mammals. class mammalia small number of species ~4500 but probably more successful than most animal...
TRANSCRIPT
MammalsMammals
Class MammaliaClass Mammalia
Small number of species ~4500
But probably more successful than most animal groups (except insects) at exploiting all available environments
Small number of species ~4500
But probably more successful than most animal groups (except insects) at exploiting all available environments
Class MammaliaClass Mammalia
Very diverse group not constrained by particular lifestyle (like flight in birds)
Diversity makes it difficult for layperson to identify various mammals as being closely related
Very diverse group not constrained by particular lifestyle (like flight in birds)
Diversity makes it difficult for layperson to identify various mammals as being closely related
Class MammaliaClass Mammalia
Descended from therapsid reptiles with mammal-like characteristics
Important structural changes from reptiles to mammals
Descended from therapsid reptiles with mammal-like characteristics
Important structural changes from reptiles to mammals
Class MammaliaClass Mammalia
Limbs from lateral to ventral
Higher center of gravity - less stability
Required greater development of cerebellum - muscular coordination center in brain
Limbs from lateral to ventral
Higher center of gravity - less stability
Required greater development of cerebellum - muscular coordination center in brain
Class MammaliaClass Mammalia
Separation of air and food passageways in head
Can breathe with mouth full of food
Allows prolonged chewing & some early digestion
Separation of air and food passageways in head
Can breathe with mouth full of food
Allows prolonged chewing & some early digestion
Subclass TheriaSubclass Theria
Most mammals belong to Subclass Theria
Descended from some common ancestor ~150 million years ago
Most mammals belong to Subclass Theria
Descended from some common ancestor ~150 million years ago
Subclass TheriaSubclass Theria
Infraclass Metatheria - marsupials - pouched mammals
Infraclass Eutheria - placental mammals
Infraclass Metatheria - marsupials - pouched mammals
Infraclass Eutheria - placental mammals
Subclass PrototheriaSubclass Prototheria
Monotremes Small group of egg-
laying mammals So different from
other groups of mammals
Entirely different origin?
Monotremes Small group of egg-
laying mammals So different from
other groups of mammals
Entirely different origin?
All mammalsAll mammals
Characteristics unique and diagnostic for mammals
Hair - greatly reduced in aquatic mammals
Mammary glands - milk secreting glands for nourishing young
Characteristics unique and diagnostic for mammals
Hair - greatly reduced in aquatic mammals
Mammary glands - milk secreting glands for nourishing young
Integument & DerivativesIntegument & Derivatives
Skin generally thicker than in other vertebrates
Dermis thicker than epidermis
Epidermis very thin where covered with hair, thicker on palms, soles
Skin generally thicker than in other vertebrates
Dermis thicker than epidermis
Epidermis very thin where covered with hair, thicker on palms, soles
Integument & DerivativesIntegument & Derivatives
Hair derived from epidermis
Probably evolved from reptilian scales
Scales still present in some (tail of rat, beaver)
Hair derived from epidermis
Probably evolved from reptilian scales
Scales still present in some (tail of rat, beaver)
Integument & DerivativesIntegument & Derivatives
Grows from follicle Epidermal structure
sunk deep into dermal layer and beyond
Grows by addition of new cells at base of follicle
Grows from follicle Epidermal structure
sunk deep into dermal layer and beyond
Grows by addition of new cells at base of follicle
Integument & DerivativesIntegument & Derivatives
Cells pushed upward die from lack of nourishment
Dead cells mostly keratin - same material in nails, claws, feathers
Cells pushed upward die from lack of nourishment
Dead cells mostly keratin - same material in nails, claws, feathers
Integument & DerivativesIntegument & Derivatives
Hair consists of 3 layers Medulla - core Cortex - contains
pigment Cuticle - composed of
imbricated scales Different types of hair
result from differential development of the 3 layers
Hair consists of 3 layers Medulla - core Cortex - contains
pigment Cuticle - composed of
imbricated scales Different types of hair
result from differential development of the 3 layers
Integument & DerivativesIntegument & Derivatives
Each follicle has muscle attached to it - erector muscle
Contraction causes hair to stand up straight
Increase insulation thickness, serve as warning
