Mockingbirds.

This feature provides an example of a gene pool large enough to give rise to a number of options which ornithologists call Phenotypes. The characteristics of these options, as determined by both genetic make-up and environmental influences, has resulted in the diverse and broadly distributed Mockingbirds.

If you want to know more about genes and phenotypes click on http://bbsi.wikidot.com/genes-evolution-environment.

This sub-group of birds, comprising 16 species within family Mimidae, are only found in the Americas. South America has 10 species, Chilean, Long-tailed, Chalk-browed, Patagonian, White-banded, Brown-backed, Galapagos, Floreana, Hood and San Cristobel. In North America the Northern Mockingbird is well established as a bird of the urban environment. Latin / Mid America has the Tropical, Socorro and the Blue Mockingbird.

The Northern Mockingbird species does not show any significant geographical variation but birds which find their way to isolated islands (including the Socorro Mockingbird and the diverse group found on various Galapagos islands) trigger the appearance of the phenotype options. Most of these species are omnivorous, some on the Galapagos are actually carnivorous.

Biochemical studies reveal that Mockingbirds are more closely related to Old World Starlings than to any other living taxon. They form a group which originated somewhere in East Asia about 25 to 20 mya and eventually found their way to South America. The Galápagos Mockingbird descended from the Ecuadorian Long-tailed Mockingbird in the period 2 to 5 mya.

In terms of appearance, apart from the long tail with white edges and the white patches in the wings when seen in flight, these birds are broadly similar to one another as illustrated in the selection of photographs taken by Nelson, Tom and myself. If you click on an image in the gallery you will see an enlarged version and a very nice looking pop-up will provide a possibility to scroll images forward / backward without reloading page / opening new tab or window.

Starting at the top left and reading from left to right the images are:-

Bob's photographs - Image 1,2 and 3 - Northern Mockingbird at Stone Harbor. Image 4, 5 and 6 - Tropical Mockingbird taken in Trinidad and Tobago.

Nelson's photographs - Images 7, 8, 9, 10, 11 and 12 are all Northern Mockingbirds taken in Stone Harbor.

Tom's photographs - Images 13 and 14 - Chalk-browed Mockingbird in Iguazu National Park in Argentina. Image 15 taken on Isabella Island, Galapagos. Images 16, 17 and 18 are the Hood Mockingbird.

Apart from the long tail and white wing patches Mockingbirds offer nothing in terms of appearance or behaviour (except for an ability to mimic sounds which some display) to make them noticeable or significant.

This contrasts with the Catbirds and Thrashers which also belong to family Mimidae. These two sub-groups are much more noticeable both in terms of appearance and behaviour.

The Catbirds are much more secretive and favour dense thickets fairly near the ground. The Thrashers are well known for using their beaks and tails to disturb the ground litter in their search for insects, invertebrates and berries.

Catbirds & Thrashers - Images 19,20 are the Grey Catbird and 21, 22, 23 are Brown Thrasher, Curve-billed Thrasher and Long-billed Thrasher.

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