Summary In recent decades, the Eurasian lynx Lynx lynx has recolonized former habitat, bringing it into potential conflict with livestock. We studied the spatial and temporal distribution of lynx attacks on sheep in the French Jura between 1984 and 1998, during and after its population expansion. We estimated the local and regional impact of lynx predation on livestock. The number of attacks increased from three in 1984 to 188 in 1989, concurrently with the colonization of the main sheep range by lynx. During subsequent years, 66–131 attacks were recorded annually (92–194 sheep killed per year). On average, 1·6 sheep were killed per attack. Lynx preyed disproportionately on lambs and subadult sheep. A small percentage of flocks (9·5–22·9%) were attacked, most of which (75·2%) were attacked once or twice a year. At the regional level, annual sheep losses to lynx were 0·14–0·59% of the total number of sheep. The major lynx–livestock problem was due to clustered attacks in a few small areas. Each year, two to six ‘hot spots’ (33–69% of the attacks) were identified. Hot spots covered 0·3–4·5% of the total area where attacks occurred (1835–4061 km2). Roe deer abundance was higher in hot spots and, even here, sheep only made up 3·1% of the lynx diet. These data show that lynx were not killing sheep due to shortages of alternative prey or in response to an increased need for food when rearing young. The concentration of hot spots in only nine small areas between 1984 and 1998 indicated that only a few individual lynx were involved. The reappearance of hot spots at the same sites, after years of interruption and despite the removal of lynx, suggested that the ultimate factors causing hot spots were factors inherent to those sites. Further investigation is needed to identify causal factors with a view to eliminating them. These may relate to landscapes features, animal husbandry practices or the behavioural ecology of lynx. In future, where large predator reintroductions are planned, the potential for concentrated, localized, impact should be evaluated and mitigation measures put in place. For scattered and episodic lynx damage, financial compensation is the only realistic option at present. In hot spots, the cost‐effectiveness of guard‐dogs or the selective removal of some individual lynx should be evaluated.

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal of Animal Ecology. Summary 1. The present study compares breeding parameters and adult survival rate in a herring gull colony before and after the closing of a large refuse tip where breeders used to find most of their food. During the first study period (1983-88) food of human origin was abundant and virtually always available. During the second period (1989-90) such food was scarce. 2. The annual adult survival rate was time-dependent. It varied from 0-826 (SE = 0.031) in 1987-88 to 0-975 (SE = 0-022) in 1985-86. The average survival rate calculated for 1983-90 was 0-881 (SE = 0-014).There was no significant difference in adult survival between males and females. The closure of the refuse tip was not followed by a significant decrease in adult survival rate. 3. After the refuse tip was closed, mean clutch size and mean production of young per breeding pair decreased by 6-7% and 49 1%, respectively. Mean adult body weight decreased by 4-6% for males and by 4-7% for females. 4. The proportion of non-breeders among former breeders and the proportion of 3and 4-year-old individuals among ringed birds did not change after closure of the tip. 5. The results are discussed in terms of the life-history theory, which predicts that in long-lived species a decrease in food supply should affect fecundity before affecting adult survival.

We studied Grey Partridge Perdix perdix mortality during breeding to identify the environmental causes of a long-term decline in adult survival. We radiotagged and monitored daily from mid-March to mid-September 1009 females on ten contrasting study sites in 1995-97. Simultaneously, we recorded habitat features and estimated the abundance of Hen and Marsh Harriers Circus cyaneus and C. aeruginosus, Red Fox Vulpes vulpes and mustelids. We experimentally tested whether scavenging could have biased predation rates. We also examined, through the necropsy of 80 carcasses of Grey Partridge, whether disease, parasites or poisoning could have been ultimate causes of high predation rates. The survival rate of radiotagged females during spring and summer ranged from 0.25 to 0.65 across study areas. Mortality peaked in May, June and July when females were laying and incubating. The direct negative impact of farming practices was low (6%). Predation was the main proximate cause of female mortality during breeding (73%) and determined the survival rate, suggesting no compensation by other causes of mortality. Ground carnivores were responsible for 64% of predation cases, and raptors for 29%, but this proportion varied across study sites. Disease and poisoning did not appear to favour predation, and scavenging was not likely to have substantially overestimated predation rates. The predation rate on breeding females was positively correlated with the abundance of Hen and Marsh Harriers, suggesting an additional mortality in areas where harriers were abundant. The proportion of raptor predation was linearly related to harrier abundance. The predation rate was not correlated with the abundance of the Red Fox and mustelids. A potential density-dependent effect on the predation rate was confounded by the abundance of harriers. We found no convincing relationship between the predation rate and habitat features, but we observed a positive relationship between the abundance of Hen and Marsh Harriers and the mean field size. This suggested that habitat characteristics may contribute to high predation rates through predator abundance or habitat-dependent predation.

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Recolonization by wolves (Canis lupus) of areas of extensive sheep breeding in the French Alps in the early 1990s led to intense conflicts over losses of domestic livestock. We used data on depredations and sheep herd management from 45 pastures of the Mercantour Mountains of the French Alps to build models of attack and kill rates and to quantify the efficiency of using livestock‐guarding dogs and of gathering or confining herds at night to prevent damage. Efficiency of livestock‐guarding dogs was lowest when sheep were ranging freely and highest when sheep were confined at night. The effect of livestockguarding dogs on depredations was heterogeneous across pastures. When sheep were confined at night, presence of 3 to 4 dogs was predicted to prevent a large majority (>95%) of kills that would have occurred in the absence of dogs for 81% of pastures. No effect of dogs was found for the other 19% of pastures. Confining or simply gathering sheep at night in the presence of 5 livestock‐guarding dogs was predicted to prevent most kills (94% and 79%, respectively) that would have occurred in similar conditions but with free‐ranging sheep. Efficiency of each of these 2 techniques was drastically reduced when they were not used jointly. This study suggested that confining sheep in the presence of several livestock‐guarding dogs can prevent a large majority of livestock losses to wolves in the southern French Alps.