21 research outputs found
The tragedy of the science-policy gap – Revised legislation fails to protect an endangered species in a managed boreal landscape
Unsustainable use of forest resources poses a serious threat to biodiversity worldwide. This threat is particularly important in boreal biomes, where intensive production-oriented forestry is widely applied. Legislation is one of the key tools for preserving nature from anthropogenic damage. Designation of environmental legislation should be grounded on sound scientific evidence in order to be effective. We assess the impact of guidelines enforcing the Finnish ad-hoc legislation aimed at preserving breeding sites and resting places of the Siberian flying squirrel (Pteromys volans), a protected species in Finland and in the European Union under the Habitats Directive. Its habitat is under pressure from widespread forest clear-cutting practices. We collected data on site occupancy by breeding female flying squirrels from 81 sites spanning 12 years (2005-2016) and on relevant habitat variables around the site. Using generalized linear mixed models we quantified the predicted occupancy of breeding female flying squirrels in relation to the cover of breeding habitat around a site. We then compared the resulting habitat requirements of breeding females with the habitat that would be retained according to the initial national legislation guidelines and their proposed first revision. We show that both the initial and the proposed revision of the habitat protection guidelines allow the retention of breeding habitat patches of minimal size, which would yield a very low (less than 5%) predicted occupancy by a breeding flying squirrel female. The current revised guidelines are not science-driven and remain ineffective in safeguarding the species habitat from expanding forestry. These results expose the wide gap between science and policy for the implementation of environmental legislation, in this case the Habitats Directive, to protect species of conservation concern. There is an urgent need to fill the science-policy gap in order to achieve the preservation of biodiversity in a world under rapid transformation.Peer reviewe
The tragedy of the science-policy gap – Revised legislation fails to protect an endangered species in a managed boreal landscape
Unsustainable use of forest resources poses a serious threat to biodiversity worldwide. This threat is particularly important in boreal biomes, where intensive production-oriented forestry is widely applied. Legislation is one of the key tools for preserving nature from anthropogenic damage. Designation of environmental legislation should be grounded on sound scientific evidence in order to be effective. We assess the impact of guidelines enforcing the Finnish ad-hoc legislation aimed at preserving breeding sites and resting places of the Siberian flying squirrel (Pteromys volans), a protected species in Finland and in the European Union under the Habitats Directive. Its habitat is under pressure from widespread forest clear-cutting practices. We collected data on site occupancy by breeding female flying squirrels from 81 sites spanning 12 years (2005-2016) and on relevant habitat variables around the site. Using generalized linear mixed models we quantified the predicted occupancy of breeding female flying squirrels in relation to the cover of breeding habitat around a site. We then compared the resulting habitat requirements of breeding females with the habitat that would be retained according to the initial national legislation guidelines and their proposed first revision. We show that both the initial and the proposed revision of the habitat protection guidelines allow the retention of breeding habitat patches of minimal size, which would yield a very low (less than 5%) predicted occupancy by a breeding flying squirrel female. The current revised guidelines are not science-driven and remain ineffective in safeguarding the species habitat from expanding forestry. These results expose the wide gap between science and policy for the implementation of environmental legislation, in this case the Habitats Directive, to protect species of conservation concern. There is an urgent need to fill the science-policy gap in order to achieve the preservation of biodiversity in a world under rapid transformation.Peer reviewe
Hair cortisol concentration in Siberian flying squirrels is unrelated to landscape and social factors
Intact ecosystems are being lost or modified worldwide, and many animal species are now forced to live in altered landscapes. A large amount of scientific studies have focused on understanding direct effects of habitat alterations on species occurrence, abundance, breeding success, and other life history aspects. Much less attention has been placed on understanding how habitat alterations impact on the physiology of species, e.g., via elevated chronic stress when living in an altered landscape. Here, we quantify the effects of individual age and sex, as well as effects of landscape and social factors on chronic stress of an endangered forest specialist species, the Siberian flying squirrel Pteromys volans. We collected hair samples over 2years from across 192 flying squirrels and quantified their chronic stress response via cortisol concentrations. We then ran statistical models to relate cortisol concentrations with landscape and social factors. We show that cortisol concentrations in flying squirrels are neither affected by habitat amount and connectivity, nor by the density of conspecifics in the area. We however found that cortisol concentration was higher in adults than in pups, and in males compared with females. Lack of an effect of environmental factors on cortisol concentrations may indicate low physiological sensitivity to alterations in the surrounding environment, possibly due to low densities of predators that could induce stress in the study area. Further research should focus on possible effects of varying predator densities, alone and in interaction with landscape features, in shaping chronic stress of this and other species.Peer reviewe
