The great cormorant
Phalacrocorax carbo
(Linnaeus, 1758) can create significant conflicts with fisheries as a result of removing significant fish biomass. This is exacerbated by recent population ...increase in most of Europe. This study uses long-term census, climate, and environmental data to explore the wintering dynamics and strategies of the species. In Turkey, the total overwintering population, population density, and distribution of cormorants have increased significantly. Correlations with different climatic accounted for 20% to 56% of the variation in the total number of overwintering cormorants. The total number of cormorants overwintering was positively affected by warmer weather conditions in autumn and negatively by increased snow cover in winter. The Principal component analysis identified attraction (At) and avoidance (Av) factors, a two-component solution involving 12 climate variables for choosing the wintering sites of cormorants, that explained 84.3% of the total variance in total number of overwintering cormorants. Linear regression using the scores of the At/Av climate factors predicted 59.0% of the total number of overwintering birds. Our study also demonstrates that long-term census data with both resident and winter migrant populations during the winter can be used to estimate the resident population size of the species.
The aims of this study were to provide a complete inventory of wetlands in Turkey including their past status (1910-1930) in comparison to the present time (2014). The types of wetlands and their ...area sizes were determined by using cartographical maps of 1/200,000 in scale made between 1910s and 1920s vs. 2006 CORINE Land Cover data, which were updated with Landsat 8 satellite images in 2014. The effect of possible climate change on wetlands sizes various local, national and regional rainfall datasets were analysed by correlation and regression analysis. A hundred years ago, the total number of natural wetlands was 1299 with a total surface area of 1,376,505 hectares. In 2014, the total number of natural wetlands had decreased to 900, with a total surface area of 1,085,936 hectares, so that 21.2% of the original wetlands were lost (291,339 hectares). The observed changes in the number of wetlands and their relative sizes cannot be attributed directly to changes in climate. Wetland drainage was largely responsible for observed wetland losses, but local changes in precipitation regimes partially contributed to this loss. Urgent conservation and restoration of wetlands are recommended to avoid further loss of wetlands in Turkey.
The Mediterranean subspecies of the European Storm Petrel Hydrobates pelagicus melitensis is suspected to be resident in the Aegean Sea off Turkey, but breeding is yet to be confirmed. Additionally, ...the area is used during the non-breeding season by individuals from elsewhere in the Mediterranean, and population sizes of over a thousand individuals have been recorded, especially in the central-south Aegean Sea.
In this study, we evaluated the potential impact of climate change on the distributions of Turkey's songbirds in the 21st century by modelling future distributions of 20 resident and nine migratory ...species under two global climate change scenarios. We combined verified data from an ornithological citizen science initiative (www.kusbank.org) with maximum entropy modeling and eight bioclimatic variables to estimate species distributions and projections for future time periods. Model predictions for resident and migratory species showed high variability, with some species projected to lose and others projected to gain suitable habitat. Our study helps improve the understanding of the current and potential future distributions of Turkey's songbirds and their responses to climate change, highlights effective strategies to maximize avian conservation efforts in the study region, and provides a model for using citizen science data for biodiversity research in a large developing country with few professional field biologists. Our results demonstrate that climate change will not affect every species equally in Turkey. Expected range reductions in some breeding species will increase the risk of local extinction, whereas others are likely to expand their ranges.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•POP concentrations represent a decreasing trend over time.•Venous blood represents promising biomonitor for internal PCB concentrations.•Enzyme activities correlate with the liver concentrations of ...several OCPs.•Egg DDE levels are below the threshold for the risk of hatch and reproductive success.
