Using a modelling approach to inform progress towards stoat eradication from the Orkney Islands

Funding For the analyses reported in this paper study, KZ was financed by the Bekker programme of the Polish National Agency for Academic Exchange (NAWA), grant PPN/BEK/2019/1/00036 to KZ. PGD and XL were supported in part by the NERC grant (NE/S011641/1). The ONWP funders: National Lottery Heritage Fund, EU life programme (LIFE17 UK/NAT/000557), Nature Scot and RSPB. Acknowledgements We would like to acknowledge all the ONWP staff and volunteers who have collected and facilitated the collection of data, all the landowners on Orkney who have generously given access to their land, the ONWP steering group members (Graham Neville and Daniel Brazier, NatureScot; Susan Shearer and Stuart West, Orkney Islands Council and Kirsty Nutt and Leigh Lock, RSPB) and the Technical Advisory Group (Peter Robertson, Newcastle University; Robbie Macdonald, University of Exeter; Des Thompson, NatureScot; Tony Martin, University of Dundee; Lindsay Waddell, National Gamekeepers' Organisation; Karen Varnham, RSPB; Grant Harper, Biodiversity Restoration; Angela Newport, Conservation Dog specialist).Peer reviewedPublisher PD

Stephanopachys linearis (Kugelann, 1792) (Coleoptera, Bostrichidae) in Poland

Stephanopachys linearis (Kugelann, 1792) belongs to the family of horned powderpost beetles (Bostrichidae), represented in the fauna of Europe by 29 native species. It is a characteristic element of the northern, boreal zone of the Palaearctic and alpine areas of central and southern Europe. This species as a rare beetle important for the European Union, has been placed in Annex II of the Habitats Directive, on the IUCN Red List of Threatened Species and European Red List of Saproxylic Beetles. S. linearis was described from Poland in 1792 and, after 220 years, again encountered in this country. The zoogeographical distribution is shown and elements of its biology and ecology are discussed

Museomics Dissects the Genetic Basis for Adaptive Seasonal Coloration in the Least Weasel

Dissecting the link between genetic variation and adaptive phenotypes provides outstanding opportunities to understand fundamental evolutionary processes. Here, we use a museomics approach to investigate the genetic basis and evolution of winter coat coloration morphs in least weasels (Mustela nivalis), a repeated adaptation for camouflage in mammals with seasonal pelage color moults across regions with varying winter snow. Whole-genome sequence data were obtained from biological collections and mapped onto a newly assembled reference genome for the species. Sampling represented two replicate transition zones between nivalis and vulgaris coloration morphs in Europe, which typically develop white or brown winter coats, respectively. Population analyses showed that the morph distribution across transition zones is not a by-product of historical structure. Association scans linked a 200-kb genomic region to coloration morph, which was validated by genotyping museum specimens from intermorph experimental crosses. Genotyping the wild populations narrowed down the association to pigmentation gene MC1R and pinpointed a candidate amino acid change cosegregating with coloration morph. This polymorphism replaces an ancestral leucine residue by lysine at the start of the first extracellular loop of the protein in the vulgaris morph. A selective sweep signature overlapped the association region in vulgaris, suggesting that past adaptation favored winter-brown morphs and can anchor future adaptive responses to decreasing winter snow. Using biological collections as valuable resources to study natural adaptations, our study showed a new evolutionary route generating winter color variation in mammals and that seasonal camouflage can be modulated by changes at single key genes

To be or not to be.... a small

Body mass (size) is a very important biological character, interrelated with key life history traits, such as fertility, age at maturity, reproductive success and mortality. On the physiological level, body mass is also closely associated with key components of energy budgets. Yet, factors moulding within-species variation of body mass and its relations to energy expenditures and life history traits are still not fully understood. The weasel (Mustela nivalis Linneaus, 1776) is an extremely interesting species almost perfectly suited to study these relations. It is characterized by a considerable variation in body mass (range 40-150 g) and extremely high metabolic rates. This highly specialised predator hunts on different species of rodents. In the forest weasel preys on the bank vole (Clethionomys glareolus) and yellow-necked mouse (Apodemus flavicollis), whereas in the open habitats it mainly preys on the voles (Microtus spp.). Due to their small body size and high metabolic rates, weasels encounter numerous constraints. The prey size is one of the main ecological factors determining variation in weasel's body mass. Males heavier than 100 g suffer from increased winter mortality. We therefore hypothesise that in summer bigger males are favoured by sexual selection, whereas in winter energy constrains select for smaller animals. To test this we investigated time budgets, resting (RMR) and field metabolic rate (FMR) in weasel males of various sizes during winter and summer. In contrast to other carnivore species the body-mass corrected RMR of weasels was lower in winter than in summer. Weasels also minimised their winter energetic expenditures by decreasing hunting activity (on average 4 h/day in summer vs. less than 2 h/day in winter). Irrespective of body mass this was usually sufficient to catch just a single prey unit. In accordance with our expectations the winter hunting activity was sufficient to balance the energy budget of small males, but compromised survival prospects of bigger individuals

