The aim of this work was to use standardized digital cartography of vegetation coverage to test whether or not the predicted range of habitat suitability for wild boar in Bulgaria coincides with the georeferenced/presence records of this species. The predicted range of habitat suitability based on potential biological resources in Bulgaria encompasses 13 land uses from the CORINE program, being “Broad-leaved forests” (23432 km2) the most representative. The total potential resources for wild boar correspond to 57.54 % of the country area. A high level of correlation (0.86) was found between inverse distance of wild boars presence and habitat suitability areas. A significant level of correlation (0.71, p < 0.0001) per Bulgarian region between area of habitat suitability category 2 (resources suitable for use as both food and shelter) and number of wild boar was also found.Suitable wild boar habitat on borders appeared
as the most relevant parameter for evaluating the risk of introduction of diseases by wild boar into the European Union from neighbouring countries. Despite being the longest (608 km), the Bulgaria-Romania border did not
represent the most important corridor for wild boar since only 12.78 % of its surface is suitable habitat; the percentage of the importance of this border edges the passage of wild boar is 20.63 %. The Bulgaria-Macedonia (FYROM) border must be regarded as the most
important passageway for wild boar (96.88 %), with 148 km of border and 12.34 % of its surface area of suitable habitat. Our findings could be highly useful for developing adequate strategies for wildlife management practices on large spatial scales, as well as for the control of wildlife and its habitats (territorial integration and spatial planning according to the casuistry of the zone), and relationships between wildlife and other human interests.
There are isolated populations of the endangered butterfly, Pyrgus sidae, on the Iberian Peninsula. The mark-release-recapture method was used to study the population parameters, the use of resources and the spatial distribution of a population in the centre of Spain. The estimated number of males and females within the population were similar and did not differ significantly from a ratio of 1 : 1. Total population size was estimated to be 569 ± 83 individuals. Potentilla recta is the principal adult nectar source and larval food plant, and its abundance is correlated with the number of marked and recaptured butterflies. The average total distance moved between capture and recapture was significantly greater for males than females, but the average daily distances moved were similar for both sexes. The spatial distribution of the movements of males and females was of a uniform type and lacked a predominant flight direction, which is typical of sedentary species. Continuing the traditional land use (cattle grazing or hay mowing) of the habitat of the species keeps the habitat open, which is necessary if the butterfly is to survive at this locality. These management practices favour P. recta, which would otherwise succumb to competition from invasive shrubs. Taking into account the habitat requirements of this species, it is important to conserve the mosaic of meadows already present in the area.
Despite their wide distribution and frequent occurrence, the spatial distribution patterns of the well-known gall-inducing insects Mikiola fagi (Hartig) and Neuroterus quercusbaccarum (L.) in the canopies of mature trees are poorly described. We made use of the Swiss Canopy Crane (SCC) near Basel, Switzerland, to gain access to the canopy of a mixed temperate forest up to a height of 35 m. Within one and a half days we scanned 6,750 beech leaves and 6,000 oak leaves. M.fagi showed a distinct vertical zonation with highest abundance in the top-most parts of the canopy as well as a significant aggregation on particular trees. N. quercusbaccarum showed an even more pronounced preference for particular trees and a general preference for Quercus robur over Q. petraea. In contrast to M. fagi, no vertical zonation could be detected. We think that both gall-inducing species have greater powers of dispersal than formerly assumed since they overwinter on the forest floor and yet are able to 1) gain access to the entire canopy, 2) show preference for certain host trees. We found little evidence for the phenological synchrony hypothesis proposed to explain the intertree distribution of N. quercusbaccarum. The highest density of M. fagi galls was in those parts of the canopy exposed to high solar radiation; their host choice is probably determined by micro-climatological factors. The consequences of the distribution patterns of N. quercusbaccarum and M. fagi for their ecological interactions with the host-plant, inquilines and parasitoids (e.g., canopy-layer specific performance linked to plant chemistry, density-dependent parasitism) need now to be subjected to further scientific investigation.