Taxonomy
The blue-naped mousebird (scientifically known as Urocolius macrourus), also formerly called the blue-naped coly (Colius macrourus) is a species of bird belonging to the family Coliidae within the order Coliiformes. They are the sister group to the clade Eucavitaves, which contains the families Leptosomiformes (the cuckoo roller), Trogoniformes(trogons), Bucerotiformes (hornbills and hoopoes), Piciformes (woodpeckers, toucans, and barbets) and Coraciformes (kingfishers, bee-eaters, rollers, motmots, and todies).
The species is found in the wild in the drier regions of West Africa to East Africa, as well as Sahel. It is one of the remaining six species of Mousebirds. The term “mousebird” comes from its habit of running along branches in a way that resembles the scurrying of a mouse.
There are a total of six recognized subspecies:
Urocolius macrourus macrourus (Distribution: Senegambia to east Ethiopia) Urocolius macrourus syntactus (Distribution: Sahel from Mali, southern Niger, and northern Nigeria east to Sudan, Eritrea, and northern Ethiopia) Urocolius macrourus laeneni (Distribution: Aïr Massif, in NC Niger.) Urocolius macrourus pulcher (Distribution: extreme South East South Sudan, Eastern Uganda, Kenya, extreme South Ethiopia, Southern Somalia and Northern Tanzania.) Urocolius macrourus abyssinicus (Distribution: Central and Southern Ethiopia, and Northern Somalia South to about Beledweyne.) Urocolius macrourus griseogularis (Distribution: South Sudan, Eastern Democrat Repbulic of Congo, Western Uganda, Rwanda, Burundi, and North Western and South Western Tanzania; this race sometimes said to occur in South Western Ethiopia.)
Description
The blue-naped mousebird is a fairly small to medium-sized bird, measuring 33-36 sm(13-14 inches) in length including the elongated tail of 20-28cm(34-65g). Adults have an ash grey plumage which is darker at top and lighter at bottom. Has a bright turquoise-blue patch on nape and hindneck, long crest, slender and steeplky graduated tail, females shorter than males. Both sexes are brown-tinged ash-grey above, greyish-buff below; bare skin on lores and around eyes crimson-red; most of upper mandible crimson-red, rest of bill black; feet purplish red. Juveniles lack the blue on nape, and have pink facial skin and greenish bills, as well as shorter crest.
Characteristic of mousebirds, the blue-naped mousebird has widely spaced and large feet for its body size, which are pamprodactylous; they are able to rotate all four toes to face forward at will. Their toes are strong and dextrous, allowing the birds to climb and scurry along branches, to hang by a toenail, or to use one foot to hold food.
Distribution and habitat
In the wild, these birds live in the semi-desert and dry regions of Africa. In East Africa are found in a band between 10°N and 20°N from the western coast to Sudan, Djibouti, Eritrea, Ethiopia and Somalia in the East and south 10°N through East Africa and on to the Eastern Zaire borders. 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).
Conservation Status
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.