Ornithology Lecture Review

Flashcards generated from lecture notes on ornithology, covering topics such as bird vocalizations, territoriality, coloniality, flocking behavior, dominance hierarchies, egg structure, clutch size, brood parasitism, cooperative breeding, survey methods, migration, and human impacts on bird populations.

Name some birds that lack a syrinx.

Vultures, Pelicans, and Mute swans

What is a song in bird terms, and what is its purpose?

Relatively long and complex displays with specific patterns, used for territory maintenance, pair bonding, and reproductive isolation.

What is a call, and what is its purpose?

Short and simple vocalizations used for purposes like enemy avoidance, fight calls, flock calls, and parent-young relations.

If you wanted to give a specific direction and distance using a mob and call, what kind of notes and frequency range would you use?

Short notes with a broad frequency range.

If you wanted to conceal your location but give information to others in the general area, what type of notes and frequency range would be used?

High-pitched, narrow frequency with a long duration.

If a bird uses a low-frequency sound, what is it likely using it for?

Long-distance communication.

How is species recognition achieved in birds?

Through the acoustical structure of their song and sometimes the syntax (repetition of syllables).

How do birds achieve individual recognition?

Specific details in pitch, phrase structure, syntax, and overall composition of calls or songs.

What is a song repertoire?

The number of different types of songs an individual bird is capable of singing.

How can having a large song repertoire increase reproductive success?

It can stimulate the female to a greater extent and help in maintaining better territories.

What is mimicry in birds, and what is its proposed function?

Imitating calls or songs of other species; function is not definitively known but may include excluding competition, aiding mob calls, or increasing song repertoire.

What are three potential types of spatial distribution during breeding season?

Random, Regular, Clumped

What is territoriality in birds?

Aggressive establishment, maintenance, and protection of spatial relationships; defending a space and maintaining proper spacing within a habitat.

What are breeding territories in birds?

Can be small areas around the nest, especially in colonial species, or large All-Purpose Territories where birds breed, roost, and feed.

What are roosting territories in birds?

Socially roosting birds defend sleeping positions, often in thick foliage for protection from weather.

What are non-breeding territories in birds?

Defense of feeding areas in winter or during the breeding season away from the nesting area.

What are the benefits of territory defense in birds?

Reduces competition for limited resources and increases reproductive success by ensuring resources for mates and offspring.

What are the costs of territory defense in birds?

Requires energy and time for fighting or threatening displays, and risks of injury or death.

If resources are predictable, what kind of nesting do you see?

Territoriality

If resources are unpredictable, what kind of nesting do you see?

Coloniality

If a territory has high food abundance, what does that do to territory size?

Tends to lead to a decrease in territory size.

What is coloniality and what causes it?

A large number of birds nesting in a small area, defending the area that surrounds the nest; caused by unpredictable food or limited nesting space.

Name one example of a bird that has a very large colony.

Guanay cormorant or the common murre.

What are some anti-predator advantages to colonies?

More eyes looking out for predators, and if you are in the center of the colony, you're better protected.

What are some feeding advantages to colonies?

Serve as information centers for observing others and following them for successful foraging, and synchronous breeding to increase food availability.

What are some risks of colonies?

Increased competition, risk of raising young other than your own, increased killing of chicks that wander from nests, and increased transmission of disease.

What are food advantages to flocking?

Find more food and catch more food.

What are the predator avoidance advantages to flocking?

Flocks confuse predators, there is safety in numbers, and increased predatory detection/decreased time watching for predators.

What are some disadvantages to flocking?

Increased competition for available food; larger flock means less food per individual.

How are dominance hierarchies established?

They fight once and are maintained by ritualistic threat displays.

What advantages do the dominant birds gain?

Access to food, nesting sites, mates, they intend to survive longer and produce more offspring

How do dominance hierarchies affect the evolution of migration systems?

Subordinates are usually the first to leave due to lack of access to food or shelter.

What are the characteristics of a winner in dominance hierarchies?

Generally males that tend to be larger in body size, have prior residency, and tend to have higher testosterone levels.

What allows multiple bird species to live in the same habitat despite competition?

Species divide the habitat through niche partitioning, avoiding direct competition.

What is the yolk and what is it made of?

Energy rich food supply for the embryo and is made up of lipids, proteins, and water

What is the albumin of an egg?

Egg white; is 90% water and 10% protein and serves as the water supply, shock absorber, insulator, and protects against bacteria

What is the blastoderm?

The thin region of cells on top of the yolk that forms the embryo and the extra embryonic membranes

What is the amnion?

Surrounds the embryo with watery environment

What is the chorion?

Outermost protective and gas-exchanging layer; closest contact to the eggshell

What is the allantois?

Outgrowth of gut that fuses with the chorion to form the gas exchange organ and waste storage

What is the yolk sac?

It's the outgrowth of the gut and it's around and digests the yolk

How does the thickness of the shell change with egg size and also through embryonic development?

Larger eggs have thicker shells; thickness decreases as the embryo uses the shell for skeletal development

What do shells have that allow gas and water exchange?

Pores

What are accessory materials and how do they interact with pores in the egg shell?

Accessory materials (iron or proteins) form a partial cap which allows the passage of only gas and prevents plugging of pores

What is clutch size?

Number of eggs laid per nest and varies greatly Gray partridge is the winner from 9 to 23 eggs

What is an altricial species?

Young hatch naked, blind, and helpless and rely on parents but have short incubation time.

What are precocial species?

Young hatch feathered and self-supporting and have longer incubation time.

What does Lack’s hypothesis suggest?

