Topic 6 Mammalogy

Abomasum

is the fourth and final gastric compartment in ruminants. (1) It is the glandular portion and will secrete enzymes for chemical digestion. 2] Some other herbivorous mammals have similar modifications. They have the pseudoruminant stomach and also conduct foregut fermentation. (include the camels, hippopotamus, kangaroos, sloths, and the colobus monkey)

reticulum

is the second portion (1) Internally it has a honey-combed appearance. (2) The fluid contents of the reticulum play a role in particle separation. [a] It sends the "cud" back to the esophagus for regurgitation.

Insectivore

is the term used for mammals that feed primarily on insects, other small arthropods, and/or worms.

Most large animals that are hindgut fermenters use the ______ for this purpose

large intestine

There are a variety of herbivorous feeding strategies including:

1] Frugivores feed on fruits 2] Folivores feed on leaves (i.e.; foliage) 3] Nectarivores feed on nectar. 4] Granivores feed on seeds 5] Palynivores feed on pollen. 6] Mucivores feed on plant fluids (i.e. sap) 7] Xylophages feed on wood.

Carnivorous bats include six families:

1] Hipposideridae, the Old World leaf nosed bats. 2] Megadermatidae, the false vampire batsa} This family includes the largest New World bat, the greater false vampire bat (Megadermalyra) that has strong canines for capturing prey and large molars for crushing bone. 3] Noctilionidae, the bulldog bats/fisherman batsa} Although smaller species are insectivorous the larger species will have elongated hindlimbs and claws to allow them to capture fish. 4] Nycteridae, the hollow faced bats 5] Phyllostomidae, the leaf nosed batsa} Although most are insectivorous this family of bat include the only Sanguinivorous mammals, the vampire bats (genus Desmodus).b} They also include some frog hunting species including the fringe lipped bat (Trachops cirrhosis) that can differentiate poisonous from nonpoisonous frogs by their calls. 6] Verspertilionidae, the vesper bats/evening batsa} Members of the genus Nyctalus have been known to hunt small birds.

Diastema

A space between two teeth

Omnivore

An animal that eats both plants and animals

Pterygoideus

Between cheekbone and mandible

facultative carnivore

Can eat meat as well as plant material

Herbivores

Herbivore (meaning "plant eater") is the term used for mammals that feed on plants. 1) These are animals that meet their nutritional and energy requirements through a diet that consists exclusively, or almost exclusively, of plants and plant products.

Phyllostomidae

Leaf-nosed bats

The main muscles for jaw adduction are the

Masseter, Temporalis, and Pterygoideus.

A simple stomach is called a

Monogastric Stomach and is found in perissodactyls, lagomorphs, and many rodents.

Another adaptation is found in insectivores that have become specialists feeding on colonial insects. These mammals are termed

Myrmecophagus, meaning "anteaters".

Hipposideridae

Old World leaf-nosed bats

The pseudoruminant stomach has three chambers:

Omasum, Abomasum, and Reticulum Lacks rumen

Hypsodont teeth

Teeth of horses, rodents, and lagomorphs Have relatively large reserve crowns beneath the gingival margin Continually grow / erupt throughout the animal's lifetime

Insectivores

mammals that feed primarily on insects, other small arthropods, and/or worms.

Aerial Insectivores

The majority (~70%) are Microchiroptera a] All bats residing between 380N and 400S are insectivorous. - will typically consume 50% of their body mass a night.

Digastric Stomach

multichambered stomach

Specialized Teeth of the Crabeater Seal

one group of Antarctic seals, the crabeater seal (Lobodon carcinophaga) have specialized teeth that allow them to filter feed.

Mammals tend to be

opportunistic feeders, using whatever is available in the environment.

Freshwater carnivores are typically

otters (subfamily Lutrinae) and representative insectivores (Ex; American water shrew, Sorex palusris) that feed on fish.

Foraging theory is discussed in terms of optimizing a

payoff from a foraging decision. a] The payoff for many of these models is the amount of energy an animal receives per unit time, more specifically, the highest ratio of energetic gain to cost while foraging. 1] This can be measured in calories gained. 2] It can also be measured in the number of offspring produced in some species.

Geomyidae

pocket gophers

Heteromyidae

pocket mice

Temporalis

powers the jaws to hold prey and so are larger in carnivores.

Aquatic carnivores are primarily

primarily piscivores, feeding on fish. a] There are exceptions such as Orca (Orcinus orca) that hunt cetaceans and pinnipeds and the Leopard seal (Hydrurga leptonyx) that hunts penguins and other seals.

aquatic carnivores

primarily piscivores, feeding on fish. a] There are exceptions such as Orca (Orcinus orca) that hunt cetaceans and pinnipeds and the Leopard seal (Hydrurga leptonyx) that hunts penguins and other seals.