Three main groups of persistent organic pollutants (POPs); namely organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenylethers (PBDEs) were quantified in water and sediment samples, as well as in various invasive and non-invasive samples from waterbirds in the Büyük Menderes River (BMR). Liver and muscle tissues, blood, and preen gland oil samples of yellow-legged gull (Larus michahellis) and Euroasian coot (Fulica atra) were collected both from the origin (Işıklı Lake) and the estuary (Söke) of the river, blood and preen gland oil samples of grey heron (Ardea cinerea) and pelican (Pelecanus crispus) were collected from the estuary only. In addition, non-hatched eggs from several above species and Mediterranean gull (Larus melanocephalus), in either station were collected. In all samples, POP contamination was measured and the potential usefulness of those invasive and non-invasive sampling for biomonitoring was evaluated. Activities of antioxidant enzymes were measured as potential indicators of POP exposure and of changes in the cellular defence. Venous blood proved to be a promising biomonitor for the concentrations in liver and muscle, especially for PCBs. Activities of antioxidant enzymes were correlated with the liver concentrations of several OCP congeners. The measured egg DDE concentrations were below the established threshold concentrations for the risk of hatch and reproductive success.
Selective pressure from pathogens is thought to shape the allelic diversity of major histocompatibility complex (MHC) genes in vertebrates. In particular, both local adaptation to pathogens and gene ...flow are thought to explain a large part of the intraspecific variation observed in MHC allelic diversity. To date, however, evidence that adaptation to locally prevalent pathogens maintains MHC variation is limited to species with limited dispersal and, hence, reduced gene flow. On the one hand high gene flow can disrupt local adaptation in species with high dispersal rates, on the other hand such species are much more likely to experience spatial variation in pathogen pressure, suggesting that there may be intense pathogen mediated selection pressure operating across breeding sites in panmictic species. Such pathogen mediated selection pressure operating across breeding sites should therefore be sufficient to maintain high MHC diversity in high dispersing species in the absence of local adaptation mechanisms. We used the Greater Flamingo, Phoenicopterus roseus, a long-lived colonial bird showing a homogeneous genetic structure of neutral markers at the scale of the Mediterranean region, to test the prediction that higher MHC allelic diversity with no population structure should occur in large panmictic populations of long-distance dispersing birds than in other resident species.
We assessed the level of allelic diversity at the MHC Class IIB exon 2 from 116 individuals born in four different breeding colonies of Greater Flamingo in the Mediterranean region. We found one of the highest allelic diversity (109 alleles, 2 loci) of any non-passerine avian species investigated so far relative to the number of individuals and loci genotyped. There was no evidence of population structure between the four major Mediterranean breeding colonies.
Our results suggest that local adaptation at MHC Class IIB in Greater Flamingos is constrained by high gene flow and high MHC diversity appears to be maintained by population wide pathogen-mediated selection rather than local pathogen-mediated selection. Further understanding of how pathogens vary across space and time will be crucial to further elucidate the mechanisms maintaining MHC diversity in species with large panmictic populations and high dispersal rates.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Wintering site selection is a major decision in a bird's annual life cycle since conditions experienced by individuals within a wintering site can influence individual fitness and ultimately ...population dynamics. If individuals show strong fidelity to specific sites, annual environmental effects can be reinforced. In this study we analyse winter resightings of ringed Dalmatian pelicans, collected during a 35-year-long ringing survey, to identify winter movement patterns of Dalmatian pelicans, assess the level of site fidelity both within and among consecutive wintering events and examine environmental factors that may contribute to an individual's decision to move towards a specific site during the winter period. Our results showed that the decision of Dalmatian pelicans to move towards a specific site was mainly driven by the site's size and temperature conditions. Larger wetlands can provide birds with higher resource abundance and offer more opportunities to exploit optimal roosting and feeding habitats, whereas wetlands that do not freeze during the winter are a definite requirement. Wintering movements were more likely to occur at short distances from a bird's natal colony, whereas it was uncommon for birds born in wetlands located in the Adriatic and Ionian coast to move eastwards during the winter, suggesting a level of spatial substructure. Furthermore, we showed that the species exhibits very strong within-year and among-year wintering site fidelity, with birds moving less during the winter, whereas juvenile birds travel greater distances than the rest of the age classes examined. Our conclusions could guide an effective approach to site-based conservation management at key wintering sites.
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