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Acta vet. scand. 1994, 35, 457-459.

Brief Communication

Behavioural Changes in Free-ranging Red ( vulpes) due to Sarcoptic Mange

Sarcoptic mange (Sarcoptes scabiei var. observations) and inactive fixes are inter• vulpes) reached Scandinavia in the mid-1970's preted as resting (e.g. by direct observations). and is mainly prevalent among red foxes As expected, an individual chi-square (Zx2) ta• (Vulpes vulpes) (Borg 1987). In the labora• ble-test indicate that healthy red foxes more tory, foxes succumb 2-4 months after being in• than the mangy red foxes are regularly noc• fested, and it is commonly thought that car• turnal. Symptoms of scab on the skin (Todd riers in the wild exhibit an abnormal be• et al. 1981) and clinical diagnosis with the as• haviour and quickly die (Marner & Christens• sistance of a veterinary surgeon were used to son 1984, Holt & Berg 1990). However, there verify mange infestation. is a lack of comparative data from free-rang• Significance (p<0.001) and close to signifi• ing animals to contribute to the ecology of the cance (p<0.10) were recorded for the 2 species in general the con• healthy individuals on the basis of regular tent of the above selected references in partic• roaming at night and resting during the day. In ular (e.g. Plowright 1988). Using telemetry comparison, the mangy individuals demon• studies, I have compared the behaviour in strated no significant values, but seemed to winter of 2 mange infested and 2 healthy red have more irregular rhytms of inactive versus foxes. The work took place in 1987 and 1990 active behaviour (Table 1). Furthermore, the in a area adjacent to farmland in cen• mangy individuals lived in very small areas tral (63°20'N10° 45'E). compared to healthy foxes and hence walked During February and March 1987, I radio• short distances (except in 1 instance), and op• tracked a male and a female red , both erated in habitats not considered normal for mange infested, and in February and March foxes; when captured for tagging, the infested 1990, 2 healthy females were radio-tracked in female had a scab about 2 cm in diameter at the same area. The individuals were tracked the base of her tail. The first 7 days after her once daily and were randomly monitored for release she showed regular nocturnal activity, periods of up to Sh (Kenward 1987). The ac• mostly inside a 1 km2 area. However, she was tivity pattern of each was tested with inactive for the following 13 days except the respect to night and day, with the expectancy last 1 when, in the middle of the day, she that normal individuals would not diverge walked 6 km away from what until then had from a regular activity pattern, i.e. active at been the area she lived in, and was shot close night and resting in daytime (Table 1). Active to human settlement. The vixen seemed le• fixes are interpreted as hunting (e.g. by direct thargic, her tail was hairless and her back had

Acta vet. scand. vol. 35 no. 4 - 1994 458 K. Overskaug

Table 1. Number of active and inactive telemetry fixes during day (07.00-19.00) and night (19.00-07.00) re• spectively of 2 mangy and 2 healthy red foxes monitored during late winter.

Date Fixes: Day Fixes: Night Fox: monitored day, month Active Inactive Active Inactive x' p

*l 22.02-13.03.1987 5 5 14 8 0.115 0.50 *2 23.03-03.04.1987 0 3 7 5 3 15.02-15.03.1990 5 13 34 2 23.37 0.001 4 15.02-15.03.1990 10 8 38 11 3.14 0.10

*Mangy fox. a 7-8 cm diameter scab. The infested male had Under normal conditions, foxes require good scabs on a large area of his back. For the first cover, e.g. old (Burrows 1968, Weber week following his release he remained active 1985), this being practised by the 2 healthy inside a 1 km2 area. He gradually spent more foxes in this study, but not, according to my time resting in a nearby den, and died there observations, by the mangy female which at around 3 April. The 2 healthy foxes showed the end of her life roamed around in daytime regular nocturnal activity, leaving their day• on open fields close to human settlement. This bed between dusk and dawn, and visiting most impression of atypical behaviour in mange• of their home ranges of 3.5 km2 and 9.5 km2, infested foxes was strengthened by random respectively. sampling of 7 foxes in the study area, all of Red foxes are mainly nocturnal, following a which had mange and were shot during the 24h rhythm (Ables 1975, Artois 1985). This day near farms. was shown by the 2 healthy foxes in this study, It has been reported that red foxes can re• but not the 2 infested ones which were inac• cover from mange (Storm et al. 1976), but a tive for periods of several days. Furthermore, marked reduction in the Scandinavian the area use of the 2 healthy foxes was within population during the late 1970s and 1980s in• the values reported for red foxes elsewhere in dicates that the disease significantly reduces Scandinavia (Lindstrom 1982), whereas the the red fox population (Lindstrom et al. 1994). mangy individuals operated within very lim• Furthermore mange has been reported in pro• ited areas, which is not considered normal tected like the mountain fox (Alopex under Nordic conditions. I suggest that the ) and lynx (Lynx lynx), the red fox be• reason for the irregular rhythm and reduced ing thought to be the vector (Bjiirvall & activity in the 2 infested individuals is reduced Lindstrom 1984). In Denmark, severe anxiety fitness as a result of mange. Long rest periods as to whether the red fox population will re• may also accelerate other possible conse• cover after mange has led to a vaccination quences of the disease, e.g. starvation and re• programme for foxes (Steinar 1993). Because duced vigilance. The latter was observed dur• of the drastic consequences the disease may ing the unexpected and hazardous daytime have for the red fox itself, and possibly also roaming of the infested female out of the area for species it interacts with, it may be worth she had inhabited, leading to her death by increasing research into the relationships to shooting. obtain more knowledge and enable active