Lophodont teeth are found in

rabbits that are grazers and in African bush elephants (Loxodonta africana) which feed on savannah grasses. -all Equidae are grazers and have lophodont teeth.

omasum

receives food from the reticulum. (1) Its functions have not been well-studied, it appears to primarily aid in the absorption of water, magnesium, and the volatile fatty acids produced by rumen fermentation, that have not been absorbed into the bloodstream yet by the fermentation division.

Terrestrial insectivores

There are a variety of terrestrial and semiaquatic insectivorous mammals. a] Many mole species are capable swimmers and there is the water shrew (Blarina brevicauda) and the platypus (O. anatinus). b] As mentioned previously, there are 12 orders containing insectivorous species. In addition, there are some orders that have such a small percentage of their species that are insectivorous that they are typically not counted.

Browsers and Grazers

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

Some insectivores produce a venom in their saliva

This is a proteolytic enzymatic compound that causes paralysis and respiratory failure in arthropods

Carnassial

Typically the canines will become long and pointed and the premolars and molars will be modified to process meat

Vespertilionidae

Vesper Bats

Pseudoruminant Stomach

a digastric stomach with 3 chambers; found in hippopotamids

The earliest mammals were insectivores and today 12 orders of modern mammals exploit this niche:

a] Order Monotremata; echidnas and platypus b] Order Notorctemorpha; the marsupial moles c] Oder Eulipotyphla; the hedgehogs, shrews, moles, selenodons, and gymnures d] Order Afrosoricidae; golden moles and tenrecs e] Order Macroscelidea; elephant shrews f] Order Scandentia; tree shrews g] Order Chiroptera; many bat species are insectivores h] Order Cingulata; armadillos i] Order Pilosa; anteaters j] Order Pholidota; pangolins k] Order Tubulidentata; the aardvark (Orycteropus afer) l] Order Carnivora; the aardwolf (Proteles cristata)

Felids

are obligate carnivores that are very well adapted predators. a] Along with the typical mammalian predatory adaptations these animals also have binocular vision, very sensitive vibrissae, and parakeratinized papillae on the tongue. 1] These papillae give cats their "rough tongue" and help them to scrap meat off a bone.

canids

are opportunistic hunters that are facultative carnivores. a] One predatory advantage that some canids employ is behavioral. 1] A number of larger canids form packs with a complex social systems. a} These can increase hunting efficiency. The most efficient nonhuman hunters are the painted wolves (Lycon pictus) due to their pack system.

Aerial carnivores

are specialized representatives of the Microchiroptera. a] These bats have become specialized to take larger (than arthropods) prey items including frogs, birds, rodents, and other bat species.

gnawing mammals

are the Lagomorpha and Rodentia, the most successful of all mammal groups in terms of species richness and diversity. 1] They are also hindgut fermenters, using the cecum and colon.

Parvorder Odontoceti

are the toothed whales and dolphins. 1] Primarily they are piscivorous and have evolved to modifications to aid with this.

Granivores

are those herbivores that have become specialized to feed on seeds and nuts. a] A number of mammals are specialized to feed on seeds but the most specialized are considered to be the heteromyid rodents such as kangaroo rats (genus Dipodomys), pocket mice (genus Perognathus), and kangaroo mice (genus Microdipodops).

Ruminant Stomach

rumen, reticulum, omasum, abomasum

Pinnipeds

seals, sea lions, walruses

Bovidae and many grazing antelopes have

selenodont teeth

Insectivores have

shorter, less specialized digestive tracts

frugivores

are those herbivores that have specialized to feed on fruits. a] A number of mammals will feed on fruits but several orders are known to specialize on fruits as their primary food source. 1] They include Megachiroptera (family Pteropodidae) and Microchiroptera (family Phyllostomidae) bats and many primates such as indrid lemurs (family Indriidae), Loris (family Lorisidae), and Old World monkeys (family Cercopithecidae).

Monogastric Stomach

simple stomach is found in perissodactyls, lagomorphs, and many rodents.

the cecum of these animals is located at the junction of the

small and large intestine

Sciuridae

squirrels

Typically insectivorous mammals have a

dentition of numerous sharp teeth modified for capturing, piercing, and crushing arthropod exoskeletons and a relatively short digestive tract lacking a cecum.

the multichambered stomach is also known as a

digastric stomach

to aid in insect capture Microchiropterans evolved

ecolocation

Masseters

facilitate chewing and are larger in herbivores.

