Item Details

title

Population Size of Blue-footed Boobies in Galápagos: Evaluation of Indications of Population Decline

author

Anchundia, David Jhon

abstract

Census and survey data for blue-footed boobies (Sula Sula nebouxii excisa) ) in Galápagos, Ecuador from 2011-2012 indicated a population reduction, probably by more than 50%. Anthropogenic effects such as introduced predators are unlikely to explain this decline, because islands with and without such factors exhibited the same low breeding. The poor reproduction seems to be linked to scarcity of food. Previous studies indicated that sardine and herring (Clupeidae) support successful breeding, but these fish were mostly absent from the diet. Elsewhere in the eastern Pacific, sardines have decreased dramatically in abundance by natural processes in the last 15 years, as part of a well-documented and apparently natural cycle. This cyclic change in abundance provides an explanation for the recent demographic changes in blue-footed boobies in Galápagos.

subject

Blue-footed booby

breeding

Clupeids

Demographic process

Galapagos

Population size

contributor

Anderson, David J (committee chair)

Silman, Miles R (committee member)

Anderson, Todd M (committee member)

date

2013-06-06T21:19:29Z (accessioned)

2013-06-06T21:19:29Z (available)

2013 (issued)

degree

Biology (discipline)

identifier

http://hdl.handle.net/10339/38539 (uri)

language

en (iso)

publisher

Wake Forest University

type

Thesis