Alpine Lynx Cat History Alpine Lynx Kittens

The common belief that Alpine Lynx Cat inhabit only forested areas is only partly true. In Europe and Siberia, they live indeed in large deciduous, mixed, or coniferous forests. In central Asia, however, Alpine lynx also inhabit quite open and sparsely wooded regions, including areas outside the wooded belt and above the permanent timberline (Breitenmoser et al. 2000). In the Alps, the extended forests of the montane and sub-alpine zones are the Alpine  lynx’ preferred living space. Areas above the timberline are not permanently occupied, and the high Alpine ridges with permanent snow and glaciers are considerable barriers to the expansion of the existing adapt to the more open parts of the Alps. Alpine Lynx Cat Females in the north-western Swiss Alps have reproduced in home-ranges with a forest cover of not more than 25-30 per cent (Breitenmoser-Würsten et al. in press). This semi-open landscape provides still good cover habitat and – compared to the bottom of the valleys – a reduced human presence. In addition, this altitude corresponds very often with the highest chamois abundance; a good prey base is at least as important as forest cover.

Alpine  Lynx Cat

Lynx are solitary living animals, except for females with the offspring of the year. Usually home ranges of males overlap at the edges to a certain extent, whereas ranges of neighbouring females overlap only slightly if ever (Haller and Breitenmoser 1986, Haller 1992). Generally, adult males share their home ranges with one or two, rarely more females. Home range sizes vary considerably depending on habitat type, composition of prey community, and density of prey. Studies based on telemetry resulted in precise estimates of Alpine lynx home ranges in the Swiss Alps: 71 – 450 km 2 for males and 45 – 197 km 2 for females (100% convex polygon; Haller and Breitenmoser 1986, Breitenmoser-Würsten et al. in press). In southern Slovenia, home ranges of 2 male and 2 female lynx ranged from 132 – 222 km 2 (Stanisa 1996).

Alpine Lynx Food Ecology

Many different items can be found in the lynx’ diet, however, the staple food of lynx in the Alps are ungulates, mainly roe deer and chamois (Breitenmoser and Haller 1987). In the eastern Alps, lynx predation on red deer has been observed regularly (Gossow and Honsig-erlenburg 1988, Molinari 1998). Lynx prey also on livestock, mainly sheep, goats and farmed fallow deer (Angst et al. 2000; see also status reports of Switzerland and Slovenia).

A lynx’ consumption rate averages 1-2.5 kg of meat per day. If undisturbed, they return to a kill until all edible parts are consumed. On average, lynx kill between 50-70 ungulates a year, depending on species, age and sex of the prey. The influence of lynx predation on a local ungulate community depends on the structure of the prey community, number and social structure of the lynx population, other causes of prey mortality like disease or hunting, presence of competitors and scavengers as well as landscape. In addition, the impact of predation may change considerably over time. Recent studies (Filonov 1980, Breitenmoser und Haller 1987, Okarma et al. 1997, Jobin 1998) have shown that roe deer mortality caused by lynx predation can be as low as 2%, but may reach locally 41%.

Alpine Lynx

The predation mortality needs to be interpreted in a wider context though; it has to be compared to all other mortalities or the prey population dynamics. Even a predation mortality of 30% does not necessarily lead to a decrease in roe deer density, if the population can compensate for this mortality. Nevertheless, few studies (e.g. Haller 1992) have shown that the quantitative impact of the Alpine lynx may cause locally a great reduction of the roe deer density. In other regions, the development of a lynx population did not hinder a considerable increase in roe deer populations (Stahl et al. 2001a). Besides, predation may also have a qualitative impact on prey populations.

In the presence of predators prey individuals may change their dispersion, their social organisation and behaviour. By influencing behavioural mechanisms e.g. by inducing competition for predator-safe space indirect effects of predation may reduce the carrying capacity for prey. However, at the time being we do not have enough case studies to draw a general picture about the significance of lynx predation for the prey populations.

Reproduction

Mating takes place from February to mid-April. Kittens are born after 67-74 days, usually in late May. Litter size is generally 2 or 3 (range 0-5). Kittens follow their mother until the next mating season. They leave the mother at the age of around 11 months, when they have a weight of 9-14 kg. Mean dispersal distance of lynx in the Swiss Alps averaged 26 km (Zimmermann, unpubl. data). In nature, lynx were reported to live up to 15 years, but the average age of adult lynx is 4.5 years (n = 52, KORA, unpubl. data). Besides, the natural mortality among juvenile lynx is high (Breitenmoser et al. 2000). Currently, the most important known mortality factors of lynx in the Alps are traffic accidents and illegal killings. Even though a viable lynx population will tolerate a controlled harvest, in Switzerland and Slovenia over-hunting or illegal killing have been considered to be the reason for the halt of the expansion or even the decline of local populations.

 Lynx Cat

Population

Under natural conditions, lynx density is obviously regulated by prey availability and social interactions among Alpine lynx. Up to now, there is no evidence for the effect of diseases or intrinsic factors on the population dynamics of lynx in the Alps, although, in the Swiss Alps, sarcoptic mange (Sarcoptes scabies) caused a few losses. In the Alps, illegal killings are the most important limiting factor of lynx density.

The density of self-provisioning lynx ranged from 1,2-2.1 individuals/100 km² in a local occurrence of the Swiss Alps (Haller and Breitenmoser 1986, Breitenmoser-Würsten et al. in press). As a consequence of its specialised feeding habits, the lynx shows numeric reaction to changes in prey base (KORA, unpubl. data, Stanisa, pers. com.).