Using sentinel prey to assess predation pressure from terrestrial predators in water-filled tree holes

Abstract

http://www.eje.cz and species richness. Depending on their exposure, waterfi lled tree holes retain water for different periods of time and show different degrees of buffering of their microclimatic conditions (Gossner, 2018).Water-fi lled tree holes in temperate forests harbour a very specialised community of invertebrates, including aquatic insect larvae of many fl ies and midges and one beetle family (Kitching, 2000). S uch insect larvae contribute substantially to forest biodiversity, for example as food for higher trophic levels, including terrestrial predators such as arthropods, small mammals and birds. In this way, they might substantially contribute to trophic chains and nutrient cycling in forest ecosystems. Despite its potential importance, our knowledge of the trophic interaction at the aquatic-terrestrial habitat interface is still limited because of the lack of suitable tools for monitoring.

The use of water-filled tree holes by vertebrates in temperate forests

“…The activities carried out at WHs by other vertebrate species, however, resembled those recorded in the tropical and subtropical environment, including drinking, bathing and feeding (Yanoviak 2001, Walters and Kneitel 2004, Vickers et al 2014, Sharma et al 2016). The importance of vertebrate predation on the aquatic insect larvae in WHs have recently been shown by experiments with fake larvae in European beech forests (Gossner et al 2020).…”

“…Possible uses include life cycle development, typical for amphibians (Yanoviak 2001); drinking, which is documented for primates (Sharma et al 2016) and suggested for bats (Boyles et al 2006); and bathing, as it has been observed for birds (Baker 1983). A field study by Gossner et al (2020) in temperate beech forests revealed that fake larvae displayed in WHs are frequently attacked by small mammals and birds, indicating WHs are used and harbor potential food resources.…”

Camera trapping reveals multispecies use of water‐filled tree holes by birds and mammals in a neotropical forest

“…In addition to being used for rehydration, water is used to thermoregulate (Hafez, 1964) and reduce ectoparasite load (Clayton et al, 2010). Moreover, water deposits commonly favor the presence of organisms that constitute an important food source for a variety of vertebrates (Gossner et al, 2020). Therefore, water availability can directly or indirectly affect population dynamics (Gandiwa et al, 2016), movement (Chamaillé‐Jammes et al, 2013), habitat use (Bennitt et al, 2014), spatial distribution (Paredes et al, 2017), and interspecific interactions (Perera‐Romero et al, 2021) of all terrestrial vertebrates.…”

“…However, in all other cases, our records show that both birds and mammals equally visit the dendrotelmata during the dry and rainy season, suggesting that dendrotelmata constitute an important resource for birds and mammals throughout the year. For both birds and mammals, foraging comprised the most frequent behavior at dendrotelmata, indicating that dendrotelmata are likely a relevant feeding ground in addition to being a source of water (Gossner et al, 2020). This could be particularly true for species that include invertebrates in their diets such as birds in the Furnariidae family (Chapman & Rosenberg, 1991), T. mexicana (Navarrete & Ortega, 2011), E. barbara (Presley, 2000), N. narica (Gompper, 1995), andD.…”

“…In addition to being used for rehydration, water is used to thermoregulate (Hafez, 1964) and reduce ectoparasite load (Clayton et al, 2010). Moreover, water deposits commonly favor the presence of organisms that constitute an important food source for a variety of vertebrates (Gossner et al, 2020). Therefore, water availability can directly or indirectly affect population dynamics…”