Each follicle has muscle attached to it - erector muscle
Contraction causes hair to stand up straight
Increase insulation thickness, serve as warning
Fur or PelageFur or Pelage
Most mammals have two kinds of hair
Thick, soft underhair - provides insulation
Coarse, long guard hair - protects and provides coloration
Most mammals have two kinds of hair
Thick, soft underhair - provides insulation
Coarse, long guard hair - protects and provides coloration
Fur or PelageFur or Pelage
Hair stops growing when it reaches certain length
Remains in follicle until new growth starts, then falls out
Hair stops growing when it reaches certain length
Remains in follicle until new growth starts, then falls out
Fur or PelageFur or Pelage
Mammals lose hair in periodic molts
Most have 2 annual molts - entire pelage shed (humans shed and replace continually)
Spring - thin summer Fall - heavy winter
Mammals lose hair in periodic molts
Most have 2 annual molts - entire pelage shed (humans shed and replace continually)
Spring - thin summer Fall - heavy winter
Fur or PelageFur or Pelage
Pigmentation and molts allow mammals to be different colors in different seasons
Brown in summer White in winter -
leukemism
Pigmentation and molts allow mammals to be different colors in different seasons
Brown in summer White in winter -
leukemism
Fur or PelageFur or Pelage
Lack of pigment results in albinism - recessive gene - blocks pigment formation (don’t confuse with leukemism)
Excess of black pigment is melanism
Lack of pigment results in albinism - recessive gene - blocks pigment formation (don’t confuse with leukemism)
Excess of black pigment is melanism
Derivatives of HairDerivatives of Hair
Vibrissae - sensory hairs on snouts, other parts of head
Incorrectly called whiskers
Vibrissae - sensory hairs on snouts, other parts of head
Incorrectly called whiskers
Derivatives of HairDerivatives of Hair
Quills - defensive structures in porcupines, hedgehogs, echidnas
Break off after barbed tip embeds in flesh of other animal
Work in deeper with time
Quills - defensive structures in porcupines, hedgehogs, echidnas
Break off after barbed tip embeds in flesh of other animal
Work in deeper with time
GlandsGlands
Mammals also have variety of epidermal glands
Greatest variety among vertebrates
4 basic types
Mammals also have variety of epidermal glands
Greatest variety among vertebrates
4 basic types
GlandsGlands
Sweat glands - simple, tubular, highly coiled
Cover most of body Not found in other
vertebrates Open directly to skin
surface Two types
Sweat glands - simple, tubular, highly coiled
Cover most of body Not found in other
vertebrates Open directly to skin
surface Two types
GlandsGlands
Sweat glands - eccrine glands
Secrete watery sweat for temperature regulation
Hairless regions in most mammals (especially foot pads)
Sweat glands - eccrine glands
Secrete watery sweat for temperature regulation
Hairless regions in most mammals (especially foot pads)
GlandsGlands
Some mammals don’t have eccrine glands - rodents, rabbits, whales
Some have them all over body - humans, horses, dogs
Racial differences in abundance in humans
Some mammals don’t have eccrine glands - rodents, rabbits, whales
Some have them all over body - humans, horses, dogs
Racial differences in abundance in humans
GlandsGlands
Sweat glands - apocrine glands
Found in all mammals Longer, more winding
than eccrine glands Open into follicle at
surface Secretion not involved
with heat regulation
Sweat glands - apocrine glands
Found in all mammals Longer, more winding
than eccrine glands Open into follicle at
surface Secretion not involved
with heat regulation
GlandsGlands
Apocrine gland activity correlated with some aspects of sexual cycles
Human females have twice as many as males
Apocrine gland activity correlated with some aspects of sexual cycles
Human females have twice as many as males
GlandsGlands
Scent glands - location and function vary
Communication, warning, defense, attraction
E.g., skunk Humans have many,
but taught to dislike their scent
Scent glands - location and function vary
Communication, warning, defense, attraction
E.g., skunk Humans have many,
but taught to dislike their scent
GlandsGlands
Sebaceous glands - associated with hair follicle
Secrete fat (sebum) to keep hair and skin soft
Polite fat - does not turn rancid
Generally all over body - most numerous on human scalp, face
Sebaceous glands - associated with hair follicle
Secrete fat (sebum) to keep hair and skin soft
Polite fat - does not turn rancid
Generally all over body - most numerous on human scalp, face
GlandsGlands
Mammary glands - modification of apocrine, sebaceous glands?
