Mercury speciation in Scottish raptors reveals high proportions of inorganic mercury in Scottish golden eagles (Aquila chrysaetos): Potential occurrence of mercury selenide nanoparticles.

Knowledge of the uptake and fate of mercury (Hg) compounds in biota is important in understanding the global cycling of Hg and its transfer pathways through food chains. In this study, we analysed total mercury (T-Hg) and methylmercury (MeHg) concentrations in 117 livers of Scottish birds of prey that were found across Scotland and submitted for post-mortem examination through the Raptor Health Scotland project between 2009 and 2019. Statistical comparisons focussed on six species (barn owl, Tyto alba; Eurasian common buzzard, Buteo buteo; golden eagle, Aquila chrysaetos; hen harrier, Circus cyaneus; Eurasian sparrowhawk, Accipiter nisus; and tawny owl, Strix aluco) and showed that golden eagles had a statistically lower fraction of MeHg compared to other raptor species. Further investigation using stable carbon and stable nitrogen isotope ratio measurements carried out for the golden eagles (n = 15) indicated that the increased presence of inorganic mercury (iHg) correlated with a marine influence on the primarily terrestrial diet. Additional bioimaging (n = 1) with laser ablation - inductively coupled plasma - mass spectrometry indicated the co-location of Hg and selenium (Se) within the liver tissue and transmission electron microscopy showed evidence of nanoparticles within the range of 10-20 nm. Further analysis using single particle - inductively coupled plasma - mass spectrometry (n = 4) confirmed the presence of Hg nanoparticles. Together, the evidence suggests the presence of mercury selenide (HgSe) nanoparticles in the liver of some golden eagles that, to our knowledge, has never been directly observed in terrestrial birds of prey. This study points to two alternative hypotheses: these golden eagles may be efficient at breaking down MeHg and form HgSe nanoparticles as a detoxification mechanism (as previously observed in cetaceans), or some golden eagles with elevated iHg may have accumulated these nanoparticles by foraging on stranded cetaceans or seabirds.

The genome sequence of the European golden eagle, Aquila chrysaetos chrysaetos Linnaeus 1758.

We present a genome assembly from an individual female Aquila chrysaetos chrysaetos (the European golden eagle; Chordata; Aves; Accipitridae). The genome sequence is 1.23 gigabases in span. The majority of the assembly is scaffolded into 28 chromosomal pseudomolecules, including the W and Z sex chromosomes.

Concentration and origin of lead (Pb) in liver and bone of Eurasian buzzards (Buteo buteo) in the United Kingdom.

Ingestion of lead (Pb) derived from ammunition used in the hunting of game animals is recognised to be a significant potential source of Pb exposure of wild birds, including birds of prey. However, there are only limited data for birds of prey in Europe regarding tissue concentrations and origins of Pb. Eurasian buzzards (Buteo buteo) found dead in the United Kingdom during an 11-year period were collected and the concentrations of Pb in the liver and femur were measured. Concentrations in the liver consistent with acute exposure to Pb were found in 2.7% of birds and concentration in the femur consistent with exposure to lethal levels were found in 4.0% of individuals. Pb concentration in the femur showed no evidence of consistent variation among or within years, but was greater for old than for young birds. The Pb concentration in the liver showed no effect of the birds' age, but varied markedly among years and showed a consistent tendency to increase substantially within years throughout the UK hunting season for gamebirds. The resemblance of the stable isotope composition of Pb from buzzard livers to that of Pb from the types of shotgun ammunition most widely-used in the UK increased markedly with increasing Pb concentration in the liver. Stable isotope results were consistent with 57% of the mass of Pb in livers of all of the buzzards sampled being derived from shotgun pellets, with this proportion being 89% for the birds with concentrations indicating acute exposure to Pb. Hence, most of the Pb acquired by Eurasian buzzards which have liver concentrations likely to be associated with lethal and sublethal effects is probably obtained when they prey upon or scavenge gamebirds and mammals shot using Pb shotgun pellets.

Eimeria spp. in captive-reared corncrakes (Crex crex): results of a GeneScan assay consistent with high prevalence of infection and extra-intestinal life stages.

