Abstract
The aim of the study was to assess the influence of corvid urban roosts on the abundance of two groups of soil mesofauna: mites and springtails. Two areas located in the city of Warsaw were taken into consideration, one subjected to winter roosting activity of corvids and the other not influenced by birds. The samples were taken three times, in May, July, and September of 2013. The results show a positive effect of corvid roosts on the density of soil mesofauna, especially in the top 0–5 cm soil layer. On each sampling date, we found more numerous communities of mites and springtails in the soil within the roosting area than in control. The average densities ofmites ranged from 30×103 ind. m–2 to 200×103 ind. m–2 in the soil within the roost and from 6 ×103 ind. m–2 to 40×103 ind. m–2 in the control. In the case of springtails the average densities ranged from 9×103 ind. m–2 to 36×103 ind. m–2 in the roost and from 4×103 ind. m–2 to 8×103 ind. m–2 in the control. Among the two groups, mites prevailed over the springtails both in the soil of roost and control area. We inferred that the corvid roosting activity, involving mainly an excrement deposition on the soil surface, influences soil mesofauna indirectly