Topic 6: modes of feeding

Coprophagy

has evolved in rodents and lagomorphs (as well as in some shrews and some marsupials) -since fermentation process occurs after the small intestine, which preforms the bulk of nutrient absorptions, theres still a good amount of nutrition in food item the first time it is defecated -consuming of feces the first time they've passed through digestive tract, animal has chance ti harvest nutrients made available through fermentation -feces "passed through twice" are not consumed again

Echolocation

is the ability to project sound waves and locate objects from the reflection of these sound waves -makes insectivorous bats very effective at catching flying insects in flight Microchiroptera evolved this for insect capture

Foraging

is the act of searching for and exploiting food resources -affects an animal's fitness bc it plays an important role in an animal's ability to survive and reproduce

Fermentation Division

is the first division in a ruminant stomach to receive the food -foregut fermentation associated with digastric stomachs It has two portions: Rumen and Reticulum **1/2 divisions in ruminant stomach

Rumen

is the first portion -It serves as the primary site for microbial fermentation of ingested feed **1/2 portions in Fermentation division **1st chamber in ruminant stomach

Herbivores

is the term used for mammals that feed on plants -"Plant Eater" -meet nutritional and energy needs through diet consisting of plants and plant products -variety of feed strategies

energy

it is clear that an approach focusing only on _________ intake will not provide an adequate model -bc there are other essential nutrient in all organisms diet -E is not the only nutritional req Ex; Moose (Alces alces) eat the energy rich leaves of deciduous trees but also the low energy, sodium rich aquatic plants of their environment because they need sodium in their diets

unspecialized

like insectivorous mammals, their digestive tracts tend to be fairly _________ ***Carnivore adaptation

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 -has 4 chambers

6 families of carnivorous bats

1. Hipposideridae, the Old World leaf nosed bats 2. Megadermatidae, the false vampire bats - includes largest new world bat, has strong canines to capture prey and large molars for crushing bone 3. Noctilionidae, the bulldog bats/ fisherman bats -smaller species are insectivorous -larger species have elongated limbs and claws to capture fish 4. Nycteridae, the hollow faced bats 5. Phyllostomidae, the leaf nosed bats -most are insectivorous, but this family include Sanguinivorous mammals, the vampire bats -also include some frog hunting species (fringe lipped bat) can differentiate poisonous frogs by their calls 6. Verspertilionidae, the vesper bats/evening bats -known to hunt small birds

Adaptation in Terrestrial Insectivores

1. Some insectivores produce a venom in their saliva -a proteolytic enzymatic compound that causes paralysis and respiratory failure in arthropods -Ex. Haitian solenodon, Mediterranean shrew, the European water shrew, the Northern short-tailed shrew 2. become specialists feeding on colonial insects - termed Myrmecophagus, "anteaters"

Herbivore modifications to the teeth

1. canines are reduced/lost typically while the molariform teeth are broad and shaped to better crush and tear plant mater 2. chew side to side

Myrmecophagus special sensory systems to capture and find prey

1. the platypus "bill" is highly innervated for tactile perception and electroreception >important bc platypi swim w eyes closed 2. The snouts of moles and desmans (family Talipidae) have Eimer Organs >tactile sensory organs in snout

Insectivore orders

12 orders 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)

pseudoruminant stomach

3 chambers: Omasum, Abomasum, and Reticulum -lacks a rumen -also conducting foregut fermentation: they include the camels, hippopotamus, kangaroos, sloths, and the colobus monkey (Colobus guereza)

Plant matter

= is lower in nutrition than is animal matter and it is harder to digest (due to the cellulose content) -result: herbivory requires more dietary adaptations than carnivory and omnivory

Diastema

=a gap between the incisors and the first premolar -herbivore modification bc the canines are often lost

piscivores

=feeding on fish -aquatic carnivores are primarily this -exceptions are Orca that hunt cetacenas and pinnipeds and the leopard seal that hunts penguins and other seals

