Lecture Exam 4 Flashcards
What are the characteristics of birds?
- Endothermic reptiles w/scales on legs
- All lay eggs, no live birth
- Two legs
- Feathers
- Keratinized beak
- One-way respiration w/air-sacs
What features are unique to birds?
idk
How do birds breathe?
One-way respiration w/air-sacs. Take two breaths for air to move all the way through the respiratory system
What are the different parts to feathers?
- Rachis – the central shaft of the feather
- Quill – the anchor point of the feather
- Vane – major portion of the feather
- Barbs – part of the vane that comes off the rachis
- Barbules – split perpendicularly from the barb
- Hooks and catches – on nearby barbules hold the barbs together
What are feathers made of?
- Keratin (90%)
- Water (8%)
- Lipids (1%)
- Other proteins and pigments (1%)
What are the purposes of feathers?
- First evolved for insulation
- Flying
- Camouflage
- Communication
- Waterproofing
What are pterylae and apteria?
Pterylae - Regions of body w/feathers
Apteria - Regions of body w/o feathers
What are the different types of contour feathers?
- Flight feathers
2. Covert Feathers
What is the function of down feathers?
Insulation
What is the function of Semiplumes?
Insulation for adult birds
What is the function of Filoplumes?
Detect air displacement while flying
What is the function of Bristles?
Protective/sensory hairs on face
What is a biochrome pigment?
Natural compounds that absorbed certain wavelengths of light
What are the different types of pigments seen among birds?
- Carotenoids - Yellow, red, and orange
- Porphyrins - Bright brown and magenta
- Melanins - Eumelanins - Greys and blacks
- Pheomelanins - Brown and tans
How do birds get their red/orange/yellow pigments?
Carotenoids
What are structural colors?
Air pockets w/in the feather vanes creates iridescence. Air pockets amplify certain wavelengths of light and mute others (create a prism!)
How do birds make iridescent green feathers?
“green” feathers are made from structural blue over yellow carotenoid pigments
Why do bird feathers reflect UV light?
Sexes that look similar to us, look different to each other under UV light. It helps birds differentiate.
What is the function of the keeled sternum?
increased muscle attachment
What is the function of the pygostyle?
Fused tailbone for tail feather attachment
What are the four forces involved in flight?
- Lift
- Weight
- Thrust
- Drag
What muscle is responsible for the powerful downstroke of bird flight?
Pectoralis Major
What muscle brings the wings back up? Where is it located?
Supracoracoideus, the chest
What is the angle of attack, and how does it help with flying?
The orientation of the wing in a current of air.
Increased angle=greater lift
How do birds land?
- Adjust their AoA
- Spread their tailfeathers
- Rotate their legs outward - Must be done close to the ground or the bird will stall-out too soon and fall
How do the feet of birds vary depending on their environment and/or mode of locomotion?
- Walking - Standard 4-toed foot
- Running - Fewer toes
- Swimming - Webbed feet or toes
- Wading - Very long and skinny toes to displace body weight in water
- Climbing - 2 toes in front, 2 toes in back
- Grasping - Large talons w/claws to grab and shred prey
- Perching - Small toes stay clenched shut, 3 in front, 1 in back
How do the beaks (and tongues) vary between the different diets of birds?
- Generalists - Have beaks that can seize both animal and plant foods (American Robin)
- Fish-eating - Have long beaks w/hook at tip (Cormorant)
- Large-seed eaters - Large, stout beaks (Cardinals)
- Probers - Gather aquatic inverts w/long pointed beaks (Sandpipers)
- Filter-feeders - Eat small aquatic organisms w/sieve-like structures around beak (Flamingo)
- Dip-netting - Lower jaw used to scoop water and prey (Pelican)
- Raptorial - Large, hooked beak to tear flesh (Hawks)
- Scavenging - Large, hooked beak w/large nostrils (turkey vulture)
- Chiseling - Sturdy pointed beak used to pierce wood (woodpeckers)
- Fruit-eating - Large bills used to gather and handle fruit (toucans)
What is the purpose of the crop, proventriculus, gizzard, and cecum of birds?
- Crop - Enlarged region of the esophagus for food storage and transportation to babies
- Proventriculus - Secretes digestive enzymes
- Gizzard - Hard and muscular, squeezes and grinds food w/small rocks
What traits do birds have to help with vision?
- Large eyes
- Optic lobes
- Cerebellum
How many cone cells do birds have? How many do mammals have?
Birds - 4
Mammals - 3
How does visual acuity and flicker-fusion frequency differ between birds and humans?
