Final Exam Study Deck

Question 1

Identify the 5 key components of conservation of raptors

Answer 1

Protecting Habitat: Keeping the places where raptors live safe and healthy.

Stopping Harm: Preventing actions like hunting and poisoning that hurt raptors.

Cleaning Up Pollution: Keeping the environment free from harmful chemicals that can hurt raptors.

Learning and Watching: Studying raptors to understand them better and keeping an eye on their numbers.

Teaching and Sharing: Helping people understand why raptors are important and what they can do to help protect them.

Question 2

Identify current ongoing threats to raptors, and challenges in addressing them

Answer 2

Habitat Loss and Degradation: Continued urbanization, deforestation, and conversion of natural habitats for agriculture and infrastructure projects threaten the habitats of raptors.

Human-Wildlife Conflict: Raptors may face persecution due to conflicts with humans over livestock predation or perceived threats to human activities like fishing or game hunting.

Electrocution and Collision: Raptors are vulnerable to electrocution on power lines and collision with structures like wind turbines and communication towers, leading to injuries and fatalities.

Poisoning: Raptors are often unintentionally poisoned by ingesting pesticides, rodenticides, and other toxic substances used in agriculture and pest control.

Illegal Wildlife Trade: Some raptor species are targeted for illegal trade, either as pets or for their body parts used in traditional medicine or cultural practices.

Question 3

What is an extinction vortex, and why do conservation biologists want to maintain populations in a way that prevents them from falling below minimum population size?

Answer 3

An extinction vortex is a process where small populations become increasingly vulnerable to a range of factors that can drive them towards extinction.

Genetic Diversity: Larger populations maintain higher genetic diversity, which is essential for adaptability and long-term survival.
Reduced Inbreeding: Higher population sizes reduce the risk of inbreeding, which can lead to genetic defects and lower overall fitness.
Resilience to Threats: Larger populations are more resilient to environmental changes, diseases, and other stochastic events.
Stability: Populations above the minimum size threshold are more stable and less likely to fall into the extinction vortex.
Long-Term Survival: Ensuring populations remain above the minimum viable size helps secure their long-term survival and ecological roles.

Question 4

Why does a certain japanese bullet train resemble a kingfisher?

Answer 4

Long, slender beak is aerodynamically shaped and reduces drag

Question 5

Describe several adaptations for living in/on rivers (diving and swimming), using specific bird examples

Answer 5

Swimming:
Webbed feet
Feathers repel water + reduce drag
Air sacs + lightweight bones for buoyancy
Use wings, feet for propulsion
Thick, insulating feathers, higher BMR, layer of subcutaneous fat to keep warm
Waterproof feathers
Diving:
Dense bones
Streamlined bodies
Short, muscular wings
Can hold breath by slowing heart rate + redirecting flow of blood to essential organs
Some: feathers not waterproof

Question 6

Compare precocial vs altricial young, and costs/benefits of each type of development

Answer 6

Precocial: eyes open, down covered, leaves nest within 2 days
Semi-precocial: eyes open, down feathers, capable of leaving but stay at nest to be fed
Semi-altricial: eyes open or closed, covered in down, incapable of leaving nest, fed by parents
Altricial: eyes closed, no down, fed by parents

Question 7

What is nest site tenacity?

Answer 7

The tendency to return each season to the same nest site or breeding colony

Question 8

Asynchronous Hatching

Answer 8

eggs within a single clutch hatch at different times, often spread over several days. By staggering the hatching, parents can allocate their limited resources more effectively, ensuring that at least some offspring survive even if food availability is low.

Question 9

Synchronous Hatching

Answer 9

In synchronous hatching, all eggs in a clutch hatch at approximately the same time or within a very short period. By hatching together, the chicks can benefit from collective warmth, protection, and parental care, which enhances their chances of survival.

Question 10

How do baby chicks get out of the egg?

Answer 10

They have an egg tooth

Question 11

How do ducks regulate the temperature of developing eggs?

Answer 11

Nest insulation using feathers

Question 12

What are some options for the host who has been parasitized?

Answer 12

She can desert the clutch and start over, to avoid spending her efforts on a mix of her own and “adopted” offspring, but then she wastes the resources tied up in her own eggs.
OR
She can identify the parasitic eggs and discard them. Or if she senses from the presence of more eggs in the nest than she laid that she has been parasitized, but cannot discriminate against the other female’s eggs, she can adjust the number of eggs she lays subsequently so as to maximize survival of her own offspring.

Question 13

Why is brood parasitism common in ducks?

Answer 13

One hypothesis is that many ducks, especially cavity nesters, face a shortage of suitable nest sites. This could drive several females to lay in the same nest.

