| 1. |
|
|
| 2. |
- Bonnot, Nadège, et al.
(författare)
-
Who’s afraid of the big bad wolf? : Variation in the stress response among personalities and populations in a large wild herbivore
- 2018
-
Ingår i: Oecologia. - Amsterdam : Springer. - 0029-8549 .- 1432-1939. ; 188:1, s. 85-95
-
Tidskriftsartikel (refereegranskat)abstract
- Faced with rapid environmental changes, individuals may express different magnitude and plasticity in their response to a given stressor. However, little is known about the causes of variation in phenotypic plasticity of the stress response in wild populations. In the present study, we repeatedly captured individual roe deer (Capreolus capreolus) from two wild populations in Sweden exposed to differing levels of predation pressure and measured plasma concentrations of stress-induced cortisol and behavioral docility. While controlling for the marked effects of habituation, we found clear between-population differences in the stress-induced cortisol response. Roe deer living in the area that was recently recolonized by lynx (Lynx lynx) and wolves (Canis lupus) expressed cortisol levels that were around 30% higher than roe deer in the human-dominated landscape free of large carnivores. In addition, for the first time to our knowledge, we investigated the stress-induced cortisol response in free-ranging newborn fawns and found no evidence for hypo-responsiveness during early life in this species. Indeed, stress-induced cortisol levels were of similar magnitude and differed between populations to a similar extent in both neonates and adults. Finally, at an individual level, we found that both cortisol and docility levels were strongly repeatable, and weakly negatively inter-correlated, suggesting that individuals differed consistently in how they respond to a stressor, and supporting the existence of a stress-management syndrome in roe deer. © 2018, The Author(s).
|
|
| 3. |
- Jarnemo, Anders, et al.
(författare)
-
Hjortvilt i Sverige - en kunskapssammanställning
- 2018
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport är en kunskapssammanställning över det svenska hjortviltets utbredning, biologi, hemområdesstorlekar, rörelsemönster och mellanartsinteraktioner. Kunskapssammanställningen är del i ett underlag för en handlingsplan under utarbetande av berörda myndigheter (Jordbruksverket, Naturvårdsverket, Statens veterinärmedicinska anstalt (SVA)) med anledning av risken för spridning av avmagringssjuka (Chronic wasting disease, CWD). Rapporten sammanställdes på uppdrag av Naturvårdsverket (NV-07973-17).Förekomst av älg, rådjur, kronvilt och dovvilt i Sverige har kartlagts med hjälp av statistik över avskjutning och viltolyckor. Älg och rådjur är fördelat över hela landet, där rådjuren förekommer i högre utsträckning söder om den biologiska norrlandsgränsen (Limes norrlandicus, genom södra Värmland i väster till Gästrikland i öster) jämfört med norr om denna. Kronvilt förekommer i samtliga län förutom Norrbottens och Gotlands län, men har en fläckvis utbredning med huvudsaklig utbredning i Götaland och södra Svealand. Starka populationer finns i Skåne, Kalmar län och Sörmland. Dovviltet förekommer främst i södra Sverige med tyngdpunkt i Skåne, Östergötland och Sörmland.Älgen är en solitärlevande art med undantag av kor med kalvar. Gruppbildning kan dock uppstå på platser med attraktiv föda, speciellt under vintern. Även om vandringar kan styras av viltstängsel, infrastruktur, vattendrag och topografi, finns inga absoluta barriärer i landskapet för älg. Medan älgar i södra Sverige är mer stationära, är det i Norrland vanligt med säsongsvandringar på upp till 200 km. Hemområdesstorlek kan variera kraftigt mellan olika populationer, men generellt har norrländska älgar större hemområden än de sydsvenska, med maximalvärden 29 000 ha respektive 6 000 ha. Likaså har inlandsälgar större hemområden än kustälgar i Norrland.Rådjur lever ensamma eller i små familjegrupper. Utvandringsfrekvensen är hög för båda könen. Arten verkar tämligen okänslig för olika typer av barriärer i landskapet och har en snabb spridningskapacitet. I södra Sverige rör det sig vanligen om en genomsnittlig utvandring på 1-3 km, men sträckor på upp till 100 km har observerats på Grimsö. I Norrland är utvandringsfrekvensen mycket hög och här utvandrar rådjuren längre sträckor med i genomsnitt 115-125 km med en längsta observerad utvandring på 470 km. I Syd- och Mellansverige verkar rådjurs hemområden sällan överstiga 100 ha, men man kan förvänta sig större hemområden i jordbruksdominerade landskap. I Västerbotten har hemområden på upp til 2 000 ha uppmätts. Kronvilt