- Visual acuity (sharpness) varies
o Wedge-tailed eagles see 2.5x better than humans
o Falcons are on par w/humans
o Pigeons may be inferior - Flicker-fusion frequency of humans is 60Hz, but it is up to 145Hz in birds, allowing them to “see faster”
How does the cochlea of bird differ from that of mammals?
Cochlea (inner ear organ) are about 10% the size of mammals
How does the asymmetrical skull of owls help them to catch prey in complete darkness?
Many have asymmetrical skulls for directionality
How do birds use olfaction in nature?
- Homing pigeons depend on olfaction when returning to their roosts
- Many seabirds are consuming floating plastics in the ocean. Plastic is covered in bacteria that release dimethyl sulfide, which smells like krill
- Vultures smell carcasses at great distances. Olfactory bulbs are 25% of brain
- Kiwis use nostrils at the tip of their beak. Stick beak in dirt to sniff-out earthworms
Why do birds make vocalizations?
- Sounds connect individuals over long distances and thru vegetation
- Some species can identify individuals by their sounds
- Demonstrate territoriality
- Mate attraction and courtship
What are non-vocal sounds?
- Stomping
- Flapping
- Tail slapping
- Woodpecker drumming
What is the syrinx?
Where bottom of trachea meets the two bronchi, used to vocalize instead of vocal chords.
How do the trachea and larynx help with vocalization?
- Mammals have vocal cords in larynx
2. Trachea length also affects the sounds produced
How do birds control their syrinx and the tones of their songs?
Muscles contract the sides of syrinx as air passes through it. Birds control sound by flaring and closing their throat and beak
What is the difference between calls and songs?
- Calls are simple and brief
2. Songs are long and complex
Which birds inherit their songs?
o Chickens, doves, flycatchers
How do birds learn songs?
- Sensory learning phase
- Listen to songs of dad and nearby males
- Auditory feedback
- Sensorimotor phase
- Produce own song practicing until it’s right
- Like a baby babbling
- Song eventually becomes crystallized
What are dialects?
Regional differences in songs
What are open-ended learners?
Continue to learn songs throughout life
Describe reproduction in birds.
idk
Which sex is heterogametic in birds?
Females
What is the significance of calcium in the shells of bird eggs?
- Forms the skeleton and powers muscles
2. Shell thins throughout gestation - Easier for baby to break-through
Describe the coevolutionary arms race seen between brood parasites and their hosts.
idk
What are sexual selection and runaway selection?
Sexual Selection: Freq of fancy plumage, intricate songs, displays, etc. change w/reproductive success
Runaway Selection: Traits get more extreme over time - tails of the peacock
Describe some of the courtship displays seen among birds.
- Fancy plumage
- Intricate songs
- Displays/dances
What is monogamy?
One opposite sex partner
What is the difference between social monogamy and genetic monogamy?
- Genetically monogamous - Males and females care for eggs/babies and are faithful to each other. Both are genetic parents of all offspring
- Socially monogamous - Male and female both care for eggs/babies but they are not faithful and eggs are not all one father’s
What are extra-pair copulations?
bird affairs, basically
Why is monogamy more common in birds than mammals?
In birds, both sexes have equal abilities to care for young. Males can incubate eggs and feed young. In mammals, only females can gestate embryos and feed newborns
What is polygyny?
Polygyny - One male mates w/multiple females
Describe the leks of sage grouse.
Males gather in a location (arena) and females assess them. Nature’s singles bar! Arenas lack resources and no pair bonds are formed. Males mate w/as many females as possible. Females only want sperm!
Causes differences in reproductive success in males. Few males usually get most of the females. “studs and duds”
What is polyandry?
One female mates w/multiple males
Describe how female spotted sandpipers mate with more than one male.
- Female mates w/male in territory, lays eggs, and leaves males to tend the nest
- She mates w/a new male in her territory
- If male loses eggs to predators, female gives him more
What is polygamy?
Males and females both have multiple partners
What type of birds have a polygamous mating system?
Common in ostrich and rheas
What roles do the males and females play in a polygamous system?
- Females lay eggs in communal nests (10-60 eggs). Incubate eggs during the day
- Males incubate eggs at night. Defend babies during the day
Why do species migrate from one area to another?
What are the different ways animals migrate?
- Magnetic compass
2. Stars?
How do birds migrate at night?
What are the different nesting behaviors in birds?
- Tree Nesters
- Ground Nesters
- Brood/nest parasites
How do nesting strategies relate to precocial and altricial species?
Altricial (underdeveloped) - Tree Nesters
Precocial (highly developed) - Ground Nesters
How have house cats impacted songbird populations?
fucking decimated them
How have birds been impacted by invasive species?
Caused the extinction of the dodo
Which birds have been hunted to extinction?
Passenger Pigeon and Moa
What is urbanization, and how has it impacted bird populations?
