Density variation in “rare” breeding birds in native forests and urban parks

Abstract

Biodiversity protection and conservation of rare species are typically the main goals of protected areas. Protected areas are commonly created within native ecosystems where anthropogenic pressure is low. Meanwhile, a growing body of literature has focused on the effectiveness of protected areas to provide important habitats for rare taxa. To highlight this issue, we examined avian species, the most diverse vertebrate class in Ukraine. Forest ecosystems vary relative to conservation status and native integrity. With this in mind, we considered Lviv, Ukraine and outskirts. To determine conservation status, we used regulatory instruments such as the National Red Book of Ukraine, Resolution 6 of the Bern Convention on the Conservation of European Wildlife and Natural Habitats and appendices, the Bonn Convention on the Conservation of Migratory Species of Wild Animals and appendices, and Species of European Conservation Concern (SPEC) status to define rare species. The weighted density of SPEC species and those listed in the Bern Convention and Bonn Convention vary considerably and are higher in forests where native integrity has been lost to various degrees. The density of rare taxa within forests exhibiting high biodiversity loss (e.g. urban parks) was starkly evident. Degree of urbanization, as a function of distance from Lviv, was an insignificant predictor of a species listed in Resolution 6 of the Bern Convention or Red Book of Ukraine. We found that weighted density of species with mean species statuses weight were lower in more native forests than parks. Given that weighted densities were highly correlated with general density, we attribute this finding to the luxury effect. That is, density of birds is higher in more urbanized areas of a particular habitat type (e.g. forests and parks). Our conclusion supports previous findings that an increase in overall bird density is common among European cities. To a lesser extent, these findings suggest ineffective nature conservation management of forests in the Lviv region of Ukraine and imply the lack of interest in urban parks as habitat for rare taxa.

Keywords

• rare species
• forest birds
• nature conservation
• conservation areas
• conservation status
• ukraine
• urban parks