The emigration of peoples from the area of Western Bosnia and Herzegovina during the Balkans civil conflict and implications for the Avifauna (Case study Pašića polje at Bosansko Grahovo)

Abstract

We compare the avifauna between two peeriods, before and after Balkans civil conflict in a region of Western Bosnia, the municipality of Bosansko Grahovo. The present study investigated bird-abundance in 3 habitats (lokalites) of the area Pašića polje: 1) Settlements/village Luka, 2) Pastures, 3) Meadow and Agricultural land. Thirty years of data on bird numbers in breading season (from 20th May until end of June) were analysed. By doing this we were able to capture the overall changes that happened at the landscape level and understand them in terms of ecological processes taking place at the habitat scale. Forty-six bird species were observed. We detected more species and more individuals in the period between 2004 and 2018. Our study demonstrated that abundance of the bird sgnificantly different before and after the Balkans civil conflict. Abundance of 35 species was different in the two study periods and during the first period the mean abundance was mostly lower than in the second one. Two species disappeared from the investigated localities, E. citrinella and A. campestris, while several species expanded their range or nesting site. The big decline in the Pašića polje region of some species such as the O. oenanthe, the M. alba, on the pastures, and the P. domesticus and P. pica in the settlements, can be explained by outmigration and changes in land use patterns, or non-use. Rural emigration has been complete (all population) during Balkans civil conflict and a smaller part of the population returned only after 3-5 years. Most of the changes observed support the hypothesis that the differences observed in the bird community are caused by the changes that occurred in the vegetation as a result of agricultural and grazing abandonment.

Changes in the Habitat and Nest Site Distribution for Two Lanius Species in Karst Poljes (Bosnia and Herzegovina)

“…Also, results show contrasted responses for diff erent bird groups, with "loser" and "winner" species (Phalan et al 2011, Teillard et al 2015. Abandonment of the villages in some karst poljes in Bosnia and Herzegovina led to changes in bird populations, some have left (disappeared) the area, some have reduced abundance, for example Emberiza citrinella or Passer domesticus, and some had a favourable effect (Marić 2022b). Some of the species whose abundance increased after the mass emigration of the human population are Lanius spp.…”

“…In general, such changes have influenced the composition of biodiversity in those/such habitats then changes in ecology, phenology and diversity of species assemblages (e.g. Chamberlain et al 2000, Marić 2022b. According to Baur et al (2006) and Queiroz et al (2014) the effects of land abandonment on biodiversity are complex and can vary regionally and between taxa.…”

“…Fruit species are dominated by plums, apples, pears and cherries (deciduous fruit trees), and in the village grow trees, such as Tilia spp., and shrubs such as Cornus mas, Rosa spp., Crataegus monogyna, Sambucus nigra, Prunus spinosa, etc. (see Marić 2022aMarić , 2022b.…”

“…Abandonment of the village and thus arable land leads to changes in the natural environment resulting in varying habitats, many of which are extreme for birds, for example Emberiza citrinella or Passer domesticus, however, for some species this had a favourable effect (Marić 2022b). Some of the species whose abundance increased after the mass emigration of the human population (during the war in Bosnia and Herzegovina -Nikolić 2021) are Lanius spp.…”