Present in both genders, functional only in female
Secrete milk to nourish young
Mammary glands - modification of apocrine, sebaceous glands?
Present in both genders, functional only in female
Secrete milk to nourish young
GlandsGlands
Contain varying quantities of fat (3-5%), protein, carbohydrate, salts
Higher fat content (30-40%) in marine and arctic mammals, where development is rapid
Contain varying quantities of fat (3-5%), protein, carbohydrate, salts
Higher fat content (30-40%) in marine and arctic mammals, where development is rapid
Horns & AntlersHorns & Antlers
3 kinds of horns or horn-like structures found in mammals
1) true horns 2) antlers 3) rhino horns
3 kinds of horns or horn-like structures found in mammals
1) true horns 2) antlers 3) rhino horns
Horns & AntlersHorns & Antlers
True horns Found in ruminants
like cows, goats, antelope
Hollow sheaths of keratinized epidermis surrounding core of bone arising from skull
True horns Found in ruminants
like cows, goats, antelope
Hollow sheaths of keratinized epidermis surrounding core of bone arising from skull
Horns & AntlersHorns & Antlers
Not normally shed Not branched (but
may be greatly curved, twisted)
Found in both sexes
Not normally shed Not branched (but
may be greatly curved, twisted)
Found in both sexes
Horns & AntlersHorns & Antlers
Antlers Deer family
(Cervidae) Generally males only
(except caribou - female’s smaller)
Entirely bone when mature
Antlers Deer family
(Cervidae) Generally males only
(except caribou - female’s smaller)
Entirely bone when mature
Horns & AntlersHorns & Antlers
Annual growth Develop beneath
cover of highly vascularized soft skin - velvet
Growth complete, blood vessels constrict, velvet dies and is rubbed off
Annual growth Develop beneath
cover of highly vascularized soft skin - velvet
Growth complete, blood vessels constrict, velvet dies and is rubbed off
Horns & AntlersHorns & Antlers
Antlers dropped after breeding season
New buds appear within few months
New pair larger, more elaborate
Strain on mineral metabolism - moose, elk must accumulate 50+ lbs of calcium salts from vegetable diet
Antlers dropped after breeding season
New buds appear within few months
New pair larger, more elaborate
Strain on mineral metabolism - moose, elk must accumulate 50+ lbs of calcium salts from vegetable diet
Horns & AntlersHorns & Antlers
Rhinoceros horn Hairlike horny fibers
arise from dermal papillae
Cemented together to form single horn
Dagger handles and medicinal uses
Rhinoceros horn Hairlike horny fibers
arise from dermal papillae
Cemented together to form single horn
Dagger handles and medicinal uses
TeethTeeth
Teeth are a less obvious characteristic of mammals
Reveal more about lifestyle than any other characteristic
Not in monotremes, some whales, anteaters
Teeth are a less obvious characteristic of mammals
Reveal more about lifestyle than any other characteristic
Not in monotremes, some whales, anteaters
TeethTeeth
Diphyodont teeth - two sets of teeth Set of deciduous “milk teeth” replaced by set of
permanent teeth Reptiles have polyphyodont teeth - many sets -
all are homodont - uniform, unspecialized
Diphyodont teeth - two sets of teeth Set of deciduous “milk teeth” replaced by set of
permanent teeth Reptiles have polyphyodont teeth - many sets -
all are homodont - uniform, unspecialized
TeethTeeth
Mammals have heterodont teeth - specialized for various functions
Mammals have heterodont teeth - specialized for various functions
TeethTeeth
TeethTeeth
Incisors - snip, bite - simple crowns, slightly sharp edges
Incisors - snip, bite - simple crowns, slightly sharp edges
TeethTeeth
Canines - piercing - pointed, long conical crowns Canines - piercing - pointed, long conical crowns
TeethTeeth
Premolars - shear, slice - flat compressed crowns with 1 or 2 cusps
Premolars - shear, slice - flat compressed crowns with 1 or 2 cusps
TeethTeeth
Molars - crushing, grinding - broad with variable cusp arrangement
Always belong to the permanent set
Molars - crushing, grinding - broad with variable cusp arrangement
