Basic concepts of Mammalogy Flashcards
What is pelage?
Whole body hair. This includes underfur (down or wool), and overfur (guard hairs).
What are hairs made of?
Three layers of keratin - a central core or medulla, layer of cortex surrounding the medulla, and an outermost layer called the cuticle
What are vibrissae?
Whiskers; specialized sensory hairs
What are the three skin glands? What are their purposes
Allow evaporative cooling and elimination of some wastes Sebaceous glands - oily secretion for lubricating hair and skin to keep pelage dry Scent and musk glands - social communication, marking territory, attracting mates, protection
What are mammary glands?
lobules of glandular tissue enclosed in connective tissue capsules the converge to a nipple or cistern for lactation
What are the purpose of claws, nails, and hooves?
Claws - tools and protect underlying tissues Nails - protect the tips of terminal phalanges (toes and fingers) Hooves - specialized claw
What are horns?
Keratinized sheaths around bony cores that do not branch except in pronghorns
What are antlers?
Bone laid down by epidermal growth layer (velvet) and typically shed annually
What are ossicones?
Similar to horns, derived from bony elements and no relation to horns or antlers (on giraffes and okapi)
What is oviparity?
Egg-laying
What is a cloaca?
Vent for digestive wastes, kidney excretions, reproductive system products found in monotremes
What reasons do mammals have for communicating?
Species, population, mate, or kin recognition; reproduction, agonism, social status, alarm, hunting, care, play
What is reciprocal altruism?
Cooperating with others, possibility of being paid back in the future
What is iteroparous?
Breeding multiple times throughout a lifetime
What is reproductive effort?
the energy put into current reproduction that reduces future survival and reproduction; increase with age in long-lived species; high at maturity for short-lived species
What are some forms of reproductive variations?
Delayed fertilization - hold sperm until later (seasons) Delayed development - slows following implantation in uterine lining Delayed implantation - suspend blastocyte development from embedding in lining (litter size of current brood) Embryonic diapause - a period of arrested development of the blastocyst (joey in pouch prevent next until he leaves)
What is the difference between altricial or precocial?
Altrical - young that are undeveloped (marsupial) Precocial - young that are more developed (placental)
What is endothermy?
ability to control body temperature by internal metabolic activity, physiological regulation of heat exchange, and behavioral thermoregulation
What are ways endotherms cope with the cold?
evolve large body size, have a more favorable ratio of surface are to volume, decrease rate of heat loss, increase insulation or thermoregulation, increase metabolic heat production, abandon normal body temp, or allow body temp to drop near ambient (hypothermia)
What is Bergmann’s Rule?
Animals in colder climates will be larger than those in warmer climates
What are ways endotherms cope with the heat?
sweating, panting, hyperthermia
What is echolocation?
short-range system where target are detected at close range
Is echolocation better for terrestrial or aquatic species?
Signals travel faster, further, and with less energy output in aquatic ecosystems
What is sexual dimorphism? Why does it occur?
One gender of a species, typically the male, is larger than the other gender. Most likely occurs due to mating rituals.