Survival of Eurasian lynx in the human-dominated landscape of Europe

Survival and cause-specific mortality rates are vital for evidence-based population forecasting and conservation, particularly for large carnivores, whose populations are often vulnerable to human-caused mortalities. It is therefore important to know the relationship between anthropogenic and natural mortality causes to evaluate whether they are additive or compensatory. Further, the relation between survival and environmental covariates could reveal whether specific landscape characteristics influence demographic performance. We used telemetry data on 681 Eurasian lynx (Lynx lynx), a model apex predator with large spatial requirements, that were tracked across their European distribution. Through time-to-event analyses, we sought to determine the variables associated with differences in their survival. Illegal killing was the main cause of mortality (33.8%), and mortality rates were similar in protected and hunted populations (8.6% and 7.0% per year, respectively). Survival varied greatly across populations (70-95% per year). Across all study sites, higher hunting and anthropogenic mortality rates were partially compensated by lower rates of other mortality causes but not by natural mortality alone. Variation in survival depended on sex (female survival was 1.5 times greater than male survival) and seasonality (highest risk during hunting season and winter), and lower survival rates were correlated with higher human modification of landscapes at both coarse (home range composition) and fine (habitat use within home range) scales. Some variation in survival was driven by unobserved factors, which, given the high rates of human-caused mortalities, including illegal killing, are of foremost concern. Due to the low natural mortality rates in protected and hunted populations, we conclude that anthropogenic causes of mortality are likely close to additive, such that maintaining or increasing refuge habitat with little human disturbance is critical to lynx conservation.Supervivencia del lince euroasiá tico en los paisajes europeos dominados por humanos Las tasas de supervivencia y mortalidad por causas especí ficas son vitales para la previsió n y conservació n de poblaciones basadas en evidencias, sobre todo en el caso de los grandes carní voros, cuyas poblaciones suelen ser vulnerables a la mortalidad causada por el hombre. Por esto es importante conocer la relació n entre las causas de mortalidad antropogé nicas y naturales para evaluar si son aditivas o compensatorias. Ademá s, la relació n entre la supervivencia y las covariables ambientales podrí a revelar si las caracterí sticas especí ficas del paisaje influyen en el rendimiento demográ fico. Utilizamos datos telemé tricos de 681 linces euroasiá ticos (Lynx lynx), un depredador á pice modelo con grandes necesidades espaciales, que fueron rastreados a lo largo de su distribució n europea. Mediante aná lisis cronoló gicos, intentamos determinar las variables asociadas a las diferencias en su supervivencia. La matanza ilegal fue la principal causa de mortalidad (33.8%), y las tasas de mortalidad auales fueron similares en las poblaciones protegidas y cazadas (8.6 y 7.0%, respectivamente). La supervivencia anual varió mucho de una població n a otra (del 70 al 95%). En todos los lugares de estudio, las mayores tasas de mortalidad antropogé nica y por caza se vieron parcialmente compensadas por las menores tasas de otras causas de mortalidad, pero no por la mortalidad natural por sí sola. La variació n en la supervivencia dependió del sexo (la supervivencia de las hembras fue 1.5 veces mayor que la de los machos) y de la estacionalidad (el mayor riesgo se registró durante la temporada de caza y el invierno), y las menores tasas de supervivencia se correlacionaron con una mayor modificació n humana de los paisajes tanto a escala gruesa (composició n del á rea de distribució n) como fina (uso del há bitat dentro del á rea de distribució n). Algunas variaciones en la supervivencia se debieron a factores no observados. Dadas las elevadas tasas de mortalidad causada por el hombre, incluidas las matanzas ilegales, estos factores son motivo de gran preocupació n. Debido a las bajas tasas de mortalidad natural en poblaciones protegidas y cazadas, concluimos que las causas antropogé nicas de mortalidad son probablemente casi aditivas, de modo que mantener o aumentar el há bitat de refugio con poca perturbació n humana es crí tico para la conservació n del lince. ResumenSupervivencia del lince euroasiá tico en los paisajes europeos dominados por humanos Las tasas de supervivencia y mortalidad por causas especí ficas son vitales para la previsió n y conservació n de poblaciones basadas en evidencias, sobre todo en el caso de los grandes carní voros, cuyas poblaciones suelen ser vulnerables a la mortalidad causada por el hombre. Por esto es importante conocer la relació n entre las causas de mortalidad antropogé nicas y naturales para evaluar si son aditivas o compensatorias. Ademá s, la relació n entre la supervivencia y las covariables ambientales podrí a revelar si las caracterí sticas especí ficas del paisaje influyen en el rendimiento demográ fico.Utilizamos datos telemé tricos de 681 linces euroasiá ticos (Lynx lynx), un depredador á pice modelo con grandes necesidades espaciales, que fueron rastreados a lo largo de su distribució n europea. Mediante aná lisis cronoló gicos, intentamos determinar las variables asociadas a las diferencias en su supervivencia. La matanza ilegal fue la principal causa de mortalidad (33.8%), y las tasas de mortalidad auales fueron similares en las poblaciones protegidas y cazadas (8.6 y 7.0%, respectivamente). La supervivencia anual varió mucho de una població n a otra (del 70 al 95%). En todos los lugares de estudio, las mayores tasas de mortalidad antropogé nica y por caza se vieron parcialmente compensadas por las menores tasas de otras causas de mortalidad, pero no por la mortalidad natural por sí sola. La variació n en la supervivencia dependió del sexo (la supervivencia de las hembras fue 1.5 veces mayor que la de los machos) y de la estacionalidad (el mayor riesgo se registró durante la temporada de caza y el invierno), y las menores tasas de supervivencia se correlacionaron con una mayor modificació n humana de los paisajes tanto a escala gruesa (composició n del á rea de distribució n) como fina (uso del há bitat dentro del á rea de distribució n). Algunas variaciones en la supervivencia se debieron a factores no observados. Dadas las elevadas tasas de mortalidad causada por el hombre, incluidas las matanzas ilegales, estos factores son motivo de gran preocupació n. Debido a las bajas tasas de mortalidad natural en poblaciones protegidas y cazadas, concluimos que las causas antropogé nicas de mortalidad son probablemente casi aditivas, de modo que mantener o aumentar el há bitat de refugio con poca perturbació n humana es crí tico para la conservació n del lince. Resume

