| 1. |
- Andren, Henrik, et al.
(författare)
-
Activity patterns of Eurasian lynx are modulated by light regime and individual traits over a wide latitudinal range
- 2014
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- The activity patterns of most terrestrial animals are regarded as being primarily influenced by light, although other factors, such as sexual cycle and climatic conditions, can modify the underlying patterns. However, most activity studies have been limited to a single study area, which in turn limit the variability of light conditions and other factors. Here we considered a range of variables that might potentially influence the activity of a large carnivore, the Eurasian lynx, in a network of studies conducted with identical methodology in different areas spanning latitudes from 49 degrees 7'N in central Europe to 70 degrees 00'N in northern Scandinavia. The variables considered both light conditions, ranging from a day with a complete day-night cycle to polar night and polar day, as well as individual traits of the animals. We analysed activity data of 38 individual free-ranging lynx equipped with GPS-collars with acceleration sensors, covering more than 11,000 lynx days. Mixed linear additive models revealed that the lynx activity level was not influenced by the daily daylight duration and the activity pattern was bimodal, even during polar night and polar day. The duration of the active phase of the activity cycle varied with the widening and narrowing of the photoperiod. Activity varied significantly with moonlight. Among adults, males were more active than females, and subadult lynx were more active than adults. In polar regions, the amplitude of the lynx daily activity pattern was low, likely as a result of the polycyclic activity pattern of their main prey, reindeer. At lower latitudes, the basic lynx activity pattern peaked during twilight, corresponding to the crepuscular activity pattern of the main prey, roe deer. Our results indicated that the basic activity of lynx is independent of light conditions, but is modified by both individual traits and the activity pattern of the locally most important prey.
|
|
| 2. |
- Andren, Henrik, et al.
(författare)
-
Season rather than habitat affects lynx survival and risk of mortality in the human-dominated landscape of southern Sweden
- 2022
-
Ingår i: Wildlife Biology. - : Wiley. - 0909-6396 .- 1903-220X. ; 2022
-
Tidskriftsartikel (refereegranskat)abstract
- Landscapes are mosaics of habitat associated with different risks and resources, including human activities, which can affect individual survival in wildlife. Different relationships between habitat characteristics and human-caused and natural mortality can result in attractive sinks. We used individual-based data from 97 Eurasian lynx Lynx lynx monitored for 160 exposure-years to link adult survival and the risk of mortality to home range habitat characteristics in the human-dominated landscape of southern Sweden. Human-caused mortality (i.e. legal hunting, poaching and vehicle accidents) dominated mortality causes (24 out of 37 deaths). We did not detect any strong effects of habitat characterises explaining the variation in mortality risk in lynx. Although the density of roe deer affects several aspects of lynx ecology, we could not detect any effects of roe deer density on lynx survival, probably because roe deer density was sufficiently high in our study area. Instead, seasonal variation was the main factor influencing mortality in lynx. Mortality was highest during the hunting season for lynx (16 February-31 March), as well as during autumn and winter, probably because lynx poaching occurs opportunistically during the hunting season for moose and roe deer. We did not find any indication that human activity created attractive sinks for lynx, since there were no contrasting patterns between human-caused and natural mortality in terms of habitat characteristics. One explanation for the limited influence of the home range characteristics may be that lynx in our study died from multiple causes. Therefore, it is less likely that one or a few habitat characteristics could explain the risk of mortality at the home range scale. There is strong evidence that lynx can coexist with humans in multi-use and human-dominated landscapes, even without large protected areas, if the management regimes are favourable.
|
|
| 3. |
|
|
| 4. |
- Johansson, Örjan, et al.
(författare)
-
Land sharing is essential for snow leopard conservation
- 2016
-
Ingår i: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 203, s. 1-7
-
Tidskriftsartikel (refereegranskat)abstract
- Conserving large carnivores in an increasingly crowded planet raises difficult challenges. A recurring debate is whether large carnivores can be conserved in human used landscapes (land sharing) or whether they require specially designated areas (land sparing). Here we show that 40% of the 170 protected areas in the global range of the snow leopard (Panthera uncia) are smaller than the home range of a single adult male and only 4-13% are large enough for a 90% probability of containing 15 or more adult females. We used data from 16 snow leopards equipped with GPS collars in the Tost Mountains of South Gobi, Mongolia, to calculate home range size and overlap using three different estimators: minimum convex polygons (MCP), kernel utility distributions (Kernel), and local convex hulls (LoCoH). Local convex hull home ranges were smaller and included lower proportions of unused habitats compared to home ranges based on minimum convex polygons and Kernels. Intra-sexual home range overlap was low, especially for adult males, suggesting that snow leopards are territorial. Mean home range size based on the LoCoH estimates was 207 km(2) +/- 63 SD for adult males and 124 km(2) +/- 41 SD for adult females. Our estimates were 6-44 times larger than earlier estimates based on VHF technology when comparing similar estimators, i.e. MCP. Our study illustrates that protected areas alone will not be able to conserve predators with large home ranges and conservationists and managers should not restrict their efforts to land sparing. (C) 2016 Elsevier Ltd. All rights reserved.
|
|
| 5. |
- Johansson, Örjan, et al.
