Nest sites as a key resource for population persistence: A case study modelling nest occupancy under forestry practices

Differential utilization of surface and arboreal water bodies by birds and mammals in a seasonally dry Neotropical forest in southern Mexico

Water availability significantly influences bird and mammal ecology in terrestrial ecosystems. However, our understanding of the role of water as a limiting resource for birds and mammals remains partial because most of the studies have focused on surface water bodies in desert and semi-desert ecosystems. This study assessed the use of two types of surface water bodies (waterholes and epikarst rock pools) and one arboreal (water-filled tree holes) by birds and mammals in the seasonally dry tropical forests of the Calakmul Biosphere Reserve in southern Mexico. We deployed camera traps in 23 waterholes, 22 rock pools, and 19 water-filled tree holes in this karstic region to record visits by small, medium, and large-bodied birds and mammals during the dry and rainy seasons. These cameras were set up for recording videos documenting when animals were making use of water for drinking, bathing, or both. We compared the species diversity and composition of bird and mammal assemblages using the different types of water bodies by calculating Hill numbers and conducting nonmetric multidimensional scaling (NMDS), indicator species, and contingency table analyses. There was a greater species richness of birds and mammals using surface water bodies than tree holes during both seasons. There were significant differences in species composition among bird assemblages using the different water bodies, but dominant species and diversity remained the same. Terrestrial and larger mammalian species preferentially used surface water bodies, whereas arboreal and scansorial small and medium mammals were more common in arboreal water bodies. These findings suggest that differences in water body characteristics might favor segregation in mammal activity. The different water bodies may act as alternative water sources for birds and complementary sources for mammals, potentially favoring species coexistence and increasing community resilience to environmental variation (e.g., fluctuations in water availability). Understanding how differences in water bodies favor species coexistence and community resilience is of great relevance from a basic ecological perspective but is also crucial for anticipating the effects that the increased demand for water by humans and climate change can have on wildlife viability.

Nesting habitat suitability and breeding of Asian woollyneck (Ciconia episcopus) in Nepal

Asian woollyneck (Ciconia episcopus) is a large wading bird species whose conservation status has been recently down-listed, despite a lack of concrete information on its nesting ecology and breeding success. In this study, we report its breeding success and nest habitat suitability in Nepal from 39 nesting sites (2016–2020). Simal (Bombax ceiba) (n = 21), followed by sal tree(Shorea robusta) (n = 6), and rani-salla (Pinus roxburghii) (n = 4) were the most common tree with mean height of the nesting tree, nest height, and tree diameter being 30 ± 5.8 m (± SD), 25.20 ± 5.75 m, and 1.03 ± 0.35 m, respectively. Nesting and fledging success were recorded from 31 nesting attempts at 19 of these sites, with an estimated nesting success probability of 0.81 ± 0.07 and a mean fledging success of 1.94 ± 0.25 chicks per nest. MaxEnt modelling identified a total potential suitable nesting habitat area of 9.64% (14,228 km²) of the area in Nepal, with this located within 72 districts, mostly in the west. The modelling parameters suggest that slope, land use, and precipitation during the driest months were important determinants of nesting habitat suitability. We recommend that priority be given to conserving taller trees (especially simal) close to settlements and croplands of Nepal. Also, that future surveys should consider examining the districts highlighted by our model as being the most likely candidates for containing woollyneck nesting habitat, especially those (such as Dang District) where woollyneck nests have not been previously reported.

Long-term population monitoring of a territorial forest raptor species

We provide field monitoring data of a territorial raptor (the booted eagle, Hieraaetus pennatus), that was intensively monitored over a period of 18 years (1998-2015) in a Mediterranean forested area of south-eastern Spain designated as a Special Protection Area (Natura 2000 Network) for this species. The data set compiles all the relevant information about the occupation of territories and nests, reproductive ecology, long-term monitoring of marked individuals and influence of parent's colour morph on brood size. Several questions concerning the population ecology of forest-dwelling raptors and factors conditioning territorial occupancy, such as location cues or site fidelity, are addressed. This type of long-term population monitoring has high potential for replication, reuse and comparison purposes, providing insights for monitoring other long-lived, territorial species.