Temporal and spatial correlation in chick production of willow grouse Lagopus lagopus in Sweden and Norway

We analysed the spatial and temporal dynamics of chick production of willow grouse "Lagopus lagopus" in the Swedish and Norwegian mountain region using harvest data covering 24-38 years and line-transect counts covering 6-10 years from the period 1960-2003. Juvenile and adult grouse were counted in the bag of harvested willow grouse in late August and throughout September at six sites in Sweden and Norway. In addition, numbers of juvenile and adult willow grouse were obtained from ine-transect counts at 21 sites in Sweden just before the hunting season started on 25 August. The juvenile:adult ratio from the harvest data, estimated as number of juveniles per two adults, showed similar long-term averages and distributions between all six sites. The results from the line-transect counts revealed an overall higher average and a greater range of production between sites. We suggest that the difference between estimates based on line-transect counts and harvest data are caused by hunter behaviour. Hunters did not sample the juvenile and adult grouse in proportion to what was present in the population, e.g., productivity estimates derived from harvest samples will underestimate the proportion of juveniles in autumn in most years. We suggest that it is the harvest process that acts to adjust the juvenile to old bird ratio in the harvest data to a similar distribution in different sites. We found little evidence of regular fluctuations/cycles in annual production of juveniles from either harvest data or line-transect data. We conclude that chick production in willow grouse appears to fluctuate more irregularly than was previously believed based on harvest data and can not be used as a potential forecasting tool in willow grouse management as suggested earlier. Spatial correlation was weak and investigating only a limited number of sites to predict the proportion of juveniles in autumn should not be considered as a management tool for large areas such as the state-owned land in Sweden. Line-transect counts are costly, but do provide a more accurate estimate of the proportion of juveniles in the fall population than is revealed by harvest data. A more detailed understanding of hunter behaviour is obviously needed for better interpretation of harvest data

Promoting hunting tourism in north Sweden : options of local hunters

Hunting tourism can help to diversify local economies in rural areas. In northern Sweden, hunting tourism has the potential to counteract outmigration and unemployment, but may entail ecological and social risks. I used a mail survey of 2,110 hunters in rural northern Sweden to assess attitudes toward hunting tourism. Respondents emphasized the importance of hunting to maintain economical, social, and cultural values in the rural areas. Most hunters estimated that game contributed equal or larger amount of meat to their household than meat bought commercially. Few respondents had first hand experience of hunting tourism and they were divided on their attitude towards promoting hunting tourism. Many (46%) were uncertain about their attitude towards hunting tourism; 36% were positive and 18% were negative. Ethical values on using wildlife in hunting tourism and the attitude towards new hunters coming to hunt influenced attitudes on development of hunting tourism. Hunters that were positive to hunting tourism believed that it would create new jobs. Because hunting in Sweden is highly organized and collective, there are no models of hunting tourism adapted to the hunting culture in northern Sweden. The uncertainty of the potential local benefits from a development of hunting tourism should be placed within a research framework, especially in the northernmost parts where governmental undertakings are large and the state can influence land use

Vurdering av effekter på det biologiske mangfoldet, dyrevelferd og dyrehelse ved innførsel, oppdrett og utsetting av fasan og rapphøns i Norge

