38 research outputs found
Conservation genetics of the pond bat (Myotis dasycneme) with special focus on the populations in northwestern Germany and in Jutland, Denmark
Conservation genetics is important in the management of endangered species, helping to understand their connectivity and long‐term viability, thus identifying populations of importance for conservation. The pond bat (Myotis dasycneme) is a rare species classified as “Near Threatened” with a wide but patchy Palearctic distribution. A total of 277 samples representing populations in Denmark, Germany, Latvia, Hungary, and Russia were used in the genetic analyses; 224 samples representing Denmark, Germany, and Russia were analyzed at 10 microsatellite loci; 241 samples representing all areas were analyzed using mitochondrial D‐loop and cytochrome B sequences. A Bayesian clustering approach revealed two poorly resolved clusters, one representing the Danish and German groups and the other the Russian group. However, significantly different pairwise FST and DEST estimates were observed between the Danish and German groups and between the Danish and Russian groups suggesting a recent population structure. These conflicting results might be attributed to the effect of migration or low resolution due to the number of microsatellite markers used. After concatenating the two mitochondrial sequences, analysis detected significant genetic differentiation between all populations, probably due to genetic drift combined with a founder event. The phylogenetic tree suggested a closer relationship between the Russian and Northern European populations compared to the Hungarian population, implying that the latter belongs to an older ancestral population. This was supported by the observed haplotype network and higher nucleotide diversity in this population. The genetic structuring observed in the Danish/German pond bat stresses the need for a cross‐border management between the two countries. Further, the pronounced mtDNA structuring, together with the indicated migration between nearby populations suggest philopatric female behavior but male migration, emphasizes the importance of protecting suitable habitat mosaics to maintain a continuum of patches with dense pond bat populations across the species' distribution range
Assessing road effects on bats: the role of landscape, road features, and bat activity on road-kills
Recent studies suggest that roads can significantly impact bat populations. Though bats are one of the most threatened groups of European vertebrates, studies aiming to quantify bat mortality and determine the main factors driving it remain scarce. Between March 16 and October 31 of 2009, we surveyed road-killed bats daily along a 51-km-long transect that incorporates different types of roads in southern Portugal. We found 154 road-killed bats of 11 species. The two most common species in the study area, Pipistrellus kuhlii and P. pygmaeus, were also the most commonly identified road-kill, representing 72 % of the total specimens collected.
About two-thirds of the total mortality occurred between mid July and late September, peaking in the second half
of August. We also recorded casualties of threatened and rare species, including Miniopterus schreibersii, Rhinolophus
ferrumequinum, R. hipposideros, Barbastella barbastellus, and Nyctalus leisleri. These species were found mostly in early autumn, corresponding to the mating and swarming periods. Landscape features were the most
important variable subset for explaining bat casualties.
Road stretches crossing or in the vicinity of high-quality habitats for bats—including dense Mediterranean woodland (‘‘montado’’) areas, water courses with riparian gallery, and water reservoirs—yielded a significantly
higher number of casualties. Additionally, more roadkilled bats were recorded on high-traffic road stretches with viaducts, in areas of higher bat activity and near
known roosts
The stranding anomaly as population indicator: the case of Harbour Porpoise <i>Phocoena phocoena</i> in North-Western Europe
Ecological indicators for monitoring strategies are expected to combine three major characteristics: ecological significance, statistical credibility, and cost-effectiveness. Strategies based on stranding networks rank highly in cost-effectiveness, but their ecological significance and statistical credibility are disputed. Our present goal is to improve the value of stranding data as population indicator as part of monitoring strategies by constructing the spatial and temporal null hypothesis for strandings. The null hypothesis is defined as: small cetacean distribution and mortality are uniform in space and constant in time. We used a drift model to map stranding probabilities and predict stranding patterns of cetacean carcasses under H-0 across the North Sea, the Channel and the Bay of Biscay, for the period 1990-2009. As the most common cetacean occurring in this area, we chose the harbour porpoise <i>Phocoena phocoena</i> for our modelling. The difference between these strandings expected under H-0 and observed strandings is defined as the stranding anomaly. It constituted the stranding data series corrected for drift conditions. Seasonal decomposition of stranding anomaly suggested that drift conditions did not explain observed seasonal variations of porpoise strandings. Long-term stranding anomalies increased first in the southern North Sea, the Channel and Bay of Biscay coasts, and finally the eastern North Sea. The hypothesis of changes in porpoise distribution was consistent with local visual surveys, mostly SCANS surveys (1994 and 2005). This new indicator could be applied to cetacean populations across the world and more widely to marine megafauna