Question 14

How does this behavior affect the parasite and how does it affect the host (costs/benefits)?

Answer 14

A female duck that is parasitized by another of the same species may have her own reproductive output reduced in several ways.

Both hatching success (whether or not an egg hatches) of her own eggs and survival of her hatchlings can be reduced

Also, larger broods tend to attract more predators.
The female faces the costs of reproduction for relatively little benefit, if a substantial portion of the clutch is not her own.

Question 15

Compare intraspecific and interspecific brood parasitism

Answer 15

interspecific brood parasitism is a different species
Intraspecific is the same species

Question 16

What are brood parasites?

Answer 16

Birds avoiding the cost of raising their young by laying in other birds’ nests

Question 17

Compare courtship strategies in shovelers and pintails, and explain how the environments of each species likely influenced the different strategies

Answer 17

Northern shovelers specialize in sieving plankton from small, permanent ponds. Males defend a small territory around their mates, forming strong, long-lasting bonds and rarely engaging with other females.

In contrast, pintails forage in temporary water bodies and nest in sparse cover away from water. Male pintails spend less time with their mates and often try to copulate with other females, leading to frequent harassment of female pintails by other males.

Question 18

Why is it adaptive for a species to have a specific courtship display?

Answer 18

The great complexity of duck courtship displays probably has evolved because ducks tend to concentrate in small areas to breed, and closely related species often give their displays in plain view of each other.

Question 19

Describe some typical components (specific behaviors) of courtship displays in ducks

Answer 19

You can see males, in the presence of females, shaking their heads (head-shake display) and tails (tail-shake), often doing the former with their breasts held clear of the water and their necks outstretched. They also raise their wingtips, heads and tails briefly and then swim with their necks outstretched and held close to the water (head-up-tail-up).
Female Mallards and other female ducks often demonstrate (inciting displays) and call to provoke males to attack other males or females. These displays may allow the female to observe the performance of males and to evaluate them as potential mates.

Question 20

Explain the concept of “descent with modification” and how this theory accounts for the origin of species, including birds.

Answer 20

The view that all organisms are related through descent from an ancestor that lived in the remote past

A process called speciation, occurs when a population changes so much, that it is no longer the same species. This change occurs via a mechanism called natural selection.

Question 21

What group of animals are the closest relatives to birds?

Answer 21

Theropods. A subgroup of saurischian dinosaurs, which include famous species like Tyrannosaurus rex and Velociraptor.

Question 22

What are adaptations, and how are they relevant to natural selection?

Answer 22

Adaptations are characteristics or traits that have evolved in organisms over time to help them survive and reproduce in their specific environments.
Adaptations are relevant to natural selection because they are the result of this process.

Question 23

Identify the 4 conditions that must be met in order for natural selection to occur.

Answer 23

Variation: Individuals in a population have differences in traits like physical characteristics, behaviors, or physiological features.
Example: In Galápagos finches, beak sizes and shapes vary; some have long, narrow beaks, while others have short, stout beaks.

Inheritance: These variations are passed down from parents to offspring through genes.
Example: Finch beak shapes are inherited, so offspring tend to have similar beak shapes as their parents.

Differential Survival and Reproduction: Individuals with certain traits survive and reproduce more successfully because those traits are better suited to the environment.
Example: During droughts, finches with beaks better suited for eating the available food are more likely to survive and reproduce.

Time: Natural selection takes place over many generations, leading to the accumulation and prevalence of advantageous traits.
Example: Over generations, finches with advantageous beak shapes become more common, demonstrating natural selection.

Question 24

What is artificial selection? Give an example in birds

Answer 24

Artificial selection is when humans breed plants or animals for specific traits.
Example: Charles Darwin studied pigeon breeding, where breeders choose pigeons with desired traits like fancy plumage or unique colors and shapes. They breed these pigeons to enhance these traits in future generations, resulting in various pigeon breeds with distinct features compared to wild pigeons.

Question 25

Explain sexual selection and how this accounts for seemingly maladaptive features in birds

Answer 25

Sexual selection is a type of natural selection where certain traits increase an individual’s chances of attracting mates and reproducing, even if these traits might be disadvantageous in other contexts.
Example: In birds, sexual selection can explain the presence of extravagant traits like bright plumage, elaborate courtship displays, or large tail feathers.

Question 26

What are 3 hypotheses to explain sexual selection?

Answer 26

Fisherian Runaway Selection:
Females prefer males with certain exaggerated traits, like bright plumage. Males with these traits attract more mates and pass on both the trait and the preference for it. Over generations, this trait becomes more exaggerated.
Example: Peacocks with large, colorful tails attract more mates, leading to future generations with even larger tails.