English: The Department of Forestry and Wildlife Management at Inland University of Applied Sciences was commissioned by Fuglehundklubbenes Forbund (FKF) and their Lavlandskomite (LK) to scientifically review and assess the practice of releasing common pheasants (Phasianus colchicus, pheasant) and grey partridges (Perdix perdix, partridge), and specifically evaluate ecosystem effects, effects on biodiversity, animal welfare during rearing, breeding, transport and release, and animal health and disease risks when importing, breeding, rearing and releasing these birds into Norwegian nature. Ecosystem effects of artificially augmenting populations may be positive, negative or negligible from a conservation standpoint. Negative effects include altering of species interactions via resource consumption, agonistic behaviour or predation. These forms of species interactions are amplified with increasing number of released birds. Under extreme circumstances, vegetation and invertebrate abundance have been negatively affected inside and around pheasant release pens in the UK and in the UK, released birds are also likely sustaining high populations of generalist predators. Positive effects of releases include supporting management actions that target factors limiting survival and population growth like predator control, supplementary feeding and habitat improvement. These factors are prerequisites for successful release programs, and they can benefit the conservation status of several other species. Because of low survival and unrealized reproductive potential, population simulations suggest that partridge and pheasant releases in Norway need supporting management efforts to avoid population extinctions. The goal when breeding partridges and pheasants is to select for wild behaviours and this require different rearing conditions compared to domesticated species. Yet, the knowledge base on rearing conditions that meet the need of pheasants and partridges is low. Increasing space and enriching habitats in rearing systems, however, will reduce stress-related behaviours. Rearing conditions should approximate natural conditions with regards to diet, unrestrained sociality between individuals and the possibility of exposure to natural stressors. Various pathogens have been recorded among pheasants in Scandinavia and imports from abroad can expose native galliformes to species-specific disease they would normally not encounter. Several measures can be adopted to minimize risks of spreading pathogens. They include hygiene at rearing farms, veterinary inspections of birds before import and secure pens that prevents contact with outside wildlife. When assessing unintentional effects on ecosystems following the release of captive-bred birds, it is important to consider the scale and extent of the release. Studies focusing on impacts of releases on fauna and flora have to our knowledge only been conducted in the UK where 47 million pheasants are released on an annual basis. The Norwegian release program is dwarfed by comparison and there is currently no information that supports the hypothesis that partridges and pheasants released in Norway the last decade have had negative effects on Norwegian ecosystems or biodiversity. With our current understanding of animal welfare, it is possible to tailor rearing and release programs which minimize risk of the spreading of pathogens and that produce healthy and viable individuals that are well adapted to a life outside of the release pen.Norsk: Institutt for Skog- og Utmarksfag ved Høgskolen i Innlandet fikk i oppdrag av Fuglehundklubbenes Forbund (FKF) og deres Lavlandskomite (LK) om å gjennomgå og vurdere praksisen med utsetting av fasaner og rapphøns, og spesielt evaluere økosystemeffekter, effekter på biodiversitet, dyrevelferd under oppdrett, avl, transport og utsetting, og risiko for dyrehelse og sykdommer ved import, avl, oppdrett og utsetting av disse fuglene i norsk natur. Økosystemeffektene av å øke populasjoner kunstig kan være positive, negative eller ubetydelige fra et bevaringsperspektiv. Negative effekter inkluderer endringer i artenes samhandling via ressursforbruk, agonistisk adferd eller predasjon. Disse formene for interaksjoner mellom arter forsterkes med økende antall fugler satt ut. Under ekstreme forhold har utsetting av fasan hatt negative effekter på vegetasjonsdekke og virvelløse dyr inne i og på utsiden av akklimatiseringshegn i Storbritannia, og i Storbritannia opprettholder utsatt fugl sannsynligvis også høye bestander av generalistpredatorer. Positive effekter av utsetting inkluderer støttende forvaltningstiltak som tar sikte på å begrense faktorer som reduserer overlevelse og populasjonsvekst som rovdyrkontroll, tilleggsfôring og habitatforbedring. Disse faktorene er forutsetninger for vellykkede utsettingsprogrammer, og de kan bedre bevaringsstatusen til flere andre arter. På grunn av lav overlevelse og uforløst reproduktivt potensial, antyder populasjonssimuleringer at utsatt rapphøns og fasan i Norge trenger støttende forvaltningstiltak for å unngå utdøing. Målet når man avler rapphøns og fasaner er å selektere for vill adferd, og dette krever ulike oppdrettsforhold sammenlignet med domestiserte arter. Kunnskapsgrunnlaget om oppdrettsforhold som oppfyller behovene til fasaner og rapphøns er imidlertid lavt. Å øke plassen og berike habitatene i oppdrettssystemene vil imidlertid redusere stressrelatert adferd. Oppdrettsforholdene bør tilnærme seg naturlige forhold når det gjelder kosthold, uregulert sosialitet mellom individer og muligheten for eksponering for naturlige stressorer. Forskjellige patogener er registrert blant fasaner i Skandinavia, og import fra utlandet kan eksponere norsk hønsefugl for artsspesifikke sykdommer de vanligvis ikke ville påtruffet. Flere tiltak kan iverksettes for å minimere risikoen for spredning av patogener. Disse inkluderer hygiene på oppdrettsanlegg, veterinærundersøkelser av fuglene før import, og sikre oppdrettsanlegg som hindrer kontakt med dyreliv utenfor. Når man vurderer utilsiktede effekter på økosystemer etter utsetting av oppdrettede fugler, er det viktig å ta hensyn til omfanget og skalaen på utsettingen. Studier som fokuserer fauna- og floraeffekter har hva vi kjenner til kun blitt utført i Storbritannia, der 47 millioner fasaner slippes ut årlig. Det norske utsettingsprogrammet er forsvinnende lite i forhold, og det finnes for øyeblikket ingen informasjon som støtter hypotesen om at rapphøns og fasaner som er satt ut i Norge de siste ti årene, har hatt negative effekter på norske økosystemer eller det biologiske mangfoldet. Med nåværende forståelse av dyrevelferd, er det også mulig å tilpasse oppdretts- og utsettingsprogrammer som minimerer risikoen for spredning av patogener og som produserer sunne og levedyktige individer som er godt tilpasset livet utenfor oppdrettsanlegget.Oppdragsgiver/Financed by: Fuglehundklubbenes Forbund v/Lavlandskomitee

Does recursive use of resource locations shape a home range? Exploring the red fox's cognitive map.