The red fox (Vulpes vulpes) is an example of a

facultative carnivore.

The digestive tracts of carnivorous species tend to be

fairly unspecialized

Megadermatidae

false vampire bats

Parvorder Mysticeti

feders using baleen to filter small marine life out of the water. a] Baleen are keratinized plates coming off of the oral epithelium of the upper jaw. 1] These hair-like plates will have some degree of mineralization (hydroxyapatites) to give them stiffness.

Carnivores

feed on other animals

herbivore

feed on plants and plant products.

fermentation division

first division to receive the food. It has two portions: rumen and reticulum

piscivorous

fish eating

For example, herbivores include

foliovores, frugivores, granivores, and nectivores.

herbivores include

foliovores, frugivores, granivores, and nectivores.

the reticulum plays a role as a

foregut fermenter

Many _____ play an important role in seed dispersal.

frugivores

diastema

gap between teeth

Most insect eating bats are

generalists, capturing any suitable size insect prey that come their way.

Cricetidae

hamsters, voles, lemmings

H

handling time, which includes capture, killing, eating and digesting. -starts once the prey has been spotted.

Aerial insectivores

1) The majority (~70%) of all Microchiroptera are insectivorous. a] All bats residing between 380N and 400S are insectivorous. b] They feed on a wide variety of arthropods, primarily insects, but including crayfish and centipedes. c] Microchiropterans are efficient insect hunters and will typically consume 50% of their body mass a night.

Dietary specializations will also show anatomical and physiological specializations of the digestive system to better process these food items. a) These changes include:

1) tooth shape and distribution 2) glandular secretions (ex; vampire bat [Desmodus sp.] salivary glands include an anticoagulant) 3) stomach shape and degree of compartmentalization (i.e.; single chambered vs. multichambered) 4) length and regional specialization of the small and large intestines

Dietary specializations will also show anatomical and physiological specializations of the digestive system to better process these food items. a) These changes include:

1) tooth shape and distribution 2) glandular secretions (ex; vampire bat [Desmodus sp.] salivary glands include an anticoagulant) 3) stomach shape and degree of compartmentalization (i.e.; single chambered vs. multichambered) 4) length and regional specialization of the small and large intestine

The second division is often called the

"True Stomach". It also has two portions: omasum and abomasum

Microchiroptera

(Bats) Small, mostly nocturnal. Use echolocation to find food at night. Cannot make loud noises

foregut fermentation is associated with

Digastric stomachs. 1] It is found in Artiodactyl mammals, the ruminants. a} The ruminant stomach involves the animal swallowing food, storing it in the first chamber of the stomach, regurgitating it to chew it thoroughly, and then swallowing it back into the stomach. b} The ruminant stomach has four chambers that are separated into two divisions.

The snouts of moles and desmans (family Talipidae) have

Eimer Organs.

There are two basic strategies:

Foregut Fermentation and Hindgut Fermentation.

Omnivores

Omnivore (meaning "eater of everything") are mammals that can consist on a wide range of food substances. 1) They tend to be unspecialized, opportunistic generalists. a] As such omnivores tend to have unspecialized digestive features. 1] Although many times they will show some specializations which are hold overs from their evolutionary past. a} Ex; the domesticated pig (Sus scrofa domesticus) is an omnivore but it has a relatively long digestive tract since it is an artiodactyl, a herbivorous group. 2] One common feature is a complete dentition and Bunodont molariform teeth.

Marine predators include the carnivore superfamily

Pinnipedia and the Artiodactyl infraorder Cetacea.

Some artiodactyls have a

Pseudoruminant Stomach composed of three, instead of four, chambers (ex; hippopotamids).

rumen

Rumen is the first portion. (1) It serves as the primary site for microbial fermentation of ingested feed.

if the digastric stomach has four chambers it is a

Ruminant Stomach and is found in the ruminant artiodactyls, some macropods, and the tylopods (the camels).

The earliest mammals were insectivores and today 12 orders of modern mammals exploit this niche:

a] Order Monotremata; echidnas and platypus b] Order Notorctemorpha; the marsupial moles c] Oder Eulipotyphla; the hedgehogs, shrews, moles, selenodons, and gymnures d] Order Afrosoricidae; golden moles and tenrecs e] Order Macroscelidea; elephant shrews f] Order Scandentia; tree shrews g] Order Chiroptera; many bat species are insectivores h] Order Cingulata; armadillos i] Order Pilosa; anteaters j] Order Pholidota; pangolins k] Order Tubulidentata; the aardvark (Orycteropus afer) l] Order Carnivora; the aardwolf (Proteles cristata)

foraging

act of searching for and exploiting food resources.

