Environmental correlates of lake occupancy and chick survival of Black-throated Divers Gavia arctica in Scotland

Capsule Lake occupancy was related to the abundance of fish prey for adults (salmonids) and chick survival was related to type of diet, prey abundance and weather.

Aims To identify the factors determining lake occupancy and chick survival of Black-throated Divers breeding in Scotland.

Methods Measures of water chemistry, fish, invertebrates and physical characteristics were made for 90 lakes where occupancy had been monitored in at least five years between 1984 and 1995. Data on chick survival were available over this period for a smaller sample of lakes.

Results High occupancy rates were associated with a high abundance of small salmonids (the birds' principal prey) and complex shorelines. The mean number of chicks fledged per nest that hatched was 0.95 at lakes where Three-spined Sticklebacks Gasterosteus aculeatus and/or Minnows Phoxinus phoxinus were present; the mean number of chicks fledged was 0.64 where they were absent (and chicks are fed invertebrates). Chick survival on lakes with sticklebacks/Minnows was positively and significantly related to June temperature, and the abundance of these fish. At lakes lacking these small fish, chick survival was inversely related to sunshine duration in June. It is suggested that sunny weather in June can accelerate the emergence of aquatic insect larvae (especially Ephemeroptera) and lead to food shortage for small diver chicks.

Conclusions It is likely that there are sufficient suitable lakes to accommodate a moderate expansion of the Scottish Black-throated Diver population. An abundance of suitable fish prey, especially small-sized (<230 mm) salmonids, is of fundamental importance for diver conservation.     

The occurrence of wildcat in the Polish Carpathian Mountains

The contemporary occurrence of wildcatFelis silvestris (Schreber, 1775) in the Polish part of the Carpathian Mountains was evaluated in 1998–2000 with personal inquiries in all forest inspectorates of Krosno and Kraków Regional Directorates of State Forests and five national parks (NP). Additional information on the presence of wildcat was collected by snow tracking in three winter seasons: 1998/1999 through 2000/2001. Wildcat presence was confirmed only for Bieszczady Mountains, Pogórze Przemyskie, and Beskid Niski Mountains (13 forest inspectorates and 2 national parks: Bieszczady NP and Magurski NP).     

Viral infections in free-living populations of the European wildcat

While the importance of viral infections is well studied in domestic cats, only limited information is available on their occurence and prevalence in the European wildcat (Felis silvestris silvestris). The aim of this study was to determine the prevalence of antibodies to feline coronavirus (FCoV), calicivirus (FCV), herpesvirus (FHV), parvovirus (FPV), immunodeficiency virus (FIV), leukemia virus (FeLV), and FeLV antigenemia in 51 European wildcat sera. Samples were collected between 1996 and 1997 from wildcat populations in France, Switzerland, and Germany. Antibodies to FCoV were detected in two cats (4%) and FCoV RNA was detected in feces of one of these two cats. Antibodies to FCV, FHV and FPV were found at relatively low frequencies of 16%, 4%, and 2%, respectively. Antibodies to FIV were not detected. Although antigen and antibodies to FeLV were detected in 49%, and 75%, respectively, no evidence of FeLV-associated pathology was found. From the low prevalence of FCoV, FCV, FHV and FPV infections and from the fact that the European wildcats live solitarily, it was concluded that these viral infections do not spread readily within a population. Therefore, it may be assumed that release into the wild of European wildcats bred in captivity would not bring about a high risk of introducing of these viral infections to the free-ranging wildcats. As an exception, wildcats should be tested for absence of FIV infection before release if they were at risk to acquire this infection from domestic cats.     

Global nucleosome occupancy in yeast

Background  

Although eukaryotic genomes are generally thought to be entirely chromatin-associated, the activated PHO5 promoter in yeast is largely devoid of nucleosomes. We systematically evaluated nucleosome occupancy in yeast promoters by immunoprecipitating nucleosomal DNA and quantifying enrichment by microarrays.     

