Ornithology Exam #1

What is a bird?

A bird is characterized by feathers, a beak (no teeth), claws, hollow bones, a keeled sternum, wings, the ability to fly, a four-chambered heart, double circulation, a gizzard for processing food, and air sacs in addition to lungs.

What are uncinate processes?

Rearward projections on ribs that strengthen the thorax, keeping the body rigid for flight.

What are pneumatic bones?

Hollow bones that contain air sacs for support and reduce weight, aiding in flight.

What is a gizzard?

A muscular stomach in birds that grinds food; it is largest in seed-eating birds.

What does 'oviparous' mean in relation to birds?

It refers to birds laying eggs rather than giving birth to live young.

What is unique about a bird's heart?

Birds have a four-chambered heart that is more efficient, allowing for greater oxygen and nutrient delivery.

Define 'endothermic'.

A term describing birds' ability to regulate their body temperature through metabolic heat production.

What is the significance of Archaeopteryx?

Archaeopteryx is considered a crucial transitional fossil demonstrating the connection between birds and reptiles; it exhibits both bird and reptile traits.

What are some characteristics that unite birds and theropod dinosaurs?

Hind foot structure, loss of the 5th toe, reversed 1st digit (hallux), furcula, pneumatic bones, air sacs, and feathers.

What is spatial memory in birds?

The ability of certain birds, like seed catchers, to remember the locations of their food caches for months.

What is optimal foraging theory?

A behavioral model that suggests animals, including birds, maximize their energy gained from food while minimizing energy spent obtaining it.

What is the principle of competitive exclusion?

A principle stating that if two species share the same ecological niche, one will outcompete the other, leading to extinction or niche differentiation.

What is the function of the pecten in birds?

The pecten is a unique structure in birds' eyes that supplies oxygen and nutrients to the retina, enhancing vision.

Define 'unihemispheric sleep' as it relates to birds.

A sleep pattern where one half of a bird's brain remains awake while the other half sleeps, allowing for predator vigilance.

What adaptations help birds in foraging?

Birds utilize adaptations such as bill structure, spatial memory, and search images to efficiently locate and capture prey.

What is the role of feathers in birds?

Feathers play several roles including enabling flight, insulation, waterproofing, sensory functions, and mate attraction.

Describe basic auditory anatomy in birds.

Birds have a tympanic membrane and a single columella bone in the middle ear; their inner ear includes a large cochlea for sound processing.

How do birds’ eyes differ from human eyes?

Birds typically have larger eyes, greater visual acuity, and can see some ultraviolet light, which enhances their vision.