Thứ Sáu, 25 tháng 5, 2012

Red-cockaded woodpecker

Picoides borealis

Photo by Matthew Hacker (Wikipedia)

Common name:
red-cockaded woodpecker (en); pica-pau-de-faces-brancas (pt); pic à face blanche (fr); pico de Florida (es); kokardenspecht (de)


Taxonomy:
Order Piciformes
Family Picidae


Range:
This species is endemic to the Unites States, with scattered populations being found in the south-eastern parts of the country, especially in Florida and South Carolina but as far north as Virginia ans as far west as eastern Texas and Oklahoma.


Size:
These birds are 18-23 cm long and have a wingspan of 34-41 cm. They weigh 40-56 g.


Habitat:
The red-cockaded woodpecker is found in fire-sustained open pine-forests, mostly longleaf pine Pinus palustris, but other species of southern pine such as shortleaf P. echinata, slash P. elliotti, or loblolly P. taeda pines are also acceptable. They are present from sea level up to an altitude of 500 m.


Diet:
They are omnivorous, eating adult and larval arthropods, especially beetles and ants, but also seeds, nuts and fruits.


Breeding:
Red-cockaded woodpeckers are cooperative breeders, lives in small family groups composed of one breeding pair and several helpers. These helpers are usually the male offspring from previous breeding seasons and help incubate the eggs and feed the chicks. They breed in April-July, nesting in cavities excavated into old living pines, often selecting trees infected with the red heart fungus, which softens the wood. The female lays 2-5 white eggs, which are incubated for 10-13 days. The chicks fledge 25-29 days after hatching, but remain with the family group for at east 5 months.


Conservation:
IUCN status - VU (Vulnerable)
This species has a large but fragmented breeding range. The population was originally distributed throughout the south-eastern united states, but it is now restricted to about 30 populations totalling 9.000-11.000 individuals, having undergone a large decrease of 26% per decade over the last 4 decades. However, some of the populations are now stable or increasing as a result of intensive management. The main threats to the red-cockaded woodpecker are habitat destruction and fragmentation caused by long-term clearance, inbreeding depression due to the small size of some of the small and isolated populations, and infestations by southern pine beetle Dendroctonus frontalis, which increase food availability, but kill the tree reducing the available nesting sites. Competition by pileated woodpeckers Dryocopus pileatus and reduced fire management due to expanding human populations may also have a negative impact.

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