales

Nectarivores include?

Bats

What are the majority of aerial insectivores?

Bats (Microchiroptera)

Omnivores include?

Bear species, raccoons, coatis, some primates

These herbivores include perissodactyls and artiodactyls as well as a number of other groups such as the macropod marsupials, sirenians, and proboscideans

Browsers and grazers

Herbivorous mammals that have the pseudoruminant stomach and conduct foregut fermentation

Camels, hippos, kangaroos, sloths, colobus monkey

Animals that feed on other animals are?

Carnivores

Animals that meet their nutritional and energy requirements through a diet that consists exclusively or almost exclusively on the flesh of other animals?

Carnivores

Hindgut fermenters generally have what digestive organs that are larger and more complex than those of other mammals

Cecum and large intestine

These herbivores include lagomorphs and rodents

Gnawers

In rodents and lagomorphs, the the incisors have been modified to be ever growing to allow for?

Gnawing

Herbivores that feed primarily on grasses

Graminivores

Herbivore that feeds on seeds?

Granivores

Animals that feed on plants and plant products are?

Herbivores

These animals meet their nutritional and energy requirements through a diet that consists exclusively, or almost exclusively of plants and plant products

Herbivores

Granivores include?

Heteromyid rodents: Kangaroo rats, pocket mice, kangaroo mice

In this type of fermentation, cellulose is digested with the aid of symbiotic bacteria located in the large intestine and cecum

Hindgut fermentation

What type of fermentation is associated with mono gastric stomachs and is found in perissodactyls, elephants, sirenians, hyrax, lagomorphs, rodents, and some arboreal marsupials?

Hindgut fermentation

Gnawing mammals are what type of fermenters?

Hindgut, using the cecum and colon (dormice lack a cecum)

Term used for mammals that feed primarily on insects, other small arthropods, and worms

Insectivores (12 orders today)

Foraging affects an animal's fitness because?

It plays an important role in an animal's ability to survive and reproduce

This muscle facilitates chewing and are larger in herbivores

Masseter

All aerial carnivorous mammals are specialized representative of the?

Microchiroptera (Bats) (eat frogs, birds, rodents, bat species) 1. Old World leaf nosed bats 2. False vampire bats 3. Bulldog bats 4. Hollow faced bats 5. Leaf nosed bats 6. Vesper bats

A simple stomach that is found in perissodactyls, lagomorphs, and many rodents is called a?

Monogastric stomach

Carnivorous mammals include what orders?

Most of the placental order Carnivora and the marsupial order Dasyuridae

Herbivore that feeds on fluids (sap)

Mucivores

An adaptation found in insectivores that have become specialists feeding on colonial insects, these animals are called?

Myrmecophagus (ant eaters) (pangolins, armadillos, ant eaters, aardvark, numbat)

Herbivore that feeds on nectar?

Nectarivores

Typically insectivorous mammals have a dentition of?

Numerous sharp teeth modified for capturing, piercing, and crushing arthropods exoskeleton

An animal that receives its nutrient requirements exclusively from meat

Obligate carnivore (felids)

Folivores include?

Okapis, sloths, koala, and a number of primate species including howler monkeys and the proboscis monkey

This portion of the true stomach receives food from the reticulum and primarily aids in the absorption of water, magnesium, and the volatile fatty acids produced by rumen fermentation

Omasum

Mysticeti feed primarily on?

Small marine life - they are filter feeders

This muscle powers the jaw to hold prey are are larger in carnivores

Temporalis

The reticulum in the pseudoruminant stomach does not account for enough fermentation and is supplemented by what other digestive organ?

The cecum (located at the junction of the small and large intestines)

What mammals groups are the most successful in terms of species richness and diversity?

The gnawing mammals (Lagomorpha and Rodentia)

Do omnivores have specialized digestive features?

no

Odontoceti are the?

Toothed whales and dolphins

Omnivores are what type of feeders?

Unspecialized, opportunistic generalists

Aerial insectivores' skulls, jaws differ based on?

What type of insects they normally prey on

Herbivore that feeds on wood?

Xylophages

Rodents will have a stomach having how many chambers?

1-3

What are the different types of insectivores?