Increasing movement of humans to cities, badly
Which type of birds are better-off with urbanization?
- Robins
- Rock pigeons
- House sparrows
- European starlings
How do noise pollution, electromagnetic radiation, artificial lights, and polarized light impact bird populations?
- Noise pollution - Common in cities, Disrupts ability to hear songs and calls
- Electromagnetic radiation - Impacts the magnetic compass of birds, inhibits navigation and migration
- Artificial lights - Impact nocturnal navigation
- Polarized light - Reflects off artificial surfaces, some birds dive into parking lots thinking it’s water
How are some solar farms impacting birds during migration?
create air pockets so hot they cause birds to overheat
How many species of mammal are there?
Only ~6400 species, but very diverse
What are the characteristics of (most) mammals?
- Endothermic
- Four-chambered hearts
- Red blood cells that lack nuclei
- Limbs more underneath body
- Muscular diaphragm - Assists breathing while moving
- Single jawbone and three middle ear bones
- External ears (pinna)
- Advanced facial nerve for control of face - Feeding and socializing
- Most have hair and specialized teeth
- Most have live birth (monotremes lay eggs)
- Sebaceous glands lubricate and waterproof fur and skin
- All have mammary glands!
What is the one unifying trait found in all mammals and no other group of animals?
Mammary glands
How do the jaws and middle-ear bones differ between mammals and their reptilian ancestors?
Middle-ear bones were once jaw bones in reptilian ancestors
What type of habitats do mammals occupy?
- Terrestrial - land
- Fossorial - underground
- Arboreal - trees
- Aerial - air
- Semi-aquatic - land/some time in water
- Aquatic - water
What are some characteristics found in mammals of each type?
- Terrestrial - Feet modified for walking or running
- Fossorial - Often have reduced eyes and ears
- Arboreal - Binocular vision, Prehensile tails, grabbing hands, etc.
- Aerial - Have skin membranes (patagium/patagia) or wings
- Semi-aquatic - Feet often webbed or modified into flippers
- Aquatic - Limbs modified into fins, little to no hair on body
What are the major parts of hair?
- Cuticle
- Medulla
- Cortex
Where are the pigments found?
Cortex
What pigments are found in mammals, and what colors do they produce?
- Pheomelanin - Reds and yellow (red fox)
2. Eumelanin - Black and brown (racoon)
What are vibrissae?
Long stiff hair w/extensive enervation at the base (whiskers)
What is pelage? What functions does it serves?
Pelage/fur
- Insulation, waterproofing, protection
- Spines in porcupines, hedgehogs, tenrecs = modified fur
How does the limb structure of mammals vary by their mode of locomotion?
- Plantigrade - Walking on soles of feet
- Digitigrade - Running on toes
- Unguligrade - Walking or running on hooves
What changes are seen among the different types of limb structure/foot orientation?
What type of mammals have each kind of limb structure?
- Plantigrade - Humans, raccoons, bears
- Digitigrade - Cheetahs, coyotes, etc.
- Unguligrade - Horses, deer, cows
What are the sagittal crest, turbinal bones, and auditory bullae? What are the functions of these structures?
- Sagittal crest - Keeled part of skull for muscle attachment. Large sagittal crest > stronger bite force
- Turbinal bones - Elaborate bones of the nasal cavity. Increases surface area inside nose for olfaction
- Auditory bullae - Encase the inner and middle-ear bones. Large auditory bullae indicates better hearing
What type of foods do mammals with homodont dentition usually eat?
Fish
What is the significance of heterodont dentition?
Differently shaped teeth
What are the different types of teeth seen in a mammal with heterodont dentition?
- Incisors – front teeth (gnawing and nipping)
- Canines – prominent teeth after incisors
- Premolars – after canines (cutting food)
- Molars – rear-most teeth (crushing food)
What is the function of each type of tooth?
- Incisors – gnawing and nipping
- Canines – Piercing.
- Premolars – cutting food
- Molars – crushing food
What are ever-growing teeth? Which mammals have them?
Never stop growing. Rodents and rabbits
Which mammals lack teeth? What do they eat?
Anteaters and Pangolins. Long-tongued Insectivores
What type of tooth cusps are seen among the different types of mammal diets?
- Insectivorous diet - V-shaped or w-shaped ridges
- Omnivorous diet - Blunt rounded teeth
- Carnivorous diet - Sharp, scissor like teeth, specifically a carnassial pair
- Herbivorous diet - Parallel ridges
- Baleen - Plates of keratin that sieve fish and krill from water
What is baleen, what has it, and how does it allow these animals to obtain their food?
Plates of keratin that sieve fish and krill from water. Whales
What are the major groups of mammals?
