Remarkable Stability of Uropodina (Acari: Mesostigmata) Communities in Artificial Microhabitats: A Case Study of Bird Nest Boxes in Bory Tucholskie National Park

The presence of nest boxes not only increases the reproductive success of many passerine birds in transformed forest habitats, but they also constitute important artificial microhabitats for many groups of invertebrates. One of such groups which have been often found in this microhabitat is saprophagous mites from the suborder Uropodina (Acari: Mesostigmata). The current study was conducted in October 2023 and 2024 in Bory Tucholskie National Park (BTNP) (northern Poland), where material from 137 tit (Paridae) and nuthatch (Sitta europaea) nest boxes was collected. The aim of this study was to analyse the stability of the communities of Uropodina in nest boxes in the park in two seasons and to determine whether the mite community structure within these nest boxes is similar in each year. The second aim was to analyse the abundance of Uropodina in relation to the composition of the nest box bedding material. This study revealed that the community in the scrutinised nest boxes was formed in both seasons by two species of nidicolous Uropodina species, i.e., Leiodinychus orbicularis (C.L. Koch, 1839) and Chiropturopoda nidiphila (Wiśniewski and Hirschmann, 1993), and that the species composition and the community structure were also very similar in both years. This study revealed that Ch. nidiphila dominated in the nest boxes with moss and grass, whereas L. orbicularis was most abundant in the boxes where the bedding was a mixture of mammalian hair and grass. However, no statistically significant differences in the abundance of these two mite species in both cases were revealed.