Ecological role of vertebrate scavengers in urban ecosystems in the UK

Recent research has demonstrated how scavenging, the act of consuming dead animals, plays a key role in ecosystem structure, functioning, and stability. A growing number of studies suggest that vertebrate scavengers also provide key ecosystem services, the benefits humans gain from the natural world, particularly in the removal of carcasses from the environment. An increasing proportion of the human population is now residing in cities and towns, many of which, despite being highly altered environments, contain significant wildlife populations, and so animal carcasses. Indeed, non‐predation fatalities may be higher within urban than natural environments. Despite this, the fate of carcasses in urban environments and the role vertebrate scavengers play in their removal have not been determined. In this study, we quantify the role of vertebrate scavengers in urban environments in three towns in the UK. Using experimentally deployed rat carcasses and rapid fire motion‐triggered cameras, we determined which species were scavenging and how removal of carcass biomass was partitioned between them. Of the 63 experimental carcasses deployed, vertebrate scavenger activity was detected at 67%. There was a significantly greater depletion in carcass biomass in the presence (mean loss of 194 g) than absence (mean loss of 14 g) of scavengers. Scavenger activity was restricted to three species, Carrion crows Corvus corone, Eurasian magpies Pica pica, and European red foxes Vulpes vulpes. From behavioral analysis, we estimated that a maximum of 73% of the carcass biomass was removed by vertebrate scavengers. Despite having low species richness, the urban scavenger community in our urban study system removed a similar proportion of carcasses to those reported in more pristine environments. Vertebrate scavengers are providing a key urban ecosystem service in terms of carcass removal. This service is, however, often overlooked, and the species that provide it are among some of the most disliked and persecuted.     

The contrasting effects of short‐ and long‐term habitat drainage on the population dynamics of freshwater turtles in a human‐dominated landscape

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Insight on Propolis from Mediterranean Countries: Chemical Composition,Biological Activities and Application Fields

This review updates the information upon the chemical composition of propolis from all Mediterranean countries as well as their biological properties and applications. The non‐volatile fraction of propolis was characterized by the presence of phenolic acids and their esters and flavonoids. Nevertheless, in some countries, diterpenes were also present: Sicily (Italy), Croatia, Malta, Creta (Greece), Turkey, Cyprus, Egypt, Libya, Algeria and Morocco. The volatile fraction of propolis was characterized by the presence of benzoic acid and its esters, mono‐ and sesquiterpenes, being the oxygenated sesquiterpene β‐eudesmol characteristic of poplar propolis, whereas the hydrocarbon monoterpene α‐pinene has been related with the presence of conifers. Regardless the chemical composition, there are common biological properties attributed to propolis. Owing to these attributes, propolis has been target of study for applications in diverse areas, such as food, medicine and livestock.     

Adapt or die—Response of large herbivores to environmental changes in Europe during the Holocene

Climate warming and human landscape transformation during the Holocene resulted in environmental changes for wild animals. The last remnants of the European Pleistocene megafauna that survived into the Holocene were particularly vulnerable to changes in habitat. To track the response of habitat use and foraging of large herbivores to natural and anthropogenic changes in environmental conditions during the Holocene, we investigated carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotope composition in bone collagen of moose (Alces alces), European bison (Bison bonasus) and aurochs (Bos primigenius) in Central and Eastern Europe. We found strong variations in isotope compositions in the studied species throughout the Holocene and diverse responses to changing environmental conditions. All three species showed significant changes in their δ¹³C values reflecting a shift of foraging habitats from more open in the Early and pre‐Neolithic Holocene to more forest during the Neolithic and Late Holocene. This shift was strongest in European bison, suggesting higher plasticity, more limited in moose, and the least in aurochs. Significant increases of δ¹⁵N values in European bison and moose are evidence of a diet change towards more grazing, but may also reflect increased nitrogen in soils following deglaciation and global temperature increases. Among the factors explaining the observed isotope variations were time (age of samples), longitude and elevation in European bison, and time, longitude and forest cover in aurochs. None of the analysed factors explained isotope variations in moose. Our results demonstrate the strong influence of natural (forest expansion) and anthropogenic (deforestation and human pressure) changes on the foraging ecology of large herbivores, with forests playing a major role as a refugial habitat since the Neolithic, particularly for European bison and aurochs. We propose that high flexibility in foraging strategy was the key for survival of large herbivores in the changing environmental conditions of the Holocene.     