A home range represents the outcome of the interplay between an environment, an animal’s understanding of that envi-ronment, and its subsequent movement decisions. Yet, recent studies suggest that recursive movement strategies have been overlooked in the shaping of animal home range patterns. Using fourteen GPS collared red foxes, we investigated within home range movements for recursive movement behaviour, suggesting a cognitive map, and explored how these shape ani-mal space-use patterns. We found that red foxes showed significant clustering in recorded positions, indicative of recursive site use. An average of 43% of positions were found in defined clusters that covered a proportional area of only 1% of their recorded range. Ground-truthing revealed that clusters were attributed to recursive visits, and extended residence time at clumped food sources, bed or den sites, routes and vantage points in the landscape. Our results provide evidence that, while red foxes maintained exploratory movement, recursive site use played a significant role in optimising movements between distinct core areas. We conclude that these patterns support the concept of cognitive mapping enabling recursive resource use, which can lead to emergence of bounded space use, rather than a continuous drifting across the landscape. We propose that by identifying resource locations that are used recursively; it is possible to move a step closer in revealing an animal’s cognitive map, or indeed, the movement behaviour underlying home range formation.publishedVersio

The optimal foraging theory, crowding and Swedish grouse hunters

This is the postprint version of the article. The published article is available from www.springerlink.com.Hunters that have options to hunt in different areas should evaluate their previous hunting success when they decide where to hunt. Following optimal foraging theory for non-human predators we investigated if hunting success and density of other hunters on the hunting area will affect the probability of return to the same area, and if such behavioural changes will result in a higher hunting success compared to hunters that change to a new area. For this purpose we used detailed information about willow grouse (Lagopus lagopus) hunters on state owned land in Sweden. We found support for the optimal foraging theory application on grouse hunters’ behavioural changes according to hunting success. The return rate increased with increasing hunting success and hunters that returned to the same area also increased their success compared to hunters that changed to a new area. Only one third of the hunters returned to the same area the subsequent year. We also found a negative effect of density of hunters in an area on hunters return rates and their hunting success, suggesting crowding among Swedish grouse hunters.2014-10-3

General Experience Rather Than of Local Knowledge is Important for Grouse Hunters Bag Size

This is the postprint version of the article. The published article can be located at the publisher's webpageWildlife harvest management requires an understanding of hunter behavioral interactions with the game. Hunter harvest is indicated to be more dependent on experience and attitudes than game abundance. We tested how the grouse hunter's bag size was affected or not by having local knowledge of the hunting ground, grouse density, and distribution. The local knowledge was acquired through approximately a decade of conducting pre-hunt counts, and was tested against hunters without the local knowledge, but who had similar experience of counting grouse from other areas. Hunters with local knowledge were not more efficient in bagging grouse than hunters without local knowledge. Rather, there seems to be the general variation in experience among hunters that regulated harvest rates, through number of grouse encounters, and gender of the hunters. The results add support to the concern of using bag statistics as an index for population changes of wildlife species.2014-06-0

Successful Adult Willow Grouse Are Exposed to Increased Harvest Risk

This is the postprint version of the article. The published version of the article can be located at the publisher's webpageAge and sex ratios in bag records are frequently used as indices of population composition for harvested populations. However, vulnerability to harvest may differ by age and sex thereby producing bias in population estimates. We assessed whether age and sex affected vulnerability to harvest for willow grouse (Lagopus lagopus) where adult density and brood size were known in the harvested populations. We collected bag records during 2 days of controlled hunting in 4 areas in 2 years (2007 and 2008) in Jämtland county, Sweden. We found that vulnerability to harvest was different for chicks and adults, but not between male and female adults. Hunters encountered broods at a higher rate than single birds compared to personnel conducting pre-harvest counts along line transects. Furthermore, the probability of shooting a grouse was higher in encounters of broods than individual grouse. Proportionally, we calculated about a 50% probability of a hunter shooting either a chick or an adult independent of encountering a single bird or broods of 2–10 grouse. Increasing adult density also increased the vulnerability to harvest for adults relative to chicks, independent of the chick to adult ratio in the pre-harvest population. The different vulnerability of adults and chicks to harvest observed in this study will dampen variation in age classes in bag records compared to the population, and we caution against extrapolation of age ratios in bag records to harvested population

