Sentence examples for based on the colouration from inspiring English sources
According to Amadon, the Rodrigues and hoopoe starlings were related to Asiatic starlings, such as some species of Sturnus, rather than the glossy starlings (Lamprotornis) of Africa and the Madagascan starling (Saroglossa aurata); he concluded this based on the colouration of the birds.
More recent experiments show that ventral colouration plays an important role during sexual selection, given that females choose their mating partners based on this colouration (Fitze et al., submitted).
When first described, Uca capricornis was believed to be 2 distinct species: U. capricornis and U. pavo, based on the extreme difference in colouration between males of different sizes [34].
These species are distinguished mainly based on the exceptionally diverse and vivid male nuptial colouration; there is relative morphological uniformity among species.
Although yellow colouration in these species (which is based on the deposition of the carotenoids lutein and zeaxanthin obtained directly from the diet [ 14]) has been intensively studied, a confirmation of its signalling function is still elusive.
Imada et al. (2010) noted that the coordinated movement may be based on the interaction with a conspecific individual and that the interaction may be mediated by factors such as movement pattern and morphology (but not body colouration or body size).
Birds were sexed based on morphology (males are larger than females [ 61]) and aged based on gape colouration (as in other corvids, gape colour in NC crows changes over time from pink, through mottled grey, to black [ 49, 62]).
Notwithstanding some uncertainty in the ageing of corvids based on gape colouration (see Methods), we are confident that birds with black gapes (>90 % black) were adults – a group of subjects that was found in our experiments to exhibit considerable variation in manufacturing behaviour (Fig. 2).