Eimeria crecis and Eimeria nenei have been detected in association with enteric disease ("coccidiosis") in the corncrake (Crex crex: Family Rallidae, Order Gruiformes). Both parasite species are common in apparently healthy free-living corncrakes, but captive-bred juvenile birds reared for reintroduction appeared particularly susceptible to clinical coccidiosis. We investigated the occurrence and relative pathogenicity of these Eimeria species in this juvenile corncrake population and developed a diagnostic species-specific polymerase chain reaction (PCR) for their identification. PCR amplification and sequencing of 18S rDNA were performed on genomic DNA extracted from samples of corncrake intestine, liver and spleen. Sequences generated were used to design a GeneScan diagnostic PCR assay targeting a species-specific TTA indel located within the 18S rDNA - the results suggested this assay was more sensitive than the 18S rDNA/amplicon sequencing approach. Eimeria sp. DNA (consistent with Eimeria sp. infection) was detected at a high prevalence and E. crecis was the predominant species. Each Eimeria species was detected in cases with and without histological evidence of coccidiosis: parasite detection was not statistically associated with disease. In addition to intestinal tissue, liver and spleen samples were positive for Eimeria sp. DNA. Its detection in tissues other than intestine is unusual and a novel finding in corncrakes, although extra-intestinal infection occurs with closely related Eimeria species in cranes (Family Gruidae, Order Gruiformes). Eimeria sp. infection of corncrakes appears typically to be chronic, and to exhibit extra-intestinal spread: as in cranes, these characteristics may be adaptations to the host's migratory nature.

Protecting Free-Living Dormice: Molecular Identification of Cestode Parasites in Captive Dormice (Muscardinus avellanarius) Destined for Reintroduction.

The success of any population translocation programme relies heavily on the measures implemented to control and monitor the spread of disease. Without these measures, programmes run the risk of releasing immunologically naïve species or, more dangerously, introducing novel infectious agents to native populations. As a precaution, a reintroduction programme for the common or hazel dormouse, Muscardinus avellanarius, in England screens dormice before release following captive breeding. Using PCR sequencing of a range of genes, we tested whether the same species of tapeworm(s) were present in captive and free-living dormice. Whilst only Rodentolepis straminea were identified in free-living dormice, cestode ova found in a captive individual produced a molecular match closely related to Hymenolepis microstoma and a previously unrecorded Rodentolepis species. To prevent putting at risk the free-living population, we recommended the continued treatment of dormice showing tapeworm infection before release. Our work demonstrates how molecular techniques can be used to inform reintroduction programmes, reduce risk from disease and increase chances of reintroduction success.

Sialolito submandibular: reporte de un caso / Submandibular sialolith: report of a case

Un sialolito es un depósito cálcico en los conductos o glándulas salivales; se encuentra con más frecuencia en la glándula submandibular debido a su confi guración anatómica, la alcalinidad de su saliva y su riqueza en mucina. La etiología exacta y la patogénesis son desconocidas. Los síntomas principales son dolor e infl amación de la glándula en respuesta a estímulos salivales. Una obstrucción completa causa dolor constante, infl amación, y pueden estar presentes algunos signos de infección sistémica. El diagnóstico se realiza mediante la palpación intraoral bimanual y estudios de imagenología. El tratamiento dependerá del tamaño y localización del cálculo, y puede ser conservador o quirúrgico. El presente artículo describe un caso clínico de un sialolito submandibular

A sialolith is a calcified stone that forms in the salivary glands or ducts, most often in the submandibular gland due to its anatomical confi guration, the higher alkalinity of its saliva, and its richness in mucin. Its precise etiology and pathogenesis are unknown. The principal symptoms are pain and infl ammation of the gland in response to salivary stimuli. When complete obstruction occurs, the result is constant pain and swelling, and signs of infection may also be present. Diagnosis is achieved by means of intraoral bimanual palpation and imagenology, and treatment depends on the size and localization of the stone; it may be conservative or surgical. The present article describes a clinical case of a submandibular sialolith.

Genetic structure of introduced populations: 120-year-old DNA footprint of historic introduction in an insular small mammal population.

Wildlife populations have been introduced to new areas by people for centuries, but this human-mediated movement can disrupt natural patterns of genetic structure by altering patterns of gene flow. Insular populations are particularly prone to these influences due to limited opportunities for natural dispersal onto islands. Consequently, understanding how genetic patterns develop in island populations is important, particularly given that islands are frequently havens for protected wildlife. We examined the evolutionary origins and extent of genetic structure within the introduced island population of red squirrels (Sciurus vulgaris) on the Channel Island of Jersey using mitochondrial DNA (mtDNA) control region sequence and nuclear microsatellite genotypes. Our findings reveal two different genetic origins and a genetic architecture reflective of the introductions 120 years ago. Genetic structure is marked within the maternally inherited mtDNA, indicating slow dispersal of female squirrels. However, nuclear markers detected only weak genetic structure, indicating substantially greater male dispersal. Data from both mitochondrial and nuclear markers support historic records that squirrels from England were introduced to the west of the island and those from mainland Europe to the east. Although some level of dispersal and introgression across the island between the two introductions is evident, there has not yet been sufficient gene flow to erase this historic genetic "footprint." We also investigated if inbreeding has contributed to high observed levels of disease, but found no association. Genetic footprints of introductions can persist for considerable periods of time and beyond traditional timeframes of wildlife management.