Ornithology Exm1

Allopatric speciation

Geographic separation

Sympatric speciation

Genetic polymorphism resulting in a new species

Peripatric speciation

New niche entered that becomes isolated

Parapatric speciation

New niche that remains connected to niche but new species forms

Trees down hypothesis

Ancestors of birds were arboreal climbers that glided from tree to tree. They began flapping their wings to extend their time in the air, which turned into flight.

Ground up hypothesis

Bird ancestors were terrestrial runners that would use proto wings to aid in running. As wings and feathers continued to evolve, they started to achieve more lift, which led to flapping flight.

Ground up example

Ground birds use their wings to assist them in running up inclines. They prefer running over flying which could possibly be an evolutionary preference

Pouncing hypothesis

Theorized that early birds pounce on prey, which prompted the development of wings and eventually flight. Led to flapping and sustained flight

Biogeography

Study of distributions of organisms, past and present

Endemic

Restricted to a specific geographical location

Ecological biogeography

Explains distributions in terms of the present interactions between organisms and their physical and biotic environments

Climate constraints

Temperature and precipitation

Habitat constraints

Plant species

Trophic constraints

Prey species

Interspecific competition

Niche overlap between closely related species

Elevation gradient

Diversity is related to productivity(temp and moisture). Increase in elevation leads to decrease in productivity and diversity

Higher speciation hypothesis

More energy available, leading to more niches. More stable environments leading to more speciation opportunities

Museum theory

Lower extinction. Minimal effect of glacial cycles outside of tropical mountains. More energy available so higher population sizes.

Time for speciation theory

Birds started as tropical and take time to adapt to temperate conditions

Parts of digestive system

Beak, tongue, crop, stomach, ceca, vent/cloaca

Crop

Softens and stores foods

Proventriculus

First half of stomach, breaks down chemicals in food

Gizzard

Second half of stomach, physical breakdown of food

Ceca

has small side sacs in intestines that aid in the digestion of fibrous plants. Not in all birds, only those who consume fibrous plants

Renal system

Birds use Uric acid instead of urea when excerpting fluids for water efficiency

Circulatory System

4 chambered hearts. High metabolic rate which leads to high blood pressure. Big heart

Resp system

Unidirectional airflow across lungs and air sacs

Resp system cycle 1

Inhaled air flows through bronchi and into posterior air sac, then moves to lungs where gas exchange occurs

Resp system cycle 2

O2 poor air moves to anterior air sacs and on exhale, the O2 poor air is pushed out of bird.

Lift

Pushes bird up

Thrust

Helps bird move forward

Drag

Force that works against birds forward movement

Angle of Attack

Angle at which wing is entering airflow

Power Curve

Energy costs associated with how much speed the bird is moving at