Download Chapter 16 Birds and Mammals Section 16.1: Birds (p.426

Chapter 16
Birds and Mammals
Section 16.1: Birds (p.426-434)
Characteristics of Birds
- Vertebrates
- Endotherms- 40 degrees Celsius (human is 37 degrees
Celsius)
- Feathers and scales
- All birds lay eggs and incubate them until they hatch
- Beaks instead of teeth
Bird Eggs
 Reproduce by laying amniotic egg
 Internal fertilization
 Egg shells made of calcium carbonate
 Stay with their eggs to incubate and raise their
young
 Incubation varies with species
 Female birds lay 2-8 eggs at a time (called a clutch)
Adaptations for Flight
- Flight requires a light, strong skeleton, wings, and
feathers
- Also requires keen senses and energy
Feathers
 Two types of feathers- contour and down
 Contour feathers
o Strong and lightweight
o Give coloring and smooth, sleek shape
o Used to fly
o Help bird to steer and keep from tipping over
 Downy feathers
o Insulating layer
o Help maintain constant body temperature
 Feathers grow from follicle
 Pushed out when it needs to be replaced
 Feather has a shaft and many branches called barbs
 Preening – bird rubs oil from gland at base of its tale
to make it water repellent
Hollow Bones
 Many bones are fused for extra strength and stability
 Bones are hollow with cross braces of bone and
hollow spaces filled with air
 Breastbone supports large chest muscles
 Last spine bones support tail feathers
Wings
 Attached to chest muscles
 Move back and forth and up and down
 Provide upward force called lift
 Larger wings provide greater lift
Getting Energy for Flight
 Obtain energy to fly from food they eat
 Birds eat large amounts of food
 Birds can digest food in an hour
 Food passes from mouth to crop (where it is
moistened and stored)
 Food passes from crop to first part of stomach
(digested partially)
 Food moves into gizzard where small stones grind
the food
 Food moves from gizzard to small intestine
(digestion completed)
 Nutrients are absorbed by the bloodstream
Maintaining Body Temperature
 Body heat generated from energy in food
 Efficient respiratory system – two lungs with balloon
like air sacs at each end
 Air sacs also make birds lighter
 Birds have a heart with four chambers
 Blood with oxygen kept separate from blood without
oxygen
 Birds hearts beat more than 1000 times a minute to
supply oxygen to cells
Kinds of Birds
- Class Aves contains almost 9000 species of birds
- Classified into orders based on beaks, feet, feathers,
and other physical features
Origins of Birds
- Few fossils of birds to study
- Scientists think birds developed from reptiles
- Birds still have reptile-like scales on their feet and legs
- Oldest bird fossil, Archaeopteryx (150 million years old)
o Had feathers and wings
o Had solid bones, teeth, tail and clawed front
toes
- Fossil of Protoavis had two characteristics of birds:
hollow bones and well-developed breastbone (225
million years old)
- Scientists are not sure Protoavis is an ancestor of birds
Section 16.2: Mammals (p.435-445)
Characteristics of Mammals
- Mammals live almost everywhere
- Endothermic
- Vertebrates
- Hair
- Produce milk to feed their young
Skin and Glands
 Skin covers and protects bodies of mammals
 Hair, horns, claws, nails, and hooves are produced by
the skin
 Mammary glands – produce milk
 Oil glands – produce oil to lubricate and condition
the hair and skin
 Sweat glands – help mammals stay cool
 Sweat glands – used to mark territory, attract mates
and for defense
Hair
 Nearly all mammals have hair on their bodies at
some point in their lives
 Thick fur – helps to trap air and keep mammals
warm
 Some have little hair and rely on a layer of fat under
the skin for warmth
 Quills and spines are modified hairs used for
protection
 Whiskers (sensory hairs) help them keep in touch
with the environment
Teeth
 Mammals have specialized teeth
 Incisors (front teeth) bite and cut
 Pointed canine teeth grip and tear
 Premolars and molars shred, crush and grind
 Herbivores – plant eaters
 Carnivores – flesh-eaters
 Omnivores – eat both plants and animals
Body Systems
 4 chambered heart and blood vessels which blood
coming from lungs to be pumped to the body
 Lungs with millions of microscopic sacs allow for
exchange of carbon dioxide and oxygen
 Nervous system made up of a brain, spinal cord, and
nerves
 Mammals have larger brains than other animals of
the same size
 Digestive system of mammals vary according to the
kind of food eaten
o Carnivores have shorter digestive systems
compared to herbivores
o Meat is more easily digested than plant material
Reproduction
 Sexual reproduction
 Most mammals give birth to live young
 Mammal parents protect their young
 Some mammals are nearly helpless when born
 Other mammals are well developed at birth
 Among most mammals, the mother raises the young
and the father provides shelter, food and protection
Classification of Mammals
- Classified into three groups based on how young
develop
Monotremes
 Mammals that lay eggs with tough, leathery shells
 Female incubates the eggs
 Young nurse by licking milk from the skin and hair
surrounding the female’s mammary glands
