Using fine-scale overlap in predator–prey distribution to assess avian predation risk to a reservoir population of threatened Macquarie Perch

Ryan, Katie Anne, Lintermans, Mark, Ebner, Brendan C., and Norris, Richard (2013) Using fine-scale overlap in predator–prey distribution to assess avian predation risk to a reservoir population of threatened Macquarie Perch. Freshwater Science, 32 (4). pp. 1057-1072.

[img] PDF (Published Version) - Published Version
Restricted to Repository staff only

View at Publisher Website: http://dx.doi.org/10.1899/12-059.1
 
3
3


Abstract

Investigations of predator–prey dynamics have largely focused on quantifying predation rates, yet achieving an appropriate sample to quantify predation is difficult when prey populations are small and individuals are rare. Moreover, quantifying rates of predation does not necessarily provide solutions for protecting threatened populations from predation. We used predator abundance and fine-scale predator–prey spatial overlap to identify trends in predation risk from cormorants, Phalacrocorax, to adults of the endangered Macquarie Perch, Macquaria australasica, in Cotter Reservoir, Australia. We made observations of cormorants at Cotter Reservoir between February 2008 and July 2009 to estimate abundance and spatial distribution. We used radiotelemetry to locate adult Macquarie Perch. Cormorant abundance was highest in spring and summer. Increased cormorant abundance corresponded with an increase in the fine-scale overlap of the distributions of Macquarie Perch and cormorant within the reservoir. Overlap was highest in the upstream section of the reservoir, which is characterized by shallow water (<5 m depth). Increased overlap corresponded with congregation of Macquarie Perch in the upper reservoir and movement toward the source river for spawning. Our results provide valuable insight into when and where predation is most likely to occur, thereby allowing conservation efforts to be tailored to protect this threatened fish population effectively.

Item ID: 32163
Item Type: Article (Refereed Research - C1)
Keywords: Macquarie Perch, cormorants, predator abundance, predator–prey overlap, predation risk, threatened species
ISSN: 2161-9565
Funders: ACTEW Corporation, eWater Cooperative Research Centre, University of Canberra
Date Deposited: 30 Apr 2014 00:14
FoR Codes: 06 BIOLOGICAL SCIENCES > 0602 Ecology > 060204 Freshwater Ecology @ 100%
SEO Codes: 96 ENVIRONMENT > 9608 Flora, Fauna and Biodiversity > 960802 Coastal and Estuarine Flora, Fauna and Biodiversity @ 100%
Downloads: Total: 3
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page