Galapagos Mockingbird (50)
|Galapagos Mockingbird |
Endemic (found only on Galapagos)
*There are 4 species of mockingbird found in Galapagos;
all have very similar pumage and all are endemic. They are excellent mimics and have even learnt to imitate the recently introduced Smooth-billed ani.
The Galapagos Mockingbird is a slim, thrush-like bird with grey-brown plumage. Its upperparts are rather darker brown, the underparts lighter. There is a distinct dark-brown patch in front of, and behind the eye. The legs, bill and feet are dark, the bill being slightly downcurved.
It nests in trees or cacti, generally after the start of the annual rains between december and april.
The species has an usual social structure whereby the older offspring help to feed the younger ones.
Birds of Galapagos
The relative paucity of species is actually one of the beauties of the birds of Galapagos. The finches and mockingbirds are excellent examples of adaptive radiation, where a species has evolved characteristically on an isolated island. This is not surprising in the case of reptiles and mammals that cannot fly but it is quite surprising with birds that could, in theory, move from island to island relatively easily. You should not look on adaptive radiation, or the evolution of new species on particular islands as a thing of the past. It is almost certainly continuing even now, but so slowly that it may be hundreds of years before any visible differences are evident.
It is also worth noting that the number of resident species of bird is growing. At least 5 species have become resident in the last 50 years, Common Egret, Cattle Egret, Paint-billed Crake, Common Gallinule and Smooth-billed ani. The last of these was almost certainly introduced by man, but the others appear to have arrived independently and thrived in a habitat conducive to development. None of these arrivals has been reported as having any negative impact on other species already in residence, but it is too early to be sure of this.
In addition to the resident species, there are a number of regular visitors. These are mainly migratory waders from North America. They are therefore generally to be seen in their winter plumage and so can be quite difficult to identify. However, some can be found in the islands all year round and it is possible that these may eventually become resident and breed.
We know of no endemic bird species that has become extinct. However, there are several species that are vulnerable owing to their very restricted breeding range and habitat. Chief among these is the Mangrove finch that is found in only a few patches of mangrove on Isabela. The total population is thought to number only in the low tens of pairs. The Charles Island mockingbird also has a very restricted range but it is not under threat , but with only 150 or so individuals, it is vulnerable. Several other species, such as the Flightless cormorant and the Galapagos Rail or Crake , are vulnerable to habitat change or the introduction of new predators. Complacency is a real danger and many species must be viewed as vulnerable. Apart from the finches and the boobies, relatively little work has been done on Galapagos bird species. It is only when armed with accurate infromation and a full understanding of the species that we can feel completely confident of their future.
*Source: Wildlife of the Galapagos
Julian Fitter,Daniel Fitter,David Hosking
Princeton Pocketguides, ISBN 0-691-10295-3
Exposure Time: 1/400
ISO Speed Ratings: 400
Focal Length: 400 mm
Date Taken: 2007-04-25 16:51
Metering Mode: Pattern