Protecting one, protecting both? Scale‐dependent ecological differences in two species using dead trees, the rosalia longicorn beetle and the barbastelle bat

Abstract

Organisms sharing the same habitats may differ in small-scale microhabitat requirements or benefit from different management. In this study, set in Italy, we focused on two species of high conservation value, the cerambycid beetle Rosalia alpina and the bat Barbastella barbastellus, which often share the same forest areas and in several cases the same individual trees. We compared the potential distribution and, at two spatial scales, the niches between such species. The predicted distributions largely overlapped between the beetle and the bat. The niches proved to be similar on a broad scale, yet not on the plot one. Compared with B. barbastellus, R. alpina tends to occur at lower altitude in more irradiated sites with lower canopy closure and uses shorter trees with wider diameters. B. barbastellus occurred more often in trees within forest or along its edges, whereas R. alpina lays eggs in trees found in clearings. B. barbastellus plots were more frequent in forest, R. alpina plots in forested pasture and open-shredded forest. Overall, exposure to sun influenced more critically site and tree selection by R. alpina, as a warm microclimate is essential for larval development. Although B. barbastellus reproduction may be favored by warmer roosting conditions, bats may also find such conditions in dense forest and in strongly irradiated cavities high up in tall trees that project above the canopy. We emphasize that subtle differences in the ecological requirements of syntopic taxa could be missed at broad scales, so multiple-scale assessment is always advisable.

Modelling bat distributions and diversity in a mountain landscape using focal predictors in ensemble of small models

“…Improvement in both sampling efficiency and modelling technique leads to an encouraging increase in studies using SDMs for bats (for a review, see Razgour, Rebelo, Febbraro, & Russo, ). However, SDM studies on bats remain scarce and often address disparate questions or single species such as disentangling niches of cryptic species (e.g., Sattler, Bontadina, Hirzel, & Arlettaz, ; Rutishauser, Bontadina, Braunisch, Ashrafi, & Arlettaz, ; Santos et al, ; Smeraldo et al, ), modelling rare species of conservation concern (e.g., Rebelo & Jones, ; Razgour, Hanmer, & Jones, ; Santos, Rodrigues, Jones, & Rebelo, ; Russo et al, ; Silva, Vieira, Silva, & Cassia Faria, ) or predicting the influence of climate change (e.g., Rebelo, Tarroso, & Jones, ; Pio et al, ; Carstens, Morales, Field, & Pelletier, ). Applications of SDMs to multiple or all species in a region at fine spatial resolution are still relatively rare due to limited data availability (but see Lisón & Calvo, ), although such effort would be needed to support conservation planning (Vincent, ).…”

Beauty and the beast: how a bat utilizes forests shaped by outbreaks of an insect pest

“…We hypothesize that beetle-induced alteration of forest structural attributes (e.g., increasing canopy opening, increasing stand structural heterogeneity) lead to an increasing foraging activity of B. barbastellus (M€ uller et al, 2012). Furthermore, we hypothesize that B. barbastellus select dead spruces killed by I. typographus as roosts (Russo et al, 2015) in stands with high stand structural heterogeneity and a moderate canopy cover for a reduced exposure and risk of predation (Russo et al, 2007).…”

“…It occurs in different forest types, especially in European beech Fagus sylvatica forests but also in pine and spruce forests, where it roosts mainly in tree cavities and behind loose bark (Steinhauser et al, 2002;Russo et al, 2004;Russo, Cistrone & Jones, 2005). Maternity colonies, whose protection is a priority aim of conservation legislation, are found in forests of low management intensity with a high amount of old and damaged trees (Russo et al, 2010(Russo et al, , 2015. These attributes are typically absent in commercially managed spruce-dominated forests, where salvage logging removes almost all damaged and injured trees (Lindenmayer et al, 2012).…”

Sociality influences thermoregulation and roost switching in a forest bat using ephemeral roosts

“…The study was carried out at the Abruzzo, Lazio, and Molise National Park (41°47′20″N, 13°46′33″E), Italy, in a mountainous area of the central Apennines of ca. 700 ha dominated by a Fagus sylvatica old forest where previous studies of B. barbastellus have taken place (Russo, Cistrone, Garonna, & Jones, ; Russo et al., , , , ). Other tree species besides beech, for example sycamores ( Acer pseudoplatanus ), are uncommon.…”

“…Other habitats in the study area comprise forested pasture, that is, pastures associated with old trees and shrubs, and open forest, where trees were historically pruned traditionally by “shredding.” Further details on the study area are given in Russo et al. (, , ).…”