First survey on the invasive Pond slider (Trachemys scripta) in Bulgaria: historic development and current situation

Crvenouha kornjača (Trachemys scripta) postala je popularni ljubimac u Bugarskoj od 1990. Kroz godine sve veći broj jedinki zabilježen je i u divljini. Iako su negativni učinci na izvornim kornjače su opsežno studirao negdje drugdje, nema posebne studije (osim kratkih izvješća) obratili invaziju T. scripta u Bugarskoj. Ova studija se temelji na više od 25 godina praćenja na terenu i predstavlja prvi izvor detaljne informacije o raspodjeli Pond klizača u Bugarskoj. Ukupno 293 UTM (10 × 10 km) kvadrata sa staništa pogodna za slatkovodne kornjače ispitano. Prikupili smo 64 zapisa za 173 osoba, od 19 UTM kvadrata. Od svih promatranih osoba, samo dvije su od nominirati podvrste - ostatak pripada T. Š. elegans. U našem istraživanju je uočeno samo jednoga djeteta. Do danas nije uspješno leženja zabilježena, iako su registrirani uspješni overwinterings. Mi smo razgovarali o raznim mjere ublažavanja koje se moraju brzo pokrenut ograničiti buduće izdanje Ribnjak klizača i za uklanjanje ne-izvornih uzoraka s bugarskim ekosustava. Akcije su zahtijevali posebno da se izbjegne potencijalne epidemiološko događaja uzrokovanih parazitima s vrlo smrtonosnim učinkom na autohtonim vrstama. Takve pojave potencijalno mogu imati veći utjecaj na autohtone vrste kornjača jezerce od raznih oblika natjecanja s T. scripta.Pond sliders (Trachemys scripta) have become a popular pet in Bulgaria since 1990. Through the years a number of released specimens were observed in the wild. Although the negative effects on native turtles have been studied extensively elsewhere, no specific studies (besides brief reports) have addressed the invasion of T. scripta in Bulgaria. The present study is based on over 25 years of field monitoring and represents the first source of detailed information on the distribution of the Pond slider in Bulgaria. A total of 293 UTM (10×10 km) squares with habitats suitable for freshwater turtles were surveyed. We collected 64 records for 173 individuals, from 19 UTM squares. From all observed individuals, only two were from the nominate subspecies – the rest belong to T. s. elegans. In our study only one subadult was observed. To date no successful hatching has been recorded, although successful overwinterings have been registered. We discuss various mitigation measures that must be rapidly initiated to limit future release of Pond sliders and to remove the non-native specimens from the Bulgarian ecosystems. Actions are demanded especially to avoid the potential epizootic events caused by parasites with highly lethal effect on native species. Such outbreaks might potentially have greater impact on the native pond turtle species than various forms of competition with T. scripta

Habitat preferences of the Eurasian Griffon Vulture (Gyps fulvus) in Bulgaria to support species management

The Eurasian Griffon Vulture (Gyps fulvus) is a large scavenger with a population ranging between Portugal and India. The species is an obligate scavenger with a narrow ecological niche and is therefore particularly dependent on, and limited by habitat availability. The study aimed, for the first time in Eastern Europe, to identify the habitat preferences of the Griffon Vulture at landscape and cliff scales. We used long-term monitoring data between 1987–2018 to analyze habitat preferences of the natal Griffon Vulture population in the Eastern Rhodope Mountains, Bulgaria. We employed single explanatory variable tests to reveal the species habitat preferences at two spatial scales. The results revealed Griffon Vultures’ high preferences towards rocky habitats at the landscape level. At a cliff scale, the height and length of the cliff, the distance to the nearest conspecific colony and the distance to the nearest feeding site were the best predictors for the species habitat preferences. We stress the importance of these findings considering the current status of the species within the region. Our results are useful to support the future conservation of the Griffon Vulture population in Bulgaria and provide a starting point for future research in the Balkans and Eastern Europe

Diversity of hemipenes and its taxonomical implication in the genus Ablepharus(Squamata: Scincidae)

The genus Ablepharus encompasses 10 species and 12 subspecies, distributed from Hungary to India. Most species and subspecies have been described from the Middle East and Central Asia, based on external morphology (pholidosis, body size and coloration). The present study is an attempt to demonstrate the hemipenial morphology throughout the genus. Some taxonomical questions arose during comparison of the hemipenes of several subspecies and species, showing the necessity of a revision of the genus. A dendrogram generated from distinctive hemipenial characters revealed rapid divergence of this structure in closely related taxa and discrepancy with the phylogenetic tree based on molecular data from previous studies

