Ornithology Final Exam

1. High frequencies propagate poorly compared to low frequencies

2. Pure tones propagate better in cluttered environments

3. Short-duration, frequency-modulated sounds are more locatable

4. Sounds with harmonics have greater complexity

What are the physical properties of sound?

Oscillogram

Displays amplitude versus time

Sonogram (Spectrogram)

Displays frequency and amplitude versus time

Calls

Short, simple, vocalizations, usually given by both sexes

Songs

Lengthy, complex, repeated vocal displays often performed by territorial males during the breeding season

Syrinx; Internal tympaniform membrane, Syringeal muscles, and Interclavicular air sac in syrinx

What is the main vocal organ in birds? Name 3 structure components

Bilateral Symmetry

This allows for the possibility of different sides producing different sounds- ‘two-voices’ e.g. the song of Wood and Hermit Thrushes

Lengthy, complex, repeated vocal displays often performed by territorial males during the breeding season for purpose of mate attraction and territorial defense

Define songs

Hermit Thrush and Northern Mockingbird

Which birds have superb songs?

Henslow’s Sparrow

Which bird has a “not so complex” song?

Alarm, contact, warning, courtship, and aggression

What are the functions of calls?

1. Alarm

2. Contact

3. Warning

4. Courtship

5. Aggressive

What type of calls exist?

Species and individual recognition, and evolution when needed.

What are some functions of vocalization?

1. Bank Swallows: complex, individually distinctive calls recognized individually by parents and offspring

2. Rough-winged Swallows: Simple calls with no vocal recognition between parents and offspring

3. Ancient Murrelet: mates never see one another in the colony; parents never see their offspring in the burrow; parents take their two-day-old chicks to sea

4. Common Murre: single chick taken to sea by a male parent (mutual recognition between male parent and chick, female- not so much)

5. Atlantic Puffin: No recognition by either parent or chick; chick is isolated in burrow and cared for there until full size

Give some examples of birds and the function of their calls.

Song learning

Vocal repertoire acquired by inheritance (i.e. genetic, innate songs) by learning, or by invention (improvisation), or by combinations of these processes

Culture (behaviour based on learned traditions)

Why does vocal imitative learning occur?

Mostly in the first year of like

When does vocal learning occur?

1. Critical learning period

2. Silent Period

3. Susbong period (babbling)

4. Song crystallization

What are the four phases of song learning?

1. Anti-habituation hypothesis

2. Different songs - different functions hypothesis

3. Beau Geste Hypothesis

4. Badge of status hypothesis

5. Location confusion hypothesis

6. Sexual selection hypothesis

7. Functionless epi-phenomenon hypothesis

What are the hypotheses to explain the evolution of song repertoires?

Anti-habituation hypothesis

States that one song is boring and listeners quickly lose interest, hence repertoires. Created by Hartshorne

Different songs - different functions hypothesis

States that different songs have different meanings or messages. Ex: one type may be used for territory defense, and another for mate attraction (Black-throated Green Warbler)

Beau Geste hypothesis

States that repertoires’ function is to confuse neighbours about how many individuals occupy an area- hearing different songs indicated the area is full (Ex: Great Tit). Named by John Krebs after the 1939 movie classic.

Badge of status hypothesis

States that a large repertoire indicates a experienced, high quality male that would be a formidable adversary (territorial defense function)

Location confusion hypothesis

States that having multiple song types is a way males prevent their neighbours from knowing their location (one song- possible to guess ranging by degradation of features). Created by Eugene Morton.

Sexual selection hypothesis

States that song functions as an ornament used for mate attraction- the more elaborate repertoire, the more attractive - leads to selection for males with the largest repertoires (possibly a health and viability indicator). Created by John Krebs.

Functionless epi-phenomenon hypothesis

States that song repertoires have no function and are simply an unselected consequence of birds having big brains, song learning ability, and spare time.

Song dialects

Learning from conspecifics lead to accents, these may be distinctive at small or continental scales

White-crowned Sparrows in California; has dozens of distinctive dialects that have been maintained for decades in the same locations

Give an example of a bird with a dialect.

