Ecology, Diet and Behaviour of Two Fox Species in a Large, Fenced Protected Area in Central Saudi Arabia
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ARTICLE IN PRESS Journal of Arid Environments Journal of Arid Environments 57 (2004) 45–60 www.elsevier.com/locate/jnlabr/yjare Ecology, diet and behaviour of two fox species in a large, fenced protected area in central Saudi Arabia Daniel M. Lenaina,b, Ernst Olfermanna, Stuart Warringtonb,* a National Wildlife Research Center, P.O. Box 1086, Taif, Saudi Arabia b Department of Environmental Sciences, University of Hertfordshire, Hatfield, Hertfordshire AL10 9AB, UK Received 1 October 2002; accepted 9 May 2003 Abstract The aim of the research was to determine the status and to study aspects of the ecology of the fox species Vulpes vulpes arabica and Vulpes ruppelli. sabea inside and outside a large fenced Protected Area, Mahazat as-Sayd in Saudi Arabia. V. ruppelli. sabea was the most abundant small carnivore, witha density of 0.7–1.0 km À2 which was about 12 times greater than V. vulpes arabica and both fox populations were greater inside Mahazat than outside. Annual survivorship of V. ruppelli. sabea was 39% (based on Jolly–Seber method) and 70% (based on mean residence rate). The fox species had similar diets with small mammals and invertebrates being the most important components. V. ruppelli. sabea population existed as pairs holding home ranges all year of 7.2 km2 and producing 3.3 cubs on average. r 2003 Elsevier Ltd. All rights reserved. Keywords: Fox; Carnivore; Arid; Desert; Home range; Population ecology; Diet; Mark–release–recapture 1. Introduction The Vulpes genus is one of the most successful of the Order Carnivora. However, limited information is available about the status and ecology of foxes in arid and semi-desert areas suchas theArabian Peninsula ( Ginsberg and Macdonald, 1990). *Corresponding author. E-mail address: [email protected] (S. Warrington). 0140-1963/03/$ - see front matter r 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0140-1963(03)00088-0 ARTICLE IN PRESS 46 D.M. Lenain et al. / Journal of Arid Environments 57 (2004) 45–60 Three Vulpes species have been recorded in Saudi Arabia. Ruppell’s. fox (Vulpes ruppelli. sabea) and the Arabian red fox (Vulpes vulpes arabica) are the most abundant and widespread (Harrison and Bates, 1991) withBlandford’s fox ( Vulpes cana) being confined to rocky, mountainous areas (Geffen et al., 1992b). In recognition of declining numbers of many species, due to hunting, disturbance and habitat degradation, His Royal Highness Prince Saud Al Faisal established the National Commission for Wildlife Conservation and Development (NCWCD) and the National Wildlife Research Center (NWRC) in Saudi Arabia in 1986. The basis of the Saudi Arabian conservation programme was the NCWCD’s Protected Area System Plan (Child and Grainger, 1990) which established a network of 11 large Protected Areas. The Protected Area Mahazat as-Sayd, established in central-west Saudi Arabia, is unique as it is the only reserve that is fenced. This large area of 2244 km2 provided an opportunity to study the recovery of an arid ecosystem now protected from grazing domestic stock and human disturbance and to evaluate re- introduction programmes that could be used later to release animals within the wider network of protected areas. Re-introduction programmes at Mahazat as-Sayd have included houbara bustard (Chlamydotis [undulata] macqueenii)(Seddon et al., 1995), Reem Gazelle (Gazella subguttorosa) and Arabian oryx (Oryx leucoryx) (Ostrowski et al., 1998). Six small carnivore species have been recorded in Mahazat as-Sayd (Table 1) including two fox species, Vulpes ruppelli. sabea and V. vulpes arabica. The fox species, especially V. vulpes arabica, have been implicated in adversely affecting the houbara bustard re-introduction programme, with over 40% of deaths of newly released sub-adult birds attributed to mammalian predators in 1992–94, but avian predators were also a cause of mortality (Combreau and Smith, 1998). There is a very limited literature on the ecology of these fox species in semi-arid areas and only one study of V. ruppelli. sabea which was conducted in Oman (Lindsay and Macdonald, 1986). Table 1 Small mammalian carnivores of Mahazat as-Sayd, Saudi Arabia Species Common name Status Canidae Vulpes vulpes arabica Thomas, 1902 Arabian red fox Common Vulpes ruppelli. sabea Pocock, 1934 Ruppell’s. fox Numerous Mustelidae Mellivora capensis (Schreber, 1776) Ratel Very rare Felidae Felis silvestris tristrami Pocock, 1944 African wild cat Occasional Felis margarita harrisoni Hemmer, Grubb and Groves, 1976 Arabian sand cat Occasional Felis domesticus (Linnaeus, 1758) Feral cat Rare Status in Mahazat is based on this study and observations by NWRC staff. ARTICLE IN PRESS D.M. Lenain et al. / Journal of Arid