Good Genes Hypothesis:
Females choose mates with traits that indicate good health and genetic quality. These traits suggest the male has good genes, which will benefit the offspring.
Example: A male bird’s bright plumage may show he is free from parasites and has a strong immune system.

Handicap Principle:
Certain costly traits signal a male’s superior genetic quality because only high-quality males can maintain them.
Example: A peacock’s large tail may hinder mobility and increase predation risk, but surviving with it shows high fitness.

Question 27

Distinguish between intra- and inter-sexual selection, and provide examples of how each of these pressures have promoted certain traits

Answer 27

Intrasexual selection is competition among the same sex for mates, leading to traits that help outcompete rivals.
Example: Male red-winged blackbirds fight and show off bright red patches to win territories and mates.

Intersexual selection (mate choice) is when one sex (usually females) chooses mates based on certain traits.
Example: Male birds of paradise have fancy plumage and dances to attract females, who choose mates based on these displays.

Question 28

Explain how beak variation in finches of the Galapagos helped Darwin to formulate his theory of evolution (natural selection and also speciation)

Answer 28

In the Galápagos Islands, Charles Darwin observed that finches, although similar in many ways, had different beak shapes and sizes depending on the islands they inhabited and the type of food they ate. This variation in beak shape among the finches became a key piece of evidence for Darwin’s theory of evolution by natural selection and speciation.

Question 29

What are the benefits of feeding birds?

Answer 29

Conservation and Biodiversity, education opportunities, ecological benefits, and research & citizen science

Question 30

What are some important things to know/things to do, when feeding hummingbirds and other songbirds?

Answer 30

Use the Right Feeder: Choose a hummingbird feeder that is easy to clean and has red coloring to attract hummingbirds. Avoid feeders with yellow coloring, as they may attract bees and wasps.
Prepare Homemade Nectar: Make hummingbird nectar by mixing four parts water with one part white granulated sugar. Avoid using honey, artificial sweeteners, or red food coloring, as they can be harmful to hummingbirds.
Keep Feeders Clean: Clean hummingbird feeders regularly, ideally every 2-3 days, to prevent the growth of mold and bacteria. Use hot water and a bottle brush to scrub the feeder thoroughly.
Place Feeders Strategically: Hang hummingbird feeders in a shaded area to prevent the nectar from spoiling too quickly. Make sure they are positioned away from windows to prevent collisions with glass.
Offer a Variety of Foods: Provide a diverse range of bird foods, including seeds, suet, mealworms, and fruits. Different species of songbirds have different dietary preferences, so offering a variety of foods attracts a greater diversity of birds.
Protect Feeders from Predators: Position feeders away from areas where predators, such as cats and squirrels, can easily access them. Use baffles or squirrel-proof feeders to deter unwanted visitors.

Question 31

What (in general) have we learned about dominance hierarchies among different species, from watching birds at the feeder?

Answer 31

Establishment of Pecking Order - individuals of certain species or individuals with specific traits assert dominance over others
Species-Specific Dominance - larger and more aggressive species may dominate smaller and less aggressive species at feeders
Territorial Behavior - Some birds may defend feeders or feeding areas as territories, asserting dominance over others and excluding intruders
Resource Partitioning - different species or individuals occupy specific feeding niches to minimize competition. For example, birds may feed at different times of day or prefer different types of food to avoid direct competition.
Social Learning and Adaptation - Individuals may adjust their behavior based on the dominance status of others or the availability of food resources.

Question 32

Describe how biologists tested whether territoriality in both blue-throated hummingbirds and rufous-tailed hummingbirds (2 different studies) is influenced by the cost/benefit of the behavior

Answer 32

At the start of the experiment, a male Blue-throated Hummingbird defended 10 closely spaced sugar-water feeders from other males, Magnificent Hummingbirds, and Black-chinned Hummingbirds.

As the feeders were gradually spread out, the Blue-throated male first allowed Black-chinned Hummingbirds to feed, then Magnificent Hummingbirds, and eventually other Blue-throated males as well. When the feeders were too far apart, the male stopped defending the territory.

The male prioritized threats: first other Blue-throated males, then Magnificent Hummingbirds, and finally Black-chinned Hummingbirds. The researchers showed that changing the cost of defending territory influenced territorial behavior.

Question 33

What is optimal foraging theory?

Answer 33

It suggests that animals have evolved to maximize their net energy intake per unit of time spent foraging, leading to the development of optimal foraging strategies.

