Grzegorz Górecki

Distribution of mitochondrial haplotypes (cytb) in Polish populations of Emys orbicularis (L., 1758)

The European pond turtle, Emys orbicularis, inhabits a wide distribution area in the western Palaearctic. Polish populations of pond turtle represent the nominotypical subspecies Emys orbicularis orbicularis. The mitochondrial DNA haplotype (cytb gene) variation among 131 turtles from 26 locations in five regions of Poland was investigated. Five haplotypes belonging to three distinct lineages were identified. Two clades (I and II) were represented by two haplotypes each, while the other clade (IV) was represented by one haplotype. Three haplotypes were reported for the first time in E. orbicularis. The eastern part of Poland is inhabited exclusively by turtles bearing haplotype Ia. The remaining four sequence variants were recorded in western Poland where only the IIb haplotype is considered endemic. The distribution of the other haplotypes in western Poland could thus reflect past introductions or accidental releases. The authors regarded the two locations (Drzeczkowo and Karpicko) that were first included in the western Poland populations as autochthonous catchment areas of haplotype Ia.

Population differentiation of the European pond turtle (Emys orbicularis) in Poland inferred by the analysis of mitochondrial and microsatellite DNA: implications for conservation

We investigated the genetic diversity of Polish populations of the European pond turtle (Emys orbicularis) using complete sequences of the mitochondrial cytochrome b gene and allelic variation at thirteen microsatellite loci. We collected data from 146 turtles from 28 locations covering most of the species’ range in Poland. Our results showed a low haplotype diversity and high levels of microsatellite diversity in all populations. We applied two Bayesian approaches using the multilocus data and determined relationships of mtDNA haplotypes by constructing a parsimony network. We observed relatively consistent results of the two Bayesian clustering methods and largely concordant differentiation patterns between mitochondrial and microsatellite markers. All eastern Polish populations were assigned in a highly supported eastern group, while the majority of turtles from western Poland were joined in a distinct western group. The most probable number of population clusters corresponded to the number of native mtDNA lineages. Additionally, we detected a hierarchical structure within the eastern lineage splitting the populations into two subgroups. Polish populations generally constitute genetically homogenous groups, characterized by a low population admixture, with only negligible impact from allochthonous turtles.

Spatio-temporal variation in nesting success of colonial waterbirds under the impact of a non-native invasive predator

Colonial breeding in birds provides protection from predators and may be particularly important when birds have to cope with an invasive predator. The probability of nest predation in a colony can vary depending on several factors, such as the nest’s location in the colony and the level of aggregation of nests. We studied the nesting success of colonial great crested grebes and monitored the occurrence of the non-native invasive American mink in the colony. From among 92 grebe nests, 54.3% were successful. The daily survival rate (DSR) of grebe nests was positively affected by the increasing distance between the nest and lake shoreline, and negatively affected by the increasing distance between the nest and the five nearest grebe nests. The probability of mink occurrence in the colony increased with consecutive days of the breeding season and decreased with increasing distance from the lake shoreline. The DSR of grebe nests decreased with the increasing probability of mink occurrence along the shoreline distance gradient and the day of the breeding season. The results of the study confirm the impact of the American mink on waterbirds during the breeding season but also indicate that large breeding colonies are partially safe from mink predation, and that nest accessibility and the dilution effect influence the probability of nest survival. Our data suggest that the limited access to safe breeding sites on large lakes that can supply adult grebes and their chicks with food may affect bird productivity and population numbers at the landscape level.

Changes of the testes parameters, carcasses and antlers mass of harvested roe deer (Capreolus capreolus) bucks

The research was conducted during the hunting season in Poland from May to September 2012 in which materials of 58 roe deer bucks carcass, antler and testis masses were compared. In addition, the size of testes with epididymides was assessed. Significantly enlarged testes masses were observed in May till July (one-way ANOVA and LSD test). In August and September, the testes underwent abrupt involution. According to the literature and the results of this study, the enlargement of the testes which starts from the end of February, indicates that spring time is a preparatory period for the rut. On the other hand, monthly carcass mass fluctuations were not observed. There is, however, a trend suggesting that heavier roe deer individuals can display larger antler mass.