är grupplevande. Hindarna är trogna sitt uppväxtområde och spridningen går långsamt. Hjortarna är mer benägna att utvandra. Kronvilt är känsliga för barriärer, vilket ytterligare fördröjer spridning. Hindar i Skåne har en genomsnittlig hemområdesstorlek på 2 600 ha (max. 5 900 ha), medan hindar i Kolmården har 1 200 ha (max 1 800 ha) och hindar på Hunneberg 900 ha (max. 1 500 ha). Medan de mellansvenska hindarna verkar stationära, kan skånska hindar säsongsvandra eller pendla på avstånd upp till 25 km. Hjortarna i Kolmården och i Skåne hade vintersommarområden på i genomsnitt 3 400 ha (max. 6 600 ha) respektive 4 300 ha (max. 8 700 ha). Det är vanligt både i Kolmården och i Skåne att hjortarna säsongsvandrar mellan vinter-sommarområde och brunstområde upp till 23 respektive 47 km. Under brunsten kan hjortar också besöka två eller flera brunstlokaler belägna på avstånd upp till 18 km ifrån varandra.Dovvilt är utpräglat grupplevande och kan bilda mycket täta populationer. Spridningen till nya områden går mycket långsamt. Det verkar vanligt att unga hjortar utvandrar, medan utvandringen av hindar är låg. På Koberg har hemområden för hindar mätts till i genomsnitt 270 ha (max. 647 ha). För hjortar har hemområden på upp till 1 760 ha uppmätts. Av 18 hjortar gjorde fyra säsongsvandringar på mer än 5 km mellan brunstplats och vinter-sommarområde.Såväl habitat- som födoöverlapp kan vara stort mellan älg, rådjur, kronvilt och dovvilt. Arterna kan också ses beta i varandras närhet på fält med attraktiva grödor, liksom att de kan utnyttja samma foderplatser och detta ibland samtidigt. Aggressivt beteende från dovvilt kan dock förmå rådjur och kronvilt att dra sig undan. En negativ effekt av dovvilt på rådjur härrör troligen både från födokonkurrens och interferens.
|
|
| 4. |
- Jarnemo, Anders, et al.
(författare)
-
Hur reagerar kronvilt på drevjakt?
- 2015
-
Ingår i: Svensk jakt. - 0039-6583. ; 153, s. 52-55
-
Tidskriftsartikel (populärvet., debatt m.m.)
|
|
| 5. |
- Jarnemo, Anders, et al.
(författare)
-
Temporal variations in activity patterns during rut - Implications for survey techniques of red deer, Cervus elaphus
- 2017
-
Ingår i: Wildlife research (East Melbourne). - Clayton : CSIRO Publishing. - 1035-3712 .- 1448-5494. ; 44:2, s. 106-113
-
Tidskriftsartikel (refereegranskat)abstract
- Context Intraspecific differences in behaviour can affect censuses and bias population estimates, suggesting that choice and implementation of census methods are fundamental, and need to be adapted to behavioural variations. Aims We investigated temporal variations in activity patterns during the rut among red deer (Cervus elaphus) categories and the implications for two different census methods. Methods We used a long-term dataset collected during 17 consecutive red deer rutting seasons in southernmost Sweden. The two census methods were: (1) a collection of observation ratios; and (2) a count of individuals including identification of males. Both methods are commonly used in ungulate management. Key results There was a difference in activity among age and sex categories, with a temporal variation in activity and/or presence at rutting grounds of adult (≥6 years) and subadult (2-5 years) males. Observation ratios of adult and subadult males increased from low at the start of the rut to a top level during peak rut, with subadults lagging behind adults. Before and during peak rut, the proportion of adult males was higher than that of subadults. After peak rut, the proportion of adult males decreased, whereas subadult males remained high, resulting in a higher number of subadults than of adults. The comparison of the two census methods revealed a strong correlation regarding the trends of population size and for the age and sex categories. There was also a strong consistency concerning the calf/female ratio. The male proportion was, however, consistently lower in the collected observations than in the counts. Conclusions The lower proportion of males in observations compared with counts may be explained by behavioural differences among male age classes, i.e. by temporal variations in presence and activity. That females, calves and yearling males are stationary during the rut, but adult and subadult males arrive and depart the rutting grounds at varying points of time, can lead to an underestimated male proportion in continuously collected observation data. Implications The results suggest that census should be conducted during peak rut, and that incorporating identification of individual males in the monitoring may be beneficiary. © CSIRO 2017.
|
|
| 6. |
- Peters, Wibke, et al.
