Can intensified forestry be responsible for changes in habitat usage by the forest-dwelling Black Stork?

• Published in: European Journal of Forest Research
• Main Authors: Treinys, Rimgaudas, Mozgeris, Gintautas, Skuja, Saulis
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2016
• Subjects: Nest site; Nest tree; Macrohabitat; Conservation; Habitat preference; White-tailed eagle
• Online Access: http://vu.lvb.lt/VU:ELABAPDB19777339&prefLang=en_US

Populations of the internationally protected Black Stork Ciconia nigra in the northern parts of the distribution range, located to the east of the Baltic Sea, have suffered decline over recent decades. Since early 1990s, however, logging intensity has increased. In this paper, considering a ten-year period from the mid-1990s, we ask: (a) Did changes occur in the habitat preferred by Black Stork in the decade? (b) did the decade of intensified forestry significantly change forest characteristics? and (c) could the intensified forestry explain any observed changes in the utilization of habitat by storks? We compared forest characteristics at the beginning and end of this period at 75 random points and compared the habitat at 75 nest sites occupied by the Black Stork in the mid-1990s and 75 occupied nest sites at the end of the 2000s. In the 0.7-km zones around the random points, the abundance of mature stands decreased between the mid-1990s and the end of the 2000s, as did the abundance of broadleaved trees, but black alders increased. Nevertheless, the age and composition of tree species within the stands around the random points remained similar. Some changes were noted though in the habitat around nests used by Black Storks during two periods, with the data indicating that the Black Storks tended to occupy sites of better habitat quality (e.g. with a higher density of hydrological network and old oak trees, older nest stands) at the end of the 2000s than in the mid- 1990s. Our results, however, do not support the idea that intensified forestry over the short term induced changes in the habitat used by the Black Storks. It is possible that nesting Black Storks became concentrated into the prime habitat when population retracted and/or abandoned habitat where recently recovered by the White-tailed Eagle.