1. Unselected consequence of learning (null hypothesis)

2. Social signaling hypothesis

3. Ecological hypothesis

What are the hypothesis of the origins of song dialects?

Social signaling hypothesis

States that dialects originated as an imitation of successful neighbours (Payne)

Ecological Hypothesis

States that dialects function to signal genetic adapted-ness to the local environment

Order Passeriformes

An order of birds with extreme development of vocal imitative learning

Duration of pair bond between mates and number of sexual partners in an individual’s breeding season or lifetime

What are avian mating systems defined by?

Monogamy

Each individual pairs with a single member of the opposite sex

Thick-billed Murre, Common Crow, and Barn Swallow

Give three examples of monogamous birds.

1. Parental care

2. Developmental constraints (high-maintenance of egg)

3. Female control

4. Lack of mammary glands

5. Confidence of paternity

6. Shared responsibilities

Why does monogamy dominate in birds?

Polygamy

Birds that mate with more than one partner during a single breeding season

Polygyny

One male mates with multiple females; a form of polygamy; less than 5% of bird species are this.

Polyandry

One female mates with multiple males; a form of polygamy; less than 1% of bird species are this.

Polygynandry

A rare mating system where each female pairs with several males and each male pairs with several females. Most nests fail.

Male territorial defense and leks

What are the two patterns of polygyny?

1. Red-winged Blackbirds

2. Marsh Wrens

3. Great Reed Warblers

Give some examples of territorial males that use polygyny?

Lek

A courtship arena visited by females only for sperm; contains no resources.

1. Ruff

2. Black Grouse

3. Greater Prairie Chicken

4. Sage Grouse

5. Swallow-tailed Manakin

6. Cock-of-the Rock

What are some examples of lekking species?

1. Classic (females divide time between two or more males, sequentially)

2. Cooperative (female assisted by several males simultaneously)

What are the two patterns of polyandry?

Classic Polyandry

Female divides time between two or more males, sequentially

Cooperative polyandry

Female is assisted by several males simultaneously

Females produce more clutches / eggs than can be cared for

Why does classic polyandry occur?

Females require extra helpers to provision her and the nestlings

Why does cooperative polyandry occur?

Sanderling and Red Phalarope

Give two examples of birds that partake in classic polyandry

Harris’s Hawk and Gallinules

Give two examples of birds that partake in cooperative polyandry

Smith’s Longspur

Give an example of a bird that partakes in polygynandry

Sexual Selection

The kind of selection that operates on traits solely as far as their role in determining mating success is concerned

Inter-sexual selection

Mate choice

Intra-sexual selection

Fighting ability or social status

True

True or False; Sexual selection is NOT mate choice

High variation in mate mating success; traits possessed by males with multiple female mates are favoured by sexual selection.

Ex: Long-tailed Widowbird + Red-winged Blackbird

Describe sexual selection in Polygyny and give some examples

Mutual sexual selection; variation in mating success by quality (associated with sexual monomorphism)

Ex: Loons, grebes, penguins, cormorants, tropicbirds, herons, motmots, bee-eaters, kingfishers, parrots

Describe sexual selection in Monogamy and give some examples

Variation in female mating success

Ex: Red Phalarope

Describe sexual selection in Polyandry and give some examples

Mating preferences

Why does sexual selection occur?

1. Fisherian Runaway

2. Viability indicator

3. Sensory exploitation

Why are there mating preferences? List the three theories.

Fisherian Runaway

States that sexual selection is a runaway coevolution between arbitrary preferences and arbitrary traits (Ronald Fisher, 1930)

Viability indicator

States that sexual selection is coevolution between preference and trait that signals viability (Marlene Zuk, 1980s)

Sensory exploitation

States that sexual selection is a pre-existing preference (a naturally selected sensory bias) (Alexandria Basolo, 1990s)

Nest

An insulated container for eggs during incubation (embryonic development outside parent’s body)

None

What type of nest do Plovers have?

Burrow / cavity

What type of nest do woodpeckers and puffins have?

