Test of Localized Management for Reducing Deer Browsing in Forest Regeneration Areas

ABSTRACT White-tailed deer (Odocoileus virginianus) browsing in forest regeneration sites can affect current and future stand structure and species composition. Removal of deer social units (localized management) has been proposed as a strategy to alleviate deer overbrowsing in forest systems. We conducted an experimental localized removal in a high-density deer population in the central Appalachians of West Virginia, USA, during winter 2002. We removed 51 deer within a 1.1-km² area that encompassed 2 forest regeneration sites (14 ha). During the summer following removal, we detected decreases in distance from the removal area in 8 of 30 (26.7%) adult females having pretreatment mean telemetry locations <2.5 km from the center of the removal area. We measured browsing rates during the summers of 2001–2004 from forest regeneration sites to examine efficacy of localized management. Browsing rates declined annually in both removal and control areas, due in part to increased timber harvesting on the larger study site, suggesting that increasing forage availability may be more effective at reducing impacts on forest regeneration than localized reductions in deer populations. Three years after the initial removal, we removed an additional 31 deer from the original 1.1-km² removal area. Home range shifts of adjacent deer coupled with the large number of animals collected in the second removal suggests that localized management only produces temporary voids within high-density deer herds. Localized management may not effectively reduce negative impacts of deer in areas of high deer density.     

How has the remnant population of the threatened frog Leiopelma pakeka (Anura: Leiopelmatidae) fared on Maud Island,New Zealand,over the past 25 years?

Despite widespread global reports of declining amphibian populations, supporting long‐term census data are few, limiting opportunities to study changes in numbers and survival over time. However, in New Zealand, for the past 25 years (1983–2008), we studied Leiopelma pakeka, a threatened, terrestrial frog that inhabits rocky boulder banks under forest on Maud Island. Using night sampling at least annually on two 12 × 12 m plots, we had 5390 captures of 1000+ individuals, 327 on one plot (grid 1), 751 on the other (grid 2). The mean (±SE) number of frogs found per night was 11.3 (±0.6) on grid 1 and 25.6 (±1.4) on grid 2. We used capture‐recapture models to estimate population size, proportion of animals remaining beneath the surface and survival rate. The mean (±SE) population estimate was 131 (±14.7) frogs on grid 1 and 367 (±38.7) on grid 2. Over 25 years the estimated population increased on grid 1 and fluctuated on grid 2. Some frogs were captured on most sampling visits, others less often, evidently failing to emerge from cover each visit. Using a combination of open and closed population models, we estimated the mean (±SE) proportion remaining underground was 0.63 (±0.12) on grid 1 and 0.53 (±0.07) on grid 2. Our research represents one of the longest‐run population studies of any frog, and we recorded significant longevity, two males reaching 35+ and 37+ years, a female 34+ years. No significant differences occurred between mean annual survival rates of apparent females and males, or between the two sites. The number of toes clipped for individual identification had little influence on the return rate, once the effect of time of first capture was removed.     

Identifying Predators and Nest Fates of Bobwhites in Southern Texas

Abstract: Predation is the primary cause of nest failure for northern bobwhites (Colinus virginianus). There are few reliable data documenting the species diversity and relative importance of bobwhite nest predators in southern Texas, USA. We used infrared video-monitoring systems to document nest fates of 127 bobwhite nests over 4 nesting seasons from 2002 to 2005 in southern Texas. A majority of depredation events (83%) were caused by 4 species: coyote (Canis latrans), striped skunk (Mephitis mephitis), southern fire ant (Solenopsis xyloni), and badger (Taxidea taxus). Observed bobwhite nest fates for the study period were 0.50 successful, 0.34 depredated, and 0.16 abandoned or undetermined. A universal approach to mitigating nest predation is not likely to be applicable in regions similar to southern Texas, with high nest-predator diversity (e.g., fire ants, rodents, and mammalian carnivores). We believe that infrared video surveillance is a valuable tool for documenting baseline information on predator context and nest fate for many avian species, considering the limitations of past methods (e.g., postfate evidence).     

The Microaerophilic Flagellate, Trichomonas vaginalis, Contains Unusual Acyl Lipids but no Detectable Cardiolipin

ABSTRACT. Previous lipid analysis of trichomonads has led to controversy as to whether these hydrogenosome-containing organisms contain cardiolipin (CL), which is a characteristic component of mitochondria. Here we report a careful lipid analysis of the sexually transmitted protist Trichomonas vaginalis . Major lipids were phosphatidylethanolamine (42%) and phosphatidylcholine (20%) with lesser amounts of phosphatidylglycerol (PG) (12%) and non-polar components. Two unusual lipids, acyl-PG (8%) and ceramide phosphorylethanolamine (2%), were also significant components. The structures of these lipids were confirmed by tandem mass spectrometry following reverse-phase high-performance liquid chromatography. This is the first time ceramide phosphorylethanolamine has been reported in a trichomonad. In contrast, CL (diphosphatidylglycerol) could not be detected either by two-dimensional thin-layer chromatography or by mass spectrometry. These data are discussed in relation to the organism's phylogenetic origin as a parasite showing secondary adaptation to microaerobic conditions.     