A Review of the Occurrence of Bats (Chiroptera) on Islands in the North East Atlantic and on North Sea Installations
The bats recorded from Iceland, the Faroe Islands, the Shetland Islands, the Orkney Islands, and North Sea installations are reviewed to the end of 2012. In total 12 species have been positively identified, while a considerable proportion of all records are sightings of unidentified bats. Eight of the species are European in origin and four originate from the New World. The largest number of species (8) has been recorded in Iceland, but the greatest number of individuals (180) has been found in Orkney. The bat invasion on the Faroe Islands in 2010 is without precedence, when 70 observations of a minimum of 45 individuals were noted. Most bat observations in the study area occurred in the autumn, with fewer in the spring. Most observations were of single animals, but there were also sightings of up to 12 individuals. There has been a marked increase in bat records in the past three decades. We discuss whether this is a real increase, or due to improved communications, increased public awareness, increased shipping, changes in weather patterns and/or the effects of climate change. All factors appear to be involved.© Museum and Institute of Zoology PAS. The attached document is the author(’s’) final accepted/submitted version of the journal article. You are advised to consult the publisher’s version if you wish to cite from it
Estresse salino na germinação de sementes e desenvolvimento de plântulas de niger (Guizotia abyssinica (L.f.) Cass.)
Genetic variability in the mitochondrial DNA of the Danish Pine marten
Here we study genetic differentiation and changes over time in genetic variability in the rare pine marten Martes martes. Samples from three isolated geographic regions: Jutland and Sealand (Denmark) and southern Scania (southernmost Sweden), were genotyped by sequencing the hypervariable domain of the mito- chondria control region. Both recent and museum samples were analysed in order to evaluate any temporal loss of genetic variability. Eight haplotypes were found. Two were main haplotypes shared by individuals from all three regions, and in all localities unique haplotypes were found. When comparing the data with previous haplotype analysis, our results suggest that at least three different haplotype groups exist in central and Northern Europe, with the samples from southern Scania being differentiated from samples previously analysed from central Swe- den, and the genotypic data for Jutland and Sealand suggest a recent independent evolutionary history for the Danish pine marten.Peer reviewe
Spatio-temporal population genetics of the Danish pine marten ( Martes martes )
A spatio-temporal study of genetic variation in the Danish pine marten (Martes martes) populations from the
Jutland peninsula and from the island of Sealand was performed using 11 microsatellite markers. Samples
obtained from 1892 to 2003 were subdivided into historical (prior to 1970) and recent (from 1970) groups. As
compared with the historical samples, there was a significant loss of genetic variation in the recent Jutland
population, but not in Sealand. Effective population sizes were estimated using Bayesian-based software (TMVP).
Historical effective population sizes were 5897 (90% highest probability density, HPD, limits: 1502–6849) in
Jutland and 1300 (90% HPD limits: 224–5929) in Sealand, whereas recent effective population sizes were 14.7
(90% HPD limits: 10.9–23.5) in Jutland and 802 (90% HPD limits: 51.8–5510) in Sealand. Significant genetic
differentiation (F
ST
) was found between the two historical samples, between the two recent samples, and between
the historical and the recent sample in Jutland; whereas the F
ST
value between the historical and the recent sample
in Sealand was not significant. The significant genetic differentiation between the historical and the recent samples
indicates changes in the genetic compositions over time, and the higher F
ST
values between the two recent samples,
as compared with the two historical samples, indicates that the populations in Sealand and Jutland have drifted
apart within a short time span. No deviation from Hardy–Weinberg equilibrium was found within populations,
indicating no further substructuringPeer reviewe