Application of a SSR‐GBS marker system on investigation of European Hedgehog species and their hybrid zone dynamics

By applying second‐generation sequencing technologies to microsatellite genotyping, sequence information is produced which can result in high‐resolution population genetics analysis populations and increased replicability between runs and laboratories. In the present study, we establish an approach to study the genetic structure patterns of two European hedgehog species Erinaceaus europaeus and E. roumanicus. These species are usually associated with human settlements and are good models to study anthropogenic impacts on the genetic diversity of wild populations. The short sequence repeats genotyping by sequence (SSR‐GBS) method presented uses amplicon sequences to determine genotypes for which allelic variants can be defined according to both length and single nucleotide polymorphisms (SNPs). To evaluate whether complete sequence information improved genetic structure definition, we compared this information with datasets based solely on length information. We identified a total of 42 markers which were successfully amplified in both species. Overall, genotyping based on complete sequence information resulted in a higher number of alleles, as well as greater genetic diversity and differentiation between species. Additionally, the structure patterns were slightly clearer with a division between both species and some potential hybrids. There was some degree of genetic structure within species, although only in E. roumanicus was this related to geographical distance. The statistically significant results obtained by SSR‐GBS demonstrate that it is superior to electrophoresis‐based methods for SSR genotyping. Moreover, the greater reproducibility and throughput with lower effort which can be obtained with SSR‐GBS and the possibility to include degraded DNA into the analysis, allow for continued relevance of SSR markers during the genomic era.     

Harvest selection on multiple traits in the wild revealed by aquatic animal telemetry

Harvesting can have profound impacts on the ecology and evolution of marine populations. However, little is known about the strength and direction of fisheries‐induced selection acting on multiple traits in the wild. Here, we used acoustic telemetry to directly monitor individual behavior and fate in an intensively harvested species, the European lobster (Homarus gammarus, n = 100), in southern Norway. Overall, 24% of the tracked lobsters survived the two‐month harvest season within the study area. Our results indicated that local survival was not random with respect to phenotype. We found no clear support for fisheries‐induced selection acting directly on body size. However, lobsters with large crusher claws relative to their body size, typical of socially dominant individuals, appeared at higher risk of being captured in the conventional trap fishery. We also detected a fine‐scale spatial gradient in survival. After accounting for this gradient, individuals displaying larger home ranges were more likely to survive the harvest season. Finally, we found significant repeatabilities for lobster behavior on a monthly timescale, indicating that individual behavioral attributes tended to persist and may reflect personality. Our study therefore provides empirical support for the need to consider an evolutionary enlightened approach to fisheries management that considers the influence of harvest on multiple traits of target species.     

The yeast acylglycerol acyltransferase LCA1 is a key component of Lands cycle for phosphatidylcholine turnover

Cellular phospholipids undergo deacylation and reacylation through a process known as Lands cycle. In this report, we provide evidence demonstrating that yeast YOR175c, herein designated as LCA1, encodes a key component of the Lands cycle, the acyl-CoA: lysophosphatidylcholine acyltransferase (LPCAT). Deletion of LCA1 resulted in a drastic reduction in LPCAT activity, while over expression led to a several fold increase in enzyme activity. We further show that disruption of LCA1 caused an enhanced production of glycerophosphorylcholine, a product of phosphatidylcholine (PC) deacylation and that the lysophosphatidic acid acyltransferase SLC1 was not involved in this process. Identification of LCA1 provides an essential molecular tool for further study of Lands cycle in PC turnover.     

Changes in recreational catfish Silurus glanis harvest rates between years 1986–2017 in Central Europe

The European catfish Silurus glanis is an important fish species in both commercial and recreational fisheries. Catfish is a spreading species that was reported to potentially benefit from increasing temperatures. The goal of this study was to estimate long‐term changes in harvest rates of catfish in Central Europe. This study used individual mandatory angling logbooks collected by the Czech Fishing Union in the Czech Republic (Central Europe) over the course of years 1986–2017 (32 years) to assess harvest rates of catfish. This study discovered that harvest of catfish has been increasing over time. Moreover, rivers that previously showed zero harvested catfish are beginning to display higher harvest rates of catfish. Increasing average air temperature and angling effort in the study area have positively affected harvest rates of catfish. The increased harvest of catfish could not be reliably explained by intensive fish stocking. In conclusion, while other studies show that many fish species are negatively affected by human activities and therefore show decreased harvest rates, catfish angling seems to benefit from anthropogenic changes.