Avian Demography: Population Dynamics, Life History, and Conservation

What is avian demography?

The study of characteristics of bird populations, including age composition, reproductive output, and mortality.

Why is avian demography important?

It helps model and predict population changes and factors influencing populations, such as anthropogenic and natural mortality events.

What does Life History Theory focus on?

It examines how individuals optimize reproductive success through parameters like age at first breeding, number of young fledged, sex ratio of offspring, and their own survival.

What is fecundity in the context of population demography?

Fecundity refers to the number of young fledged per year.

What is the difference between 'R-selected' and 'K-selected' species?

'R-selected' species, like ducks, produce many young with lower survival rates, while 'K-selected' species, like seabirds, have fewer young but higher survival rates.

What is a major method used for avian population surveys?

Direct counts at breeding colonies, such as photography of seabirds.

What is the purpose of capture-mark-recapture techniques?

To estimate survival rates and population dynamics by marking individuals and observing them over time.

How is mortality estimated from carcass counts?

Mortality = carcass count x (1/detection rate).

What is the detection rate in mortality studies?

The proportion of dead individuals found, best measured experimentally.

What does BACI stand for in avian population studies?

Before-After-Controlled-Impact, a study design to measure effects before and after an event.

What is the formula for modeling a stable avian population?

Births + Immigration = Deaths + Emigration.

What is the significance of 'R' in Life History Theory?

'R' represents reproductive success, often associated with species that produce many offspring.

What is 'K' in the context of avian demography?

'K' refers to the carrying capacity and survival of individuals in a population.

What is the relationship between longevity and fecundity in birds?

Long-lived species tend to have low fecundity (high K), while species with high fecundity have shorter lifespans (high R).

What is the purpose of using markers in capture-mark-recapture studies?

To identify and track individual birds over time to estimate survival and recapture rates.

What are common tools used for estimating survival rates in bird populations?

SURGE (SURvival Generalized Estimation) and MARK.

What is the role of covariates in survival estimation?

Covariates are traits measured to determine their relationship with survival rates.

What is the significance of the term 'natural history' in relation to Life History?

Natural history refers to the study of organisms in their natural environment, while Life History focuses on the schedule of activities maximizing reproductive success.

What is the method used to measure the impact of pollution on bird populations?

BACI experiments are required to assess the effects of stressors on populations.

What is the importance of measuring mortality events in avian studies?

To understand population impacts and identify causes of population changes.

What is the significance of the example of road-killed birds in mortality studies?

It illustrates how direct counts and detection rates can be used to estimate overall mortality.

What is the significance of the study of Northern Fulmar and Atlantic Puffin?

These studies provide long-term data on bird populations and their dynamics.

What does the term 'die-offs' refer to in avian demography?

Significant mortality events affecting a large number of individuals in a population.

How do researchers infer population trends from migration monitoring?

By measuring long-term changes and inferring trends based on observed data.

What is the role of productivity estimation techniques in avian studies?

To assess the reproductive success of bird populations and their chances of survival.

What is the significance of the term 'carcass count' in mortality estimation?

It refers to the number of dead birds found, which is used to estimate total mortality.

What is one of the most important demographic parameters in bird populations?

Annual adult survival

What is the survival rate range for gallinaceous birds?

0.20 - 0.50

What is the survival rate range for small tropical passerines?

0.50 - 0.90

What is the longevity record for the Laysan Albatross?

70 years

What is the typical survival rate from fledging to one year old?

Usually about half the typical adult survival rate

What is fecundity in the context of bird populations?

The number of young successfully raised per year

What factors determine fecundity in birds?

Number of breeding attempts, clutch size, and breeding success

What is the typical clutch size adjustment according to Lack's hypothesis?

Adjusted by natural selection to the maximum number of nestlings the parents can nourish

What is the trade-off hypothesis regarding clutch size?

Clutch size is adjusted to optimize reproductive success balancing current and future reproductive efforts

What is the biggest cause of nestling failure?

Nestling starvation

What is the expected sex ratio of eggs in bird nests?

50/50 male/female

What is a common reason for differing offspring and adult sex ratios in birds?

Differential mortality, where the rarer sex is more likely to die

What is the significance of senescence in birds?

Age-related deterioration affecting survival and fecundity

What is the typical age at first breeding for long-lived species like seabirds?

5-10 years

What does the term 'philopatry' refer to in bird populations?

Living in a location that has become unsuitable

How do females in bird populations adjust the sex ratio of their offspring?

Based on parental quality and environmental conditions

What is the role of food availability in breeding success?

It is a major determinant of breeding success

What is the impact of commercial fishing on the African Penguin population?

Population declined from 250,000 to over 20,000 due to chick starvation

What is the significance of measuring bird populations?

Essential for management, conservation, and understanding life history theory

What are the key parameters in bird demography?

R, K, emigration, immigration, and population size

What is the difference between R-selected and K-selected species?

R-selected species prioritize rapid reproduction, while K-selected species focus on survival and quality

What is the expected outcome of delayed breeding in birds?

It is characteristic of long-lived species

What is the relationship between age and breeding success in young birds?

Young birds have low success rates in nesting attempts

What is the effect of environmental factors on sex ratio adjustment in birds?

Females may adjust the sex ratio of their eggs based on ecological or social factors

What is the significance of parental attentiveness in hatching success?

It directly influences the hatching success of eggs

What is the role of predation in determining sex ratios in bird populations?

Females may face higher predation risks, leading to biased sex ratios

What is the evidence for senescence in bird populations?

Found in species like Common Tern, Barn Swallow, and Black-legged Kittiwake