The role of ant nests in European ground squirrel’s (Spermophilus citellus) post-reintroduction adaptation in two Bulgarian mountains

Abstract

The European ground squirrel (Spermophilus citellus) is a vulnerable species, whose populations are declining throughout its entire range in Central and South-Eastern Europe. To a great extent, its conservation depends on habitat restoration, maintenance and protection. In order to improve the conservation status of the species, reintroductions are increasingly applied. Therefore, researchers focus their attention on factors that facilitate these activities and contribute to their success. In addition to the well-known factors like grass height and exposition, others, related to the underground characteristics, are more difficult to evaluate. The presence of other digging species could help this evaluation. Here, we present two reintroduced ground squirrel colonies, where the vast majority of the burrows are located in the base of anthills, mainly of yellow meadow ant (Lasius flavus). This interspecies relationship offers numerous advantages for the ground squirrel and is mostly neutral for the ants. The benefits for the ground squirrel, including reduced energy demand for digging, as well as additional surveillance and hiding places available, could greatly enhance the post-reintroduction adaptation process.

Detection of spatial avoidance between sousliks and moles by combining field observations, remote sensing and deep learning techniques

“…Importantly, in the current guidelines of souslik conservation, the issue of the competition with other species and its impact on spatial distribution is not considered. In turn, there is evidence in the literature that interspecies interactions may be important for the souslik population 21 . In periods of low abundance, when the survival of the population is at risk, the sousliks may have different habitat preferences than in periods of the abundant population 20 .…”

“…It has also been reported that unexpected interspecies interactions may sometimes be important for the habitat preferences of the souslik during the colonization of a new area, e.g. in Bulgaria, Lasius flavus anthills were chosen by the souslik as preferred places to locate burrows 21 . It can therefore be expected that the presence of another mammalian burrowing species, such as the mole, may also affect the souslik, especially in critical periods of low population abundance.…”

Rise and fall: Results of a multidisciplinary study and 5-year long monitoring of conservation translocation of the European ground squirrel

“…Recapture sessions were organised monthly. The stress levels, spatial behaviour and parasite loads were monitored and most of the results are published ( Kachamakova et al 2019 , Kachamakova and Koshev 2021 ) or in preparation. Аt every first animal capture during both translocation efforts and recapture sessions, standard morphometric measurements were taken with a vernier caliper with 1 mm accuracy, except for some cases where the measurement was not possible due to technical issues.…”

Ants in restoration ecology: Why, what's and the way forward

“…For example, they impact resource heterogeneity within a landscape by creating diversity in nutrient concentrations (Dostál, 2007) and thus potentially enhancing the restoration of degraded grasslands (Lane & BassiriRad, 2005). Their nests may foster recolonization by other organisms, mainly plants but also fauna (Kachamakova et al, 2019; Nicolai, 2019), throughout the degraded ecosystem. Moreover, their impacts are detected not only during nest occupation but also up to more than 20 years after colony disappearance (Kristiansen & Amelung, 2001; Lane & BassiriRad, 2005), thus increasing their spatial and temporal environmental impact.…”