Feral donkey Equus asinus populations on the Karpaz peninsula, Cyprus
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Numerous researchers have documented the adverse effects of feral donkeys Equus asinus introduced to semi-arid ecosystems. With the release of feral donkeys and potential increasing populations in natural habitats in northern Cyprus, there is concern for negative impacts on vegetation and native species. In the north of the island, there has been only one published study of feral donkey populations, and population estimators were relatively subjective. We estimated feral donkey populations on the Karpaz Peninsula using line transect surveys and quantitative distance sampling estimators. We stratified the sampling by using 11 sample units within the study area. We evaluated potential biases associated with habitat, topography, and perpendicular distance from the transect line and found that these variables did not bias donkey detections during our surveys. Using program DISTANCE, we found that a hazard rate cosine model was the best model that described our distance data based on model selection criterion (Akaike’s Information Criteria adjusted for small sample bias). Estimated effective strip width was 280.19 m and detection probability was 0.47 with this model. Estimated donkey density was 6.7 donkeys/km2, and estimated total abundance was 800 donkeys for the entire 132.5 km2 study area. Of 95 donkey groups detected: 16% were detected in agricultural habitats with flat topography, 9% were detected in agricultural habitats with sloped topography, 24% were detected in shrub/forest habitats with flat topography, and 51% were detected in shrub/forest habitats with sloped topography. Of 102 behavioral observations recorded (multiple behaviors were detected in groups), frequencies of behaviors were 1% bedded, 70% standing, 22% grazing, 6% moving, and 2% other. Our estimated donkey population density in the Karpaz Peninsula was >2 times densities reported in arid regions of the United States and Australia, but slightly lower than earlier density estimates reported for the Karpaz region. These estimates of feral donkey populations in the Karpaz Peninsula provide a quantitative baseline from which to make population management decisions.
KeywordsAbundance estimation Cyprus Density estimation Distance sampling Equus asinus Feral donkeys Karpaz Peninsula Line transect
A large number of people assisted with the field surveys, including students at Lefke European University, Near East University, Eastern Mediterranean University, and Girne American University. Other volunteer participants in the surveys included members of the Biologists Society, Women Organisation KAYAD, and Anglo Turkish Society. We thank Mr Hasan Karaokcu and Mr Haluk Dogandor for their support. We thank SID -Lefkosa Chapter for creating an awareness of this issue. Maps and GPS used in the survey supplied by the Karpaz Peninsula Mapping office, the Karpaz Peninsula Environmental Protection Office director and personel made great contribution to the survey. Major funding for the research was provided by Turkish Embassy (mainland Turkish Republic), the the Karpaz Peninsula Hunting Association, and Warnell School of Forest Resources of the University of Georgia.
- Buckland ST, Anderson DR, Burnham KP, Laake JL (1993) Distance sampling: estimating abundance of biological populations. Chapman and Hall, London. (http://www.colostate.edu/depts/coopUnit/distancebook/download.html)Google Scholar
- Choquenot D (1990) Rate of increase for populations of feral donkeys in northern Australia. J Mamm 71:151–155Google Scholar
- Choquenot D (1991) Density-dependent growth, body condition, and demography in feral donkeys: testing the food hypothesis. Ecology 72:805–813Google Scholar
- Hanley TA, Brady WW (1977) Feral burro impact on a Sonoran Desert range. J Range Manag 30:374–377Google Scholar
- Johnson RA, Carothers SW, McGill TJ (1987) Demography of feral burros in the Mohave Desert. J Wildl Manag 51:916–920Google Scholar
- Reid SWJ, Godley BJ, Henderson SM, Lawrie GJ, Loyd D, Small K, Swannie N, Thomas RL (1997) Ecology and behaviour of the feral donkey, Equus asinus, population of the Karpas Peninsula, northern Cyprus. Zool Middle East 14:27–36Google Scholar
- Seegmiller RF, Ohmart RD (1981) Ecological relationships of feral burros and desert bighorn sheep. Wildl Monogr 78, 58 ppGoogle Scholar
- Thomas L, Laake JL, Strindberg S, Marques FFC, Buckland ST, Borchers DL, Anderson DR, Burnham KP, Hedley SL, Pollard JH (2002) Distance 4.0. Release 2. Research Unit for Wildlife Population Assessment, University of St. Andrews, UK. http://www.ruwpa.st-and.ac.uk/distance/
- Wagner FH (1983) Status of wild horse and burro management of public rangelands. Trans North Am Wildl Nat Res Conf 48:116–133Google Scholar
- Woodward SL, Ohmart RD (1976) Habitat use and fecal analysis of feral burros (Equus asinus), Chemehuevi Mountains, California, 1974. J Range Manag 29:482–485Google Scholar