Sławomir Mitrus

Headstarting in European pond turtles ( Emys orbicularis ): Does it work?

The European pond turtle ( Emys orbicularis ) is an endangered species in Poland. From 1998 to 2000, as part of an active protection program for the species in central Poland, 123 one-year-old headstarted individuals were released into their original population. Survival rate in artificial rearing was 0.85. Annual recapture rate of the released turtles during the first year in the wild was 0.24, and during next year 0.43 or higher. For comparable groups of one-year-old turtles the annual recapture rates of wild vs. headstarted were not statistically different, but they were based on small samples. Analysis of the data based on a life table for Emydoidea blandingii and data on survival rate of E. orbicularis to age one suggests that headstarting programs can increase population size only if a large percentage of hatchlings is taken to artificial rearing. However, as we know nothing about behaviour and survivorship of older headstarted turtles, such programs still should be considered as experiments.

Effect of tin and lead chlorotriphenyl analogues on fruit fly Drosophila hydei and liposomes membrane

This article presents the results of a study investigating the biological activity of triphenyltin chloride (TPhT) and two metalloorganic compounds, triphenyllead chloride (TPhL) and triphenylmethane chloride (TPhC), in their interaction with model membranes and the living organisms of fruit flies Drosophila hydei. The study of model membranes (sonicated liposomes) was conducted using the electron spin resonance (ESR) spin probe technique, whereas the experiment on fruit flies involved investigating their viability on media containing the studied compounds. The test results clearly demonstrate that TPhT affects fruit flies more actively than TPhL (complete lethality after 7 days of culture with a TPhT‐containing medium). No toxic effect of TPhC on fruit flies was shown. The results of the biological experiment were reflected in the physical experiment involving an ESR study of liposomes: TPhT activity manifested itself as a considerable increase in fluidity of the central region of the liposome lipid bilayer.

Disappearance rates of old nest material from tree cavities: An experimental study

Abstract Numerous forest organisms critically depend on availability of tree cavities. Some birds and rodents fill their cavities with bulky nests, which – if not removed – could accumulate and render cavities unusable, as recorded in nest-box studies. Data from earlier studies indicate that old nests can disappear from tree cavities so fast that practically no remnants are detectable the following spring. Rapid decomposition of nests in situ, augmented by physical removal of nest material by the cavity-users have been proposed as possible causative mechanisms. We tested these hypotheses in cavities used by tits (Parus major L., Poecile palustris L.) in the Białowieża National Park (E Poland). To mimic typical components of their nests – moss and mammalian hair – we inserted into cavities litter-bags filled with either cellulose or fleece of sheep. After 9,5 months of exposure a third of bags were missing from cavities, and 92–100% of cellulose and 84–98% of hair disappeared from the remaining ones. These results confirm that the rapid decomposition of the tit nests in cavities reinforced by material removed by vertebrates would suffice to “clean” the cavities between the consecutive seasons. To conclude, accumulation of litter in natural nests holes does not seem to affect nest hole availability.

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.

Decomposition rate of old nest material in tree holes

Abstract. We experimentally tested whether old nest material could decompose fast enough to clear tree holes between the consecutive seasons. To mimic the nest material we filled litter-bags with either 1 g of cellulose, or with 0.5 g of dog moulted hair. In August 2009 we placed pairs of these bags in 23 tree holes used by breeding birds in a deciduous forest in SW Poland. For reference, we placed the same sets of bags in the litter, at 23 random sites in the forest. The bags were removed in March 2010. After seven months of exposure almost all cellulose (median 92%) and most of hair (median 57%) disappeared from bags in the holes. These values were as high as (for cellulose) or even higher than (for hair) as in the litter samples. Additionally, some bags disappeared from almost every second hole, which suggests their removal by larger animals. The high decomposition rates alone would suffice to clear holes between consecutive seasons but, in the study area, this process was apparently enhanced by mechanical cleaning.

