| 1. |
- Josefsson, Jonas, et al.
(author)
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Improving scientific rigour in conservation evaluations and a plea deal for transparency on potential biases
- 2020
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In: Conservation Letters. - : Wiley. - 1755-263X. ; 13:5
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Research review (peer-reviewed)abstract
- The delivery of rigorous and unbiased evidence on the effects of interventions lay at the heart of the scientific method. Here we examine scientific papers evaluating agri-environment schemes, the principal instrument to mitigate farmland biodiversity declines worldwide. Despite previous warnings about rudimentary study designs in this field, we found that the majority of studies published between 2008 and 2017 still lack robust study designs to strictly evaluate intervention effects. Potential sources of bias that arise from the correlative nature are rarely mentioned, and results are still promoted by using a causal language. This lack of robust study designs likely results from poor integration of research and policy, while the erroneous use of causal language and an unwillingness to discuss bias may stem from publication pressures. We conclude that scientific reporting and discussion of study limitations in intervention research must improve and propose some practices toward this goal.
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| 2. |
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| 3. |
- Rosin, Zuzanna, et al.
(author)
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Village modernization may contribute more to farmland bird declines than agricultural intensification
- 2021
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In: Conservation Letters. - : Wiley. - 1755-263X. ; 14
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Journal article (peer-reviewed)abstract
- The central tenet of European farmland ecology is that agricultural intensification during the 20th century was largely responsible for dramatic declines in species abundances. However, during this time, human rural settlements were also undergoing radical changes through modernization, with undocumented biodiversity impacts in this important wildlife habitat. We performed the first ever large-scale study to disentangle the impact of these simultaneous processes on farmland bird diversity in 104 Polish villages. We show that modernized villages and their surrounding agricultural fields had 50-60% fewer birds than those in and around comparable older villages. The relative contribution of modernization versus agricultural intensification to predicted bird declines was 88% versus 12% for bird communities in villages and 56% versus 44% in surrounding croplands, with considerable variation among ecological species subgroups. These results challenge our current understanding of agricultural ecosystem ecology and how best to implement conservation measures costing billions of euros annually.
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| 4. |
- Aronsson, Malin, et al.
(author)
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Resource dispersion and relatedness interact to explain space use in a solitary predator
- 2020
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In: Oikos. - : Wiley. - 0030-1299 .- 1600-0706. ; 129, s. 1174-1184
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Journal article (peer-reviewed)abstract
- Resource dispersion or kin selection are commonly used to explain animal spatial and social organization. Despite this, studies examining how these factors interact in wild populations of solitary animals are rare. We used 16 years of individual-level spatial and genetic data to disentangle how resources and relatedness influence spatial organization of a solitary predator, the Eurasian lynx Lynx lynx. As expected, space-use overlap between neighbouring individuals increased when food resources were heterogeneous and unpredictably distributed (as predicted from resource dispersion) or when neighbours were closely related (as predicted from kin selection). However, these patterns were highly dependent on each other. Increased spatial overlap was restricted to mother-daughter dyads, with this effect only occurring in areas and during seasons when prey was clumped and irregularly distributed in the landscape. Additionally, full-siblings with similar levels of genetic relatedness did not show these patterns, suggesting that kin selection is mediated through mother-daughter recognition, and is only beneficial under specific resource dispersion circumstances. Our results provide key insights into the flexibility of spatial organization of solitary animals, and clearly show the importance of considering the interaction between resources and kinship when assessing animal space use patterns.
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| 5. |
- Ball, Elisabeth, et al.