Always belong to the permanent set
TeethTeeth
Different diets necessitate differing development of different teeth
Carnivores - large canines, some small and/or modified molars and premolars
Different diets necessitate differing development of different teeth
Carnivores - large canines, some small and/or modified molars and premolars
TeethTeeth
Rodents and herbivores - large incisors, reduced canines, large molars
Incisors grow continually, must be worn away to keep pace with growth
Rodents and herbivores - large incisors, reduced canines, large molars
Incisors grow continually, must be worn away to keep pace with growth
TeethTeeth
Digestive SystemsDigestive Systems
Different diets also necessitate differing digestive systems
Herbivores face special problem - indigestibility of cellulose, chief carbohydrate in plants
Different diets also necessitate differing digestive systems
Herbivores face special problem - indigestibility of cellulose, chief carbohydrate in plants
Digestive SystemsDigestive Systems
No digestive enzyme to break down cellulose
Depend on anaerobic bacteria to do it
Developed various digestive structures where microbes can do their thing
No digestive enzyme to break down cellulose
Depend on anaerobic bacteria to do it
Developed various digestive structures where microbes can do their thing
Digestive SystemsDigestive Systems
Two basic approaches
1) hind-gut approach 2) fore-gut approach
Two basic approaches
1) hind-gut approach 2) fore-gut approach
Digestive SystemsDigestive Systems
Hind-gut approach Horses and rabbits
and others Large sidepocket -
cecum - at junction of small, large intestines
Houses microbes
Hind-gut approach Horses and rabbits
and others Large sidepocket -
cecum - at junction of small, large intestines
Houses microbes
Digestive SystemsDigestive Systems
Sometimes all isn’t digested first time through
Rabbits, hares, some rodents eat fecal pellets - coprophagy
More bacterial fermentation, chance to absorb vitamins manufactured by bacteria
Sometimes all isn’t digested first time through
Rabbits, hares, some rodents eat fecal pellets - coprophagy
More bacterial fermentation, chance to absorb vitamins manufactured by bacteria
Digestive SystemsDigestive Systems
Humans have vestigial cecum - appendix
Humans have vestigial cecum - appendix
Digestive SystemsDigestive Systems
Fore-gut approach Cattle, deer, sheep,
antelope are ruminants
Have huge, 4-chambered stomach where digestion occurs
Fore-gut approach Cattle, deer, sheep,
antelope are ruminants
Have huge, 4-chambered stomach where digestion occurs
Digestive SystemsDigestive Systems
Grass passed down esophagus to rumen
Broken down by bacteria and formed into small balls of cud in reticulum
Regurgitated to mouth and chewed to crush fibers
Grass passed down esophagus to rumen
Broken down by bacteria and formed into small balls of cud in reticulum
Regurgitated to mouth and chewed to crush fibers
Digestive SystemsDigestive Systems
Swallowed to rumen again for further digestion by bacteria
Finally passed through reticulum and churned in omasum
Swallowed to rumen again for further digestion by bacteria
Finally passed through reticulum and churned in omasum
Digestive SystemsDigestive Systems
Passed into abomasum - true stomach
Proteolytic enzymes secreted, normal digestion occurs
Passed into abomasum - true stomach
Proteolytic enzymes secreted, normal digestion occurs
Digestive SystemsDigestive Systems
Small intestine very long, coiled
Much longer in herbivores than in carnivores, insectivores
Cow small intestine - 50+ m (165 feet)
Small intestine very long, coiled
Much longer in herbivores than in carnivores, insectivores
Cow small intestine - 50+ m (165 feet)
Size vs. Food ConsumptionSize vs. Food Consumption
The smaller the mammal, the greater its metabolic rate, and the more it must eat relative to its size
Small mammals spend more time hunting, eating than large mammals
The smaller the mammal, the greater its metabolic rate, and the more it must eat relative to its size
Small mammals spend more time hunting, eating than large mammals
