Birds in grasslands: a comparison of East Africa with North America

Grasslands are extensive in west-central North America, and far less extensive in East Africa. The climates in these areas are quite different, but the vegetation is similar.

How similar are the avifaunas of grasslands in North America vs East Africa?

Certain similarities, both phylogenetically and ecological, are obvious.

Several birds are closely related - down to the same genus in some cases. And approximate ecological analogues occur, as reflected by size, shape, microhabitat, foraging niche, and movement patterns.

Taxa shared are Accipitridae (e.g. Buteo,, Falconidae, Tytonidae, Strigidae, Gruidae, Columbidae, Caprimulgidae, Hirundinidae, Corvidae (e.g. Corvus), and Motacillidae (e.g. Anthus,

Some sharing of families applies also to the birds entering the grassland only in association with trees and shrubs, e.g. Cuculidae, Picidae, Paridae, Turdidae, and Laniidae.

Phylogenetically unrelated birds that have evolved to have comparable ecological characters include:

  • Cathartidae with African vultures,
  • Tetraonidae with African Phasianidae/Pteroclidae/Otidae,
  • Icteridae (e.g. Sturnella) with African Motacillidae (e.g. Macronyx), and
  • Icteridae and Cardinalidae with African Ploceidae.

Among the birds associated with trees in grasslands are:

  • Tyrannidae vs African Muscicapidae,
  • Corvidae vs African Coraciidae, and
  • Trochilidae vs African Nectariniidae.

A further similarity is the way the bird community becomes poorer where trees and shrubs disappear from the grassland. Many birds are closely associated with stands of trees and shrubs irrespective of the presence of grass. The birds extending into treeless grassland are relatively few on both continents.

However, the differences seem more important than the similarities.

The avian community of treeless grassland is poorer in North America than in East Africa. This applies particularly to scavengers, large raptors, large terrestrial birds with mixed diets (e.g. Otidae of Africa), doves (Columbidae), walking insect-eaters (Alaudidae, Motacillidae, Turdidae), perching insect-eaters (e.g. Laniidae), and 'wrens' (e.g. see and

The birds of North America are also more restricted seasonally in their occupation of grassland, and are progressively impoverished northwards - presumably a result of the increasingly cold and snowbound conditions at higher latitudes.

Guilds of birds associated with trees and shrubs on both continents extend into pure grassland in East Africa whereas they fail to do so in North America, especially in the northern parts of the North American grassland.

'Wrens', in particular, do not occur in treeless grassland in North America (see, but are common in East Africa in the form of several species of Cisticola.

Starlings (Sturnidae) are common in woodlands and grasslands alike in East Africa, whereas in North America the birds most closely resembling starlings, drawn from e.g. Bombycillidae (, and Icteridae (Euphagus and grackles, barely enter treeless grasslands.

The same is true for widowbirds (types of Ploceidae) and their North American counterparts, viz certain Icteridae (blackbirds Agelaius, and bobolinks and certain finch-like birds (

The only birds of grasslands, commoner or represented by more species in North America than in East Africa, seem to be:

Publicado el marzo 14, 2022 04:28 MAÑANA por milewski milewski


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