Seasonal movements and dispersal patterns: Implications for recruitment and management of willow ptarmigan (Lagopus lagopus)

We investigated the general patterns of movements in willow ptarmigan (Lagopus lagopus) populations. We analyzed data from 300 radiocollared willow ptarmigan from 3 study areas in the Swedish mountain range, and from 2 previous studies of recoveries of wing-tagged chicks from 3 areas in southern Norway. We found that 80% of juvenile females dispersed more than 5 km from their natal area, whereas only 25% of juvenile males established a summer range more than 5 km from the area where they were caught as chicks. Mean dispersal distances of juvenile females were 3 times longer (10.4 km) than those of juvenile males (2.4 km). Movement differences within sexes were not associated with apparent female breeding success or ptarmigan density in the natal area, and adult females migrated between wintering areas used as juveniles and their first breeding site. We found no differences in dispersal distances between the Norwegian and Swedish populations. Movements of adult and juvenile females during spring were similar in all respects. At scales of more than 5 km, the movements of juveniles and adult females play a role in redistributing birds within landscape units, and represent important inter-population movements. The results of this study explain the apparent contradiction between non-compensatory mortality based on data from radio-marked ptarmigan, and the almost complete compensation based on annual counts. Estimating the extent of immigration into areas with high local mortality is difficult because of predation or harvest under conditions of high, fixed emigration and immigration dependent on local conditions. This represents a problem if dispersal distances include areas that are considerably larger than the size of the study are

Survival of female capercaillie Tetrao urogallus in northern Sweden

We studied survival and cause-specific mortality of radio-marked capercaillie Tetrao urogallus females relative to habitat type in northern Sweden during 2000-2004. Our high-mountain area (1,600 km2) consisted of the alpine transition zone from Norway spruce Picea abies-dominated forest,mountain birch Betula pubescens and alpine heath. Our low-mountain areas consisted of two forest areas (300 and 160 km2) dominated by Scots pine Pinus sylvestris and characterised by more intensive forestry than the first-mentioned area. Predation was the most common cause of mortality in both the highmountain (70%) and low-mountain (90%) areas. We attributed 10% of mortality in both areas to hunting. Collisions with cars and power lines were only documented in the high-mountain area. A Cox-proportional regression model stratified by year suggested that hazard was lower for yearlings and birds using low-mountain areas, but these estimates were associated with large uncertainties. Pooling all individuals showed an average annual survival probability of 0.68 (0.62-0.75; 95%CI), with no tendency for hazard to vary among seasons. Because survival of females was comparable to those reported in other studies and the harvest mortality was low, we suggest that the capercaillie population in the Swedish high-mountain region does not need any changes in the present management strategy

Declining survival rates of red foxes Vulpes vulpes during the first outbreak of sarcoptic mange in Sweden

Rapid declines in red fox Vulpes vulpes populations have followed outbreaks of epizootic mange caused by the mite Sarcoptes scabiei. In Sweden, the first outbreak of sarcoptic mange started in 1977/1978 and affected the whole country by 1984. Here we used data on the number of harvested red foxes (51 480) from Gävleborg county (18 199 km2) in Sweden between 1970 and 1994. We used data on the prevalence of sarcoptic mange in a sample of harvested red foxes (2694) from 1974 to 1982. A rapid decline in harvested foxes occurred two to three years after the prevalence of sarcoptic mange first became evident. In the same period, mark–recovery data were used to estimate changes in survival rates, and the best model included an effect of age (young or adult) and period (annual) on the survival and recapture probabilities. The analysis was based on data from 701 young foxes of which 523 were recovered, and 133 adults of which 131 were recovered. Average annual survival was 0.55 (range = 0.53–0.58) for adults and 0.36 (range = 0.32–0.39) for young foxes in the three years preceding the outbreak. During the outbreak and the remaining six years of the study, the average survival was reduced to 0.41 (range = 0.30–0.48) for adults and to 0.25 (range = 0.17–0.30) for young foxes. A population model, based on results on our survival analysis and literature data on fecundity, was developed to project the decline of the fox population. The rate and magnitude of the reduction in projected population and harvested foxes were similar, with both reduced by almost ninety percent. Harvest statistics indicate the fox population recovered to pre-mange densities in less than 10 years after the first detection of mange indicating a rapid development of resistance in the host. This study shows the importance of long-term population monitoring in combination with large-scale field-experiments to devise alternative management options.publishedVersio