Size vs. Food ConsumptionSize vs. Food Consumption
2 g shrew eats > its body weight in food each day
Will starve to death in few hours if deprived of food
2 g shrew eats > its body weight in food each day
Will starve to death in few hours if deprived of food
Size vs. Food ConsumptionSize vs. Food Consumption
Large carnivore may only need one meal every few days to remain healthy
Large carnivore may only need one meal every few days to remain healthy
MigrationMigration
Few mammals make seasonal migrations
Much more difficult than for birds
Most that do live in, near North America
Few mammals make seasonal migrations
Much more difficult than for birds
Most that do live in, near North America
MigrationMigration
Barren-ground caribou - seasonal movements >1000 km
North for calving, south for winter
Barren-ground caribou - seasonal movements >1000 km
North for calving, south for winter
MigrationMigration
Longest mammal migrants are whales, seals
Fur seal females migrate 2800 km to give birth, winter
Males stay north
Longest mammal migrants are whales, seals
Fur seal females migrate 2800 km to give birth, winter
Males stay north
MigrationMigration
Few bats with power of flight use it to migrate
Most hibernate during winter
4 spp. of American bats migrate - red bat
Winter in Mexico, summer north, west
Few bats with power of flight use it to migrate
Most hibernate during winter
4 spp. of American bats migrate - red bat
Winter in Mexico, summer north, west
FlightFlight
Flight, gliding evolved independently in several different groups: marsupials, rodents, lemurs, bats
Bats are only true fliers - nocturnal insectivore niche left open by most birds
Flight, gliding evolved independently in several different groups: marsupials, rodents, lemurs, bats
Bats are only true fliers - nocturnal insectivore niche left open by most birds
FlightFlight
Success of bats: 1) flight 2) ability to navigate
via echolocation
Success of bats: 1) flight 2) ability to navigate
via echolocation
EcholocationEcholocation
Fly and avoid obstacles in complete darkness
Locate & catch insects with precision and speed
Find way deep into caves - new habitat
Fly and avoid obstacles in complete darkness
Locate & catch insects with precision and speed
Find way deep into caves - new habitat
EcholocationEcholocation
Emit short pulses (5-10 msec) from mouth
Ultrasonic to human ear 10-200 pulses/sec Echo received with
great ears - form image of surroundings as good as eyes of other mammals
Emit short pulses (5-10 msec) from mouth
Ultrasonic to human ear 10-200 pulses/sec Echo received with
great ears - form image of surroundings as good as eyes of other mammals
EcholocationEcholocation
May be used by other insectivorous mammals: shrews, tenrecs
Crudely developed compared to bats
May be used by other insectivorous mammals: shrews, tenrecs
Crudely developed compared to bats
EcholocationEcholocation
Echolocation highly developed in toothed whales, e.g., sperm whale
Varying frequency clicks produced in sinus passages
Echolocation highly developed in toothed whales, e.g., sperm whale
Varying frequency clicks produced in sinus passages
EcholocationEcholocation
Focused by lens-shaped melon in forehead
Returning echoes channeled through oil-filled cavity in lower jaw to inner ear
Focused by lens-shaped melon in forehead
Returning echoes channeled through oil-filled cavity in lower jaw to inner ear
EcholocationEcholocation
Allows whales to determine size, shape, speed, distance, directions, density of everything in water
Keep track of members of pod
Allows whales to determine size, shape, speed, distance, directions, density of everything in water
Keep track of members of pod
HibernationHibernation
True hibernators: ground squirrels, woodchucks
Body temperature falls within few degrees of freezing
Breathing, heart rates drop extremely low
True hibernators: ground squirrels, woodchucks
Body temperature falls within few degrees of freezing
Breathing, heart rates drop extremely low
HibernationHibernation
Not true hibernation: bears