Clutch size is dependent on the maximum number of young that a parent can care for

What does the trade-off hypothesis suggest?

Birds balance current reproductive effort with future survival, aiming to maximize total lifetime reproductive success—not just yearly offspring numbers.

What does the predation hypothesis suggest?

Smaller clutches for birds that are more preyed upon

What does the seasonality hypothesis suggest?

Clutch size reflects seasonal availability of food resources relative to the population size.

What is the overall conclusion of clutch size variation?

Clutch size is probably as a result of many selective factors like parental care seasonality or predation

How can large clutch sizes have an impact on development and fitness of young?

Large clutches have increased temperature variability among the eggs this can lead to delayed of development which is often negatively correlated with fitness

What is a brood patch?

Bare, featherless area on a bird’s belly that develops during breeding and helps transfer body heat to eggs during incubation.

What is a result of incubating with the first egg?

Hatching asynchrony which then has young hatching out at different times

What happens when you incubate when clutch is complete?

Hatching synchrony when all the young had at approximately the same time allows for immediate switch from incubation to care occurs in species with predictable Food Supplies

What is the evolution steps of brood parasitism?

intraspecific- laying eggs in other members of the same species facultative parasitism - laying eggs in nest of related species with similar eggs obligate bird parasitism expands from there

What are some effects of parasitism on host species?

Rarely fletching their own young, parasite young may actually remove host eggs or kill host young, exhaustion of the host parent providing abilities

What are some parasite adaptations?

produce more eggs with short incubation time, A protruding cloaca that allows them to lay eggs in small nests, egg mimicry to look more like the host egg chick mimicry in plumage pattern or gait coloration

What are some host adaptations to parasites?

egg and chick recognition devices, Leaving nest or building new floor of nest, Toleration if parasite helps host young to survive

What is cooperative breeding in birds?

It’s when non-breeding individuals help raise the young.

What are key traits of species that show cooperative breeding?

Low breeding rates, high adult survival, low dispersal, and delayed maturity.

What is a typical cooperative breeding system?

A breeding pair plus related male helpers defending an all-purpose territory.

What do descriptive studies asks?

what type of birds occur in particular habitat and can give a crude estimate of common or rare

What do distribution studies asks?

Where do or don't birds occur and provides a general picture of habitat associations

what is population monitoring asks?

if bird densities with any particular area or give in habitat has changed over time

What does assessing habitat requirements ask?

do birds occur at higher or lower densities in different habitat types; What habitats support higher densities of a particular species

What does management experiment asks?

do alterations of the habitat impact the bird densities

what types of surveys that are large-scale methods?

low accuracy of abundance but better indications over large areas Christmas bird count breeding bird survey eBird

What are types of surveys that are small-scale methods?

Point count line transects spot mapping

What is the Christmas bird count?

Occurs 3 weeks around Christmas to measure winter populations

What are some errors with the Christmas Bird Count?

Observer coverage and expertise, double counting, and weather variations.

What is the value of the Breeding Bird Survey?

Good for broad-scale population changes and breeding bird abundance

What is the Breeding Bird Atlas good for?

Good for bird distributional data

What are Point counts good for?

Good for relative abundance of individual species And are better suited for dense habitats

What are line transects good for?

Measuring relative abundance and better suited for open habitats

What is spot mapping good for?

(Only true method of measuring density) Denser vegetation and higher density is required smaller plot sizes

What is marking methods good for?

Touring population changes within species

What is Mark recapture good for?

using the number of individuals were recaptured out of total numbers captured is index of population size

What is a neotropical migrant?

A bird that breeds in temperate or Arctic regions and then migrates to the tropics for the winter

What bird has the longest migration?

The Arctic tern

Describe scenario one for the evolution of migration.

Birds in low latitude migrated to more temperate latitudes for breeding (changed their breeding ground)

Describe scenario two for the evolution of migration.

Temperate latitude residents migrated to Tropical latitudes for winter ( changed their winter ground)

What are the reproductive success and survival rate of temperate Birds?

High reproductive but low survival

What are the reproductive success and survival rate of migrant Birds?

Mid reproductive and survival

What is/are the reproductive success and survival rate of tropical birds?

Low reproductive success but High survival rates

What is partial migration?

Some of the population may grades will some are residents

What is differential migration?

Different portions of the population migrate different distances

What is irruptive movements?

Some species migrate only in some years and migration distances vary

What is the definition of directional orientation?

Moving in the right general direction and is genetically determined.

What is the definition of navigation?

Finding their way back to a specific location and involves previous experience or learning

What is visual orientation for navigation?

Using geographic landmarks often seen in day migrants and less of importance in nocturnal migrants

What is Celestial navigation?

Nocturnal migrants use the position of the stars for orientation

What is geomagnetism?

Birds use the Earth's magnetic field for orientation

What is the ultimate approximal control for timing of migration?

ultimate is the long-term climate Trends tracked by photoperiod proximate is the immediate weather conditions like the warm temperatures in the spring are cold temperatures in the fall and good weather in the fall may inhibit migration Etc

What is migratory fattening?

Migrants develop stores of fat which is their major fuel source during migration

How can migratory speeds change during the time of year?

Spring migration rates are usually faster if not double

What are human Associated effects on bird population decreases?

we take up space and destroy available habitats excessive hunting Roadkills Collisions light and sound pollution cats

What is the leading cause of population decline?

Habitat destruction either loss and destroyed altogether or fragmentation where once connected areas are not isolated

What are some habitat conservation efforts?

preservatives like national parks or state parks

conservation Estates like private land set aside

The Endangered Species Act