Worldwide distribution Migration Falconiformes 3 families, 304 species Worldwide distribution

Eagles, hawks, kites, Old World vultures Accipitridae Eagles, hawks, kites, Old World vultures 233 species

European Sea Eagles

Old World Vultures 15 species Many threatened Griffon Vulture

Cathartidae New World Vultures 7 species King Vulture

California Condor

Pervious nares, urohydrosis

Caracaras, falcons and falconets Falconidae Caracaras, falcons and falconets 64 species Gyrfalcon

Merlin

Migration

What is migration? What are its advantages? General features

Definition Population movements in a predictable direction at predictable times of year between breeding areas and one or more non-breeding areas

Advantages of migration 1) Avoid harsh climate 2) Secure more abundant food 3) Longer days for feeding young in the north (clutch size increases in the north) 4) May reduce predation 5) Reduces disease and parasites 6) Increase space available for each pair 7) Genetic selection for fitness?

Migration timing Varies by species Varies from year to year depending upon weather Some species remarkably consistent

Since 1777, Cliff Swallows have arrived the week of March 19th Cliff Swallows arrive the week of March 19 at San Juan Capistrano; Short-tailed Shearwaters arrive at breeding colonies off southern Australia within a week of the same date each year. Short-tailed Shearwater South Australia

Non-migratory movements Dispersal Irruption Nomadism

Dispersal Natal – away from birth place Breeding – away from breeding place Movements typically unidirectional

Irruption Mass movement away from usual range Typically caused by food shortage

Nomadism Irregular, seemingly random movements

General Features ca. 4,000 bird species migrate (42%) Most from temperate or high latitudes Geographic asymmetry Old World asymmetry even greater

New World Warblers

Yellow Warbler

Migration study methods Banding/radiotracking Direct observation Radar Laboratory studies

Site fidelity Ovenbird

Migrate faster in spring than fall and adults travel faster than young General Features Migrate faster in spring than fall and adults travel faster than young

Day v night Most small birds migrate at night (stopping by 2 a.m.) and feed during the day

Duration James Bay to Louisiana (2,700 km) in 60 hrs 1,100 km/day or 46 km/hr Radar gives 30-70 km/hr for most species

Speed Northward in spring at 32 km/day Black-and-white Warbler

Most species fly at 1,500 m or less during the day, higher at night Altitude Most species fly at 1,500 m or less during the day, higher at night

Rueppell’s Griffon 37,000’. Bar-headed Goose 27,880’ Ivory Coast Rueppell’s Griffon 37,000’ Bar-headed Goose 27,880’ Ivory Coast Himalayas Griffin collided with airplane Yellow-billed Chough 26,900’ Himalayas

Long-distance v short-distant migrants

Long-distance migrant Short-distance migrant

Longest distance migrant 35,000 km

Partial v Complete Migrants Fox Sparrow

Ringed Plover

Loop Migration

If a Blackpoll were burning gas it would get 720,000 miles/gallon If a Blackpoll were burning gas it would get 720,000 miles/gallon. Running 4-min miles for 80 hours 720,000 miles/gallon!

Physiological Preparation Short days trigger hyperphagia Nocturnal restlessness Zugunruhe – captive birds hop and flutter in normal migration direction Warm weather inc zugunruhe in spring, cold weather depresses it Castrated birds still exhibit zugunruhe

Barriers to migration can shape species diversity Large bodies of water Mountain ranges Inhospitable habitat Western warbler example

Number of warbler species Western NA 12 (Wash., Ore., Ca) Eastern NA 38 Europe 50