Wolverine denning behaviour and its implications for monitoring reproductive females

Knowledge about the number of reproductive females is important for monitoring population dynamics, and can be critical for managing human-wildlife conflicts. For wolverines Gulo gulo, counts of reproductive females is the basis for estimates of population size in Scandinavia, as well as a key measure for compensation payments to Sami reindeer-herders in Sweden. However, documenting wolverine reproductive events in the field is challenging and requires knowledge of female denning behaviour. Furthermore, females may shift den sites, presenting difficulties in determining whether two den sites belong to the same or two neighbouring females. In this study, we used data from 18 GPS-collared wolverine females, monitored intensively during the denning season (15 February-31 May) in 2004-2014, to provide baseline information on denning behaviour. We documented reproductive events in 32 of 54 potential denning seasons, and identified a total of 245 den sites. Females used 8.8 +/- 8.5 (mean +/- SD) den sites per denning season (median = 6, range: 1-28). The number of den site shifts, the distance between subsequent den sites, and the time and distance females spent away from a den site increased during the denning season; while distances between neighbouring females' den sites remained constant. From late April, the distance between consecutive den sites used by the same female overlapped with distances between neighbouring females' den sites, resulting in increased uncertainty regarding whether two den sites belonged to one or two females. Using Bayesian modelling we calculated probabilities that two den sites belonged to the same female, or neighbouring females, conditional on the time of season and the distance between den sites. These findings will allow the monitoring program to adapt its methods for determining if multiple den sites belong to one or two reproductive events, using seasonally-dynamic threshold based on an understanding of wolverine denning behaviour