Sex-specific patterns in body mass and mating system in the Siberian flying squirrel
Background: Reproductive strategies and evolutionary pressures differ between males and females. This often results in size differences between the sexes, and also in sex-specific seasonal variation in body mass. Seasonal variation in body mass is also affected by other factors, such as weather. Studies on sex-specific body mass patterns may contribute to better understand the mating system of a species. Here we quantify patterns underlying sex-specific body mass variation using a long-term dataset on body mass in the Siberian flying squirrel, Pteromys volans. Results: We show that female flying squirrels were larger than males based on body mass and other body measures. Males had lowest body mass after the breeding season, whereas female body mass was more constant between seasons, when the pregnancy period was excluded. Male body mass did not increase before the mating season, despite the general pattern that males with higher body mass are usually dominant in squirrel species. Seasonal body mass variation was linked to weather factors, but this relationship was not straightforward to interpret, and did not clearly affect the trend in body mass observed over the 22 years of study. Conclusions: Our study supports the view that arboreal squirrels often deviate from the general pattern found in mammals for larger males than females. The mating system seems to be the main driver of sex-specific seasonal body mass variation in flying squirrels, and conflicting selective pressure may occur for males to have low body mass to facilitate gliding versus high body mass to facilitate dominance.Peer reviewe
Energiförbrukning och potentiell energibesparing vid badanläggningar : förstudie /
1. The relative contributions of habitat and food availability on fitness may provide evidence for key habitat features needed to safeguard population persistence. However, defining habitat quality for a species can be a complex task, especially if knowledge on the relationship between individual performance and habitat quality is lacking. 2. Here, we determined the relative importance of availability of suitable forest habitat, body mass, and food from masting tree species on female lifetime reproductive success (LRS) of Siberian flying squirrels (Pteromys volans). 3. We calculated LRS of 500 female flying squirrels based on a 22 year-long longitudinal data set of two populations from western Finland. We assessed with generalised additive models the potential effects of availability of suitable habitat and cumulative lifetime availability of food from masting tree species on female LRS, longevity and fecundity. On a reduced dataset, we evaluated the importance of female winter body mass and conducted a piecewise path analysis to determine how variables were connected. 4. According to generalised additive models female longevity, fecundity and LRS were mainly determined by variation in cumulative lifetime availability of food from masting alder and birch. Instead, habitat and body mass had smaller role. The path analysis indicated that lifetime food availability had direct effect on longevity and fecundity, and these had equal effect on LRS at both study sites. 5. Our results on LRS shows that the occurrence of tree masting events during a flying squirrel female’s lifetime have profoundly larger effect on lifetime reproductive success than the cover of suitable forest habitat. Furthermore, this study emphasises the importance of both fecundity and longevity, and the indirect effects of food availability via those components, as determinants of lifetime fitness of female flying squirrels
Satellite tracking of red-listed nominate lesser black-backed gulls (Larus f. fuscus):habitat specialisation in foraging movements raises novel conservation needs
In contrast to many other gull species, nominate lesser black-backed gulls (Larus fuscus fuscus, nLBBG) have shown generally decreasing population trends throughout their breeding area in northern and eastern Fennoscandia over the past decades and are now red-listed. Interspecific competition, predation, increased disturbance, organochlorine poisoning and food shortages were suggested as main reasons for the overall decrease. Here we contribute to a better understanding of population declines by comparing foraging movements of satellite tracked adult gulls in three geographical areas of Finland (West, South, and East) that differ in their population trends. Our analysis examines potential differences and preferences in the feeding site behaviour of adult gulls. Our comparison of the three geographical areas showed that nLBBGs preferred feeding at fur farms in West Finland, waste dumps in South Finland, and lakes and fields in East Finland. We found individual gulls of this purportedly generalist species to be highly specialised in their foraging behaviour, particularly those that might be associated with their survival probabilities. We hypothesise that differences in foraging behaviour and food availability during the breeding season are partially responsible for differences in demographic trends between populations. Specifically, we identify potential local conservation problems such as shooting in birds visiting fur farms. Our data suggest that the effective conservation and management of endangered nLBBGs could be aided by simple actions in the breeding areas in addition to better protection throughout the annual movement cycle