Question 34

Why don’t hummingbirds maximize their intake of nectar (sipping constantly) when they are feeding?

Answer 34

Energy Efficiency: Hovering and sipping nectar require a lot of energy. Continuous feeding would quickly deplete their energy reserves.

Digestive Capacity: Hummingbirds have small digestive systems and can’t process large amounts of nectar at once. Continuous feeding would overload their digestion.

Risk of Predation: Feeding constantly makes hummingbirds vulnerable to predators since they are less vigilant.

Resource Management: Hummingbirds need to balance feeding with other activities like mating and defending territory. Taking breaks helps them conserve energy.

Foraging Strategy: Hummingbirds visit multiple flowers instead of feeding at one flower continuously. This maximizes their efficiency and helps them find more food.

Question 35

Why do marsh wrens build padded nests?

Answer 35

Thermal Insulation, cushioning, camouflage, nest stability

Question 36

Name the components of life history traits that vary among birds

Answer 36

Lifespan, survivorship
clutch size ( how many eggs to lay)?
how long to incubate eggs?
hatch eggs all at once (synchronous) or one per day (asynchronous)?
how long young stay in the nest before fledging?
how quickly the nestlings grow, how long depending on their parents?
migrate or be a resident?

Question 37

Identify three hypotheses explaining variation in clutch size in a species

Answer 37

food abundance, climate factors, predators, disease

Question 38

Describe the evidence that clutch size influences adult survivorship, and how this potentially explains a limit to clutch size

Answer 38

Evidence suggests that clutch size in wetland birds influences adult survivorship, potentially explaining a limit to clutch size. Larger clutches require more parental effort for incubation, feeding, and protection, increasing the energy expenditure and stress on adult birds. This heightened effort can lead to reduced adult survivorship

Question 39

Is there evidence that latitude influences clutch size? What about predation risk?

Answer 39

both latitude and predation risk are important factors influencing clutch size in birds, with higher latitudes generally favoring larger clutches due to more favorable conditions during the breeding season, and higher predation risks often resulting in smaller clutches to reduce potential losses.

Question 40

Explain the value of flashy wing patches in red-winged blackbirds, and how this was tested.

Answer 40

Experiments showed that male Redwings with dyed black epaulets had trouble holding their territories compared to those with natural red epaulets. Scientists tested this by using Redwing mounts with epaulets that were blackened, half-blackened, normal, and double-sized. Males reacted more aggressively to larger epaulets, sometimes violently attacking mounts with double epaulets.

This supports the “coverable badge hypothesis,” which suggests that Redwings benefit from signaling their intentions to fight or submit by showing or hiding their epaulets. This system evolves where territory owners can evict intruders, males often trespass, fights are risky, and males can’t predict if they’ll own a territory or not. In Redwings, intruders hide their badges and leave when owners display theirs.

Question 41

Describe the mating system in red-winged blackbirds and how patchy resources make this adaptive

Answer 41

The mating system of red-winged blackbirds (Agelaius phoeniceus) is primarily polygynous, where one male mates with multiple females.
the polygynous mating system of red-winged blackbirds is adaptive in environments with patchy resources because it allows for efficient use of high-quality territories, enhances offspring survival, and maximizes reproductive success for both males and females.

Question 42

Why do ducks peek while sleeping?

Answer 42

Peeking happens more when you are a duck that is:
In a small flock
Closer to a perceived threat/ in a less protected position in the flock
Male, especially mated males
There are more females in the flock to keep an eye on
More brightly colored

Question 43

Compare the feeding strategies “dabbling” and “diving” in open water. Why are divers restricted to larger lakes?

Answer 43

Diving ducks, or “divers,” are ducks that propel themselves underwater with large feet attached to short legs situated far back on the body.
“Dabblers,” in contrast, have smaller feet and their legs are situated farther forward. While a few dabblers may occasionally dive to feed or to escape predators, typically they skim food from the surface or feed in the shallows by tipping forward to submerge their heads and necks.

Question 44

Give a brief history of duck conservation in the US and political strategies to promote it (such as duck stamps)

Answer 44

In the 1930s, habitat loss and hunting brought waterfowl to the brink of extinction, with populations at historic lows. The Great Depression and world wars led to uncontrolled hunting for food and sport, and wetlands were drained to grow food for a booming population. This, along with commercial hunting, drastically reduced waterfowl numbers. Concern grew after extinctions like the bison and passenger pigeon.

In 1918, the Migratory Bird Treaty Act with Canada marked the first major conservation effort, later joined by Russia, Japan, and Mexico. However, without enforcement funding or wetlands conservation support, its impact was limited.