Fishing long-fingered bats (<i>Myotis capaccinii</i>) prey regularly upon exotic fish

7 p.The long-fingered bat Myotis capaccinii is a European trawling bat reported to feed on fish in several Mediterranean locations, but the ecological circumstances of this behavior have not yet been studied. To elucidate the importance of fishing in this bat's diet, we evaluated the frequency and seasonal variation of fish remains in 3,000 fecal pellets collected from M. capaccinii at a nursery roost in Dénia (Eastern Iberian Peninsula) in 2008, 2009, and 2010. Fish consumption occurred evenly throughout the year. All otoliths found in feces were identified as belonging to the surface-feeding fish Gambusia holbrooki. Measuring otoliths, we estimated that the mean size of consumed fish was significantly smaller than the mean measured for available fish, suggesting that the long-fingered bat's relatively small body may constrain its handling of larger prey. Of note, one bat had eaten 15 fish, showing that fish may be a locally or seasonally important trophic resource for this species. By capturing 15 bats and radio-tracking the four with the most fish remains in their droppings, we also identified fishing areas, including a single fishing ground comprising several ponds within a golf course. Ponds hold a high density of G. holbrooki, suggesting that the amount of fish at the water surface may be the principal factor triggering fishing. The observed six-fold increase in percentage of consumed fish across the study period may be related to recent pond-building in the area. We discuss whether this quick behavioral response is a novel feature of M. capaccinii or an intrinsic feature that has erupted and faded locally along the species' history.This study was part of the MICINN project CGL2009-12393 coordinated by J. Aihartza, UPV/EHU. The Basque Government provided grant support to O. Aizpurua and A. Alberdi (BFI-2009-252 and BFI-2010-190). Support was also provided by the University of The Basque Country UPV/EHU (INF09/15) and the Basque Government (IT385-07 and IT301-10). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This study was performed with the permission of the Valencian Government

What mechanism of niche segregation allows the coexistence of sympatric sibling rhinolophid bats?

Introduction: Our purpose was to assess how pairs of sibling horseshoe bats coexists when their morphology and echolocation are almost identical. We collected data on echolocation, wing morphology, diet, and habitat use of sympatric Rhinolophus mehelyi and R. euryale. We compared our results with literature data collected in allopatry with similar protocols and at the same time of the year (breeding season). Results:Echolocation frequencies recorded in sympatry for R. mehelyi (mean = 106.8 kHz) and R. euryale (105.1 kHz) were similar to those reported in allopatry (R. mehelyi 105–111 kHz; R. euryale 101–109 kHz). Wing parameters were larger in R. mehelyi than R. euryale for both sympatric and allopatric conditions. Moths constitute the bulk of the diet of both species in sympatry and allopatry, with minor variation in the amounts of other prey. There were no inter-specific differences in the use of foraging habitats in allopatry in terms of structural complexity, however we found inter-specific differences between sympatric populations: R. mehelyi foraged in less complex habitats. The subtle inter-specific differences in echolocation frequency seems to be unlikely to facilitate dietary niche partitioning; overall divergences observed in diet may be explained as a consequence of differential prey availability among foraging habitats. Inter-specific differences in the use of foraging habitats in sympatry seems to be the main dimension for niche partitioning between R. mehelyi and R. euryale, probably due to letter differences in wing morphology. Conclusions: Coexistence between sympatric sibling horseshoe bats is likely allowed by a displacement in spatial niche dimension, presumably due to the wing morphology of each species, and shifts the niche domains that minimise competition. Effective measures for conservation of sibling/similar horseshoe bats should guarantee structural diversity of foraging habitats

Surveying for the rare Bechstein’s bat (&lt;em&gt;Myotis bechsteinii&lt;/em&gt;) in northern Iberian peninsula by means of an acoustic lure

&lt;Strong&gt;Abstract&lt;/strong&gt;&#13; In the Araba province (Basque Country, Iberian Peninsula) we surveyed for the rare Bechstein’s bat (&lt;em&gt;Myotis bechsteinii&lt;/em&gt;) using a recently developed method based on an acoustic lure, the Sussex AutoBat. We surveyed 16 deciduous woodlands, an irrigation pool and a cave, a total of 45 sites. The synthesized calls were played behind mist nets following an established protocol. In total, we captured 32 bats representing 6 genera and 10 species; among these, 6 &lt;em&gt;M. bechsteinii&lt;/em&gt;, 3 &lt;em&gt;M. daubentonii&lt;/em&gt;, 4 &lt;em&gt;Nyctalus leisleri&lt;/em&gt;, 5 &lt;em&gt;Plecotus auritus&lt;/em&gt;, 1 &lt;em&gt;P. austriacus&lt;/em&gt;, and 1 &lt;em&gt;Barbastella barbastellus&lt;/em&gt; were caught using the acoustic lure. Two of the Bechstein’s bats were lactating females. By radiotracking one of them, we found the third known breeding colony for this rare species in the Iberian Peninsula. The acoustic lure proved to be a promising method for improving the trapping success of this species.&#13; &#13; &lt;strong&gt;Riassunto&lt;/strong&gt;&#13; &lt;strong&gt;Indagine sul Vespertilio di Bechstein (&lt;em&gt;Myotis bechsteinii&lt;/em&gt;) in Spagna mediante emissioni sonore.&lt;/strong&gt;&#13; Il monitoraggio del Vespertilio di Bechstein (&lt;em&gt;Myotis bechsteinii&lt;/em&gt;), specie rara di chirottero nella provincia di Araba (Paesi Baschi, penisola iberica), è stato effettuato mediante l’utilizzo di emissioni ultrasonore per attrarre gli animali (Sussex AutoBat). Sono stati monitorati 45 siti, distribuiti in 16 differenti boschi a latifoglie, un bacino utilizzato per scopi irrigui e una grotta. In ciascun sito sono state utilizzate reti mist net di varia lunghezza e sono stati emessi richiami ultrasonori in prossimità delle reti stesse, secondo una procedura standardizzata. In totale, grazie all'utilizzo delle emissioni sonore sono stati caturati 32 pipistrelli appartenenti a 10 specie, tra cui 6 &lt;em&gt;M. bechsteinii&lt;/em&gt;, 3 &lt;em&gt;M. daubentonii&lt;/em&gt;, 4 &lt;em&gt;Nyctalus leisleri&lt;/em&gt;, 5 &lt;em&gt;Plecotus auritus&lt;/em&gt;, 1 &lt;em&gt;P. austriacus&lt;/em&gt;, e 1 &lt;em&gt;Barbastella barbastellus&lt;/em&gt;. Due esemplari di Vespertilio di Bechstein erano femmine in allattamento. L'applicazione di un radiocollare ad una di queste femmine ha consentito di identificare mediante radiotracking la terza colonia riproduttiva nota nella penisola iberica per questa specie. L’uso di “esche acustiche” si è dimostrato una tecnica particolarmente efficace, in particolare nel caso di specie rare o poco contattabili