Breathing, heart rates fall, but body temperature remains similar
Not true hibernation: bears
Breathing, heart rates fall, but body temperature remains similar
ReproductionReproduction
Most mammals have definite mating seasons
Usually winter or spring
Timed to coincide with most favorable time for rearing young after birth
Most mammals have definite mating seasons
Usually winter or spring
Timed to coincide with most favorable time for rearing young after birth
ReproductionReproduction
Female mating function restricted to time during periodic cycle - estrous cycle
Female receptive during brief period of cycle - estrus or heat
Several other stages
Female mating function restricted to time during periodic cycle - estrous cycle
Female receptive during brief period of cycle - estrus or heat
Several other stages
ReproductionReproduction
Proestrus - period of preparation
New ovarian follicles grow
Proestrus - period of preparation
New ovarian follicles grow
ReproductionReproduction
Estrus - mating, ovulation, fertilization, implantation, pregnancy
Estrus - mating, ovulation, fertilization, implantation, pregnancy
ReproductionReproduction
Metestrus - if no mating or fertilization, a period of repair
Metestrus - if no mating or fertilization, a period of repair
ReproductionReproduction
Diestrus - uterus becomes small, anemic
Diestrus - uterus becomes small, anemic
ReproductionReproduction
Monestrous - single estrus during breeding season
Dogs, foxes, bats Polyestrous -
recurrence of estrus during breeding season
Mice squirrels, tropical animals
Monestrous - single estrus during breeding season
Dogs, foxes, bats Polyestrous -
recurrence of estrus during breeding season
Mice squirrels, tropical animals
ReproductionReproduction
Humans and Old World monkeys have slightly different cycle
Post-ovulation period terminated by menstration - menstrual cycle
Humans and Old World monkeys have slightly different cycle
Post-ovulation period terminated by menstration - menstrual cycle
ReproductionReproduction
3 different patterns of reproduction among mammals
1) monotremes 2) marsupials 3) placentals
3 different patterns of reproduction among mammals
1) monotremes 2) marsupials 3) placentals
ReproductionReproduction
Monotremes - egg-laying mammals
One breeding season each year
Ovulated eggs (2) fertilized in oviduct
Shell added in oviduct Eggs laid in burrow
nest Incubated for 12 days
Monotremes - egg-laying mammals
One breeding season each year
Ovulated eggs (2) fertilized in oviduct
Shell added in oviduct Eggs laid in burrow
nest Incubated for 12 days
ReproductionReproduction
Hatch, fed milk (licking, not suckling)
No gestation - period of pregnancy
Developing embryo uses nutrients in egg
Young reared on milk
Hatch, fed milk (licking, not suckling)
No gestation - period of pregnancy
Developing embryo uses nutrients in egg
Young reared on milk
ReproductionReproduction
Marsupials - pouched mammals
Brief gestation period, but physiology and lactation complicated
E.g., red kangaroo
Marsupials - pouched mammals
Brief gestation period, but physiology and lactation complicated
E.g., red kangaroo
ReproductionReproduction
1st pregnancy of season followed by 33-day gestation, joey born underdeveloped
Crawls into pouch, attaches to nipple
Mother immediately becomes pregnant again
1st pregnancy of season followed by 33-day gestation, joey born underdeveloped
Crawls into pouch, attaches to nipple
Mother immediately becomes pregnant again
ReproductionReproduction
Presence of young in pouch arrests development at 100-cell stage - diapause
Lasts ~235 days until joey leaves pouch
2nd joey develops, born in ~month, enters pouch
Presence of young in pouch arrests development at 100-cell stage - diapause
Lasts ~235 days until joey leaves pouch
2nd joey develops, born in ~month, enters pouch
ReproductionReproduction
Becomes pregnant again
Arrested development Oldest joey returns to
nurse from time to time
3 young at once
Becomes pregnant again
Arrested development Oldest joey returns to
nurse from time to time
3 young at once