(author)
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Repeatability of radiographic assessments for feline hip dysplasia suggest consensus scores in radiology are more uncertain than commonly assumed
- 2022
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12
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Journal article (peer-reviewed)abstract
- Variation in the diagnostic interpretation of radiographs is a well-recognised problem in human and veterinary medicine. One common solution is to create a 'consensus' score based on a majority or unanimous decision from multiple observers. While consensus approaches are generally assumed to improve diagnostic repeatability, the extent to which consensus scores are themselves repeatable has rarely been examined. Here we use repeated assessments by three radiologists of 196 hip radiographs from 98 cats within a health-screening programme to examine intra-observer, interobserver, majority-consensus and unanimous-consensus repeatability scores for feline hip dysplasia. In line with other studies, intra-observer and inter-observer repeatability was moderate (63-71%), and related to the reference assessment and time taken to reach a decision. Consensus scores did show reduced variation between assessments compared to individuals, but consensus repeatability was far from perfect. Only 75% of majority consensus scores were in agreement between assessments, and based on Bayesian multinomial modelling we estimate that unanimous consensus scores can have repeatabilities as low as 83%. These results clearly show that consensus scores in radiology can have large uncertainties, and that future studies in both human and veterinary medicine need to include consensus-uncertainty estimates if we are to properly interpret radiological diagnoses and the extent to which consensus scores improve diagnostic accuracy.
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| 6. |
- Johansson, Örjan, et al.
(author)
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Identification errors in camera-trap studies result in systematic population overestimation
- 2020
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10
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Journal article (peer-reviewed)abstract
- Reliable assessments of animal abundance are key for successful conservation of endangered species. For elusive animals with individually-unique markings, camera-trap surveys are a benchmark standard for estimating local and global population abundance. Central to the reliability of resulting abundance estimates is the assumption that individuals are accurately identified from photographic captures. To quantify the risk of individual misidentification and its impact on population abundance estimates we performed an experiment under controlled conditions in which 16 captive snow leopards (Panthera uncia) were camera-trapped on 40 occasions and eight observers independently identified individuals and recaptures. Observers misclassified 12.5% of all capture occasions, resulting in systematically inflated population abundance estimates on average by one third (mean +/- SD = 35 +/- 21%). Our results show that identifying individually-unique individuals from camera-trap photos may not be as reliable as previously believed, implying that elusive and endangered species could be less abundant than current estimates indicate.
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| 7. |
- Johansson, Örjan, et al.
(author)
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Seasonal variation in daily activity patterns of snow leopards and their prey
- 2022
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12
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Journal article (peer-reviewed)abstract
- The daily and seasonal activity patterns of snow leopards (Panthera uncia) are poorly understood, limiting our ecological understanding and hampering our ability to mitigate threats such as climate change and retaliatory killing in response to livestock predation. We fitted GPS-collars with activity loggers to snow leopards, Siberian ibex (Capra sibirica: their main prey), and domestic goats (Capra hircus: common livestock prey) in Mongolia between 2009 and 2020. Snow leopards were facultatively nocturnal with season-specific crepuscular activity peaks: seasonal activity shifted towards night-sunrise during summer, and day-sunset in winter. Snow leopard activity was in contrast to their prey, which were consistently diurnal. We interpret these results in relation to: (1) darkness as concealment for snow leopards when stalking in an open landscape (nocturnal activity), (2) low-intermediate light preferred for predatory ambush in steep rocky terrain (dawn and dusk activity), and (3) seasonal activity adjustments to facilitate thermoregulation in an extreme environment. These patterns suggest that to minimise human-wildlife conflict, livestock should be corralled at night and dawn in summer, and dusk in winter. It is likely that climate change will intensify seasonal effects on the snow leopard's daily temporal niche for thermoregulation in the future.
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| 8. |
- Johansson, Örjan, et al.
(author)
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The timing of breeding and independence for snow leopard females and their cubs
- 2021
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In: Mammalian Biology. - : Springer Science and Business Media LLC. - 1616-5047 .- 1618-1476. ; 101, s. 173-180
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Journal article (peer-reviewed)abstract
- Significant knowledge gaps persist on snow leopard demography and reproductive behavior. From a GPS-collared population in Mongolia, we estimated the timing of mating, parturition and independence. Based on three mother-cub pairs, we describe the separation phase of the cub from its mother as it gains independence. Snow leopards mated from January-March and gave birth from April-June. Cubs remained with their mother until their second winter (20-22 months of age) when cubs started showing movements away from their mother for days at a time. This initiation of independence appeared to coincide with their mother mating with the territorial male. Two female cubs remained in their mothers' territory for several months after initial separation, whereas the male cub quickly dispersed. By comparing the relationship between body size and age of independence across 11 solitary, medium-to-large felid species, it was clear that snow leopards have a delayed timing of separation compared to other species. We suggest this may be related to their mating behavior and the difficulty of the habitat and prey capture for juvenile snow leopards. Our results, while limited, provide empirical estimates for understanding snow leopard ecology and for parameterizing population models.
