Artificial Wetlands as Breeding Habitats for Colonial Waterbirds within Central Romania

• Main Authors: Dan Traian Ionescu, Călin Vasile Hodor, Ion Cătălin Petritan
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: Diversity
• Subjects: cormorant; heron; egret distribution; population dynamics; Natura 2000; Ramsar
• Online Access: https://www.mdpi.com/1424-2818/12/10/371

The historical loss of natural wetlands in Romania is significant. The building of lakes, ponds, and dams has compensated for some of these losses, as was the case in the study area, the artificial wetlands designated as the Natura 2000 (special protection area, SPA) and Ramsar sites. In this context, to evaluate the conservation status of colonial waterbirds (cormorants, herons, and egrets), we analyzed actual distributions, habitat selection, features, and population sizes. Standardized counting of colonial species was used, supplemented by nest counting and colony-area estimation during winter, and drone footage. All species and their colonies were built in artificial or anthropically influenced habitats. Concerning distribution and population sizes, <i>Phalacrocorax carbo</i> and <i>Microcarbo pygmeus</i> were found to nest only in central Romania. The pair numbers of <i>Ardea alba</i>, <i>Ardea purpurea</i>, <i>Ardea cinerea</i>, and <i>Nycticorax nycticorax</i> in the area exceeded 1% of the national minimum breeding population. There was a statistically significant positive trend of breeding populations for <i>Ardea alba</i>, <i>Nycticorax nycticorax,</i> and <i>Egretta garzetta</i>. In conclusion, these artificial wetlands offer optimal breeding conditions for a relatively large diversity of colonial bird species over areas that are not very large.