64 research outputs found

    Evolution of mitochondrial relationships and biogeography of Palearctic green toads (Bufo viridis subgroup) with insights in their genomic plasticity.

    Get PDF
    Taxa involving three bisexually reproducing ploidy levels make green toads a unique amphibian system. We put a cytogenetic dataset from Central Asia in a molecular framework and apply phylogenetic and demographic methods to data from the entire Palearctic range. We study the mitochondrial relationships of diploids to infer their phylogeography and the maternal ancestry of polyploids. Control regions (and tRNAs between ND1 and ND2 in representatives) characterize a deeply branched assemblage of twelve haplotype groups, diverged since the Lower Miocene. Polyploidy has evolved several times: Central Asian tetraploids (B. oblongus, B. pewzowi) have at least two maternal origins. Intriguingly, the mitochondrial ancestor of morphologically distinctive, sexually reproducing triploid taxa (B. pseudoraddei) from Karakoram and Hindukush represents a different lineage. We report another potential case of bisexual triploid toads (B. zugmayeri). Identical d-loops in diploids and tetraploids from Iran and Turkmenistan, which differ in morphology, karyotypes and calls, suggest multiple origins and retained polymorphism and/or hybridization. A similar system involves diploids, triploids and tetraploids from Kyrgyzstan and Kazakhstan where green toads exemplify vertebrate genomic plasticity. A new form from Sicily and its African sister species (B. boulengeri) allow internal calibration and divergence time estimates for major clades. The subgroup may have originated in Eurasia rather than Africa since the earliest diverged lineages (B. latastii, B. surdus) and earliest fossils occur in Asia. We delineate ranges, contact and hybrid zones. Phylogeography, including one of the first non-avian datasets from Central Asian high mountains, reflects Quaternary climate and glaciation

    Fluorescent non-toxic bait as a new method for black rat (Rattus rattus) monitoring

    Get PDF
    The detection of synathropic rodents may be difficult since they are animals with nocturnal activity. Methods of their detection and monitoring rely mostly on indirect signs of their activity such as the presence of faeces, urine, consumed foods and damaged materials. Our experimental hypothesis was that the production of fluorescent faeces - following consumption of fluorescent bait - may be used for rodent monitoring. For this purpose we studied the production of fluorescent faeces, temporal dynamics and detectability in wild black rat (Rattus rattus). Wild black rats were individually housed in experimental cages with the wire-mesh grid floor and faeces were collected in short-time intervals. The peak of fluorescent activity in faeces was detected 10-20 hours after bait ingestion. We found that there is only relatively short delay between bait consumption and defecation and fluorescent faeces are easily detectable at distance using an ultraviolet hand lamp. Thus, this method can contribute to effective monitoring of rodent pests.Keywords: Rattus rattus, Fluorescent bait, Monitoring, Rodent contro

    Snakes Represent Emotionally Salient Stimuli That May Evoke Both Fear and Disgust

    Get PDF
    Humans perceive snakes as threatening stimuli, resulting in fast emotional and behavioral responses. However, snake species differ in their true level of danger and are highly variable in appearance despite the uniform legless form. Different snakes may evoke fear or disgust in humans, or even both emotions simultaneously. We designed three-step-selection experiments to identify prototypical snake species evoking exclusively fear or disgust. First, two independent groups of respondents evaluated 45 images covering most of the natural variability of snakes and rated responses to either perceived fear (n = 175) or disgust (n = 167). Snakes rated as the most fear-evoking were from the family Viperidae (Crotalinae, Viperinae, and Azemiopinae), while the ones rated as the most disgusting were from the group of blind snakes called Typhlopoidea (Xenotyphlopinae, Typhlopinae, and Anomalepidinae). We then identified the specific traits contributing to the perception of fear (large body size, expressive scales with contrasting patterns, and bright coloration) and disgust (thin body, smooth texture, small eyes, and dull coloration). Second, to create stimuli evoking a discrete emotional response, we developed a picture set consisting of 40 snakes with exclusively fear-eliciting and 40 snakes with disgust-eliciting features. Another set of respondents (n = 172) sorted the set, once according to perceived fear and the second time according to perceived disgust. The results showed that the fear-evoking and disgust-evoking snakes fit mainly into their respective groups. Third, we randomly selected 20 species (10 fear-evoking and 10 disgust-evoking) out of the previous set and had them professionally illustrated. A new set of subjects (n = 104) sorted these snakes and confirmed that the illustrated snakes evoked the same discrete emotions as their photographic counterparts. These illustrations are included in the study and may be freely used as a standardized assessment tool when investigating the role of fear and disgust in human emotional response to snakes