Emigration speed and the production of sexuals in colonies of the ant Temnothorax crassispinus under high and low levels of disturbance

A nest relocation is costly for social insects, and involves hazards. Emigrations were studied in Temnothorax crassispinus ant colonies, which inhabit ephemeral nest sites, and which frequently change their nests. In a laboratory experiment, ant colonies from one group were forced to change their nest sites 10 times over a ca. 3-month period, whilst colonies from the second group were forced to adopt this practice twice (on the beginning of May, and in the second half of July). Colonies of the ant from both the groups reduced their total emigration duration. However, the duration of the transport phase remained unchanged. In the case of colonies with higher level of disturbance, there was no relation between colony growth rate and energy allocation in sexual individuals, whilst a negative correlation between these parameters was present in group with lower level of disturbance. In colonies with lower level of disturbance, the investment in sexuals was not correlated with the number of workers at the end of the experiment, whereas such a correlation was demonstrated for colonies with higher level of disturbance. The disturbance, and thus necessity of frequent nest relocations, may be perceived by ants as a signal that nest sites are of a lower quality and may contribute to a change in energy allocation.

Decomposition of Nest Material in Tree Holes and Nest-Boxes Occupied by European Starlings Sturnus vulgaris: An Experimental Study

Abstract. Numerous bird species depend on the availability of tree cavities, and most non-excavators fill their cavities with considerable amounts of nest material. If not removed, this material can accumulate and render cavities unusable, as recorded in some nest-box studies. Data from earlier studies of tree cavities, however, showed that nest material can decrease mostly due to in situ decomposition, but the relative difference between nest decomposition in tree holes and nest-boxes is still unknown. We undertook parallel studies of decay in tree holes and nest-boxes used by European Starlings Sturnus vulgaris in oak-hornbeam stands (SW Poland). We inserted into its tree holes and nest-boxes litter-bags filled with cellulose and wool. After 7.5 months of exposure we detected much greater decomposition in tree holes than in nest-boxes. In tree holes a median 75% of cellulose and 26% of wool disappeared, whilst in nest-boxes a median of only 2% of cellulose and 14% of wool. These results are the first to document the relative difference between natural and artificial breeding cavities in the extent of nest decomposition. We also discuss the effect of nest material accumulation in tree holes and nest-boxes on the different nesting conditions available for hole-nesting birds. Taken together with: microclimate, nest safety, competition with social insects and presence of ectoparasites, the physical accumulation of nest material appear to be distinctive feature that differentiates the natural and artificial sites of tree-hole-nesting birds.

Cohabitation of tree holes by ants and breeding birds in a temperate deciduous forest

ABSTRACT A previously unknown association of ants with birds breeding in tree holes is described. Ants Lasius brunneus Latreille (Hymenoptera: Formicidae) were found in c. 15% of nests of Parus major L. and Poecile palustris L. (Paridae) breeding in tree holes in the primeval deciduous forest located in the Białowieża National Park (Poland). The ants preferably used holes located higher above the ground. As such holes are warmer than the unused holes or other nest sites, it is suggested that the ants cohabit holes utilized by the tits to gain thermal benefits.

Migrations of hatchling European pond turtles (Emys orbicularis) after nest emergence

Distances between nest sites of Emys orbicularis and the nearest water bodies can be long. We studied whether a longer distance could affect the probability of hatchling survival, migration time, and body mass loss. In our research area (Lubuskie district, western Poland), nest sites were situated on a slope; the closest water body was in a distance of 72-290 m. Near the water body we constructed a 550 m long drift fence to recapture hatchlings migrating down the slope. We monitored 32 hatchlings from 7 different nests deposited in the years 2008-2010. The hatchlings started to emerge from their nests on 9 and 13 April 2009, 7 and 9 April 2010, 30 March, 7 and 8 April 2011. Then, hatchlings were radiotracked using transmitters glued on their carapaces. Individuals ( n = 20 ) recaptured near the fence travelled the distance between the nest site and the fence within 18-727 hours (0.75-∼30 days). Hatchlings from nests situated only a short distance away (72-81 m) were recaptured in higher numbers, compared to those from nests situated further away (227-290 m). During the journey the hatchlings lost on average ∼3.8% of their initial body mass. The hatchlings which migrated longer lose more of their initial body mass than those which migrated shorter.