Giant Coua
Encyclopedia
The Giant Coua is a bird species
from the Cuckoo
family that is endemic to the dry forests of western and southern Madagascar
. It is suggested that Couas probably originated from a particular Asian ground-cuckoo (Dinets 2007). Genus Coua contains 10 species, more than any other genus in Madagascar (Moreau 1966). Although the bird is listed under Least Concern
(LC) in the IUCN Red List of Threatened Species, C. gigas only persist in the biological hot spot of Madagascar, warranting its recognition as a species of conservation concern at the global scale.
C. gigas subsist on seeds (Capurodendron madagascariensis and Buxus madagascariensis), insects and some small vertebrates such as chameleon
s (Furcifer sp.) (Chouteau 2006A). This species of bird is often encountered in large unlogged gallery forests that lack dense shrub layers, which provides greater mobility and implies a preference for undisturbed forest with tall trees (Chouteau 2006A & 2006B; 2004). Studies indicate that in logged forests, Giant Coua usually glean
during dry seasons and more often leap and sally
during rainy seasons (Chouteau 2006A). In contrast, they have been found to do the opposite in forested areas (more often glean during rainy seasons and more often probe during dry seasons), which suggests the significant role that environment plays in foraging behavior (Chouteau 2006A; 2006B; 2004). Giant coua tend to utilize microhabitats in logged forests with a greater canopy cover, and forage in logged gallery forest
s with higher canopies than other areas while avoiding sites with more stems and obstacles (Chouteau 2006A; 2004).
by the official Red List Authority for birds for IUCN.
Continual studies of Giant Coua's foraging compliments forest conservation (Chouteau 2004). Selective logging could be restricted to the typically dry forest while gallery forests could be kept as corridor for conservation, especially for this bird species (Chouteau 2006B). Conservation of the gallery forest would be improved by logging both forest types (gallery & dry) at the same rate and implementing fire control measures (Chouteau 2006B).
Recent sightings in Sainte Luce testify that the tail of the Giant Coua appears to be longer than in other regions (Ellis 2003). This negates the claim that the genus Coua has no morphological specialization, instead indicating distinctive morphological differences that warrant further studies for species change (Moreau 1966). Sainte Luce is currently one of the best areas to see these birds in certain forest fragments that should have long-term management to foster limited populations (Ellis 2003). As one of the proposed conservation zones currently managed by the local community, the region has great potential for eco-tourism to promote continued conservation of the species (Ellis 2003).
Sibley-Monroe checklist 4
: landmark document in the study of birds
Photo links
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
from the Cuckoo
Cuckoo
The cuckoos are a family, Cuculidae, of near passerine birds. The order Cuculiformes, in addition to the cuckoos, also includes the turacos . Some zoologists and taxonomists have also included the unique Hoatzin in the Cuculiformes, but its taxonomy remains in dispute...
family that is endemic to the dry forests of western and southern Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
. It is suggested that Couas probably originated from a particular Asian ground-cuckoo (Dinets 2007). Genus Coua contains 10 species, more than any other genus in Madagascar (Moreau 1966). Although the bird is listed under Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
(LC) in the IUCN Red List of Threatened Species, C. gigas only persist in the biological hot spot of Madagascar, warranting its recognition as a species of conservation concern at the global scale.
Ecology
Giant Couas are approximately 62 cm in length (nearly double the size of Coua Couquereli) and have a blue patch around their eyes, characteristic of the Coua genus and similar to African Turacos (Chouteau 2006A). As a member of the Cuckoo family, they have a reversible third toe and resemble Coucals in their method of scrambling through plant tangles for food. Observations indicate that they can climb 10 meters high from the ground(Chouteau 2006A).C. gigas subsist on seeds (Capurodendron madagascariensis and Buxus madagascariensis), insects and some small vertebrates such as chameleon
Chameleon
Chameleons are a distinctive and highly specialized clade of lizards. They are distinguished by their parrot-like zygodactylous feet, their separately mobile and stereoscopic eyes, their very long, highly modified, and rapidly extrudable tongues, their swaying gait, the possession by many of a...
s (Furcifer sp.) (Chouteau 2006A). This species of bird is often encountered in large unlogged gallery forests that lack dense shrub layers, which provides greater mobility and implies a preference for undisturbed forest with tall trees (Chouteau 2006A & 2006B; 2004). Studies indicate that in logged forests, Giant Coua usually glean
Gleaning (birds)
Gleaning is a term for a feeding strategy by birds in which they catch invertebrate prey, mainly arthropods, by plucking them from foliage or the ground, from crevices such as rock faces and under the eaves of houses, or even, as in the case of ticks and lice, from living animals. This behavior is...
