Zoology- Mammals and Animal Behavior

under hair

dense and soft hair, insulation to retain body temperature

guard hair

coarse and longer hair, for protection and coloration

vibrissae

(whiskers, bristles) attached to nerves and transmit sensory information

true horns

occur in Bovidae family… bony core extending from skull with epidermal layer covering bone and keratin layer covering epidermal

antlers

occur in cervidae family, antlers are solid bone covered by velvet… shed after breeding season and usually only occur in males (exception for caribou/reindeer)

mammary glands

secretes milk… ductal system surrounded by milk producing cells… grow late in pregnancy due to response from hormones

sebaceous glands

secrete sebum to keep hair and skin soft and pliable (also helps in waterproofing skin)

eccrine glands

secrete watery liquid… perspiration for temperature regulation… not all animals have these glands

apocrine glands

secrete milky odorous fluid… scent glands… used for communication… develop during sexual development… location is species specific

abductor muscles

muscles that close the jaw

temporalis and masseter muscles

muscles that allow for the up and down movement and side to side movement of the jaw

heterodont teeth

teeth with more then one tooth morphology (for specialization)

diphyodonts

animals with “baby” and “adult” teeth… teeth are replaced

insectivores

feed on insects and other inverts… short intestinal tract… specialized teeth to crush exoskeletons

herbivores

feed on grass and other vegetation… no canine teeth… have premolars/molars for grinding… specific bacteria that produces cellulase to digest cellulose… very long digestive tract

carnivores

feed on other vertebrates… mollusks… crustaceans… have canine teeth and pre-molars/molars are adapted to shear muscle away from bone… short digestive tract

omnivores

feed on plants and other animals…versatile teeth with rounded molars for crushing

four chambered heart

DO blood into RA, RV, lungs to be oxygenated, O blood to LA, LV, and fully O blood goes back to heart

monoestrous

one estrus cycle per breeding season

polyestrous

multiple estrus cycles per breeding season

monotremes

one breeding season… eggs (typically 2) are fertilized in the oviduct… embryos develop in uterus for 10 days, and are then laid and typically hatch in 12 days… young are underdeveloped… mammary glands but no nipples, so young lap up milk from fur

marsupials

pouched viviparous mammals… short placental gestation… young are underdeveloped… once born they crawl into the pouch and attach to nipple

eutherians/placentals

gestation time increases as size of animal increases… placenta connects embryo to mothers uterus… mother produces milk for young to nurse and teaches the young how to survive

altricial

young that are blind, sometimes hairless, and helpless

precocial

young that have fur, open eyes, and can move around

ultimate causation

the “why”… the evolutionary explanation… how does the animal behavior increase relative fitness

proximate causation

the “how”… the physiological explanation and the mechanisms that caused the behavior to occur

innate behaviors

instinctual behaviors… have genetic component… independent of environmental influence… occur in response to specific stimulus

learned behaviors

behaviors that are flexible and can be modified… occur as a result of experience… able to adapt to changes in the environment

kinesis

undirected movement in response to stimulus

taxis

directed movement towards or away from the stimulus

fixed action pattern

movement elicited in response to a stimulus… movement continues when stimulus is changed or removed

migration

long range seasonal movements of animals

foraging

movement to search for food/water

pheromones

chemical signals that elicit a specific response

aural signals

sounds that elicit a response

visual signals

displays that elicit a response

altruism

behaviors that lower the fitness of the individual exhibiting the behavior, and increase the fitness of another individual

intersexual selection

individuals of one sex choose mates of the other sex based on signals

intrasexual selection

competition for mates with the same sex, involving displays and aggressive rituals

monogamous

one male and one female pair for at least one breeding season

polygynous

one male mates with multiple females

polyandrous

one female mates with many males

habituation

simple form of learning where animals stop responding to a stimulus after repeated exposure

imprinting

simple form of learning occurring at a specific age or life stage