Birds and Their Adaptations

Flashcards to aid in the understanding of bird evolution, adaptations, characteristics, and behavior.

When did birds appear in evolutionary history?

In the Jurassic period.

From which type of dinosaurs did birds evolve?

Theropod dinosaurs

What is the scientific name for one of the earliest known birds?

Archaeopteryx lithographica

What are tetrapodomorphs?

Stem group that includes early ancestors to tetrapods.

What are amniotes?

Group of vertebrates that lay eggs on land or retain eggs inside the mother

What defines synapsids?

They have a single hole in their skull behind the eyes.

What defines diapsids?

They have two holes in their skull behind the eyes.

What characterizes archosaurs?

They have a tendency toward bipedalism and a fenestra in front of the eye

What are some adaptations of birds that relate to flight?

Low weight relative to size, high power, and aerodynamic shape

What is unique about a bird's skeletal structure?

Bones are thin-walled and hollow

How do birds reduce weight for flight?

Through skeletal adaptations such as fusion and loss of bones

What is the uropygial gland's function?

It secretes oils used to waterproof feathers

What nitrogenous waste do birds excrete?

Uric acid

How are bird reproductive systems adapted?

Most birds are oviparous and only have a functional left ovary and oviduct.

What is the major function of the crop in birds?

Food storage.

What is the role of the gizzard in a bird's digestive system?

To perform mechanical digestion of food.

What are pneumatic bones?

Bones that are hollow or contain air pockets.

What defines bird vocalizations?

Acoustic communication for long-distance detection and individual recognition

What are songs in bird communication?

Long vocal displays with specific, repeated patterns, usually produced by males

What is the primary purpose of bird migration?

To exploit seasonal feeding opportunities.

How do birds learn their songs?

Through a combination of inherited traits and learned behaviors.

What are the two main types of pigments found in bird feathers?

Melanins and carotenoids

What structural color principle explains bird colors like blue?

Produced by nanometer-scale barb structures

What is the purpose of feathers in birds?

Insulation, waterproofing, and aiding in flight

What is meant by 'lekking' in birds?

Males display on communal grounds for females to choose mates.

What is brood parasitism?

When a bird lays its eggs in the nest of another species.

What are the advantages of having a lightweight structure in birds?

Improved flight efficiency and energy conservation.

What is a characteristic of bird feet and legs?

They have digits for greater mobility and adaptation.

How do birds maintain their feathers?

Through preening, which restores vane integrity

What are contour feathers?

Feathers that cover the body surface and may be modified for flight

What are semi-plume feathers used for?

Insulation, buoyancy, and display.

What is the function of filoplume feathers?

To monitor the movement and position of adjacent feathers.

What are typical examples of bird migration routes?

North-South migrants and East-West migrants.

What physiological response triggers migration in birds?

Changes in photoperiod (day length).

How do birds navigate using the sun?

Using a sun compass to determine direction

What is visual landmark navigation in birds?

Following coastlines, rivers, or other visual cues

What defines the 'Critical Learning Period' in bird song development?

A period early in life when the bird must hear an adult song

What does the term 'hypertrophy' refer to in the context of bird muscles?

Enlargement of muscles, particularly flight muscles

What is a major factor affecting territory size in birds?

Population density and resource availability.

What evolutionary adaptations aid in avian flight?

Light body weight, strong flight muscles, and efficient respiratory systems

What role does the syrinx play in birds?

It is the organ responsible for sound production.

What is the significance of the keeled sternum in birds?

It provides an anchor for powerful flight muscles

Why do many birds have a short, well-defined breeding season?

To optimize conditions during peak resource availability.

What types of information can bird vocalizations convey?

Species identity, individual identity, and territory.

What are the main components of the avian digestive system?

Crop, proventriculus, gizzard, and caeca

What feature of bird vision is exceptional?

High density of cone cells allows for better color vision, including UV light detection.

What are the primary characteristics of the nervous system in birds?

Large brains relative to body size, contributing to high coordination

What is the purpose of plumage?

It is the entire feather covering of a bird.

What is the distinction between basic and alternate plumage?

Basic plumage is non-breeding/winter plumage; alternate plumage is breeding plumage.

What is the advantage of a complete molt in birds?

Ensures that all feathers, including flight feathers, are renewed

How does the structure of feathers facilitate their functions?

Feathers have a complex structure that maximizes lightweight, strength, and aerodynamic properties

What is the primary cue for migratory birds when determining when to migrate?

Photoperiod

What factor influences a bird's navigation when flying at night?

Celestial navigation using stars

What is one of the main roles of vision in birds?

To find food and detect predators