Harris et al. Biology of Tibetan fox Canid News Copyright © 2008 by the IUCN/SSC Canid Specialist Group. ISSN 1478-2677 The following is the established format for referencing this article: Harris et al. 2008. Notes on the biology of the Tibetan fox. Canid News 11.1 [online] URL: http://www.canids.org/canidnews/11/ Biology_of_Tibetan_fox.pdf. Research Report Notes on the biology of the Tibetan fox Richard B. Harris1*, Wang Zhenghuan2, Zhou Jiake1, and Liu Qunxiu2 1 Department of Ecosystem and Conservation Sciences, College of Forestry and Conservation, Univer- sity of Montana, Missoula, Montana, USA. 2 School of Life Science, East China Normal University, Shanghai, People’s Republic of China. * Correspondence author. Email: [email protected] Keywords: body size; brown bear; China; mating; Ursus arctos; Vulpes ferrilata; whelping Abstract Introduction We report on three aspects of the biology of Until recently, biological data on the Tibetan Tibetan foxes Vulpes ferrilata for which existing fox was gained mostly from anecdotal reports, literature is either absent or misleading. Our observations of their sign, or hunting records two field studies in western China each in- (e.g. Gong and Hu 2003; Schaller and Gisnberg volved capture (and subsequent radio- 2004; Wang et al. 2003, 2004, 2007). Because marking) of foxes, allowing us to refine exist- Tibetan foxes live in remote, mountainous en- ing information on body size and mass. Ti- vironments and are rarely observed in the betan foxes we captured were somewhat lar- wild, some aspects of their biology have been ger and heavier than the current literature difficult to document. Although classified by suggests is characteristic of the species. Our IUCN as Least Concern, the species remains observations of marked foxes during winter poorly studied. Within China some zoological and spring suggested that in our study areas museums contain skins and skulls of Tibetan whelping occurs in late January. We also re- foxes, but poor management and record keep- port that brown bears Ursus arctos, which also ing has limited the usefulness of these speci- appear to subsist largely on plateau pikas mens. To our knowledge there are no Tibetan Ochotona curzoniae, are frequently accompa- foxes held in captivity. nied by Tibetan foxes and the foxes seem to benefit from preying on pikas excavated by We recently initiated two independent studies the bears. of Tibetan fox ecology using radio-marked individuals; handling animals and being able to observe them more frequently have allowed 1 Harris et al. Biology of Tibetan fox us to update and improve existing information Stipa spp.) and shrubs (mainly Sibiraea angus- on this little known canid of the Tibetan tata, Potentilla fruticosa, Spiraea spp. and Salix steppe (Figure 1). Here we provide informa- spp.). Extensive pastoralism by Tibetan herd- tion on body size and mass, whelping dates, ers was the predominant land use in both and associations with other species. In some study areas. In addition to Tibetan foxes, red cases, our more intensive studies allow us to foxes V. vulpes were present at both sites (and correct information currently in the literature, occasionally captured). much of which is poorly documented. Methods Capture and handling At the Shiqu site foxes were caught with snares set at den entrances. Snares were de- signed with a fixed smallest neck size (15cm) and checked every 12 hours to avoid potential damage to captured foxes. Foxes were immo- bilized without anaesthetic (Arjo et al. 2002). At the Dulan site, foxes were captured with leghold traps (Victor Soft-Catch®, Wood- stream Corporation, Lititz, Pennsylvania, USA), or Belisle® (Edouard Belisle, Sainte- Veronique, Quebec, Canada) and immobilized with ketamine hydrochloride (approximately 6mg/kg) and medetomidine (approximately Figure 1. Tibetan fox, Shiqu, Sichuan, China. Photo 0.05 mg/kg). At the Dulan site all capture and by Zhang Kejia. handling procedures complied with Univer- sity of Montana Animal Use Committee Proto- cols. Fox capture work at the Shiqu study site took place during the last week of September Study areas 2003, the last two weeks of May 2006, and 10 May-12 June 2007. At the Dulan site, trapping occurred during 10-20 April and 22-25 Sep- We studied Tibetan foxes in two separate tember 2006, and 15-26 September 2007. study areas in Qinghai and Sichuan provinces, People’s Republic of China. Our Qinghai We captured a total of 18 individual foxes at study was initiated primarily to document the Shiqu study site (nine