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Providing evidence to improve practice

Individual study: Winter roost harassment for dispersing double-crested cormorants Phalacrocorax auritus away from catfish production areas in the Mississippi Delta Region, USA

Published source details

Mott D.F., Glahn J.F., Smith P.L., Reinhold D.S., Bruce K.J. & Sloan C.A. (1998) An evaluation of winter roost harassment for dispersing double-crested cormorants away from catfish production areas in Mississippi. Wildlife Society Bulletin, 26, 584-591


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Disturb birds at roosts Bird Conservation

A controlled experiment over three winters in the vicinity of channel catfish Ictalurus punctatus rearing ponds in the Mississippi delta region, USA (Mott et al. 1998), found that the number of double-crested cormorants Phalacrocorax auritus on or near fish ponds was reduced by approximately 70% following a winter of extensive harassment at roosts. Catfish farmers within an area of intensive roost harassment also reported a reduction in fish predation by cormorants. Significantly fewer cormorants used intensely harassed night roosts than less intensely harassed or roosts that were not harassed. Pyrotechnics (designed to scare birds) were fired at roosting cormorants and those flying towards the roost during the two hours before sunset. Cormorants were counted on or near ponds and comparisons made between intensely harassed, less intensely harassed and non-harassed roost sites.