Black shag (Phalacrocorax carbo): roost counts at Melling, Hutt Valley, and breeding in the Wellington region | Notornis and Birds New Zealand

[摘要] We counted the black shags (Phalacrocorax carbo) frequenting a night roost at Melling, 4.5 km up-river from the Hutt River mouth, Wellington, New Zealand, and studied the timing of breeding at various colonies in the Wellington region. Numbers at the roost were counted from Oct 1993 to Sep 1998: maximum and minimum mean monthly counts were in Feb and Aug, respectively. The main egg-laying period of 3 coastal colonies (0–2 km) (Mar–May) was c. 3 months earlier than at 2 inland (5 - 33 km) colonies (Jun–Aug. We discuss the possibility that the difference in timing of breeding by shags in colonies at different distances from the coast is related to the different timing of peak prey availability in the 2 habitats (coastal marine, and inland riverine).

[学科分类] 动物科学

[关键词] breeding phenology;coastal;diet;inland;night roosts;Phalacrocorax carbo