 Duckbilled platypus
Marsupials
 Pouched mammals that give birth to tiny, immature
offspring
 Kangaroos born few days after fertilization (size of
honeybee)
 After birth the young crawl into the pouch and
attach to a nipple
 Kangaroos, opossums, koalas, Tasmanian devils, and
wallabies are all marsupials
Placental Mammals
 Embryo develops inside the female uterus
 Gestation period – time during which embryo
develops
 Named for the placenta which is attached to the
uterus
 Placenta absorbs oxygen and food from the mother’s
blood
 Umbilical cord attaches the embryo to the placenta
 Umbilical cord transports food and oxygen from the
placenta to the embryo and takes wastes away from
the embryo
 Mother and baby’s blood never mixes
Diversity of Mammals
- Monotremes make up one order of mammals
- Marsupials are divided into about 7 orders
Origin of Mammals
- More than 4000 species of mammals evolved from tiny,
shrew like creatures (200 million years ago)
- Mammals are important for maintaining balance in the
environment
Chapter 16
Birds and Mammals
Section 16.1: Birds (p.426-434)
Characteristics of Birds
- Vertebrates
- Endotherms- 40 degrees Celsius
- Feathers and
- All birds lay eggs and incubate them
- Beaks
Bird Eggs
 Reproduce by laying
 Internal
 Egg shells made of
 Stay with their eggs to
 Incubation varies with
 Female birds lay
Adaptations for Flight
- Flight requires a
- Also requires keen
Feathers
 Two types of feathers Contour feathers
o Strong and lightweight
o Give coloring and
o Used to
o Help bird to
 Downy feathers
o Insulating
o Help maintain constant
 Feathers grow from
 Pushed out when it needs to be
 Feather has a shaft and many
 Preening – bird rubs oil from gland at base of its
Hollow Bones
 Many bones are fused for extra
 Bones are hollow with
 Breastbone supports large
 Last spine bones support
Wings
 Attached to chest
 Move back and forth and
 Provide upward force called
 Larger wings provide
Getting Energy for Flight
 Obtain energy to fly from
 Birds eat large amounts of food
 Birds can digest food
 Food passes from mouth to crop
 Food passes from crop to first part of stomach
 Food moves into gizzard where
 Food moves from gizzard to small intestine
 Nutrients are absorbed by the
Maintaining Body Temperature
 Body heat generated from
 Efficient respiratory system – two lungs with balloon
 Air sacs also make birds
 Birds have a heart with
 Blood with oxygen kept separate from blood without
oxygen
 Birds hearts beat more than
Kinds of Birds
- Class Aves contains almost
- Classified into orders based on
species of birds
Origins of Birds
- Few fossils of birds to
- Scientists think birds developed from
- Birds still have reptile-like scales on their
- Oldest bird fossil,
(150 million years old)
o Had feathers and
o Had solid
- Fossil of Protoavis had two characteristics of birds:
(225 million years old)
- Scientists are not sure Protoavis is an
Section 16.2: Mammals (p.435-445)
Characteristics of Mammals
- Mammals live almost
-
- Vertebrates
- Produce milk to
Skin and Glands
 Skin
bodies of mammals
 Hair, horns, claws, nails, and hooves are
 Mammary glands – produce
 Oil glands – produce
 Sweat glands – help mammals
 Sweat glands – used to
Hair
 Nearly all mammals have hair on their bodies at
some point in their lives
 Thick fur – helps to trap
 Some have little hair and rely on a layer of
 Quills and spines are
 Whiskers (sensory hairs) help them keep in
Teeth
 Mammals have specialized teeth
 Incisors (front teeth)
 Pointed canine teeth
 Premolars and molars
 Herbivores –
 Carnivores –
 Omnivores – eat both
Body Systems
 4 chambered heart and blood vessels which blood
coming from lungs to be pumped to the body
 Lungs with millions of microscopic sacs allow for
exchange of
 Nervous system made up of a
 Mammals have larger brains than other animals of
 Digestive system of mammals vary according to the
kind of food eaten
o Carnivores have shorter digestive systems
compared to
o Meat is more
Reproduction






Sexual reproduction
Most mammals give birth to
Mammal parents
Some mammals are nearly
Other mammals are
Among most mammals, the mother
and the father provides
Classification of Mammals
- Classified into three groups based on how young
develop
Monotremes
 Mammals that lay eggs with
 Female
the eggs
 Young nurse by licking milk from the skin and hair
surrounding the female’s mammary glands

Marsupials
 Pouched mammals that give birth to
 Kangaroos born few days after fertilization
 After birth the young crawl into
 Kangaroos, opossums, koalas, Tasmanian devils, and
wallabies are all marsupials
Placental Mammals
 Embryo develops inside the
 Gestation period – time during
 Named for the placenta which is
 Placenta absorbs oxygen and food from the
 Umbilical cord attaches the embryo to the
 Umbilical cord transports
the placenta to the embryo and
from the embryo
 Mother and baby’s blood
from
Diversity of Mammals
- Monotremes make up
of mammals
- Marsupials are divided into about
Origin of Mammals
- More than
species of mammals evolved from
tiny,
(200 million years ago)
- Mammals are important for