ornithology final exam (2)
Chapter 10
Do birds rely on their vision or hearing more?
Vision
Which groups of birds have the best vision?
Songbirds and raptors
Can birds see into the ultraviolet spectrum and what decisions are made based on these colors?
Yes, birds can see and use UV to make social and sexual selections
Describe the differences between binocular and monocular vision.
Monocular – seeing through one eye
Binocular – seeing through both eyes
Understand where birds generally use binocular and monocular fields vision in relation to positions around their head.
Binocular–directly in front
Monocular–around the sides
Define the nictitating membrane and describe its main function.
Thin transparent eyelid used for cleaning cornea, or goggles for diving birds.
What are the three main structures of the avian ear?
External, middle, inner
What are semi-circular canals and their function?
Three tubes in the ear for balance and equilibrium
How does size of the semi-circular canals relate to flight performance/ability?
Larger canals = greater flight ability
Define mechanoreceptors and provide two examples of how birds use them.
Specialized nerve endings that respond to mechanical stimuli. Woodpeckers have them on tip of bill and use them to probe. Waterfowl have them on bill as well.
Describe a bird’s sense of taste.
Few taste buds, can only taste basics – sweet, salty, sour, bitter.
Describe a bird’s sense of smell and how it is used in everyday life.
Sense of smell is similar to mammals. Used to find food, or identify individuals.
What are the three main components of the brain?
Forebrain, midbrain, hindbrain
Forebrain
responsible for behavioral instincts, sensory integration, and learned intelligence
Midbrain
regulates vision, muscle coordination and balance, physiological controls, and
seasonal reproduction
Hindbrain
links spinal cord and nervous system to brain
Describe why synapses are created and destroyed in some bird species and provide a specific example.
Adult brains are dynamic – New synapses created in spring and destroyed in fall, such as chickadees increasing hippocampus size to remember seed caches in the spring.
Describe the two kinds of sleep exhibited by birds.
Slow Wave (SWS), one side of brain sleeps.
REM sleep, both sides sleep.
How can birds sleep during flight?
Using Unhemipsherical SWS to glide up thermals and REM on the way down
What are some benefits of cognition?
They can use TOOLS!!!!
What are some costs of cognition?
Greater investment in metabolic and cellular resources
Longer incubation periods
Chapter 11
What is the sound producing organ in birds called?
Syrinx
Describe the differences between a bird song and bird call.
Song – louder longer vocal displays from territorial or courting males
Calls – short simple vocalizations from males or females
What kinds of calls are more effective for long distance communication and why?
Low frequency calls because less subject to distortion or interference
What songs are best in open habitats and why?
Because reverberations off vegetation or habitat can distort song structure
What is a vocal repertoire and how/why can it vary among populations?
All calls and songs a bird can make. Varies because it is a partially learned social
behavior.
At some point in avian history, did birds lose the ability to make sounds?
Yes, and they evolved the syrinx to regain the ability.
What are the 4 groups of birds that are able to learn how to sing?
Oscine Songbirds, Parrots, Hummingbirds, Neotropical suboscine bellbirds
How do different bird dialects develop?
Learning the errors or innovations in vocalizations from neighbors.
How do new songs come about and become established in a population?
Young birds colonizing new areas, or imperfect learning.
Define vocal mimicry and why is it used?
Mimicking other sounds, and is used to enhance the birds repertoire
Do female birds sing? Why or why not?
Yes, including duet behaviors to communicate or strengthen pair bonds.
How do songs and song repertoires evolve?
Sexual selection.
Why did demonstrating vocal performance evolve? Is it to show genetic quality or was it strictly through female preference?
There is evidence for both.
What cues activate internal endocrine management systems?
Environmental and social cues
Chapter 12
Adult birds invest time and energy above and beyond what is required for daily survival into three main efforts. What are they?
Reproduction, Molt, Migration.
Understand the main components of a bird’s annual cycle and what time of year they take place.
Migrating North (Spring) -> Breeding (Summer) -> Migrating South (Fall) → Overwintering
What are the three main tasks of the simplest annual cycle?
Breed, Molt, Survive
Do all birds follow a 12-month annual cycle? If no, provide and describe the annual cycle of a bird whose cycle is longer or shorter than 12 months.
No, a species may breed every six months or every few years.
What do internal clocks and physiological controls regulate?
Reproduction, molt, sleep, feeding, migration
Describe the difference between endogenous rhythms and circadian rhythms. What do they control and how?
Endogenous rhythms use hormones to regulate physiological behaviors
Circadian rhythms use the 24hr clock
What is the function of the pineal gland?
Houses biological clock
What is the function of the paired nuclei on the hypothalamus?
release neurotransmitters regulating metabolic activity
Much of the annual cycle is controlled by hormones. Name the structure and the two hormones it releases.