- Monotremes
- Marsupials
- Eutherians
What are horns, pronghorns, antlers, and ossicones?
even-toed ungulate decoration
What is the most trafficked animal in the world? Why?
Pangolin for Eastern “Medicine”
What is a baculum?
Penis Bone
Why are relatively few mammals monogamous?
- Females can only be pregnant once at a time
- Males can impregnate numerous females at once
- Males can’t gestate or breastfeed, so don’t hang around
What is placenta?
temporary fetal organ. It plays critical roles in facilitating nutrient, gas and waste exchange between maternal and fetal circulations, and is an important endocrine organ producing hormones that regulate both maternal and fetal physiology during pregnancy
What are the basic steps to reproduction?
- Copulation
- Fertilization
- Implantation
- Gestation
- Parturition
- Lactation
How do monotremes reproduce and feed their young?
- Have cloaca; only left ovary is functional
- Eggs have leathery shells
- Have mammary glands
How do marsupials reproduce?
Weak placenta and extremely altricial (underdeveloped) young! Short time in uterus, long period of lactation in pouch
How many vaginas do marsupials have? Why?
- Sperm is released and travels up the two side vaginas. Babies birthed through central vagina
How many heads are there to the glans penis of marsupials?
2
Where does most of the fetal development occur in marsupials?
The mother’s pouch
Why are there no marsupial ungulates, bats, or whales?
They have to crawl to the pouch which is impossible with hooves, flippers, or wings
What is a “placental” mammal?
Full uterine gestation w/stronger placenta. Longer gestation, often shorter lactation
What is the difference between precocial and altricial?
- Altricial = underdeveloped
2. Precocial = pretty developed
What type of mammals are precocial, and what type are altricial?
- Altricial (underdeveloped) - predatory species (cats, dogs, bears) and species that burrow (rabbits, mice)
- Precocial (more developed) - terrestrial prey species (deer, cattle, antelope) or fully aquatic (whales and manatees) that need to run or swim immediately
Describe delayed fertilization. What type of mammals have this form of reproduction, and why?
- Copulation occurs in Sep/Oct but females don’t release eggs until months later
- Males immotile sperm stored in uterus through hibernation
- After waking from hibernation in late spring, eggs are released, and sperm become motile
- Young born in early summer when insects are available
- Only occurs in 2 families of bats (including Michigan bats!)
Describe delayed implantation. What type of mammals have this form of reproduction, and why?
- Ovulation and fertilization occur normally
- Fertilized egg does not implant in uterine wall right away
- Floats around until environment is better
- Young born when food is plentiful
- Armadillos, bears, seals, weasels
Describe delayed development. What type of mammals have this form of reproduction, and why?
- Ovulation, fertilization, and implantation occur normally, but…
- Fetal development stops early or is very slow
- Only occurs in some bats like flying foxes
Describe embryonic diapause in macropods.
Mothers can have 3 babies at once, all in different stages of development.
How can kangaroos and wallabies have three babies at different developmental stages?
- Gives vaginal birth to one joey at a time
- Mother mates again when joey is 6 months old, but!
- Suckling from baby #1 (pouch) stops the embryo (baby #2) from developing past a 100-cell stage
- 2nd baby is born immediately after 1st leaves pouch
- At this point, mother can mate again!
What hormones are involved in lactation?
- Glands enlarge due to progesterone (pregnancy hormone)
- After birth, prolactin stimulates milk let-down
- Suckling increases oxytocin, which creates a positive feedback loop for lactation
What is milk made of?
- Fat
- Proteins
- Lactose
- Vitamins
- Salts
What is colostrum?
1st milk, full of antibodies. Contains lysozymes that kill bacteria and fungi and has digestive enzymes
What are the major threats to mammals?
- Habitat loss and livestock
- Roads
- Pollution
- Acid Rain
- Nuclear Radiation
- Exploitation
How did Chernobyl impact caribou in Norway?
Cesium-137 from Chernobyl found in lichens and bioaccumulated in caribou in Norway
How are humans exploiting mammals?
- bush meat
- pet trade
- hunting and poaching
How is climate change impacting mammals?
melting ice, wildfires
What are some solutions to our conservation problem?
- regulate human population growth
- Establish/maintain wildlife reserves
- Enforce laws on trading and exporting
- Conserve umbrellas species
- Teach about benefits of animals
- Promote ecotourism
What are umbrella species?
Umbrella species are species selected for making conservation-related decisions, typically because protecting these species indirectly protects the many other species that make up the ecological community of its habitat
How can you help to reduce your impact on the planet and its wildlife?
- Lower my ecological footprint
- Reduce consumption of animal products
- Limit use of fossil fuels
- Reduce production of trash
- Limit wasted food
- Teach about awesomeness of animals