Assessing niche partitioning of co‐occurring sibling bat species by DNA metabarcoding

Abstract

Niche partitioning through foraging is a mechanism likely involved in facilitating the coexistence of ecologically similar and co-occurring animal species by separating their use of resources. Yet, this mechanism is not well understood in flying insectivorous animals. This is particularly true of bats, where many ecologically similar or cryptic species coexist. The detailed analysis of the foraging niche in sympatric, cryptic sibling species provides an excellent framework to disentangle the role of specific niche factors likely involved in facilitating coexistence. We used DNA metabarcoding to determine the prey species consumed by a population of sympatric sibling Rhinolophus euryale and Rhinolophus mehelyi whose use of habitat in both sympatric and allopatric ranges has been well established through radio tracking. Although some subtle dietary differences exist in prey species composition, the diet of both bats greatly overlapped (O = 0.83) due to the consumption of the same common and widespread moths. Those dietary differences we did detect might be related to divergences in prey availabilities among foraging habitats, which prior radio tracking on the same population showed are differentially used and selected when both species co-occur. This minor dietary segregation in sympatry may be the result of foraging on the same prey-types and could contribute to reduce potential competitive interactions (e.g., for prey, acoustic space). Our results highlight the need to evaluate the spatial niche dimension in mediating the co-occurrence of similar insectivorous bat species, a niche factor likely involved in processes of bat species coexistence.

Molecular diet analysis finds an insectivorous desert bat community dominated by resource sharing despite diverse echolocation and foraging strategies

“…Thus, we suggest that principles of both niche theory and optimal foraging may help us to understand to the structure of this community. Previous work has found only minimal evidence of niche partitioning in bats (Arrizabalaga‐Escudero et al, ; Matthews, Neiswenter, & Ammerman, ; Razgour et al, ; Salinas‐Ramos et al, ); however, almost all previous work has been limited to a small subset of the community (though see for example Emrich et al, ; Galan et al, ). Here, we have taken a novel approach of considering partitioning at the level of the community and as such we can analyze categories of behavior rather than species in isolation and we observe that partitioning is more apparent or more detectable at this level.…”

“…Studies of trophic interactions between species increase our understanding of how intrinsic and extrinsic characteristics structure resource use in communities (Arrizabalaga‐Escudero et al, ), how populations respond to resource limitations, and what impact these responses have on ecological processes (Amarasekare, ; McCann, ; Milo et al, ; Rooney & McCann, ). Niche is an N‐dimensional concept, and thus impossible to quantify, but a number of key niche indicators are measured regularly.…”

Approaches to integrating genetic data into ecological networks

“…Metabarcoding is best applied to mixed faecal samples, gut contents (particularly liquid feeders, e.g., Piñol, San Andrés, Clare, Mir, & Symondson, ) or pollen carried by generalists. However, it is challenging to generate reliable metabarcoded data (Alberdi et al, ; Arrizabalaga‐Escudero et al, ; Atwell et al, ; King, Read, Traugott, & Symondson, ). The methods of interpreting individual dietary analyses using these data have been studied in several contexts (Clare et al, ; Flynn et al, ; Pompanon et al, ; Symondson, ).…”

“…The data suggest extraordinary behavioural flexibility of insectivorous bats and their lack of reliance on specific prey. While there is evidence for resource specialization (e.g., the preference for beetles in Eptesicus (Clare, Symondson, & Fenton, 2014) or moths in sibling rhinolophids (Arrizabalaga-Escudero et al, 2018), most studies that have employed molecular techniques have observed very generalist flexible behaviour in bat foraging (Salinas-Ramos et al, 2015;Sedlock, for 10 s (depending on primer set), 72°C for 7-10 s (depending on region), followed by a final extension at 72°C for 60 s and hold at 4°C (see primer references for additional details).…”

Promises and pitfalls of using high‐throughput sequencing for diet analysis

“…The strategy used to characterize and compare the taxonomic diversity of the diets can also determine the results. Most studies treat taxa or OTUs as discrete independent components, rather than phylogenetically correlated elements (e.g., Arrizabalaga-Escudero et al, 2018;Cheng & Lin, 2016;Kartzinel et al, 2015). This entails losing large part of the taxonomic information molecular diet studies provide.…”