Effect of roost harassment on cormorant movements and roosting in the delta region of Mississippi

  • Published source details Tobin M.E., King D.T., Dorr B.S., Werner S.J. & Reinhold D.S. (2002) Effect of roost harassment on cormorant movements and roosting in the delta region of Mississippi. Waterbirds, 25, 44-51.


This study is summarised as evidence for the following.

Action Category

Disturb birds at roosts

Action Link
Bird Conservation
  1. Disturb birds at roosts

    A replicated, controlled study in 1997 near channel catfish Ictalurus punctatus ponds in the Mississippi delta, USA (Tobin et al. 2002), found that harassed double-crested cormorants Phalacrocorax auritus flew farther to their next roost than birds not harassed the previous night. Only 11% of harassed birds returned to the same roost within 48 hours, compared with 81% return to non-harassed roosts. Harassment shifted birds away from areas of catfish farm concentrations, but effects were temporary. Farmers undertook co-ordinated night-roost harassment patrols and prior to patrols, 50 cormorants were radio-tagged and their movements monitored from January through March 1997.


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