Saturday, 19 April 2014

Galapagos rail

Laterallus spilonotus

Photo by George Armistead (Neotropical Birds)

Common name:
Galapagos rail (en);  franga-d'água-das-Galápagos (pt); râle des Galapagos (fr); polluela de Galápagos (es); galapagosralle (de)

Taxonomy:
Order Gruiformes
Family Rallidae

Range:
This species is endemic to the Galápagos Islands, where it occurs on the islands of Pinta, Fernandina, Isabela, Santiago, Santa Cruz, Floreana, and San Cristóbal.

Size:
These birds are 15-16 cm long and weigh 35-45 g.

Habitat:
The Galapagos rail is mostly found in high-altitude grasslands and scrublands, especially ferns and sedges, as well as moist forests and freshwater lakes and marshes. They also use mangroves and arable land. This species is present from sea level up to an altitude of 1.700 m.

Diet:
They are mainly insectivorous, taking ants, dragonflies, moths, bugs, isopods, spiders, amphipods and snails. They are also known to eat the seeds of Miconia robinsonia and a few other plants.

Breeding:
Galapagos rails are monogamous and breed in September-April. They nest on the ground, in a cup made of plant stems with a side entrance. The female lays 3-6 beige eggs with reddish-brown and grey speckles, which are incubated by both parents for 23-25 days. The chicks leave the nest soon after hatching and reach adult size 80-85 days after hatching.

Conservation:
IUCN status - VU (Vulnerable)
This species has a relatively small and disjunct breeding range. The global population is estimated at 3.300-6.700 individuals. The population is estimated to be declining at rate of 9% per year, possibly due to predation by introduced mammals such as rats, cats, dogs and pigs, and natural predators like the short-eared owl Asio flammeus and the barn owl Tyto alba. Another threat is habitat destruction as a result of grazing by introduced herbivores such as goats, cattle and horses. The small size of several of the populations If makes them vulnerable to extinction through natural disturbances, inbreeding and population changes of predators and herbivores. The invasion of the highlands of Santa Cruz by exotic Cinchona may lead to a reduction in the fern and sedge vegetation types it favours.

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