ReproductionReproduction
Some marsupial variations Development delays
Common features Born at
underdeveloped stage
Prolonged development attached to mammary gland
Some marsupial variations Development delays
Common features Born at
underdeveloped stage
Prolonged development attached to mammary gland
ReproductionReproduction
Placentals - most successful mammals
Reproductive investment is in gestation
Embryo nourished by food via placenta
Placentals - most successful mammals
Reproductive investment is in gestation
Embryo nourished by food via placenta
ReproductionReproduction
Gestation variable Mice - 21 days Rabbits - 30-36 days Cats, dogs - 60 days Cattle - 280 days Elephants - 22 months Baleen whales - 12
months Bats - 4-5 months
Gestation variable Mice - 21 days Rabbits - 30-36 days Cats, dogs - 60 days Cattle - 280 days Elephants - 22 months Baleen whales - 12
months Bats - 4-5 months
ReproductionReproduction
Variable condition at birth - well-furred and mobile to naked, blind, helpless
Human growth slower than any other mammal
Variable condition at birth - well-furred and mobile to naked, blind, helpless
Human growth slower than any other mammal
# of Young# of Young
Smaller animals, larger litters
Larger animals, smaller litters
Status in food web important
Carnivores - 1 litter of 3-5 young
Mice - 17 litters of 4-9 young per year
Smaller animals, larger litters
Larger animals, smaller litters
Status in food web important
Carnivores - 1 litter of 3-5 young
Mice - 17 litters of 4-9 young per year
# of Young# of Young
Large mammals - single young with each pregnancy
Elephant - 4 young per 50-year reproductive life
Large mammals - single young with each pregnancy
Elephant - 4 young per 50-year reproductive life
TerritoryTerritory
Defended area for exclusive use
Marked using scent glands
Varies in size from huge (grizzly bear) to small (squirrel)
Defended area for exclusive use
Marked using scent glands
Varies in size from huge (grizzly bear) to small (squirrel)
TerritoryTerritory
Owner comfortable within territory, intruder at “psychological” disadvantage
Owner comfortable within territory, intruder at “psychological” disadvantage
TerritoryTerritory
Owner comfortable within territory, intruder at “psychological” disadvantage
Owner comfortable within territory, intruder at “psychological” disadvantage
TerritoryTerritory
Some territories established for use by family unit
Male beaver defends territory, female and young use it
Some territories established for use by family unit
Male beaver defends territory, female and young use it
TerritoryTerritory
Some live in friendly towns - prairie dog
Parents give old home to young and move out
Some live in friendly towns - prairie dog
Parents give old home to young and move out
Home RangeHome Range
Larger foraging area surrounding defended territory
Neutral zone used for foraging by owners of several territories
Larger foraging area surrounding defended territory
Neutral zone used for foraging by owners of several territories
Us & ThemUs & Them
Biggest impact - domestication
Dogs, cats 10,000 years ago
Food animals much later
Biggest impact - domestication
Dogs, cats 10,000 years ago
Food animals much later
Us & ThemUs & Them
Beasts of burden Some no longer
exist in wild - llama, alpaca, 1-humped Arabian camel
Beasts of burden Some no longer
exist in wild - llama, alpaca, 1-humped Arabian camel
Us & ThemUs & Them
Some not truly domesticated - do not breed in captivity
Reindeer, Asian elephant
Some not truly domesticated - do not breed in captivity
Reindeer, Asian elephant
Us & ThemUs & Them
Problem mammals - rodents, rabbits
Damage crops, foods, carry diseases
Problem mammals - rodents, rabbits
Damage crops, foods, carry diseases
Us & ThemUs & Them
Problems with us 300 species
endangered Includes all cetaceans,
cats, otters, primates Hunting, collecting,
habitat destruction, species introductions
Problems with us 300 species
endangered Includes all cetaceans,
cats, otters, primates Hunting, collecting,
habitat destruction, species introductions