Heterothermy use in winter is associated with reduced litter size during following breeding season

Heterothermy is considered to be the most effective energy-saving strategy improving survival under natural conditions. Interspecific studies suggest that this strategy is also associated with reduced reproductive output. Yet little is known about the reproductive consequences of heterothermy use at the intraspecific level and thus its repercussions for microevolutionary processes. Moreover, as yet no study has aimed to test if litter size and juvenile mass are affected by torpor use in wild captured animals under undemanding laboratory conditions. Here we tested the hypothesis that intraspecific variation in heterothermy use is associated with different reproductive successes, being the result of the evolution of distinct life histories. We predicted that heterothermy use in winter negatively correlates with litter size and juvenile body mass during the subsequent breeding season. To test this prediction, we used yellow-necked mice from a population in which individuals consistently differ in their use of heterothermy in winter. We measured body size (head width) and body mass, basal metabolic rate, as well as metabolism and body temperature during fasting-induced torpor in wild caught mice in winter. Phenotyped mice were bred in the subsequent summer selectively – males and females with similar heterothermy characteristics were paired, the most to the least heterothermic. Dam body size, but not basal metabolism, was positively correlated with litter size (but not juvenile mass). However, when accounting for this relationship, litter size was negatively while juvenile mass was positively correlated with the average heterothermy use of a given couple. Our study indicates that heterothermy use correlates with specific life-history strategies arising from a fundamental evolutionary trade-off between survival and reproduction

Male weasels decrease activity and energy expenditure in response to high ambient temperatures.

The heat dissipation limit (HDL) hypothesis suggests that the capacity of endotherms to dissipate body heat may impose constraints on their energy expenditure. Specifically, this hypothesis predicts that endotherms should avoid the detrimental consequences of hyperthermia by lowering their energy expenditure and reducing their activity in response to high ambient temperatures (T(a)). We used an extensive data set on the daily energy expenditure (DEE, n = 27) and the daily activity time (AT, n = 48) of male weasels (Mustela nivalis) during the spring and summer breeding season to test these predictions. We found that T(a) was related in a "hump-shaped" (i.e. convex) manner to AT, DEE, resting metabolic rate (RMR) and metabolic scope (the ratio of DEE to RMR). These results support the HDL hypothesis because in response to warm Tas male weasels reduced their AT, DEE, and RMR. Although the activity and energy expenditure of large endotherms are most likely to be constrained in response to warm Tas because they are less able to dissipate heat, our results suggest that small endotherms may also experience constraints consistent with the HDL hypothesis

Stephanopachys linearis (Kugelann, 1792) (Coleoptera, Bostrichidae) in Poland

Stephanopachys linearis (Kugelann, 1792) belongs to the family of horned powderpost beetles (Bostrichidae), represented in the fauna of Europe by 29 native species. It is a characteristic element of the northern, boreal zone of the Palaearctic and alpine areas of central and southern Europe. This species as a rare beetle important for the European Union, has been placed in Annex II of the Habitats Directive, on the IUCN Red List of Threatened Species and European Red List of Saproxylic Beetles. S. linearis was described from Poland in 1792 and, after 220 years, again encountered in this country. The zoogeographical distribution is shown and elements of its biology and ecology are discussed

Data from: Plant-herbivore interactions: silicon concentration in tussock sedges and population dynamics of root voles

1. It has been hypothesized that the induction of silicon (Si)-based plant defence in response to herbivore damage may engender rodent population cycles. Many studies have also considered accumulation of Si as a process controlled by geo-hydrological factors. 2. To test these ideas, we investigated the relationship between concentration of Si in fibrous tussock sedge (Carex appropinquata) and the population density of a major sedge consumer, the root vole (Microtus oeconomus), in field enclosures in natural habitat under a variety of natural water regimes and weather conditions. 3. We found that a high density of voles at the end of summer resulted in the immediate accumulation of Si by rhizomes, followed by accumulation of Si in leaves with a one-year lag time. The level of river flooding in the same year had an additional impact on Si concentration in rhizomes but did not affect silicification of leaves. 4. Overwinter changes in concentration of Si in sedges were influenced by fluctuations in ambient temperature and the depth of snow cover (multiple freeze-thaw cycles), thus affecting the quality of winter food available for voles. 5. Smaller voles had lower mortality during early winter than large voles, which seemed to be connected with changes in the quality of the autumn rather than the winter food base. Winter survival of voles was not associated with Si concentration in their faeces, however. 6. Our results suggest that changes in Si concentration in fibrous tussock sedge can be induced by changes in vole population density and are also additionally affected by the amount of flooding and weather conditions