Environments 57 (2004) 45–60 47 The aim of this project was to determine the status and to study aspects of the ecology of fox populations inside and outside the Mahazat as-Sayd Protected Area. The fox population studies were based on intensive mark–release–recapture (MRR) techniques, with some radio-tracking work to research home range and faecal analysis for diet investigations. The results of the study are intended to provide a quantitative basis for the formulation of management plans in Mahazat as-Sayd and other arid region protected areas to ensure that the conservation of native small carnivores and the restoration of potential prey species are complementary endeavours. For example, translocation of foxes away from a houbara release area had not proved to be a cost-effective approach to reducing predation (Lenain and Warrington, 2001). In addition, this is the first extensive study of the ecology of these two fox species in the central plateau of the Arabian Peninsula. 2. The study site, Mahazat as-Sayd The 2244 km2 Mahazat as-Sayd was declared a Protected Area in 1988 and was surrounded by about 220 km of chainlink fence, topped with barbed wire to a height of 2.1 m by March 1989. The approximate centre of the area is located at 22150N, 41400E, some 150 km north-east of the city of Taif. Mahazat as-Sayd is a hot and semi-arid to arid desert steppe habitat, typical of the central plateau of the Arabian Peninsula, gently undulating at elevations of 900–1050 m above sea level. Three distinct substrates could be distinguished from a 1995 LANDSAT image; a gravel plain, a basalt undulating plain, and a chert area interspersed with basaltic outcrops. Sand and fine gravel are the dominant surface substrates covering over 95% of the Area. Mean monthly maximum temperatures range from 19Cto42C and minimums from 6Cto25C. Rainfall is very variable ranging from 46 to 240 mm per annum over the study period, with an average of 100 mm, and typically occurs between Marchto May eachyear, but withoccasional important rain events at other times. There is no permanent source of water above ground level in Mahazat as-Sayd but ephemeral pools exist for short periods after heavy rain. After completion of the fence 112 vascular plant species were identified, this figure had increased to 142 species by 1994 and 156 species by 1997 (Collenette, 1997). 16 mammal species have been recorded and 159 species of birds, of which 17 have been confirmed as breeding. 3. Methods The investigations into fox ecology in Mahazat were divided into two phases: (1) an intensive study from May 1992 to January 1994 of foxes in 100 km2 (about 5%) of Mahazat including detailed observation of individual foxes, and (2) a more extensive study from September 1996 to April 1998 across the whole of Mahazat including three sites outside of Mahazat (see Fig. 1). For the purposes of the study, the seasons ARTICLE IN PRESS 48 D.M. Lenain et al. / Journal of Arid Environments 57 (2004) 45–60 Motorway to Riyadh 670 km To Taif 160 km N 0 20 km Fig. 1. The fenced Protected Area of Mahazat as-Sayd in central Saudi Arabia. The rectangular box is the trapped area for Phase 1 of the research. indicates the location of a trapping grid from Phase 2 inside Mahazat. J indicate the location of trapping grids outside of Mahazat. The two research camps and the location of gates in the fence are also shown. were defined as: Spring (March–May), Summer (June–August), Autumn (Septem- ber–November), Winter (December–February). 3.1. Population studies Investigations into fox population abundance were based on mark–release– recapture (MRR) techniques. Tomohawk live traps (Tomohawk Live Trap Company, Wisconsin, USA) of 40 Â 40 Â 108 cm in size were used, and although double ended, only one door was opened. The other end was baited with a piece of raw chicken and was rebaited after 2 days or if the bait had been consumed. The traps have a metal plate, which rises when the trap is set and when tripped causes the door to close. Traps were set and baited in the 2 h before dusk and each trap was placed by vegetation where it would be shaded from the morning sun. Traps were visited within 3 h of first light and all foxes trapped were individually marked using numbered plastic ear tags (Rototags, Dalton Supplies Ltd., UK). All animals on capture or recapture were identified, sexed, weighed to the nearest 10 g and released at the point of capture. The trapping procedures were as follows: Phase 1. Fifty-two traps were established in a 13 Â 4 grid, trap spacing 1 km, and 12 trapping sessions of 10 nights in length were carried out at 45 day intervals. Phase 2. Twelve random points (all more than 2 km from the fence and 10 km from each other) were located across Mahazat and were the centre of the trapping grids. Eachtrapping grid consisted of 10 traps (2 Â 5 grid, trap spacing 1 km).