Mud

What type of nest to Cliff Swallows have?

Plant material

What type of nest do Passeriformes have?

Floating

What type of nest do grebes have?

Communal grass

What type of nest do Sociable Weavers have?

Saliva

What type of nest do Edible-nest Swiftlets have?

Compost

What type of nests do Megapodes have?

Weaver Finch

Nest building is an innate behavior in?

Incubation

Egg warming using brood patches (lacking in brood parasitic species such as Sulidae (Boobies and Gannets)); varies from 10 to 90 days in length.

Emperor penguin

The “ultimate incubator”; males only incubate for 62-67 days during Antarctic winter, in a ‘huddle’ holding the eggs on top of their feet, before being relieved by the female

Ancient Murrelet

Eggs vary in resistance to chilling (and heating). Seabird eggs can hatch even after being left in near freezing conditions. This idea of “egg neglect” can be seen in which species of bird?

2-25%

Dodo eggs = 25%

Ancient Murrelet eggs = 2%

Eggs can account for what percent of body mass?

Colonality

Highly clumped nesting aggregations

Seabirds, sea ducks, marsh nesting birds, aerial insectivores, and seed eating birds

What types of birds form colonies?

1. Nesting habitat shortage- if suitable nesting habitat is rare, everyone will crowd into existing habitats

2. Related to food- centrally located colony minimizes travel time to feeding areas

3. Information Centre Hypothesis- based on cooperation, two-function corollary; experienced dominant members shielded from predators, subordinate, inexperienced birds get information about the location of food

4. Related to predation- vigilance, mobbing, predator swamping

Why does coloniality occur?

Information Centre Hypothesis

States that coloniality is based on cooperation, two-function corollary, in which experienced, dominant members are shielded from predators while subordinate, inexperienced birds get information about the location of food (terns, murres, and osprey). (Ward and Zahavi, 1973)

Vigilance, mobbing, and predator swamping

What are the benefits of coloniality?

Increased competition for food, increased competition for mates, increased transmission of diseases and parasites, and increased risks of misdirected parental care

What are the costs associated with coloniality

Parental care

Effort (incubation, brooding protection, provisioning, and teaching) expended by parents to raise their offspring to independence

Parental investment concept

Parental care can sometimes be referred to as this; implying current sacrifice (lower survival) for future gain (chicks surviving to breed)

Energy, time, and high mortality risk

What are the costs of incubation?

Iteroparous

an organism that reproduces multiple times during its lifetime, rather than having a single reproductive event before death

Chicks: concern in short term (survival to fledging), hence they demand maximum short-term care from their parents

Parents: concern is long term, they are concerned not only about this year’s chicks but about surviving to next year to breed again

Describe the parent-offspring conflict birds face when brooding.

Tradeoff hypothesis

Increased parental effort will increase chick survival but decrease parental survival, causing a tradeoff between short term reproductive success and future survival (long-term reproductive success)

Superprecocial

Wholly independent at hatching, no parental care (Moundbuilders, Black-headed Duck)

Precocial

Leave nest immediately and feed themselves, but parent(s) lead (shorebirds, ducks, Synthliboramphus murrelets)

Semiprecocial

Capable of thermoregulation soon after hatching, stay in nest (gulls, terns, most auks, petrels, and penguins)

Altricial

Naked, blind, and helpless at hatching (Passeriformes)

Brood parasitism

Foist offspring on unwitting adoptive parents (deceptive egg laying by females)

Intra-specific brood parasitism

Laying of an egg in the nest of another individual of the same species (never the sole strategy of an individual female bird)

Ducks and Nearctic cuckoos

Give some examples of birds that partake in Intra-specific brood parasitism.

Inter-specific brood parasitism

Laying of an egg in the nest of an individual of a different species (always the sole strategy of an individual female bird)

Cowbirds, Honeyguides, Cuckoos, Weaver finches, and Black-headed Duck

Give some examples of birds that partake in inter-specific brood parasitism.

Egg mimicry, chick mimicry, and nestling behaviour (hatch before host offspring)

List some parasite tactics