Distribution, population density and habitat preferences of the Barn Owl (Tyto alba) in Sliven and Yambol districts, SE Bulgaria

The Barn Owl (Tyto alba Gould, 1837) is a rare and endangered species in Bulgaria, included in the Red Data Book (Golemansky 2015) as “Vulnerable”, with national population estimated at 200–700 pairs. Barn Owl presence was surveyed using sound provocation during the night at 161 points in 52 small to medium-sized settlements in Sliven and Yambol districts (Thracian plain, SE Bulgaria). The studied territory was about 1190 km2. The habitats presented in a 3-km radius around the presence and potential absence points were statistically analysed. The species was found to be a quite common breeding species in the study area – a total of 56 Barn Owls were registered, at 50 points (31.1%), in 31 settlements (62% of all studied). Clear defensive behavior was observed against the source of the sound in many occasions. The average density of the population was 4.2 occupied territories / 100 km2. The occupied locations were situated mostly in settlements laying in deforested lowland areas (far from large forest patches), with flat or hilly relief, covered by agricultural lands, pastures and steppes. The number of presences was found to be scarce in villages along heavily used motorways. Traffic-caused mortality of Barn Owls is commented as a probable explanation

Distribution model and habitat characteristics of Morimus asper funereus Mulsant, 1863 (Coleoptera: Cerambycidae) in Bulgaria

Morimus asper funereus is a protected longhorn beetle species of community interest and conservation importance. It is included in Annex II of the Habitats Directive (as M. funereus) and protected under the Bulgarian Biodiversity Act. Although this saproxylic beetle is widespread in old-growth forests or well-structured woodlands in Central and Southeast Europe, its populations are currently threatened by forest practices, such as the removal of wood (branches and logs) (Hardersen et al. 2017). The species is with limited dispersal ability (due to lack of wings) and is very likely to possess very isolated and localized populations.   In addition, M. asper funereus is of considerable interest from a taxonomic point of view with unclear taxonomic status for as much as Morimus asper is a morphologically highly variable species. At present, at least three species/subspecies of the genus Morimus are known from the territory of Bulgaria - Morimus asper, M. orientalis and M. vercundus bulgaricus (Danilevsky et al. 2016). Although, it is considered M. asper to be met almost everywhere in Bulgaria, its distribution is still not sufficiently known. We started a systematic and more intensive study on the species distribution in 2012 with the mapping of NATURA 2000 sites. Until the present study 54 localities from the literature had been known, after 562 new records have been added. The available information is organised in a database incorporated into the platform “SmartBirds Pro” - https://smartbirds.org (Popgeorgiev et al. 2015), part of which gives the possibility for registration of protected beetle species. In addition, the platform provides free access to all data (type, location, coordinates, date, observer).  Here we present all available data for the species records, and its potential distribution and habitat preference for the territory of Bulgaria via deductive model, using the possibilities of GIS and MAXENT (Fourcade et al. 2014)

First exhaustive distribution and habitat modelling of Morimus asper (Sulzer, 1776) sensu lato (Coleoptera, Cerambycidae) in Bulgaria

Although Morimus asper, in particular the ssp. funereus, is considered as widespread throughout Bulgaria, a current national mapping of the species is missing. Thus, here we present the first exhaustive study on the distribution of M. asper in Bulgaria. Our research combined 967 georeferenced presence records from scientific publications, from the museum collection of the National Museum of Natural History-BAS, as well as authors’ and citizen scientists’ field observations. An Ecological Niche Model (ENM) was generated using software MaxEnt to identify the potential distribution of the species based on niche suitability. The potentially suitable area for the species was 26% of Bulgaria (29 059 km2). The main predictor variables in M. asper’s ENM assessed by а Jackknife test were the distance to mixed Fagus-Carpinus forests, the mean forest age, the mean tree height, the maximal temperature during the hottest month and the altitude. The percentage contribution to the model of the first two variables was also the largest – respectively 40% and 11%. The remaining variables contributed less than 10% each. Furthermore, we recommend some changes to the current species monitoring methodology to the National Biodiversity Monitoring System