Pituitary gland, luteinizing hormone and follicle stimulating hormone.
What is the role of the luteinizing hormone?
Testosterone production in males, progesterone and testosterone in females
What is the role of the follicle-stimulating hormone?
Sperm production in males, egg follicles in females
Define proximate factors, and list 3 examples
Immediate environmental and physiological triggers, hormonal changes, food
availability, weather
Define ultimate factors and list 3 examples
evolutionary drivers that maximize fitness, migration timing, resource competition, reducing predation
Define zugunruhe.
Migratory restlessness
Define hyperphagia.
Excessive eating in the spring
Do sex hormones directly regulate migration? If no, what is it?
No, migration is indirectly set by springtime activities.
Why are reproduction and molt scheduled at different times during the annual cycle?
Because they are both costly and need to occur when self-maintenance costs are low
What are some issues with climate change and timing of the annual cycle of birds? Provide an example discussed in lecture.
Birds arriving earlier or later to wintering or breeding grounds leading to food supply issues and shifting evolutionary trajectories with early migrants.
Chapter 13
Why do birds migrate?
To take advantage of seasonal opportunities–find food or optimal nesting and wintering sites
Define flyway.
Major migration routes, particularly North South in Americas, and East West in Eurasia.
When do birds choose to fly and why? Provide a single species example.
When travel is less costly, safest and quickest, such as the blackpoll warbler flying a quick 3 days over 3000 miles of ocean.
What is a migratory fallout?
When birds ground themselves due to exhaustion particularly in bad weather.
Why do birds store fat for migration?
Fat yields 2x the energy per gram, and flight distance depends on fat reserves
Describe the role of stopover sites during migration.
Place for birds to rest refuel and seek shelter
What are the costs and benefits for obligate migrants?
Less winter mortalities but later access to territories and food in the spring.
What are the costs and benefits for faculative migrants?
Suffer higher winter mortalities, but better access to territories and food in the spring.
What is the difference between obligate vs faculative migrants?
Obligate migrants regularly migrate each year and faculative migrants migrate in response to environmental conditions.
What do birds use to navigate during migration? We discussed 5 in lecture. Be familiar with each.
Landmarks, Sun & stars, Geomagnetism, Oders, Twilight cues
How do young birds know when / where to migrate?
Innate internal mechanisms and learning from parents.
Chapter 15
Define sexual selection.
Mating success based on competition and female preference
What drives the evolution of ornamentation in birds?
Female preference
Define sexual dimorphism.
The sexes of the same species portray two different morphologies.
List and describe the 3 main theories as to why females choose mates with elaborate plumages.
Good genes – signals physiological superiority
Direct benefits – communicates potential to provide resources
Arbitrary choice – aesthetically attractive
Define lek.
Gathering of males who defend pieces of territory to do courtship displays and compete for females
List and define the three models for the evolution of leks.
Hotspot model – most likely to encounter roaming females
Hotshot model – gather around other experienced males
Female Preference model – females visit large clusters of males
How do song repertoires enhance low-quality males?
Shows females that they are more experienced
Know the male and female reproductive and excretory systems.
Males – testes -> vas deferens
Females – eggs -> oviduct -> uterus
What are the bird sex chromosomes?
Females ZW heterogametic
Males ZZ homogametic
What are the principal sex hormones released by the gonads and what behaviors do they induce?
Follicle stimulating - gamete production
Luteinizing hormone - hormone secretion
Can birds in theory select the gender of their offspring? Why or why not and provide an example.
Yes – female body condition determines sex. Seychelles warblers favor female offspring
What is an extra-pair copulation (EPC)?
duck rape
How have female birds evolved to offset effects of EPCs?
corkscrew vagina
Know the main components of an egg and the function of each.
Albumen – main water supply
Yolk – food supply for embryo
Know the 7 breeding systems we talked about in lecture.
Monogamy
Polygamy
Polygyny
Polyandry
Polygynandry
Cooperative Breeding
Brood Parasitism
Define monogamy.
M + F
Define polygyny.
M + FF
Define polyandry.
F+ MM
What is cooperative breeding and what are the benefits?
Helpers caring for young that are not their own
What are the benefits to cooperative breeding?
Additional territory defense, enhances their own reproductive skills, reproduction of genetic relatives,
What is the difference between intra- and interspecific brood parasitism?
Intra- laying eggs in the nest of the same species
Inter- laying eggs in nest of different species
What is the difference between obligate and facultative brood parasites?
Obligate - don’t have a nest, only lay eggs in other nests
Facultative - have a nest but still lay eggs in other nests
What are some counter adaptations to brood parasitism?
Defend nest, distract parasites, sit on nest, make it difficult to find nest, remove egg or abandon nest
Describe the effects of brood parasites on host populations using an example discussed in lecture.
Reduces host fitness, cowbirds can drive a single species to extinction