1. Aerial insectivores 2. Terrestrial insectivores

Optimal Foraging Theory

1. Animals behave in such a way as to find, capture, and consume food containing the most calories while expending the least amount of time possible in doing so 2. No animal eats everything available 3. Animals typically eat the most profitable food items more than would be expected by chance since it will appear in the diet at a higher proportion than is encountered in the environment

Mysticeti adapations

1. Baleen are keratinized plates coming off of the oral epithelium of the upper jaw

Sanguinivorous mammals

(Vampire bats) blood drinking

This has evolved in rodents and lagomorphs. When the fermentation process occurs after the small intestine, there will still be a good amount of nutrients in the food item the first time it is defecated, so the animal will consume it to harvest the nutrients

Coprophagy

Because canines are often lost in herbivores, there is a gap between incisors and the first premolar termed a?

Diastema

Plant matter is lower in nutrition than is animal matter and is harder to digest, as a result herbivory has required more _____ than carnivory or omnivory

Dietary adaptations

What shows anatomical and physiological specialization of the digestive system to better process food items?

Dietary specializations

Individuals will eat different food items at different life stages due to?

Different nutritional needs

What is a multi chambered stomach known as?

Digastric Stomach

E/h

E=amount of energy (calories) from a prey item H= handling time, capture, killing, eating, digesting (profitability of the item)

To aid in insect capture, Microchiropterans evolved?

Echolocation

Tactile sensory organs found on the snout of some insectivorous mammals

Eimer organs •Snout is arranged into bulbous papillae that are rich in tactile receptors (ex: star nosed mole)

An animal that receives its nutritional needs mainly from meat, but may supplement their diets

Facultative carnivore (red fox)

Herbivore that feeds on leaves/foliage

Folivores

The act of searching for and exploiting food resources?

Foraging

This theory is a branch of behavioral ecology that studies the foraging behavior of animals in response to the environment where the animal lives

Foraging theory

This type of fermentation is associated with digastric stomachs, is found in artiodactyl mammals, the ruminants

Foregut fermentation

Herbivore that feeds on fruits

Frugivores

Most insect eating bats are?

Generalists, capturing any suitable size insect pretty that come their way

Animals that feed on both animal and plant material are?

Omnivores

Mammals tend to be what type of feeders?

Opportunistic feeders, using whatever is available in the environment

An idea in ecology based on the study of foraging behavior and states that organism forage in such a way as to maximize their net energy intake per unit time

Optimal Foraging theory

Foraging theory is discussed in terms of?

Optimizing a payoff from a foraging decision (amount of energy the animal receives per unit time measured in calories gained or number of offspring)

Semiaquatic carnivorous mammals

Otters

Freshwater carnivores are?

Otters, and representative insectivores (water shrew) that feed on fish

Herbivore that feeds on pollen?

Palynivores

Marine carnivores are?

Pinnipedia, Cetacea

Aquatic carnivores are primarily?

Piscivores (feeding on fish) •Orca hunts cetaceans and pinnipeds •Leopard seal hunts penguins and seals

Odontoceti are primarily?

Piscivorous

Carnivores meet their nutritional and energy requirements through?

Predation, scavenging, or both

Echolocation is the ability to?

Project sounds waves and locate objects from the reflection of these sound waves

Some artiodactyls have a stomach composed of three chambers called a?

Pseudoruminant stomach

This chamber of the pseudoruminant stomach plays a role as the foregut fermenter

Reticulum

This second portion of the fermentation division internally has a honey combed appearance and the fluid contents of it play a role in particle separation

Reticulum

This first portion of the fermentation division serves as the primary site for microbial fermentation of ingested food

Rumen

If a digastric stomach ha four chambers, it is known as?

Ruminant stomach (found only in the ruminant artiodactyls, some macropods, and the tylopods)

Marine carnivorous mammals

Sea otters

Individuals will eat different food items at different times of the year based on?

Seasonal availability

Many frugivores play an important role in?

Seed dispersal

Foraging theory predicts that decisions that maximize energy per unit time and thus delivers the highest payoff will be?

Selected for and persist, plays a major role in debt selection

Terrestrial insectivores

•Moles, platypus, and water shrews are semi-aquatic insectivores •Omnivorous species eat insects