Rimvydas Juškaitis

Determination of national conservation responsibilities for species conservation in regions with multiple political jurisdictions

The Convention on Biodiversity (CBD) commits its signatories to the identification and monitoring of biodiversity. The European Union has implemented this commitment into its legislation. Despite the legal requirement resources are scarce, requiring a prioritization of conservation actions, including e.g. monitoring. Red lists are currently the most prominent tool for priority setting in applied conservation, despite the fact that they were not developed for that purpose. Therefore, it is hardly surprising that they do not always reflect actual conservation needs. As a response, the concept of national responsibility as a complementary tool was developed during the last two decades. The existing methods are country specific and mainly incomparable on an international scale. Here, we present a newly developed method, which is applicable to any taxonomic group, adjustable to different geographic scales, with little data requirements and clear categorizations. We apply the new method to over 1,000 species in several countries of different size and report on the applicability of our method and discuss problems that derive from the currently available data. Our method has several major advantages compared to currently available methods. It is applicable to any geographic range, allows automatization, given database availability, and is readily adjustable to future data improvements. It further has comparably low data demands by exploiting one of the most commonly available information on biodiversity, i.e. distribution maps. We believe that our method allows the allocation of the limited resources in nature conservation in the most sensible way, e.g. the sharing of monitoring duties, effectively selecting networks of protected areas, improving knowledge on biodiversity, and closing information gaps in many species groups.

The Diet of rhe Tawny Owl (Strix Aluco) in South-Western Lithuania during the Breeding Period

The paper presents the material on the Tawny Owl (Strix aluco) diet collected during the breeding period (April–May) in Sakiai district. Prey remains from 11 nestboxes occupied by owls in 1986–1987 and 1997–2004 were analysed. The remains of 15 small mammal species, 18 bird species, two amphibian species and two genera of insects were recovered. The dominating small mammal species (n = 361) were Clethrionomys glareolus (24.6%), Microtus arvalis (20.5%), Apodemus flavicollis (11.6%), Microtus agrestis (8.8%) and Sorex araneus (8.6%). Among birds, the most often preyed were Turdus philomelos, T. merula, Fringilla coelebs and Coccothraustes coccothraustes. Frogs Rana arvalis and R. temporaria as well as insects Dytiscus sp. and Melolontha sp. were also present in the food remains. The species composition and the number of small mammals preyed in Sakiai district were compared to the respective data from Kėdainiai district, Kurtuvėnai Regional Park and Kamanos Strict Nature Reserve. The diet of the Tawny Owl i...

The influence of high nestbox density on the common dormouseMuscardinus avellanarius population

The response of common dormouseMuscardinus avellanarius Linnaeus, 1758 population to availability of nest sites was studied by manipulating the nestbox grid and ring-marking dormice. Abundance of adult dormice more than doubled in the 25 × 25 m nestbox grid in comparison to the 50 × 50 m grid, as a result of increased nestbox density from four to 16 boxes/ha. This effect already became apparent in the first year after additional nestboxes were made available and resulted from dormouse immigration, mostly from adjacent areas without nestboxes. In the second and third years, the number of two-year-old and older resident dormice, which had their home ranges in this plot, increased considerably. The average size of dormouse home range decreased by approximately half both in males and females in the 25 × 25 m grid compared to the 50 × 50 m grid. The proportion of breeding adult females did not differ between the two grids in spite of different adult dormouse density. Shortage of secure nest sites was a limiting factor for the common dormouse population abundance in the forest where natural tree hollows were absent, and high nestbox density increased environmental carrying capacity.

DIVERSITY OF SMALL MAMMAL COMMUNITIES IN LITHUANIA (1. A REVIEW)

Abstract Summary of small mammal trapping data in Lithuania is given in the first article of a series. Results are reviewed from the point of view of trapping effort, character of investigation and the interdependencies of community indexes. Consideration about the threshold of trapping effort is presented along with practical implications on the correct use of community indexes.

Identification of Shrews and Rodents from Skull Remains according to the Length of a Tooth Row

In the article, measurements of lengths of maxillary and mandibular tooth rows in three species of shrews (Sorex araneus, S. minutus, Neomys fodiens) found in Lithuania, the birch mouse (Sicista betulina), six species of mice (Mus musculus, Apodemus agrarius, A. flavicollis, A. sylvaticus, A. uralensis, Micromys minutus), and three species of voles (Microtus arvalis, M. oeconomus, M. agrestis) are presented and suitability of these measurements for species identification given. It has been established that according to these measurements species of shrews can be identified unmistakably. Species of mice and voles could be identified with reservation. Intervals are presented within the ranges of which species of mice and voles could be identified. The method is useful while working with incomplete skulls, such as those found in owl and birds of prey pellets. While using data from mammal identification keys and from other literature sources of foreign countries for identification of mammals of Lithuania, pos...

