Cape Vultures Gyps coprotheres have black patches on their upperwing greater secondary coverts and black spots on their underwing greater secondary coverts. These have been physically observed to differ with individuals. This study examined the effects of age in years and sex on the size of the patches and spots using computer feather image analysis of birds with known ages in order account for differences that pure observation alone could possibly miss. Despite statistical analysis of computer enhanced imagery of micro detail the chosen plumage pattern failed to yield a reliable way to age and sex Cape Vultures. Annual moult is not expected in this species making the correlation of moult to age a muddle as it is also influenced by external...
In some sexually dichromatic passerines, juvenile males retain a plumage similar to that of adult fe...
Little is known about how the timing and duration of gonadal maturation varies between raptor specie...
The Skylark Alauda arvensis is a European passerine species lacking plumage dimorphism and having a ...
Cape Vultures Gyps coprotheres have black patches on their upperwing greater secondary coverts and b...
The plumage of young Cape Vultures Gyps coprotheres is streaked to varying degrees on the breast, ru...
The Cape Vulture Gyps coprotheres is considered sexually monomorphic in the literature, but visual d...
Curs 2014-2015Griffon Vultures (Gyps fulvus) moult is poorly known due to hardness to trap them; how...
[EN]: Many bird families, including the Rallidae, are characterised by a lack of plumage sexual dimo...
Wing, tail and bill lengths of Hooded Vultures were measured on 36 wild-caught birds and 75 in museu...
Molting is an important process of birds’ natural history and learning about molt and plumage allows...
Rufford Foundation and the Peregrine Fund.http://www.tandfonline.com/loi/tost202018-05-19hj2017Mamma...
The variable plumage characteristics of the sub-adult male cohort of the red-winged blackbird (Agela...
External ageing of Common Snipe (Gallinago gallinago) still engenders considerable problems. To impr...
Systematic sex-related differences in size and plumage are informative of sex-specific selection pre...
The ecological conditions that a bird experiences during any stage of its life cycle may have conseq...
In some sexually dichromatic passerines, juvenile males retain a plumage similar to that of adult fe...
Little is known about how the timing and duration of gonadal maturation varies between raptor specie...
The Skylark Alauda arvensis is a European passerine species lacking plumage dimorphism and having a ...
Cape Vultures Gyps coprotheres have black patches on their upperwing greater secondary coverts and b...
The plumage of young Cape Vultures Gyps coprotheres is streaked to varying degrees on the breast, ru...
The Cape Vulture Gyps coprotheres is considered sexually monomorphic in the literature, but visual d...
Curs 2014-2015Griffon Vultures (Gyps fulvus) moult is poorly known due to hardness to trap them; how...
[EN]: Many bird families, including the Rallidae, are characterised by a lack of plumage sexual dimo...
Wing, tail and bill lengths of Hooded Vultures were measured on 36 wild-caught birds and 75 in museu...
Molting is an important process of birds’ natural history and learning about molt and plumage allows...
Rufford Foundation and the Peregrine Fund.http://www.tandfonline.com/loi/tost202018-05-19hj2017Mamma...
The variable plumage characteristics of the sub-adult male cohort of the red-winged blackbird (Agela...
External ageing of Common Snipe (Gallinago gallinago) still engenders considerable problems. To impr...
Systematic sex-related differences in size and plumage are informative of sex-specific selection pre...
The ecological conditions that a bird experiences during any stage of its life cycle may have conseq...
In some sexually dichromatic passerines, juvenile males retain a plumage similar to that of adult fe...
Little is known about how the timing and duration of gonadal maturation varies between raptor specie...
The Skylark Alauda arvensis is a European passerine species lacking plumage dimorphism and having a ...