(Results of an expedition undertaken by zoologists of the International Radioecology Laboratory (IRL) and Kharkiv Natonal University under the Scientific Research Program implemented within the Chornobyl Exclusion Zone)
Collection of actual data on the rear and protected fauna representatives using the Exclusion Zone’s territory for their vital activity is a direction of the IRL’s Scientific Research Program being implemented within the Exclusion Zone during 2008 (“Zoological Survey of the Exclusion Zone and Zone of Absolute (Obligatory) Resettlement (EZ&ZAOR) performed to assess value of some sites within the framework of the initiative for development of a reserved locations network”). Combination of such information will evidence both natural value of a particular site within the Chornobyl Zone, and health of the natural environment in general. In particular, the group of chiroptera (serotines, or as they say ‘bats’) is related to these animals.
Owing to their biological and ecological features, chiropterans are extremely vulnerable. They suffer from the effects of human activity in consequence of accumulating toxic agents (insecticides, herbicides, heavy metals, etc.) via trophic chains; although even to a greater extent they suffer due to disappearance of their habitat (old hollow, climax forests and safe underground shelters). Notwithstanding the fact that this group of mammals is one of the most diverse (900-1000 species), their lion’s share is represented by tropic species. Whereas, only about four dozen species reside in Europe and most of these are not able to adapt themselves to anthropogenic changes occurring in the environment. Therefore, their number is currently reducing everywhere and hence needs protection.
Up to 26-28 chiroptera species live in Ukraine and are the most diverse in the Carpathian Mountains, Crimea and Podolye. North forests are not considered to be the most abundant in these mammal species. However, data on this fact have never been confirmed; on the other hand, numerous opportunities for habitation of dendrophilous species (live in hollow trees) exist right here, in the north of Ukraine, and within the Chornobyl Zone in particular.
Moreover, abandoned constructions and the lowest factor of human intrusion create additional opportunities for other species habitation either. As a result, survey of the Chornobyl Zone’s lands with the objective to reveal species’ composition, distribution, status of population, etc. not only establishes pre-conditions for a reservation process, but also appears a unique initiative in itself.
In late July – early August 2008, IRL scientists executed the second chiropterologic (i.e. focused on chiroptera) expedition within the Exclusion Zone territory that was undertaken jointly with zoologists from Kharkiv National University. The first expedition took place in May 2007.
The specificity of activities implied search of the chiroptera habitats and approximate assessment of their species’ composition using detectors trapping the ultra-sounds produced by the bats. Further, special chiropterologic nets were installed at the registered locations with the objective to catch flying bats. In case of detecting hollows with colonies, special wood traps were used.
The bats were captured at cuttings, near forest water bodies, on the river banks and nearby abandoned buildings. Following night captures, the animals were described, ringed and set free again at capture sites.
Totally, nearly 780 animals, referred to 10-11 species, have been caught during the two years. Due to previous lack of information on chiroptera within this region, the obtained results are valuable even for common and widely-spread species. Though, the species included into the Red Book of Ukraine were also detected: lesser noctule, Kuhl’s pipistrelle and mouse-eared bat (myotis). Moreover, whereas the first two species are quite usual for the Chornobyl Zone, the lesser noctule propagates within this geographical area and this fact has been unknown before. Highly successful captures also confirm high number of the serotines and general health of their population.
Based on the bulk of results, we may say straight away that old broad-leaved and mixed forests, as well as flood-plain sites with tree vegetation are very attractive for serotines and play a large role in sustaining vital capacity of their populations.
Unfortunately, meanwhile there is no information regarding several more possible species, inclusive of very rare ones. Also, there is a complete lack of data on the locations of their wintering grounds. Additional investigations at new sites and involving new methods and approaches are required.
(Based on the data presented in the report on the results of the expedition, prepared by S.P. Gaschak, Deputy Director for Science, International radioecology Laboratory).