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Surveying seabirds in polar latitudes can be challenging due to sparse human populations, lack of infrastructure and the risk of disturbance to wildlife or damage to habitats. Counting populations using un-crewed aerial vehicles (UAVs) is a promising approach to overcoming these difficulties. However, a careful validation of the approach is needed to ensure comparability with counts collected using conventional methods. Here, we report on surveys of three Antarctic bird species breeding on Signy Island, South Orkney Islands; Chinstrap (Pygoscelis antarctica) and Gentoo (Pygoscelis papua) Penguins, and the South Georgia Shag (Leucocarbo atriceps georgianus). We show that images from low-altitude UAV surveys have sufficient resolution to allow separation of Chinstrap Penguins from contiguously breeding Adélie Penguins (Pygoscelis adéliae), which are very similar in appearance when viewed from overhead. We compare data from ground counts with manual counts of nesting birds on images collected simultaneously by low-altitude aerial photography from multi-rotor UAVs at the same colonies. Results at this long-term monitoring site confirmed a continued population decline for Chinstrap Penguins and increasing Gentoo Penguin population. Although both methods provided breeding pair counts that were generally within ~ 5%, there were significant differences at some locations. We examine these differences in order to highlight potential biases or methodological constraints that should be considered when analysing similar aerial census surveys and comparing them with ground counts. [ABSTRACT FROM AUTHOR]

Tracking individual marine predators can provide vital information to aid the identification of important activity (foraging, commuting, rafting, resting, etc.) hotspots and therefore also to delineate priority sites for conservation. However, in certain locations (e.g. Antarctica) many marine mammal or seabird colonies remain untracked due to logistical constraints, and the colonies that are studied may not be the most important in terms of conservation priorities. Using data for one of the most abundant seabirds in the Antarctic as a case study (the Chinstrap Penguin Pygoscelis antarcticus), we tested the use of correlative habitat models (used to predict distribution around untracked colonies) to overcome this limitation, and to enable the identification of important areas at-sea for colonies where tracking data are not available. First, marine Important Bird and Biodiversity Areas (IBA) were identified using a standardised, published approach using empirical data from birds tracked from colonies located in the South Orkney Islands. Subsequently, novel approaches using predicted distributions of Chinstrap Penguins derived from correlative habitat models were applied to identify important marine areas, and the results compared with the IBAs. Data were collected from four colonies over 4 years and during different stages of the breeding season. Results showed a high degree of overlap between the areas identified as important by observed data (IBAs) and by predicted distributions, revealing that habitat preference models can be used to identify marine IBAs for these penguins. We provide a new method for designating a network of marine IBAs for penguins in Antarctic waters, based on outputs from correlative habitat models when tracking data are not available. This can contribute to an evidence-based and precautionary approach to aid the management framework for Antarctic fisheries and for the protection of birds. [ABSTRACT FROM AUTHOR]

Information is needed on how anomalous environmental conditions affect important Antarctic ecological sentinels during the winter. Using a non-invasive method (scats), the diet of non-breeding gentoo penguins Pygoscelis papua at Bird Island, South Georgia, was examined during the winter of 2009 when local environmental conditions were abnormal (e.g. warmer sea surface waters). Scats were collected every 2 weeks from May until October 2009 (N = 168); the diet was dominated by the amphipod Themisto gaudichaudii by frequency of occurrence (77.5% of the samples) and by number (70.5% of the total individuals). By mass, different species of crustaceans (T. gaudichaudii and Antarctic krill Euphausia superba) and fish (Champsocephalus gunnari, Lepidonotothen larseni and Pseudochaenichthys georgianus) were the most important in different periods. Numerically, prey switching occurred at the end of winter, when E. superba became more abundant in the penguins’ diets in late September and early October (austral spring), when sea surface temperatures became colder. T. gaudichaudii is sub-optimal prey for gentoo penguins and its consumption most likely reflects a lack of E. superba in local waters. The consumption of T. gaudichaudii and fish, in place of E. superba, was probably insufficient for the penguins to maintain a body condition suitable for reproduction, contributing to the observed late commencement of breeding (i.e. 2-3 weeks) that year. Our results highlight the sensitivity of gentoo penguin populations to variations in environmental conditions, particularly in terms of how these conditions affect the availability of preferred dietary items and potential follow-on effects in the subsequent breeding season. [ABSTRACT FROM AUTHOR]

