June 6, 2013 — Colonies of gannets maintain vast exclusive fishing ranges despite doing nothing to defend their territory from rival colonies, scientists have discovered.
A team of researchers led by the University of Leeds and the University of Exeter observed that northern gannets, which can fly hundreds of kilometres on a single fishing trip, avoided visiting the fishing grounds of gannets from neighbouring colonies.
The findings, published in the journal Science, could transform our understanding of animals' foraging patterns because individual gannets do nothing to enforce this territory or communicate its boundaries when out at sea. A bird entering from a neighbouring colony would be free to fly and fish unhindered.
Co-lead author Dr Ewan Wakefield, postdoctoral researcher in the University of Leeds' Faculty of Biological Sciences, said: "The accepted view is that exclusive foraging territories are associated with species such as ants, which aggressively defend the feeding areas around their colonies, but this opens the door to a completely new way of thinking about territory. We found the gannet colonies also had neatly abutting and clearly defined feeding areas. Gannets may be a byword for gluttony but, clearly, they don't eat off each other's plates."
Continued
No comments:
Post a Comment