(författare)
-
Large herbivore migration plasticity along environmental gradients in Europe : life-history traits modulate forage effects
- 2018
-
Ingår i: Oikos. - Chichester : Wiley-Blackwell Publishing Inc.. - 0030-1299 .- 1600-0706. ; 128, s. 416-429
-
Tidskriftsartikel (refereegranskat)abstract
- The most common framework under which ungulate migration is studied predicts that it is driven by spatio–temporal variation in plant phenology, yet other hypotheses may explain differences within and between species. To disentangle more complex patterns than those based on single species/ single populations, we quantified migration variability using two sympatric ungulate species differing in their foraging strategy, mating system and physiological constraints due to body size. We related observed variation to a set of hypotheses. We used GPS-collar data from 537 individuals in 10 roe Capreolus capreolus and 12 red deer Cervus elaphus populations spanning environmental gradients across Europe to assess variation in migration propensity, distance and timing. Using time-to-event models, we explored how the probability of migration varied in relation to sex, landscape (e.g. topography, forest cover) and temporally-varying environmental factors (e.g. plant green-up, snow cover). Migration propensity varied across study areas. Red deer were, on average, three times more migratory than roe deer (56% versus 18%). This relationship was mainly driven by red deer males which were twice as migratory as females (82% versus 38%). The probability of roe deer migration was similar between sexes. Roe deer (both sexes) migrated earliest in spring. While territorial male roe deer migrated last in autumn, male and female red deer migrated around the same time in autumn, likely due to their polygynous mating system. Plant productivity determined the onset of spring migration in both species, but if plant productivity on winter ranges was sufficiently high, roe deer were less likely to leave. In autumn, migration coincided with reduced plant productivity for both species. This relationship was stronger for red deer. Our results confirm that ungulate migration is influenced by plant phenology, but in a novel way, that these effects appear to be modulated by species-specific traits, especially mating strategies. © 2018 The Authors. Oikos © 2018 Nordic Society Oikos
|
|
| 7. |
- Wikenros, Camilla, et al.
(författare)
-
Fear or food - Abundance of red fox in relation to occurrence of lynx and Wolf
- 2017
-
Ingår i: Scientific Reports. - London : Nature Publishing Group. - 2045-2322. ; 7:1
-
Tidskriftsartikel (refereegranskat)abstract
- Apex predators may affect mesopredators through intraguild predation and/or supply of carrion from their prey, causing a trade-off between avoidance and attractiveness. We used wildlife triangle snow-tracking data to investigate the abundance of red fox (Vulpes vulpes) in relation to lynx (Lynx lynx) and wolf (Canis lupus) occurrence as well as land composition and vole (Microtus spp.) density. Data from the Swedish wolf-monitoring system and VHF/GPS-collared wolves were used to study the effect of wolf pack size and time since wolf territory establishment on fox abundance. Bottom-up processes were more influential than top-down effects as the proportion of arable land was the key indicator of fox abundance at the landscape level. At this spatial scale, there was no effect of wolf abundance on fox abundance, whereas lynx abundance had a positive effect. In contrast, at the wolf territory level there was a negative effect of wolves on fox abundance when including detailed information of pack size and time since territory establishment, whereas there was no effect of lynx abundance. This study shows that different apex predator species may affect mesopredator abundance in different ways and that the results may be dependent on the spatiotemporal scale and resolution of the data. © 2017 The Author(s).
|
|
| 8. |
- Wikenros, Camilla, et al.
(författare)
-
Mesopredator behavioral response to olfactory signals of an apex predator
- 2017
-
Ingår i: Journal of ethology. - Tokyo : Springer-Verlag Tokyo Inc.. - 0289-0771 .- 1439-5444. ; 35:2, s. 161-168
-
Tidskriftsartikel (refereegranskat)abstract
- Olfactory signals constitute an important mechanism in interspecific interactions, but little is known regarding their role in communication between predator species. We analyzed the behavioral responses of a mesopredator, the red fox (Vulpes vulpes), to an olfactory cue (scat) of an apex predator, the lynx (Lynx lynx) in BiaÅ‚owieÅŒa Primeval Forest, Poland, using video camera traps. Red fox visited sites with scats more often than expected and the duration of their visits was longer at scat sites than at control sites (no scat added). Vigilant behavior, sniffing and scent marking (including over-marking) occurred more often at scat sites compared to control sites, where foxes mainly passed by. Vigilance was most pronounced during the first days of the recordings. Red fox behavior was also influenced by foxes previously visiting scat sites. They sniffed and scent marked (multiple over-marking) more frequently when the lynx scat had been over-marked previously by red fox. Fox visits to lynx scats may be seen as a trade-off between obtaining information on a potential food source (prey killed by lynx) and the potential risk of predation by an apex predator. © 2017, The Author(s).
|
|