(författare)
-
Sex-specific seasonal variation in puma and snow leopard home range utilization
- 2018
-
Ingår i: Ecosphere. - : Wiley. - 2150-8925. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Territory size is often larger for males than for females in species without biparental care. For large solitary carnivores, this is explained by males encompassing a set of female territories to monopolize their reproduction during mating (area maximization). However, males are expected to behave more like females outside of breeding, with their area utilization being dependent on the range required to secure food resources (area minimization). To examine how male and female solitary carnivores adjust their spatial organization during the year as key resources (mates and prey) change, we radio-collared 17 pumas (Puma concolor; nine males and eight females) and 14 snow leopards (Panthera uncia; seven males and seven females) and estimated home range size and overlap on two temporal scales (annual vs. monthly). Contrary to expectation, we found no evidence that males monopolized females (the mean territory overlap between females and the focal male during the mating season was 0.28 and 0.64 in pumas and snow leopards, respectively). Although male-male overlap of annual home ranges was comparatively high (snow leopards [0.21] vs. pumas [0.11]), monthly home range overlaps were small (snow leopards [0.02] vs. pumas [0.08]) suggesting strong territoriality. In pumas, both males and females reduced their monthly home ranges in winter, and at the same time, prey distribution was clumped and mating activity increased. In snow leopards, females showed little variation in seasonal home range size, following the seasonal stability in their primary prey. However, male snow leopards reduced their monthly home range utilization in the mating season. In line with other studies, our results suggest that female seasonal home range variation is largely explained by changes in food resource distribution. However, contrary to expectations, male territories did not generally encompass those of females, and males reduced their home ranges during mating. Our results show that male and female territorial boundaries tend to intersect in these species, and hint at the operation of female choice and male mate guarding within these mating systems.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Mattisson, Jenny, et al.
(författare)
-
Lethal male–male interactions in Eurasian lynx
- 2013
-
Ingår i: Mammalian Biology. - : Springer Science and Business Media LLC. - 1616-5047 .- 1618-1476. ; 78, s. 304-308
-
Tidskriftsartikel (refereegranskat)abstract
- Eurasian lynx (Lynx lynx) is considered a solitary, territorial felid with a low degree of direct intraspecific interactions. Between 2002 and 2011 we observed four aggressive interactions between five different male Eurasian lynx, where two were lethal. All interactions occurred during the mating season and three of the interactions resulted in takeover of the home range by the intruder. Thus, in this study we demonstrate that aggressive interactions, sometimes with severe consequences, occur in male Eurasian lynx and suggest that they are driven primarily by access to female lynx in the mating season. (C) 2012 Deutsche Gesellschaft far Saugetierkunde. Published by Elsevier GmbH. All rights reserved.
|
|
| 9. |
- Mattisson, Jenny, et al.
(författare)
-
Predation or scavenging? Prey body condition influences decision-making in a facultative predator, the wolverine
- 2016
-
Ingår i: Ecosphere. - : Wiley. - 2150-8925. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- The interaction between predators and their prey is a key factor driving population dynamics and shaping wildlife communities. Most predators will scavenge in addition to killing their own prey, which alters predation effects and implies that one cannot treat these as independent processes. However, the relative importance of predation vs. scavenging and the mechanisms driving variation of such are relatively unstudied in ecological research on predator-prey relationships. Foraging decisions in facultative predators are likely to respond to environmental conditions (e.g., seasonality) and inter- or intraspecific interactions (e.g., prey availability, presence of top predators, scavenging competition). Using data on 41 GPS-collared wolverines (Gulo gulo) during 2401 monitoring days, in four study sites in Scandinavia, we studied variation in diet and feeding strategies (predation vs. scavenging), along a gradient of environmental productivity, seasonality, density, and body mass of their main prey, semidomestic reindeer (Rangifer tarandus). The most important factor affecting the relative extent of predation and scavenging was mean prey body mass. Predation was more pronounced in summer, when vulnerable reindeer calves are abundant, and individual kill rates were negatively related to local reindeer body mass. This relationship was absent in winter. The probability of scavenging was higher in winter and increased with decreasing local reindeer body mass, likely as a response to increased carrion supply. Wolverine feeding strategy was further influenced by predictable anthropogenic food resources (e.g., slaughter remains from hunted ungulates) and the presence of a top predator, Eurasian lynx (Lynx lynx), which provided a continuous carrion supply promoting scavenging. Our results suggest that wolverine feeding strategies are flexible and strongly influenced by seasonally dependent responses to prey body condition in combination with carrion supply. This study demonstrates that large-scale environmental variation can result in contrasting predator feeding strategies, strongly affecting trophic interactions and potentially shaping the dynamics of ecological communities.
|
|
| 10. |
|
|
