AN EXPERIMENTAL-STUDY OF THE IMPACT OF FERAL SWAMP BUFFALO, BUBALUS-BUBALIS, ON THE BREEDING HABITAT AND NESTING SUCCESS OF MAGPIE GEESE, ANSERANAS-SEMIPALMATA, IN KAKADU-NATIONAL-PARK
L. Corbett et Al. Hertog, AN EXPERIMENTAL-STUDY OF THE IMPACT OF FERAL SWAMP BUFFALO, BUBALUS-BUBALIS, ON THE BREEDING HABITAT AND NESTING SUCCESS OF MAGPIE GEESE, ANSERANAS-SEMIPALMATA, IN KAKADU-NATIONAL-PARK, Biological Conservation, 76(3), 1996, pp. 277-287
The impact of buffalo Bubalus bubalis grazing and trampling on magpie
goose. Anseranas semipalmata breeding habitat and nest numbers was stu
died over nine wet seasons (1980-88) at Kapalga within Kakadu National
Park. Aerial photographs provided data to compare nest densities with
in six vegetation types in an area where buffalo grazed throughout the
study with an area where buffalo were removed midway through. Buffalo
had no significant effect on the abundance or distribution of vegetat
ion types important to geese for breeding. However, high densities of
buffalo suppressed the growth of several other species, particularly t
he grass Hymenachne acutigluma which increasingly displaced the deep w
ater spike-rush Eleocharis sphacelata after buffalo were removed. The
annual number of nests fluctuated between 7 and 2028, apparently in re
sponse to rain. Most nests were built in the spike-rush/wildrice Eleoc
haris spp./Oryza rufipogon association (71%) and in E. sphacelata (20%
). Buffalo trampling and grazing influenced the location of nests but
not number. After buffalo were removed, more nests were built in deep
water areas at the forest edge of the floodplain. Copyright (C) 1996 E
lsevier Science Limited.