Monogastric Stomach

A simple stomach is called a ___________ -is found in perissodactyls, lagomorphs, and many rodents

aerial carnivorous mammals

All are specialized representatives of the Microchiroptera -have become specialized to take larger (than arthropods) prey items including frogs, birds, rodents, and other bat species

profitible

Animals typically eat the most _________ food items more than would be expected by chance since it will appear in the diet at a higher proportion than it is encountered in the environment -animals do not eat only the most _______ food types -other prey types may be easier to find, and E is not the only nutritional req

selenodont teeth

Bovidae and many grazing antelopes have

Ruminant Stomach

If the digastric stomach has four chambers it is a ___________ -found primarily in the ruminant artiodactyls, some macropods, and the tylopods (the camels) ***chambers in a digastric stomach

hindgut fermentation

In _____ __________ cellulose is digested with the aid of symbiotic bacteria located in the large intestine and cecum

Microchiroptera

Most __________ are generalists, capturing any suitable size insect prey that come their way (aka insect eating bats) -few are insect specialists >Pallid bat feeds off of large arthropods -their skulls will differ based on what type and size of insects they normally prey on -size of prey reflects on the bat species jaw morphology -Ex. moth eaters have delicate jaws with many small teeth vs beetle eaters have robust jaws and a few, large teeth ******Aerial Insectivores

opportunstic feeders

mammals tend to be _____________, using whatever is available in the environment -Individuals will eat different food items at different life stages due to different nutritional needs >juvenile female vs pregnant female -Individuals will eat different food items at different times of the year based on seasonal availability >brown bears feed on salmon in autumn

learning and genetics; learn

Several factors affect an animal's ability to forage and acquire highly profitable resources. These include ... -The ability to _______ is one adaptation that has helped mammals to dominate the ecosystems that they exist in today

Herbivores

The intestines are longer in ____________ and may include a well developed cecum

Digastric Stomach

The multichambered stomach is also known as a ________ -Ruminant Stomach = 4 chambers -Pseudoruminant Stomach = 3 chambers

Reticulum

The second portion is the __________ -internally it has a honey-combed appearance -fluid contents play a role in particle separation >it sends the "cud" back to the esophagus for regurgitation **1/2 portions in Fermentation division **2nd chamber in ruminant stomach

toxins

may be present in many prey types -variability of diet prevents any one toxin from reaching dangerous levels

Carnivores

meaning "meat eater" -is the term used for mammals that feed on other animals (excluding arthropods) -meet nutritional and energy requirements through diet of flesh of other animals -done through predation, scavenging, or combo of both -include most of: > placental order Carnivora >marsupial order Dasyuridae >Microchiroptera

dormice

one rodent group, lacks a cecum -this may be an adaptation to having a low cellulose diet -family Giridae -gnawing mammals

temporalis

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

Foraging theory

predicts that the decisions that maximize energy per unit time and thus deliver the highest payoff will be selected for and persist -plays major role in diet selection

Gnawers

These include lagomorphs and rodents -mammalian herbivores including some of the Carnivora broken up into 1/2 groups

Browsers and Grazers

These include perissodactyls and artiodactyls as well as a number of other groups such as the macropod marsupials, sirenians, and proboscideans -mammalian herbivores including some of the Carnivora broken up into 1/2 groups

jaw muscles

To power these teeth carnivores tend to have powerful __________ -require well-developed attachment points on the skull and mandible >Ex; sagittal crest on the skull of the coyote, Canis latrans. ***Carnivore adaptation

Baleen

are keratinized plates coming off of the oral epithelium of the upper jaw -filters small marine life out of water -These hair-like plates will have some degree of mineralization (hydroxyapatites) to give them stiffness -used in baleen whales (Parvorder Mysticeti)

Felids

are obligate carnivores that are very well adapted predators - with the typical mammalian predatory adaptations these animals also have: >binocular vision, >very sensitive vibrissae, >parakeratinized papillae on the tongue -these pappillae give the cats their "rough tongue" and help them scrap meat off of bone ***Terrestrial Carnivore