males, five females, relationships between fine-scale habitat selec- four juveniles) and six individual foxes at the tion (i.e. within home-range, second order se- Dulan study site (four males, one female, one lection, sensu Johnson 1980) and the density of juvenile; one male was captured in both 2006 their primary prey, plateau pikas. Our Si- and 2007). Body mass was estimated using a chuan study area was selected because of on- spring scale (Figure 2), and standard body going research on the parasite Echinococcus measurements were obtained using flexible, multilocularis, for which the Tibetan fox is an cloth tapes. We judged animals captured dur- important definitive host (Qiu et al. 1995). In ing April-June trapping periods to be juveniles Qinghai, our study site was centred on ap- (animals less than six months old) if they ap- proximately 35.5º N, 98.7º E, in Gouli Town- peared to have large head and paws relative to ship, Dulan County; we refer to this as the their body size, very sharp and unworn teeth, “Dulan site” hereafter. In Sichuan, our study and slender tails; we lacked a way to estimate site was centred on approximately 34º N, 98º E ages of animals older than six months old and in Shiqu County; we refer to this as the “Shiqu considered them all adults. site” hereafter. Both study areas consisted of rolling hills and mountains at elevations of 4,000-4,500m, with vegetation typified by grassland (dominated by Kobresia spp. and 2 Harris et al. Biology of Tibetan fox Observations data had not been given. Our field studies did not provide opportunity for us to observe mat- We made observations incidental to radio- ing; thus we cannot be sure when this occurs. tracking in Dulan on most days between 15 April 2006 and 26 September 2007. Radio- collars were attached to most captured indi- viduals, and foxes were tracked on the ground Table 1. Body measurements of live, adult Tibetan daily in Dulan and during occasional, inten- foxes obtained in Shiqu, Sichuan, and Dulan, Qing- hai, 2003-2007. Mass in kg. HB = head-body length, sive tracking periods in Shiqu. T = tail length, E = ear length (all in cm). Males Females Mass x 4.9 3.9 sd 0.6 0.3 n 6.0 6.0 HB x 67.3 62.8 sd 4.4 3.4 n 13.0 6.0 T x 27.4 27.5 Figure 2. Weighing an immobilized Tibetan fox, sd 4.1 3.7 Dulan, Qinghai, China. Photo by Marie-Claire Be- dard. n 13.0 6.0 E x 6.5 6.7 sd 0.8 0.4 Results n 10.0 5.0 Body size of Tibetan foxes Mean (± SD) body mass of captured Tibetan However, we were able to observe three of our foxes was 4.9 (±0.6) kg for males (range 4.4- radio-marked foxes (two males, one female) at 5.7kg) and 3.9 (±0.3) kg for females (range 3.6- the Dulan site on an almost daily basis during 4.1kg) (Table 1). Head-body length averaged the period January – June 2007. We observed 67.3 (±4.4) cm for males and 62.8 (±3.4) cm for pups (identified visually by much smaller size females. Four animals captured in Shiqu dur- than adults) with one of the males at a den site ing late June and early July, 2007 and judged as early as 10 February, and observed this to be juveniles, had a mean body mass of 2.2 male in the company of three pups and an (±0.1) kg, and a mean head-body length of 52.5 unidentified adult on 11 February. During (±3.1) cm. A female captured in late Septem- this time period, this male killed pikas for the ber 2007 in Dulan weighed 3.4kg, and her pups, often spending time in the company of head-body length was 57.5cm; we judged her the pups while the female was absent, sug- to be less than one year old. gesting that male Tibetan foxes participate in pup rearing. By 1 May, three pups we were Mating and whelping dates able to observe in the vicinity of this den ap- peared to be approximately ¾ the size of the According to Ginsberg and Macdonald (1990), adult male. We continued to observe pups in mating occurs in February with two to five the vicinity of this den until 3 June, after young born in May. This information was which we no longer observed pups that we repeated by Nowak (1999), Hayssen et al. could reliably associate with the male or den- (1994), and by Schaller and Ginsberg (2004), site. Our second radio-collared male was ob- who noted however, that the source for these 3 Harris et al. Biology of Tibetan fox served with a second fox that that appeared to successfully capturing a pika. In September be a pup of similar size to those we had ob- 2002, we first documented a Tibetan fox asso- served during the same time period with the ciating with a brown bear that was digging first radio-marked male on 6 May.