The control of feral goats (Capra hircus) and relevant aspects of their biology were
studied on Aldabra Atoll, Republic of Seychelles, from October 1993 - May 1994 and
November 1994 - May 1995. A total of 832 goats were killed on Aldabra using both
the Judas goat technique and traditional hunting methods; a total of 28 Judas goats
were used during the entire campaign. The remnant goat populations on Ile Picard
(N=13) and Ile Malabar (N=19) were eradicated during the first season. On Grande
Terre, a total of 798 (374 M: 424 F) goats were killed. The overall kill rate on Grande
Terre was 0.37 goats killed/hour with 1.66 shots fired/goat. A total of 1,042 goats were
encountered of which 26.1% escaped. Mean group size was 3.2 with a range of 1 to 20.
Judas goat hunting became increasingly important over time with 18.0% (n=85) of
goats killed in the first season being in the presence of Judas goats; 42.3% (n=126) of
goats killed during the second season were in the presence of Judas goats. The overall
kill rate for the project was almost 2 times greater for Judas goat hunting (0.61 goats
killed/hr) than traditional hunting (0.32 goats killed/hr); Judas goat hunting was
approximately 70% more effective than traditional hunting when compared using
multiple linear regression. There was a significant relationship between Judas goat
home range size and the number of conspecifics killed. Feral goats on Aldabra may be
unique among feral goat populations by apparently not responding to population
reductions in a density-dependent manner. For the first season, the intrinsic rate of
increase (r) was 0.45; r=0.39 for the second season. Twinning rates were 30.7% and
37.5% in the first and second seasons, respectively. I subjectively estimated
approximately 60-120 goats remaining on all of Grande Terre at the end of the project; 84 goats were estimated using the Leslie-Davis removal method of population estimation. / Graduation date: 1998
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/33921 |
| Date | 09 October 1997 |
| Creators | Rainbolt, Raymond E. |
| Contributors | Coblentz, Bruce E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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