Original Research
Precision of helicopter-based total-area counts of large ungulates in bushveld
Koedoe | Vol 45, No 2 | a33 |
DOI: https://doi.org/10.4102/koedoe.v45i2.33
| © 2002 B.K. Reilly
| This work is licensed under CC Attribution 4.0
Submitted: 14 December 2002 | Published: 14 December 2002
Submitted: 14 December 2002 | Published: 14 December 2002
About the author(s)
B.K. Reilly, Technikon Pretoria, South AfricaFull Text:
PDF (145KB)Abstract
Precision in helicopter total-area counts in bushveld for a range of common species are evaluated. Counts were conducted on properties ranging in size from 250 ha to 10 000 ha as part of experiments on precision and power. Counts were conducted in three vegetation types: mopane veld, sourish mixed bushveld and arid bushveld. Scant regard is given to precision as a factor in large herbivore monitoring, with more effort often devoted to accuracy. Coefficients of variation varied from 3.2 % to 70.9 %. Median values are generally acceptable for the establishment of trends for long-term monitoring, but might be inadequate for annual population size monitoring and evaluation. A regression of all species and vegetation types by the standard error showed a significant correlation. Similar regressions were also developed for impala, kudu, warthog, and zebra. Regressions by vegetation type for mopane veld, sourish mixed bushveld, and northwest arid bushveld were also significant. However, the high correlation for some vegetation types might be an artifact of the small sample sizes.
Keywords
Census; Game counting; Helicopter counts; Impala; Kudu; Zebra; Wildebeest
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