Hematologic and serum chemistry values of the captive European wildcat

Hematologic and serum chemistry values were determined for 20 adult captive European wildcats (Felis silvestris) in Lleida (Catalonia, Spain). Seven wildcats (4 females and 3 males) were captured in the wild and 13 (4 females and 9 males) were born and raised in captivity. Samples were collected between September and December from 1993 to 1998. Blood was obtained by jugular venipuncture after administration of either ketamine and xylazine or ketamine and medetomidine. Females had significantly higher mean eosinophil counts, albumin concentration, (and A/G ratio) and lower mature neutrophil counts, although these differences were not clinically relevant. Results for many of the blood parameters fall within the reference range for domestic cats. Mean values for alanine aminotransferase, aspartate aminotransferase, creatine phosphokinase, and lactate dehydrogenase activities as well as blood urea nitrogen, glucose, and sodium concentrations were higher than the upper limit of the reference range for domestic cats.     

Comparative analysis of the diet of feral and house cats and wildcat in Europe

Differences in availability of food resources are often manifested in the differentiation of feeding habits of closely related mammal species. Therefore, we assumed that the diet composition and trophic niche of house (i.e., highly dependent on human households), feral (i.e. independent on human households) domestic cats (Felis silvestris catus) and wildcats (Felis s. silvestris) differs. Based on the literature data from Europe (53 study sites), we compared the diet of these three felids analyzed with use of indirect methods (stomach and scat analyses). In the case of the house cat, we additionally compared consumption data obtained directly from prey brought home. Data were expressed as the relative frequency of occurrence to compare dietary patterns. The main prey of the three cat types were small mammals in different ratios. According to the stomach and scat samples, the diet composition of the cat types showed differences in the consumption of rodents, insectivores, wild ungulates, and household food, supporting the “dietary differences originate from varying resources” hypothesis. More opportunistic house cats had a broader trophic niche than feeding specialist wildcats, while feral cats had an intermediate position. The trophic niche breadth of all three cat types increased along a latitudinal gradient from northern to southern areas of Europe. The predation of the house cat which was examined from prey brought home differed from the data obtained by indirect diet analysis; however, it yielded similar results to the diet of the feral cat and the wildcat. Due to their high numbers and similarity of its diet to the wildcat, house cats are a threat to wild animals; therefore, their predation pressure needs to be further investigated.     

Myco-ecology in Scotland

Summary

A history of ecological studies in mycology developed around the trophic state of the fungi is taken from the rich heritage of information available. With the renewed interest in biodiversity and the array of molecular and complementary techniques available the future could be very rewarding.     

Mesothelioma in Scotland

In a retrospective study of the incidence of mesothelioma in Scotland for 1950-67 80 cases were traced from pathological reports and biopsy material of malignant tumours invading the pleura and peritoneum. These cases were matched with two sets of controls. Detailed histories of residence, occupation, and degree of exposure to asbestos confirmed that the incidence of mesothelioma in Scotland is similar to that in other parts of Britain.     

Salamander occupancy in headwater stream networks

1. Stream ecosystems exhibit a highly consistent dendritic geometry in which linear habitat units intersect to create a hierarchical network of connected branches.
2. Ecological and life history traits of species living in streams, such as the potential for overland movement, may interact with this architecture to shape patterns of occupancy and response to disturbance. Specifically, large-scale habitat alteration that fragments stream networks and reduces connectivity may reduce the probability a stream is occupied by sensitive species, such as stream salamanders.
3. We collected habitat occupancy data on four species of stream salamanders in first-order (i.e. headwater) streams in undeveloped and urbanised regions of the eastern U.S.A. We then used an information–theoretic approach to test alternative models of salamander occupancy based on a priori predictions of the effects of network configuration, region and salamander life history.
4. Across all four species, we found that streams connected to other first-order streams had higher occupancy than those flowing directly into larger streams and rivers. For three of the four species, occupancy was lower in the urbanised region than in the undeveloped region.
5. These results demonstrate that the spatial configuration of stream networks within protected areas affects the occurrences of stream salamander species. We strongly encourage preservation of network connections between first-order streams in conservation planning and management decisions that may affect stream species.