Abstract
According to our surveys carried out in the Gödöllő Hills between 2009–2012, a relatively high proportion (39-57%) of the known 36-40 Bee-eater nesting sites can be found in natural habitats, on hillsides as opposed to nests excavated into man-made artificial walls. 51.8% of the nesting population breeds under such natural circumstances in loess and sandy hillsides, and the nests are excavated into the soil covered by vegetation. We have shown that 61.9% of the nests were built in loess, 28.4% in sandy and 9.7% in mixed type of substrate. Bee-eaters nesting on hillsides prefer the slopes between 11-30°. The slope of the hill is higher on loess grounds (average: 24.67°) as opposed to the sandy ones (average: 13.97°). The length of the nesting cavities differs significantly between the two substrate, those built in sandy areas being longer. The cavities in loess are deeper underground. The Bee-eaters nesting on hillsides prefer places with low vegetation cover