Canids

are opportunistic hunters that are facultative carnivores -One predatory advantage that some of their employ is behavioral - a number of larger canids form packs with a complex social systems -this increases hunting efficiency -The most efficient nonhuman hunters are the painted wolves (Lycon pictus) due to their pack system

Eimer Organs

are tactile sensory organs found on the snout -to increase surface area the epidermis of the snout is arranged into bulbous papillae >papillae rich in tactile receptors -allows them to feed for their prey while traveling in their burrows -reach greatest evolution in the star-nosed mole which has 25,000 Eimer organs on its snout

Granivores

are those herbivores that have become specialized to feed on seeds and nuts -A number of mammals are specialized to feed on seeds but the most specialized are considered to be the heteromyid rodents such a kangaroo rats, pocket mice, and kangaroo mice -american desert rodents that harvest seed and cache them for later consumptions. -get most or all of water from seeds -adaptation= cheek pouches to carry a collection of nuts to a cache point Ex. chipmunks and squirrels

hypsodont molariform teeth

result from grasses are high in silicates which can cause wear on teeth -in Graminivores

Frugivores

are those herbivores that have specialized to feed on fruits -number of mammals will feed on fruits but several orders are known to specialize on fruits as their primary food source -decr. # of molars, since chewing isnt an issue -retained sharp canines to pierce skin -primates can see color which could be an adaptation to find ripe fruit -play role in seed dispersal

Herbivores

chew side to side (not up and down like carnivores) -result in diff muscles emphasized -pterygoideus and the masseter incr in size -temporalis is reduced when compared to a carnivore -simple or multichambered stomach

Pseudoruminant Stomach

composed of three, instead of four, chambers -in some artiodactyls -(ex. hippopotamids) ***chambers in a digastric stomach

Masseter

facilitate chewing and are larger in herbivores

Frugivores

feed on fruits **herbivorous feeding strategy

Folivores

feed on leaves (i.e.; foliage) **herbivorous feeding strategy

Nectarivores

feed on nectar **herbivorous feeding strategy

Mucivores

feed on plant fluids (i.e. sap) **herbivorous feeding strategy

Palynivores

feed on pollen **herbivorous feeding strategy

Granivores

feed on seeds **herbivorous feeding strategy

Xylophages

feed on wood **herbivorous feeding strategy

Abomasum

fourth and final gastric compartment in ruminants -It is the glandular portion and will secrete enzymes for chemical digestion **1/2 portions in True Stomach **4th chamber in ruminant stomach

Hindgut fermenters

generally have a cecum and large intestine much larger and more complex than those of other mammals -use cecum and colon -most large animals that are this use the large intestine for this purpose -Most small animals that are this use the cecum for this purpose

teeth

greatest degree of specialization of their digestive system is found in the _______ >typically canines become long and pointed and premolars and molars will be modified to process meat (ex. carnassials) >Some will have molars designed to crush bone (ex; Hyaenidae) ***Carnivore adaptation

insectivorous mammals

-have a dentition of numerous sharp teeth >modified for capturing, piercing, and crushing arthropod exoskeletons -shorter, less specialized digestive tract lacking a cecum -some are very specialized & have lost their teeth -EX. anteaters - use long sticky tongue to capture small insects

Cecum

-located at the junction of the small and large intestines -digestive organ supplementing enough fermentation, when reticulum could not

Terrestrial Insectivores

-mole species are capable swimmers -water shrew -platypus -some species not counted in 12 orders bc such small percentage -Ex. grasshopper mouse of U.S feeds exclusively on crickets and grasshoppers -even in some omnivorous species, insects are majority of diet

Gnawing Mammals

-the most successful of all mammal groups in terms of species richness and diversity -the Lagomorpha and Rodentia -hindgut fermenters, using cecum and colon -only 1 rodent group lack a cecum -will have stomach w 1-3 chambers

