n African Zoology - Sex differentiation based on the gular stripe in the apparently monomorphic Cape gannet : research article

Volume 49, Issue 1
  • ISSN : 1562-7020
  • E-ISSN: 2224-073X
This article is unavailable for purchase outside of Africa



The Cape gannet, , has long been considered a monomorphic species despite attempts at phenotypically separating the sexes. In a further effort we here recorded morphometric measurements from genetically sexed Cape gannets. Discriminant function analysis was used to classify sexes according to these morphometric measurements. Culmen and gular stripe lengths were selected as the best discriminators, correctly classifying 65% of birds. Male Cape gannets had significantly longer culmens and gular stripes than females. We thereby provide the first evidence suggesting that the Cape gannet demonstrates some level of dimorphism. Nonetheless, morphometric criteria used to separate sexes holds limited value due to overlap in measurements between sexes.

Loading full text...

Full text loading...


Article metrics loading...


This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error