Dynamin-like proteins are potentially involved in membrane dynamics within chloroplasts and cyanobacteria

Dynamin-like proteins are a family of membrane-active proteins with low sequence identity. The proteins operate in different organelles in eukaryotic cells, where they trigger vesicle formation, membrane fusion or organelle division. As discussed here, representatives of this protein family have also been identified in chloroplasts and DLPs are very common in cyanobacteria. Since cyanobacteria and chloroplasts, an organelle of bacterial origin, have similar internal membrane systems, we suggest that dynamin-like proteins are involved in membrane dynamics in cyanobacteria and chloroplasts. Here, we discuss the features and activities of dynamin-like proteins with a focus on their potential presence and activity in chloroplasts and cyanobacteria

No Allee effect detected during the natural recolonization by a large carnivore despite low growth rate

Eurasian lynx (Lynx lynx) have recently naturally recolonized southern Sweden. The first documented reproduction of lynx in recent times occurred in 2003, and the population increased from 2 to 48 family groups (the unit of measurement in Swedish monitoring) during its first 18 years (2003/2004-2020/2021). We did not detect any Allee effect, that is, lower growth rate at low population density, during the recolonization of southern Sweden, although our population simulations revealed a non-negligible (30%) chance that population observed development could include an Allee effect. The probable absence of an Allee effect was likely because colonizing females did not lack mating partners, as a larger number of wide-ranging males were established in the area before documented reproduction took place. Despite the absence of an Allee effect, the growth rate during recolonization was lower in southern Sweden (lambda = 1.20) than in central Sweden (lambda = 1.29). We have no evidence of higher mortality, including that from poaching, or lower reproduction in southern Sweden could explain the lower growth rate. Instead, we suggest that the lower growth rate during the recolonization of southern Sweden was explained by fewer immigrants arriving from central Sweden due to areas of less suitable habitat between central and southern Sweden, partially preventing immigration southward. From a conservation point of view, it is positive that this small population could recover without being negatively influenced by an Allee effect, as small populations with an Allee effect experience lower viability than those without

Recolonization following past persecution questions the importance of persistent snow cover as a range limiting factor for wolverines

Globally, climate is changing rapidly, which causes shifts in many species' distributions, stressing the need to understand their response to changing environmental conditions to inform conservation and management. Northern latitudes are expected to experience strongest changes in climate, with milder winters and decreasing snow cover. The wolverine (Gulo gulo) is a circumpolar, threatened carnivore distributed in northern tundra, boreal, and subboreal habitats. Previous studies have suggested that wolverine distribution and reproduction are constrained by a strong association with persistent spring snow cover. We assess this hypothesis by relating spatial distribution of 1589 reproductive events, a fitness-related proxy for female reproduction and survival, to snow cover over two decades. Wolverine distribution has increased and number of reproductive events increased 20 times in areas lacking spring snow cover during our study period, despite low monitoring effort where snow is sparse. Thus, the relationship between reproductive events and persistent spring snow cover weakened during this period. These findings show that wolverine reproductive success and hence distribution are less dependent on spring snow cover than expected. This has important implications for projections of future habitat availability, and thus distribution, of this threatened species. Our study also illustrates how past persecution, or other factors, that have restricted species distribution to remote areas can mask actual effects of environmental parameters, whose importance reveals when populations expand beyond previously restricted ranges. Overwhelming evidence shows that climate change is affecting many species and ecological processes, but forecasting potential consequences on a given species requires longitudinal data to revisit hypotheses and reassess the direction and magnitude of climate effects with new data. This is especially important for conservation-oriented management of species inhabiting dynamic systems where environmental factors and human activities interact, a common scenario for many species in different ecosystems around the globe