Acta vet. scand. vol. 35 no. 4 - 1994 Behavioural changes due to sarcoptic mange 459 management if this is deemed desirable. One Borg K: A review of wildlife diseases from Scandina• contribution could be to study aspects of basic via. Journal of Wildlife Diseases. 1987, 23, 527- 533. biology in individual, healthy and infested Burrows R: Wild Fox. Newton Abbot, Devon. 1968, free-living . 203 pp. Despite some weaknesses, e.g. few animals Holt G, Berg C: Sarcoptesskabb hos r¢drev og andre and tracking in different years, the results of viltlevende rovdyr i Norge (Sarcoptic mange in this study support the assumptions of Marner red fox and other wild carnivores in Norway). Norsk Veterimertidsskrift. 1990, 102, 427-432. & Christensson (1984) that infested foxes ex• Kenward R: Wildlife Radio Tagging. Equipment, perience particular difficulties in finding food, Field Techniques and Data Analysis. Biological in this case during long rest periods within Techniques series. 1987, 203 pp. limited areas lacking access to food. As Holt Lindstrom E: Population ecology of the Red Fox (Vulpes vulpes L.) in relation to food supply. & Berg (1990) supposed, it also seems that in• Ph.D. Thesis, Univ. of Stockholm . 1982, fested individuals may deviate from a normal 150pp. nocturnal life in dense habitats - resulting in Lindstrom ER, Andr'en H, Angelstam P, Cederlund daytime exposure near humans. G, Hornfeldt B, Jiiderberg L, Lemnell PA, Mar• tinsson B, Skold, K, Swenson J E: Disease reveals Acknowledgements the predator: sarcoptic mange, red fox , I thank the veterinary surgeon, M. Fj¢lstad, for help• and prey populations. Ecology, 1994, 75, 1042- ing to diagnose mange and for valuable discussions 1049. on the topic, and E. R¢skaft and 2 anonymous refer• Marner T, Christensson D: Experimental infection of ees for valuable comments on the manuscript. The red foxes (Vulpes vulpes) with Sarcoptes scabiei Environmental Division of the County Office in var. vulpes. Veterinary Parasitol. 1984, 15, 159- South Tr¢ndelag County and the Sch¢yen Trust at 164. the University of Trondheim - Norway provided fi• Plowright W- Research on wildlife diseases: is a reap• nancial support. praisal necessary? Rev. sci. tech. Off. int. Epiz. 1988, 7, 783-795. Steinar M: (Request to hunters: livetrap and disin• Kristian Overskaug fect a red fox!) Opfordring ti! Jcegerne fra DMU: Norwegian Institute for Nature Research (Tunas• Fang og vask en rcev! Jceger, 1993, 4, 32-33. letta, 7005) Trondheim, Norway. Storm GL, Andrews RD, Phillips RL, Bishop RA, Siniff DB, Tester JR: Morphology, reproduction, References dispersal, and mortality of Midwestern red fox Ables ED: Ecology of the red fox in America. The populations. Wildlife Monographs, 1976, 49, 82 wild canids; their systematics, behavioral ecology pp. and evolution. Van Nostrand Reinhold Co., New Todd AW, Gunson JR, Samuel WM: Sarcoptic York, N.Y. 1975, 216-236. mange: an important disease of and Artois M: Use of space and time in the red fox of , . In Proc. First World• (Vulpes vulpes) and the wild ( silvestris) wide Furbearer Conf., J.A. Chapman and D. in Lorraine. Gibier Faune Sauvage. 1985, 33-57. Pursley (eds.). 1981, 706-729. Bjiirvall A, Lindstrom D: Lodjuret 1974-83 i Norr• Weber D: Zur Baubenutzung und ihrer Funktion bottens fjallvarld. Fauna och flora, 1984, 79, 213- beim Fuchs (Vulpes vulpes). Z. Saugtierk. 1985, 226. 50, 356-368.

(Received November 20, 1993; accepted September 24, 1994).

Reprints may be requested from: K. Overskaug, Norwegian Institute for Nature Research, Tungesletta 2, N-7005 Trondheim, Norway.

Acta vet. scand. vol. 35 no. 4 - 1994