Using molecules and morphology to infer the phylogenetic relationships and evolutionary history of the Dirini (Nymphalidae: Satyrinae), a tribe of butterflies endemic to Southern Africa

The first empirically supported phylogenetic hypothesis of relationships for the southern African endemic butterfly tribe Dirini is presented. Data derived from the morphology and ecology of the adults and immature stages (33 characters), and portions of the mitochondrial gene cytochrome oxidase I (COI) and the nuclear genes elongation factor 1α (EF1α) and wingless (WG) (totalling 1734 bp) were used to infer the relationships of the in‐group genera. An expanded molecular dataset using four genera from the Nymphalini and Satyrini to root the tree, and three genera from the Melanitini to test the monophyly of the tribe, was analysed using parsimony and Bayesian methods. Estimates of divergence times were calculated using two fossil calibrations under a relaxed molecular clock model. The monophyly of the tribe and each in‐group genus were strongly supported. Key findings are the sister‐taxon relationship of Aeropetes and Tarsocera, the apparent simultaneous or nearly simultaneous radiation of four lineages, the polyphyly of the species within Torynesis, and the apparent trans‐Atlantic dispersal of the ancestors of Manataria about 40 Ma. Estimates of divergence times indicate that the tribe has undergone two major radiations since its origin: the first when they left forest habitats in the mid–late Oligocene, shortly after the radiation of the grasses (Poaceae), and the second in the early‐middle Pliocene, coinciding with the aridification of southern Africa and the spread of conditions that favoured C₄ grasses over the C₃ grasses that dirine larvae prefer to eat. The high species diversity within the tribe appears to be partly a taxonomic artefact that may have resulted from the misinterpretation of climate‐related phenotypic variation within extant species. Relocation and breeding experiments should test this hypothesis.     

NEW ALBIAN (EARLY CRETACEOUS) OPHIUROIDS FROM THE TLAYÚA QUARRY, PUEBLA, MEXICO

Abstract:  On the basis of six articulated individuals from the middle to late Albian lithographic limestone at Tlayúa near Tepexi de Rodríguez (Puebla, Mexico), a new species of ophiuroid, Ophiactis applegatei , is described. The material adds to the rather poor record of Early Cretaceous brittlestars and represents the oldest known member of the family Ophiactidae, being based on well-preserved and articulated specimens and thus reasonably well defined morphologically. The rarity of ophiuroids, their complete preservation as well as the unnatural contortions of their arms suggest these specimens to be allochthonous, having been transported into a hostile environment where burial was rapid.     

Mercapturic acids as biomarkers of exposure to electrophilic chemicals:applications to environmental and industrial chemicals

The use of mercapturic acids (N-acetyl-L-cysteine S-conjugates, MAs) in the biological monitoring of human exposure to environmental and industrial chemicals is receiving more and more attention. Mercapturic acids (MAs) are formed from glutathione (GSH) S-conjugates via the MA-pathway. Although this pathway can lead to different end-products, the formation of MAs is the predominant route in most species, including man. Two GSH S-transferases (GSTs) show genetic polymorphisms in humans and this can have major consequences for individual susceptibility to toxic effects and for MA formation. In occupational toxicology, adducts to biomacromolecules are also used as biomarkers. DNA adducts are a measure for the effective dose, while protein adducts are related to the dose at critical site. Both type of adducts are normally determined in blood, while MAs are determined in urine. Most MAs are excreted with relatively short half-lifes, allowing a direct evaluation of the occupational circumstances. For many compounds similar (linear) dose-dependency was found for MA excretion, formation of macromolecular adducts, and for various biomarkers of toxic effects. These relations together with fact that MAs relate to the electrophilic character of compounds, allows for the conclusion that MAs are biomarkers of toxicologically relevant internal doses of chemicals or their metabolites. An overview will be given here of the use of MAs in the assessment of internal human exposure to electrophilic environmental and industrial chemicals. Additionally, the formation of GSH S-conjugates, their catabolism to MAs and several of the frequently used analytical approaches are discussed. When appropriate, the influence of genetic polymorphisms on formation of MAs and on susceptibility to toxicity will be discussed for different chemicals as well.