The Falkland Islands currently supports one of the largest Southern Rockhopper Penguin ( Eudyptes c. chrysocome) populations. Archipelago-wide censuses conducted in 2000 and 2005 revealed that the number of breeding pairs had declined by 30 % during this period. To establish whether the breeding population continued to decline, an archipelago-wide census was conducted in 2010. We report a conservative estimate of 319,163 ±SD 24,820 pairs breeding at the Falkland Islands in 2010. This represents a 51 % increase when compared with the number counted in 2005. A simple stochastic population model was developed to investigate the extent to which changes in demographic parameters between 2005 and 2010 could account for the increase in breeding pairs. The population model predicted a 38 % increase in the number of breeding pairs over a 5-year period (289,431 ±SD 24,615). The increase in the number of breeding pairs was therefore probably attributed to improved vital rates in the period between the 2005 and 2010 archipelago-wide censuses in combination with other factors such as a reduction in the proportion of adult birds that abstained from breeding. Based on the 2010 Falkland Islands estimate, the global population of the subspecies E. c. chrysocome is now closer to 870,000 breeding pairs of which the Falkland Islands accounts for approximately 36 %, the second largest proportion after Chile. We conclude that despite fluctuations, the number of Southern Rockhopper Penguins breeding at the Falkland Islands has increased over the last 15 years and suggest that the 'Vulnerable' conservation status of the species be re-assessed. [ABSTRACT FROM AUTHOR]

Verrucous carcinoma is a rare squamous cell variant that may arise in the bladder. We present a case of verrucous carcinoma of the bladder with radiologic-pathologic correlations that demonstrate the characteristic frond-like growth pattern. Verrucous carcinoma is an invasive but not a metastizing lesion, and therefore recognizing this lesion may have prognostic and therapeutic implications. [ABSTRACT FROM AUTHOR]

Monoclonal antibodies specific for haemocyte sub-populations in the mussel, Mytilus edulis, were raised by use of separated basophilic and eosinophilic cell types as antigens. The antibodies could be broadly divided into 3 groups, reactive with sub-populations of (1) basophilic granular haemocytes, (2) basophilic granular and hyaline cells and (3) eosinophilic granular cells. Non-selective antibodies staining all haemocytes were also generated. The antibodies bound to epitopes of differing molecular masses and, at the ultrastructural level, reacted principally with the granules of the haemocyte sub-populations. The antibodies were used to investigate haemocyte function and ontogeny and to test reactivity with haemocytes from mussels subject to varying degrees of pollution stress. Five antibodies showed reactivity with cells from the trochophore and veliger larvae of M. edulis, indicating that epitopes on adult mussel hae-mocytes are also present at much earlier stages in the life history. Reactivity with the larval stages was most prevalent with non-selective antibodies and those selective for basophilic haemocytes. When mussels from different sites were examined, both immunocytochemistry and ELISA showed reduced expression of a 140 kDa epitope in the haemocytes of mussels subject to greater contaminant loads. These results show that the monoclonal antibodies of the present study are valuable both in tracing immune-cell development and in detecting molecular changes under conditions of stress. [ABSTRACT FROM AUTHOR]

A simplified insect haemocyte classification has been formulated by a light microscopic examination of the haemolymph of insects from fifteen Orders. Six cell types or developmental stages can be distinguished: (1) Prohaemocytes, (2) Plasmatocytes, (3) Granular Cells, (4) Spherule Cells, (5) Cystocytes, and (6) Oenocytoids. The structure and occurrence of these haemocytes are described together with the structural variations which occur in each cell type. Due to considerable overlap in structure and the presence of numerous intermediates the six cell types may represent different developmental and/or functional stages of one basic cell type. The available evidence for this unitarian hypothesis is discussed. [ABSTRACT FROM AUTHOR]

The tubular hindgut of the intertidal herbivorous isopod, Dynamene bidentata, consists of a long dorso-ventrally flattened anterior region, surrounded by a network of muscles, and a short muscular sphincter which grades into a pair of anal flaps. The monolayer of epithelial cells forming the wall of the hindgut appears to take no part in the production of digestive enzymes, food absorption, or glycogen and lipid storage. One function of the hindgut is to propel undigested food material, enclosed within a peritrophic membrane, to the sphincter and anal flaps where faecal pellets are formed and ejected. At the fine structural level lateral plasma membranes, often partially obliterated by microtubules, are visible. The basal plasma membrane of a typical epithelial cell is deeply infolded, associated with mitochondria, and pinocytotic. The apical plasma membrane is irregularly folded, engaged in pinocytosis, and often encloses subcuticular spaces containing an acid mucopolysaccharide substance. An intima, composed of a thin double-layered epicuticle, and a thick acid mucopolysaccharide-positive endocuticle, overlies the cells. The endocuticle may selectively bind substances to the apical plasma membrane before they are engulfed by pinocytosis. The cells resemble those of osmoregulatory organs and may help counterbalance changes in the haemolymph concentration resulting from the intertidal existence of this isopod. [ABSTRACT FROM AUTHOR]

The formation of mitochondrial-cytoplasmic complexes and their transformation into lipid droplets in the acid gland of Nasonia vitripennis is described. Electron microscopy and histochemistry show that lipid droplets are absent from acid glands in newly emerged, fed and re-fed insects. The droplets develop in the cytoplasm after varying periods of starvation and are not associated with acid phosphatase activity. The mature lipid droplets are rarely associated with intact mitochondria and are probably the residual end-product of the mitochondrial-cytoplasmic associations. The possible role of the associations in the maintenance of mitochondrial function and structure is discussed. [ABSTRACT FROM AUTHOR]

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