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| 9. |
- Kanuch, Peter, et al.
(author)
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Gene flow relates to evolutionary divergence among populations at the range margin
- 2020
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In: PeerJ. - : PeerJ. - 2167-8359. ; 8
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Journal article (peer-reviewed)abstract
- Background: Morphological differentiation between populations resulting from local adaptations to environmental conditions is likely to be more pronounced in populations with increasing genetic isolation. In a previous study a positive clinal variation in body size was observed in isolated Roesel's bush-cricket, Metrioptera roeselii, populations, but were absent from populations within a continuous distribution at the same latitudinal range. This observational study inferred that there was a phenotypic effect of gene flow on climate-induced selection in this species. Methods: To disentangle genetic versus environmental drivers of population differences in morphology, we measured the size of four different body traits in wild-caught individuals from the two most distinct latitudinally-matched pairs of populations occurring at about 60 degrees N latitude in northern Europe, characterised by either restricted or continuous gene flow, and corresponding individuals raised under laboratory conditions. Results: Individuals that originated from the genetically isolated populations were always bigger (femur, pronotum and genital appendages) when compared to individuals from latitudinally-matched areas characterised by continuous gene flow between populations. The magnitude of this effect was similar for wild-caught and laboratory-reared individuals. We found that previously observed size cline variation in both male and female crickets was likely to be the result of local genetic adaptation rather than phenotypic plasticity. Conclusions: This strongly suggests that restricted gene flow is of major importance for frequencies of alleles that participate in climate-induced selection acting to favour larger phenotypes in isolated populations towards colder latitudes.
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| 10. |
- Klein, Julian, et al.
(author)
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Short-term experimental support for bird diversity retention measures during thinning in European boreal forests
- 2022
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In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 509
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Journal article (peer-reviewed)abstract
- Current levels of forestry expansion in boreal forests threaten to radically reduce biodiversity. For many forest dwelling species the threat is not simply because the forest is used for biomass production, but rather how it is used. Retention forestry practices aim to limit impacts on biodiversity during the final felling stage of a forestry cycle. However, the efficiency of such methods in retaining biodiversity have rarely been studied for intermediate forestry stages (e.g., forest thinning) with experimental approaches entirely absent from boreal forests. Therefore, we conducted a before-after control-impact experiment in Sweden to investigate the short-term response in occurrence of individual bird species, guilds, and population trend groups (positive, stable, or negative population trend), as well as the response in nest box occupancy and in the reproductive success of Parus major to three different thinning treatments. The three treatments were i) conventional thinning at the plot and stand scale, (ii) understory retention thinning, where at least 250 spruces with live branches below 2 m above ground are retained per hectare, and (iii) complete retention plots, where the forest was not thinned on-1 ha plots within conventionally thinned forest stands. We found that conventional forest thinning was likely the cause for observed declines in bird occurrence, with-20% of the species showing clear negative responses. Our results indicate that understory retention thinning with double the retention level as previously suggested and combining conventional thinning with complete retention plots, could largely alleviate the short term negative effects of conventional thinning. This was the case for all guilds, population trend groups and individual bird species, except for Poecile montanus, which responded negatively to complete retention. Among the birds occupying the nest boxes, only Cyanistes caeruleus responded to any of the treatments, with higher nest box occupancy upon understory retention thinning. No thinning treatment affected reproductive success in P. major. Our results clearly show that thinning practices that retain the diversity of forest-dwelling birds are possible. Hence, this study provides a crucial puzzle piece towards more sustainable forestry practices in the boreal region.
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