    Being Attractive Brings Advantages: The Case of Parrot Species in Captivity

    Get PDF
    Background: Parrots are one of the most frequently kept and bred bird orders in captivity. This increases poaching and thus the potential importance of captive populations for rescue programmes managed by zoos and related institutions. Both captive breeding and poaching are selective and may be influenced by the attractiveness of particular species to humans. In this paper, we tested the hypothesis that the size of zoo populations is not only determined by conservation needs, but also by the perceived beauty of individual parrot species assessed by human observers. Methodology/Principal Findings: For the purpose of data collection, we defined four sets of species (40 parrots, 367 parrots, 34 amazons, 17 macaws). Then, we asked 776 human respondents to evaluate parrot pictures of the selected species according to perceived beauty and we analyzed its association with color and morphological characters. Irrespective of the species set, we found a good agreement among the respondents. The preferred species tended to be large, colorful, and long-tailed. Conclusions/Significance: We repeatedly confirmed significant, positive association between the perceived beauty and the size of worldwide zoo population. Moreover, the range size and body size appeared to be significant predictors of zoo population size. In contrast, the effects of other explanatory variables, including the IUCN (International Union for Conservation of Nature) listing, appeared insignificant. Our results may suggest that zoos preferentially keep beautifu

    Multiple Geographic Origins of Commensalism and Complex Dispersal History of Black Rats

    Get PDF
    The Black Rat (Rattus rattus) spread out of Asia to become one of the world's worst agricultural and urban pests, and a reservoir or vector of numerous zoonotic diseases, including the devastating plague. Despite the global scale and inestimable cost of their impacts on both human livelihoods and natural ecosystems, little is known of the global genetic diversity of Black Rats, the timing and directions of their historical dispersals, and the risks associated with contemporary movements. We surveyed mitochondrial DNA of Black Rats collected across their global range as a first step towards obtaining an historical genetic perspective on this socioeconomically important group of rodents. We found a strong phylogeographic pattern with well-differentiated lineages of Black Rats native to South Asia, the Himalayan region, southern Indochina, and northern Indochina to East Asia, and a diversification that probably commenced in the early Middle Pleistocene. We also identified two other currently recognised species of Rattus as potential derivatives of a paraphyletic R. rattus. Three of the four phylogenetic lineage units within R. rattus show clear genetic signatures of major population expansion in prehistoric times, and the distribution of particular haplogroups mirrors archaeologically and historically documented patterns of human dispersal and trade. Commensalism clearly arose multiple times in R. rattus and in widely separated geographic regions, and this may account for apparent regionalism in their associated pathogens. Our findings represent an important step towards deeper understanding the complex and influential relationship that has developed between Black Rats and humans, and invite a thorough re-examination of host-pathogen associations among Black Rats

    Mediterranean populations of the lesser white-toothed shrew (Crocidura suaveolens group): an unexpected puzzle of Pleistocene survivors and prehistoric introductions.

    Get PDF
    An earlier study revealed the strong phylogeographical structure of the lesser white-toothed shrew (Crocidura suaveolens group) within the northern Palaearctic. Here, we aim to reconstruct the colonization history of Mediterranean islands and to clarify the biogeography and phylogeographical relationships of the poorly documented Middle East region with the northern Palaearctic. We performed analyses on 998-bp-long haplotypes of the mitochondrial cytochrome b gene of 143 samples collected around the Mediterranean basin, including islands and the Middle East. The analyses suggest that the Cypriot shrew belongs to the rare group of relict insular Pleistocene mammal taxa that have survived to the present day. In contrast, the Cretan, Corsican and Menorcan populations were independently introduced from the Middle East during the Holocene. The phylogeographical structure of this temperate Palaearctic species within the Middle East appears to be complex and rich in diversity, probably reflecting fragmentation of the area by numerous mountain chains. Four deeply divergent clades of the C. suaveolens group occur in the area, meaning that a hypothetical contact zone remains to be located in central western Iran

    Test of character displacement in urban populations of <i>Apodemus sylvaticus</i>

    No full text

    Test of character displacement in urban populations of <i>Apodemus sylvaticus</i>

    Full text link
    We studied the wood mouse, Apodemus sylvaticus, inhabiting parks, cemeteries, suburban woods, and other green areas in the city of Prague. To assess the character displacement and (or) release hypothesis we compared seven samples from local populations occurring sympatrically with Apodemus flavicollis with 10 samples from those localities in which A. flavicollis has never been recorded. The analysis included 1410 specimens of A. sylvaticus collected during the years 1980–1990. Seventeen skull and body characters were measured. Then the data were age- or size-adjusted and treated by principal-component analyses. Factor scores were further subjected to statistical testing. Although the results revealed considerable variation among localities, they did not suggest character displacement and (or) release. Apodemus sylvaticus from populations sympatric with A. flavicollis were morphometrically similar to their conspecifics from other populations collected at the periphery of the city. However, slight but statistically highly significant differences were found between samples from localities in the city centre and those from the periphery. This phenomenon may be interpreted as the effect of urbanisation or isolation by built-up areas. </jats:p

    Offspring sex ratio in domestic goats: Trivers-Willard out of natural selection

    No full text
    corecore