during dry seasons and more often leap and sally
Hawking (birds)
Hawking is a feeding strategy in birds involving catching flying insects in the air. The term usually refers to a technique of sallying out from a perch to snatch an insect and then returning to the same or a different perch...
during rainy seasons (Chouteau 2006A). In contrast, they have been found to do the opposite in forested areas (more often glean during rainy seasons and more often probe during dry seasons), which suggests the significant role that environment plays in foraging behavior (Chouteau 2006A; 2006B; 2004). Giant coua tend to utilize microhabitats in logged forests with a greater canopy cover, and forage in logged gallery forest
Gallery forest
Gallery forests are evergreen forests that form as corridors along rivers or wetlands and project into landscapes that are otherwise only sparsely treed such as savannas, grasslands or deserts....
s with higher canopies than other areas while avoiding sites with more stems and obstacles (Chouteau 2006A; 2004).
Range
C. gigas are found in lowlands to 700 meters of Western and Southern Madagascar (Sibley 2007). The range of this bird species is considered large with an estimated global Extent of Occurrence of 50,000-100,000 km². Global population size hasn't been quantified yet believed to be large since it is described as 'common' in at least parts of its range. Similarly, global population trends are not available, and even though it is believed that the species are not approaching the population decline thresholds for the criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations), there is evidence for population decline. This summarizes the reasons for evaluating Giant Coua as Least ConcernLeast Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
by the official Red List Authority for birds for IUCN.
Conservation
Several studies support the need to conserve the Giant Coua. C. gigas are among locally vulnerable species of Madagascar that are occasionally hunted and trapped by children (Ellis 2003). Disturbance by fire or logging can potentially compromise their resource use and result in an added threat to these species (Chouteau 2006). Human alteration modifies the habitat structure and has an impact on foraging behavior and habitat selection (Chouteau 2004). Selective logging is a major disturbance for forest insectivorous birds, particularly the Giant Coua (Chouteau 2004; 2006B). Logging imposes a negative impact on C. gigas density, and increased logging or burning could reduce the optimal habitat and decrease the density of this species (Chouteau 2006B). It is necessary to retain a diversity of foraging nutrients in different habitat types to sustain the normal foraging activities of these birds (Chouteau 2006B).Continual studies of Giant Coua's foraging compliments forest conservation (Chouteau 2004). Selective logging could be restricted to the typically dry forest while gallery forests could be kept as corridor for conservation, especially for this bird species (Chouteau 2006B). Conservation of the gallery forest would be improved by logging both forest types (gallery & dry) at the same rate and implementing fire control measures (Chouteau 2006B).
Recent sightings in Sainte Luce testify that the tail of the Giant Coua appears to be longer than in other regions (Ellis 2003). This negates the claim that the genus Coua has no morphological specialization, instead indicating distinctive morphological differences that warrant further studies for species change (Moreau 1966). Sainte Luce is currently one of the best areas to see these birds in certain forest fragments that should have long-term management to foster limited populations (Ellis 2003). As one of the proposed conservation zones currently managed by the local community, the region has great potential for eco-tourism to promote continued conservation of the species (Ellis 2003).
External links
Endemic birds of Madagascar and western Indian Ocean islandsEndemic birds of Madagascar and western Indian Ocean islands
This article is one of a series providing information about endemism among birds in the World's various zoogeographic zones. For an overview of this subject see Endemism in birds.- Patterns of endemism :...
Sibley-Monroe checklist 4
Sibley-Monroe checklist 4
The Sibley-Monroe checklist was a landmark document in the study of birds. It drew on extensive DNA-DNA hybridisation studies to reassess the relationships between modern birds.-Alcedinidae:* Alcedo hercules Blyth's Kingfisher...
: landmark document in the study of birds
- ***Giant Coua Species Range***: Under Important Bird Areas Section, click "here"
Photo links
- http://www.avesphoto.com/website/MA/species/COAGIA-1.htm
- http://avesphoto.com/website/MA/species/COAGIA-2.htm
- http://photos.wildmadagascar.org/images/giant_coua_4.shtml\
- http://photos.wildmadagascar.org/images/giant_coua_1.shtml
- http://photos.wildmadagascar.org/images/giant_coua_5.shtml
- http://www.mangoverde.com/birdsound/picpages/pic76-69-1.html
- http://calphotos.berkeley.edu/cgi/img_query?query_src=&enlarge=0024+3291+2008+0059