Population fluctuations and spatial synchrony in an arboreal rodent
Climatic conditions, trophic links between species and dispersal may induce spatial synchrony in population fluctuations. Spatial synchrony increases the extinction risk of populations and, thus, it is important to understand how synchrony-inducing mechanisms affect populations already threatened by habitat loss and climate change. For many species, it is unclear how population fluctuations vary over time and space, and what factors potentially drive this variation. In this study, we focus on factors determining population fluctuations and spatial synchrony in the Siberian flying squirrel, Pteromys volans, using long-term monitoring data from 16 Finnish populations located 2-400 km apart. We found an indication of synchronous population dynamics on a large scale in flying squirrels. However, the synchrony was not found to be clearly related to distance between study sites because the populations seemed to be strongly affected by small-scale local factors. The regularity of population fluctuations varied over time. The fluctuations were linked to changes in winter precipitation, which has previously been linked to the reproductive success of flying squirrels. Food abundance (tree mast) and predator abundance were not related to population fluctuations in this study. We conclude that spatial synchrony was not unequivocally related to distance in flying squirrels, as has been observed in earlier studies for more abundant rodent species. Our study also emphasises the role of climate in population fluctuations and the synchrony of the species
Population fluctuations and spatial synchrony in an arboreal rodent
Climatic conditions, trophic links between species and dispersal may induce spatial synchrony in population fluctuations. Spatial synchrony increases the extinction risk of populations and, thus, it is important to understand how synchrony-inducing mechanisms affect populations already threatened by habitat loss and climate change. For many species, it is unclear how population fluctuations vary over time and space, and what factors potentially drive this variation. In this study, we focus on factors determining population fluctuations and spatial synchrony in the Siberian flying squirrel, Pteromys volans, using long-term monitoring data from 16 Finnish populations located 2-400 km apart. We found an indication of synchronous population dynamics on a large scale in flying squirrels. However, the synchrony was not found to be clearly related to distance between study sites because the populations seemed to be strongly affected by small-scale local factors. The regularity of population fluctuations varied over time. The fluctuations were linked to changes in winter precipitation, which has previously been linked to the reproductive success of flying squirrels. Food abundance (tree mast) and predator abundance were not related to population fluctuations in this study. We conclude that spatial synchrony was not unequivocally related to distance in flying squirrels, as has been observed in earlier studies for more abundant rodent species. Our study also emphasises the role of climate in population fluctuations and the synchrony of the species.Peer reviewe
Satellite tracking of red-listed nominate lesser black-backed gulls (Larus f. fuscus): Habitat specialisation in foraging movements raises novel conservation needs
In contrast to many other gull species, nominate lesser black-backed gulls (Larus fuscus fuscus, nLBBG) have shown generally decreasing population trends throughout their breeding area in northern and eastern Fennoscandia over the past decades and are now red-listed. Interspecific competition, predation, increased disturbance, organochlorine poisoning and food shortages were suggested as main reasons for the overall decrease. Here we contribute to a better understanding of population declines by comparing foraging movements of satellite tracked adult gulls in three geographical areas of Finland (West, South, and East) that differ in their population trends. Our analysis examines potential differences and preferences in the feeding site behaviour of adult gulls. Our comparison of the three geographical areas showed that nLBBGs preferred feeding at fur farms in West Finland, waste dumps in South Finland, and lakes and fields in East Finland. We found individual gulls of this purportedly generalist species to be highly specialised in their foraging behaviour, particularly those that might be associated with their survival probabilities. We hypothesise that differences in foraging behaviour and food availability during the breeding season are partially responsible for differences in demographic trends between populations. Specifically, we identify potential local conservation problems such as shooting in birds visiting fur farms. Our data suggest that the effective conservation and management of endangered nLBBGs could be aided by simple actions in the breeding areas in addition to better protection throughout the annual movement cycle. (C) 2017 The Authors. Published by Elsevier B.V