Determination of conservation priorities in regions with multiple political jurisdictions

Red lists serve as the most prominent tool for priority setting in applied conservation, even though they were not originally designed for this task. Hence, threat status does not always reflect actual conservation needs and can be very different from actual conservation priorities. Therefore, red lists may at best be a suboptimal tool for setting conservation priorities in a country or region. As a response, a range of alternative or complementary tools have been developed, with approaches, methods, and parameters such as population decline, population center etc. used, differing widely among countries. One recent development is the combination of conservation status with a measure of the international importance of a population in a focal region for the global survival of a species. Here, we provide a new method that integrates the two concepts while keeping them conceptually separate. The main benefit of this method is that it can be applied across variable geographical scales such as regions, countries, and even continents. Furthermore, it allows for better recommendations for applied conservation and conservation policy development than the two concepts in isolation. Our method, if applied internationally, would allow for a standardized priority setting in species conservation, would be highly comparable between countries, and would lead to a more efficient use of the limited financial and human resources for monitoring and conservation of biodiversity.

FEEDING BY THE COMMON DORMOUSE (MUSCARDINUS AVELLANARIUS): A REVIEW

The common dormouse (Muscardinus avellanarius) feeds on both vegetable food and food of animal origin. The dormouse has a varied diet, which depends upon latitude and nutritional plant species available and follows a strongly seasonal pattern. The main vegetable food sources are flowers in spring, berries in summer, nuts and soft fruits in autumn, but dormice also use many other food sources. Among vegetable foods, generative parts of plants (flower-buds, catkins, flowers, berries, and seeds) are preferred, whereas vegetative parts (leaf-buds, leaves, and shoots) are only subsidiary foods for these rodents. In spite of tannins that oak acorns contain, they may play an important part in the diet of dormice. During periods of scarcity of suitable vegetable food (e.g. in late spring and early summer), dormice use food of animal origin, primarily insects and bird eggs. Feeding on food of animal origin is expected to be more important in suboptimal habitats with a low diversity of nutritious plants. Some feedi...

Diet of the fat dormouse (Glis glis) on the northern periphery of its distributional range

We studied the seasonal and annual variation in diet composition of the fat dormouse (Glis glis) in Lithuania, a locality situated on the northern periphery of the dormouse range and outside of the range of the European beech (Fagus sylvatica). After emergence from hibernation, dormice fed on oak acorns (from the previous year), inflorescences of various trees, vegetative parts of plants and food of animal origin (birds, their eggs and insects). In June, soft mast and seeds of birches supplemented the dormouse diet, and diet composition was the most diverse during this period. In July, raspberries and fruits of glossy buckthorn constituted the bulk of dormouse diet, but seeds of birches dominated in a specific year. Hard mast (mainly acorns) dominated the diet of G. glis from August until the beginning of hibernation in October. A high prevalence of acorns, comparatively high proportion of birch seeds and low proportion of food of animal origin in the diet, as well as feeding on fruits of glossy buckthorn, are specific features of feeding by G. glis in Lithuania. The diet of G. glis on the northern periphery of its range resembles its diet on the eastern periphery of the range where beech trees are also absent. According to the composition of G. glis diet, feeding conditions in both of these peripheral regions are poorer in comparison to central or southern regions.

New Data on the Pygmy Field Mouse (Apodemus Uralensis) Distribution and Habitats in Lithuania

Pygmy field mouse (Apodemus uralensis) was identified as a new mammal species in Lithuania only in 1999. Despite that, many new localities of this species were discovered in northwestern and western Lithuania during 1999–2000: in Žemaitija National Park, Kurtuvėnai and Varniai regional parks, Kamanos strict nature reserve and almost on all the territory of Mažeikiai administrative district. A total of 62 individuals of A. uralensis were captured in 33 localities in 1996–2000. The collected data on A. uralensis dwelling places prove that it is an ‘ecotonic’ species most often residing on the edges of forests and in open habitats bordering on forests. The greatest number of these mice were captured in the ecotones of forests and open habitats (meadows, cornfields and fallow fields) and in open habitats bordering on forests or situated close to them (natural meadows overgrown with shrubs, grass-covered reclamation canals, cornfields). Rather few mice of this species were captured in forests, most often close...

Diversity of Small Mammals in the Northwestern Lithuania (Mažeikiai District)

During the investigation carried out in 1997 and 2000 on the territory of Mažeikiai district small mammals representing 13 species were found. The most widespread and abundant were Sorex araneus and Clethrionomys glareolus, captured in all the 20 investigated UTM squares. In more than half of the investigated squares Apodemus agrarius, A. flavicollis, A. uralensis, Microtus arvalis and M. agrestis were detected. Sorex minutes, Neomys fodiens, Mus musculus, Micromys minutes, Microtus oeconomus and M. rossiaemeridionalis were comparatively rare and were captured in less than half of the investigated squares. Rarity of some of the species during the investigation could have been related to their natural fluctuation in abundance. Noteworthy is the wide distribution of Apodemus uralensis quite a recently identified species in Lithuania - on the territory of Mažeikiai district.