The ability to learn is one

adaptation that has helped mammals to dominate the ecosystems that they exist in today.

E

amount of energy (calories) from a prey item.

obligate carnivore

animal receives its nutrient requirements exclusively from meat it is

myrmecophagus

anteaters specialists feeding on colonial insects.

Mustelids

are another group of obligate carnivores. a] Most are terrestrial hunters. 1] Some are semiaquatic (otters, subfamily Lutrinae) and one is a marine predator (the sea otter, Enhydra lutris)

graminivores

are herbivores that feed primarily on grasses. a] Grasses are high in silicates which can cause wear on teeth. 1] As a result many graminivores have hypsodont molariform teeth. -These teeth tend to have complex patterns on the occlusal surface.

Nectarivores

are herbivores that specialize in feeding on nectar. a] Most nectarivores are bats, both of the microchiroptera and megachiroptera . 1] These bats have evolved long tongues to reach deep into the flower and play a role in pollination. b] Another nectarivore is the honey possum (Tarsipes rostratus) c) Adaptations include an elongated tongue and muzzle and a reduction in the number and size of teeth (since chewing is not important).

Folivores

are those herbivores that have specialized to feed on leaves. a] Leaves, like grass, are high in cellulose and relatively low in nutrients so both herbivorous groups have long digestive tracts and symbiotic bacteria to assist in digestion. include: okapis (Okapi johnstoni), sloths (suborder Folivora), koala (Phascolarctos cinerus), and a number of primate species including the howler monkeys (genus Alouatta) and the Proboscis monkey (Nasalis larvatus).

foregut fermentation

associated with Digastric stomachs. 1] It is found in Artiodactyl mammals, the ruminants. a} The ruminant stomach involves the animal swallowing food, storing it in the first chamber of the stomach, regurgitating it to chew it thoroughly, and then swallowing it back into the stomach. b} The ruminant stomach has four chambers that are separated into two divisions.

hindgut fermenters

associated with Monogastric stomachs. 1] Hindgut fermentation is found in perissodactyls, elephants, sirenians, hyrax, lagomorphs, rodents, and some arboreal marsupials -hindgut fermentation cellulose is digested with the aid of symbiotic bacteria located in the large intestine and cecum

Myrmecophagy

a} Their dentition has changed to simple, peg-like teeth and in some groups these teeth are lost completely b} They tend to have powerful forelimbs with well developed claws to open termite mounds. c} The mouth typically becomes elongated and tubular. d} The tongue is elongated. e} The salivary glands include secretions high in mucus to make the tongue sticky.

Noctilionidae

bulldog bats

omnviore

can feed on both animal and plant material

Marine predators include the

carnivore superfamily Pinnipedia and the Artiodactyl infraorder Cetacea.

Most small animals that are hindgut fermenters use the ______ for this purpose

cecum

fermentation and typically is supplemented by another digestive organ, the

cecum

Coprophagy

has evolved in rodents and lagomorphs (as well as in some shrews and some marsupials). 1] Since the fermentation process occurs after the small intestine, which performs the bulk of nutrient absorption, there will still be a good amount of nutrients in the food item the first time that it is defecated. a} By consuming the feces the first time that they have passed through the digestive tract the animal has the opportunity to harvest the nutrients made available through fermentation. 1} Feces that have "passed through twice" are presumably not consumed again.

granivorous rodents

have a simpler digestive tract than do graminivorous (grass eating) rodents such as lemmings and voles of the subfamily Arvicolinae.

Nycteridae

hollow-faced bats

carnivore

if it receives it nutritional needs mainly from meat

Both lagomorphs and rodents have

incisors that grow throughout life and are self-sharpening to make effective chisel, gnawing, structures.

foraging theory

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

optimal foraging theory

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

The "bill" of the platypus is highly innervated for

tactile perception and for electroreception.

Eimer Organs

tactile sensory organs found on the snout (bulbous papillae)

Eimer Organs

tactile sensory organs found on the snout. 1} To increase surface area the epidermis of the snout is arranged into bulbous papillae. (a) These papillae are rich in tactile receptors

echolocation

the ability to project sound waves and locate objects from the reflection of these sound waves.

Which family lacks a cecum?

the dormice (family Giridae)

E/h

the profitability of the prey item

gnawers

these include lagomorphs and rodents.

rough tongue

used for grooming & licking meat from the bone

Pocket Gopher

will have cheek pouches which allow them to temporarily store food. a} This is seen in pocket gophers (family Geomyidae), hamsters (family Cricetidae), squirrels (family Sciuridae), and pocket mice (family Heteromyidae).