Cracids are a family of gamebirds (Cracidae), found predominantly throughout the Latin American tropics. Cracids (chachalacas, guans and curassows) live in a variety of tropical and subtropical habitats, The northern most species gets into the extreme southern portion of Texas, and the southern most species ranges as far south as the Plate River Basin in Buenos Aires Province, Argentina!
Sizes range from small pheasant to a large turkey. Their larger size compared to most species of birds makes them an ideal protein source for people living in the same region. However; unfortunately, they are not always harvested sustainably (i.e., severely overhunted in many regions), and consequently their populations are plummeting rapidly throughout their range. The other factor that threatens Cracids is depletion of their natural forest habitat. Although some species can tolerate moderate forest alteration, most species disappear when their natural habitat is destroyed.
Cracids have an economic importance in the ecological maintenance and preservation of Latin American forest reserves. As indicators of human perturbation and habitat quality, cracids are second to none among Neotropical bird groups as outstanding heuristic tools for the design and implementation of monitoring conditions in natural areas.
The curassow are the largest members of the Family Cracidae. There are 14 species: 7 True Curassows (Crax), 4 Razor-billed Curassows (Mitu), 2 Helmeted Curassows (Pauxi) and the monotypic Nocturnal Curassow (Nothocrax).
(Source: http://www.cracids.org/home.php , http://www.cracids.org/AP_Engl_ebook.pdf).
In the RDS-PP, we can find two species of curassows, which are:
The Wattled Curassow Crax globulosa
The Wattled Curassow is about 82–89 cm (32–35 in) long, and weighs around 2,500 g (88 oz). It is a large curassow lacking the white tail-tips found in many of these birds; the feathers along the crest of its head are curled forwards. Males have black plumage all over except for the white crissum (area between legs and tail). The irides are dark brown; legs, feet and bill are blackish. It has conspicuous crimson bill ornaments—a round red knob with bony core adorns the maxilla base, while the cere extends apically at least halfway under this knob and below the mandible base forms a small fleshy wattle.
Females have black plumage just like the male, but their crissal area is reddish buff. In some, the remiges and sometimes the wing coverts have faint brownish marbling. Their bills and irides are also blackish, but their feet and legs are a greyish flesh color. They lack the bill knob and wattles, and their cere is bright orange-red. Young males have less well-developed facial ornaments, usually with a more yellowish hue like females do.
 |
| Wattled Curassow adult male. Photo taken in the RDS-PP, by Carolina Bertsch. |
 |
| Wattled Curassow adult female (in front) and male. Photo taken in the RDS-PP, by Carolina Bertsch. |
The hatchlings are covered in brown down above and whitish down below.
 |
| Crax globulosa's hatchling. Photo taken in the RDS-PP, by Carolina Bertsch. |
Work to Date
Based on the species revision of the last Cracidae Action Plan http://www.cracids.org/AP_Engl_ebook.pdf
The Wattled Curassow has a discontinuous distribution through the Amazon Basin that encompasses NW Brazil, SE Colombia, E Ecuador, E Peru and N Bolivia (BirdLife International 2014). In contrast to other curassows it is considered primarily an arboreal species strongly associated with forest habitats periodically flooded by white and black water, as well as forest and swampland islands. During the dry season this species feeds of small fish, crustaceans and other invertebrates, which differs from the rainy season when fruits and seeds are preferred.
Although, the breeding season is not strictly seasonal, two optimum nesting periods are observed in Colombia. The first period is between July-August and the second between January-February. The clutch size can range from 2-6 eggs, but are typically at the lower end of the spectrum. Preliminary evidence on the social system indicates solitary males and females, as well as groups ranging up to 15 individuals.
Status and Threats
The Wattled Curassow is regionally considered Endangered (EN - A2b,c,d; A3b,c,d; C2a(i)) since the smallest subpopulations are fewer than 250 individuals, (61 individuals on Isla Mocagua [Bennett 2003]; 40 individuals on Mirití Island [Alarcón-Nieto and Palacios 2005], Colombia). In Ecuador this species is probably extinct (Johnson 1993). This species is considered a high priority for conservation.
Principal threats for this species today are related to subsistence and sales hunting, as well as habitat loss due to logging. Another mid- and long-term potential threat is isolation that some subpopulations face, which can cause local extinction due to loss of genetic viability.
In Brazil, the following conservation action have been proposed:
- Generate a potential captive reproduction program with other countries to maintain the genetic viability of the existing group. However, it will be important to maintain pure stock with respect to different populations.
- Continue research of ecology, distribution and monitoring programs of hunting.
The Razor-billed Curassow Mitu tuberosa
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
 |
| Couple of adult Razor-billed Curassow. Photo taken in the RDS-PP, by Carolina Bertsch. |
 |
| Razor-billed Curassow hatchling. Photo taken in the RDS-PP, by Carolina Bertsch. |
You can find more information of these species on the following links:
Cracid Group of the Galliformes Specialist Group IUCN/SSC
Birdlife International 2014
The IUCN Red List of Threatened Species
No comments:
Post a Comment