Fish and harlequin ducks compete on breeding streams
Back to previous page
| Authors: | LeBourdais, SV; Ydenberg, RC; Esler, D |
| Year: | 2009 |
| Journal: | Canadian Journal of Zoology-Revue Canadienne de Zoologie 87: 31-40 Article Link (DOI) |
| Title: | Fish and harlequin ducks compete on breeding streams |
| Abstract: | We investigated interactions among harlequin ducks (Histrionicus histrionicus ( L., 1758)), fish, and their shared aquatic insect prey. We measured flow variability, benthic aquatic prey abundance, fish presence, and breeding density of harlequins on eight rivers in the Southern Coast Mountain Range in British Columbia, Canada, in 2003 and 2004. Rivers with lower flow variability had higher abundance of aquatic insects. Densities of harlequins and fish presence on the rivers were both significantly and positively related to insect abundance, but path analysis revealed a strong negative correlation between them. We interpret this as an indirect interaction between harlequins and fish mediated by anti-predator behaviour of insects in the presence of fish, which reduces insect availability, rather than as a reduction in the abundance of aquatic insects through consumption by fishes. We hypothesize that the ongoing and widespread introduction of fish into historically fishless waters throughout North America may have contributed to the current low productivity and recruitment measured in populations of harlequins by reducing quality of breeding habitat. |
Please send suggestions for improving this publication database to
sass-support@sfu.ca.
Departmental members may update their publication list.