Myrmecophagus evolutions

-their dentition has changed to simple, peg-like teeth and in some groups these teeth are lost completely -powerful forelimbs with well developed claws to open termite mounds -mouth becomes elongated and tubular -elongated tongue >anteaters have a tongue that anchors on sternum (usually on hyoid) >in some the tongue can be 3x as long as head -salivary glands include secretions high in mucus to make tongue sticky ***Terrestrial insectivore

Odontoceti

-toothed whales and dolphins -primarily piscivorous -have evolved to modifications to aid 1. homodontic dentition -uniform teeth better to capture fish -heterodonty is unnecessary since mastication doesnt work well under water 2. ecolocation -to easily find food -ex. orca can stun fish w a pulse of sound for easier capture ***1/2 Cetacea parvorder

Sanguinivorous mammals

-vampire bats (genus Desmodus) -carnivorous mammal included in the family Phyllostomidae, the leaf nosed bats

Myrmecophagus

"anteater" -adaptation is found: become specialists feeding on colonial insects -terrestrial insectivore -have evolved in diff mammalian groups including armadillos, anteaters, pangolins, aardvark, and numbat -evolved from typical insectivores to feed on ants and termites

Omnivores

"eater of everything" =mammals that consist on a wide range of food substances -tend to be unspecialized, opportunistic generalists -unspecialized digestive features -common feature is complete dentition and Bunodont molariform teeth -show some specializations which are hold overs from their evolutionary past Ex. domesticated pig- omnivore but has a relatively long digestive tract since it is an artiodactyl, a herbivorous group -include some pigs, some bears, the members of the family Procyonidae, a number of primates including Homo sapiens

Microchiroptera

-The majority (~70%) of all _______ are insectivorous. -all bats residing between 38N and 40S degrees are insectivorous -they feed on variety of arthropods, primarily insects, but includes crayfish and centipedes -efficient insect hunters -consume 50% of their body mass a night >study by Kurta about lactating, big brown bat consumes that much -evolved echolocation for insect capture ******Aerial Insectivores

Mysticeti

-baleen whales -filter feeders using baleen to filter small marine life out of the water ***1/2 Cetacea parvorder

Pinnipedia

-carnivore superfamily -marine predator primarily piscivorous 1. Different species have different shaped teeth >reflects diff types and sizes of fish they prey on Ex. leopard seals have massive teeth and jaws for dispatching seals Ex. a group of Antarctic seals, the crabeater seal (Lobodon carcinophaga) have specialized teeth that allow them to filter feed 2. fairly short digestive tracts -exceptions: >southern elephant sea tract is 202m bc of need to obtain all of their water through metabolic water. a longer gut assists with this

plant based

One of the problems with a ________ diet is dealing with all of the cellulose. Mammals do not produce cellulase and must use fermentation to break down cellulose -two basic strategies: Foregut Fermentation and Hindgut Fermentation

Dasyuridae

are a family of Australasian marsupials that include all extant marsupial carnivores -They include the catlike quolls (genus Dasyurus) and the Tasmanian devil (Sarcophilus harrisii) ***Terrestrial Carnivore

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

Mustelids

are group of obligate carnivores -most are terrestrial hunters -some are semiaquatic (otters, subfamily Lutrinae) -one is a marine predator (the sea otter, Enhydra lutris) ***Terrestrial Carnivore

Nectarivores

are herbivores that specialize in feeding on nectar -most are bats, both of the microchiroptera and megachiroptera -have evolved long tongues to reach deep into flower -play role in pollination -also the honey possum -Adaptations include: -an elongated tongue -muzzle -reduction in the number and size of teeth (since chewing is not important).

Folivores

are those herbivores that have specialized to feed on leaves -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 -most prefer immature leaves, >easier to chew, higher in energy and protein, and lower in cellulose and poisons than mature leaves -show many of same adaptations that graminivores have -some developed a flexible upper lip, flexible long tongue -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)

Freshwater carnivores

are typically otters (subfamily Lutrinae) and representative insectivores (Ex; American water shrew, Sorex palusris) that feed on fish ***aquatic carnivore division

mammals

have diversified to fill a number of ecological niches and part of this is adopting different feeding strategies reflective of these niches -strategies include: 1. carnivores 2. herbivores 3. omnivores

lagomorphs and rodents

have incisors that grow throughout life and are self-sharpening to make effective chisel, gnawing, structures -some rodents will have cheek pouches which allow them to temporarily store food >in pocket gophers, hamsters, squirrels, and pocket mice

Cetacea

have split into two Parvorders based on different feeding strategies and evolution -Artiodactyl infraorder included in marine predator

Graminivores

herbivores that feed primarily on grasses -Grasses are high in silicates which can cause wear on teeth -result: have hypsodont molariform teeth -these teeth tend to have complex patterns on the occlusal surface -tend to have wider mouths on the anterior portion

Facultative Carnivore

if an animal receives it nutritional needs mainly from meat it is a ____________ -The red fox (Vulpes vulpes) is an example of this

Obligate Carnivore

if the animal receives its nutrient requirements exclusively from meat it is an ___________ -Most felids are this

Reticulum

in pseudoruminant stomach -plays a role as a foregut fermenter -does not account for enough fermentation -typically is supplemented by another digestive organ, the Cecum

herbivores

include foliovores, frugivores, granivores, and nectivores -specializations -not exclusive, represents major dietary preferences -ex. carnivores purposely digest plant matter -ex. red deer (herbivores) consuming discarded antlers for minerals

Foraging theory

is a branch of behavioral ecology that studies the foraging behavior of animals in response to the environment where the animal lives -discussed in terms of optimizing a payoff from a foraging decision >payoff is amount of energy an animal receives per unit time, specifically the highest ratio of energetic cost while foraging >measured in calories gained >&measured in # of offspring produced in some species 9some produce more offspring when taking in more food)

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 -behave this way to find, capture, and consume food containing the most calories while expending the least amount of time doing so

Foregut fermentation

is associated with Digastric stomachs -found in Artiodactyl mammals, the ruminants =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

Hindgut fermentation

is associated with Monogastric stomachs -cellulose is digested with the aid of symbiotic bacteria located in the large intestine and cecum -found in perissodactyls, elephants, sirenians, hyrax, lagomorphs, rodents, and some arboreal marsupials (including koalas, Phascolarctos cinereus).

Omasum

that receives food from the reticulum -functions not well studied -primary aid in absorptino of water, magnesium, and volatile fatty acids produced by rumen fermentation, that have not been absorbed into bloodstream yet by fermentation division **1/2 portions in True Stomach **3rd chamber in ruminant stomach

Masseter, Temporalis, and Pterygoideus

the main muscles for jaw adduction are the __________, ________, and _________ -How these muscles work in processing food differs between herbivores and carnivores -Masseters facilitate chewing and are larger in herbivores -the temporalis powers the jaws to hold prey and so are larger in carnivores ***Carnivore adaptation

True Stomach

the second division in a ruminant stomach -2 portions: Omasum and Abomasum **1/2 divisions in ruminant stomach

Insectivores

the term used for mammals that feed primarily on insects, other small arthropods, and/or worms -earliest mammals were this -12 orders of mammals exploit this niche *mode of feeding

No animal eats everything available

typically due to habitat and size constraints, but even within habitats, predators eat only a proportion of what is available -explained by ratio: E/h -E = amount of energy (calories) frmo a prey item -h= handling time, includes capturiing, killing, eating and digesting -h starts once the prey has been spotted -E/h is profitability of the prey item

rodents

typically they have a simple small intestine but a complex large intestine with a cecum that may show folding, sac-like extensions, and recesses -anatomy will reflect the diet Ex. Granivorous rodents (ex; Sciurids) have a simple digestive tract than do graminivorous (grass eating) rodents such as lemmings and voles of the subfamily Arvicolinae

Dietary specializations

will also show anatomical and physiological specializations of the digestive system to better process these food items, including: 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