Echolocation calls and morphology in the Mehelyi’s (&lt;em&gt;Rhinolophus mehelyi&lt;/em&gt;) and mediterranean (&lt;em&gt;R. euryale&lt;/em&gt;) horseshoe bats: implications for resource partitioning

&lt;strong&gt;Abstract&lt;/strong&gt;&#13; &lt;em&gt;Rhinolophus euryale&lt;/em&gt; and &lt;em&gt;R. mehelyi&lt;/em&gt; are morphologically very similar species and their distributions overlap extensively in the Mediterranean basin. We modelled their foraging behaviour using echolocation calls and wing morphology and, assuming niche segregation occurs between the two species, we explored how it is shaped by these factors. Resting frequency of echolocation calls was recorded and weight, forearm length, wing loading, aspect ratio and wing tip shape index were measured. &lt;em&gt;R. mehelyi&lt;/em&gt; showed a significantly higher resting frequency than &lt;em&gt;R. euryale&lt;/em&gt;, but differences are deemed insufficient for dietary niche segregation. Weight and forearm length were significantly larger in &lt;em&gt;R. mehelyi&lt;/em&gt;. The higher values of aspect ratio and wing loading and a lower value of wing tip shape index in &lt;em&gt;R. melehyi&lt;/em&gt; restrict its flight manoeuvrability and agility. Therefore, the flight ability of &lt;em&gt;R. mehelyi&lt;/em&gt; may decrease as habitat complexity increases. Thus, the principal mechanism for resource partitioning seems to be based on differing habitat use arising from differences in wing morphology.&#13; &#13; &lt;strong&gt;Riassunto&lt;/strong&gt;&#13; &lt;strong&gt;Ecolocalizzazione e morfologia nei rinolofi di Mehely (&lt;em&gt;Rhinolophus mehelyi&lt;/em&gt;) e euriale (&lt;em&gt;R. euryale&lt;/em&gt;): implicazioni nella segregazione delle risorse trofiche.&lt;/strong&gt; &lt;em&gt;Rhinolophus euryale&lt;/em&gt; e &lt;em&gt;R. mehelyi&lt;/em&gt; sono specie morfologicamente molto simili, la cui distribuzione risulta largamente coincidente in area mediterranea. Il comportamento di foraggiamento delle due specie è stato analizzato in funzione delle caratteristiche dei segnali di ecolocalizzazione e della morfologia alare, ed è stata valutata l’incidenza di questi fattori nell’ipotesi di una segregazione delle nicchie. È stata rilevata la frequenza a riposo dei segnali ultrasonori, così come il peso, la lunghezza dell’avambraccio, il carico alare, e due indici di forma dell'ala (&lt;em&gt;aspect ratio&lt;/em&gt; e &lt;em&gt;wing tip shape index&lt;/em&gt;). &lt;em&gt;R. mehelyi&lt;/em&gt; presenta una frequenza di riposo maggiore rispetto a &lt;em&gt;R. euryale&lt;/em&gt;, ma la differenza non sembra sufficiente per spiegare la separazione delle nicchie trofiche. Il peso e la lunghezza dell'avambraccio risultano significativamente più elevati in &lt;em&gt;R. mehelyi&lt;/em&gt;. I valori piú elevati relativamente ad &lt;em&gt;aspect ratio&lt;/em&gt; e &lt;em&gt;wing loading&lt;/em&gt; e il minor valore del &lt;em&gt;wing tip shape index&lt;/em&gt; in &lt;em&gt;R. melehyi&lt;/em&gt; indicano una minore manovrabilità in volo e una minore agilità. La capacità di &lt;em&gt;R. mehelyi&lt;/em&gt; di sfruttare efficacemente un ambiente complesso decresce con il livello di complessità dell'habitat stesso. È possibile quindi ipotizzare un meccanismo di separazione nell’uso delle risorse basato su un differente uso dell’habitat, spiegabile in termini di differenze nella morfologia alare

Data from: Assessing niche partitioning of co-occurring sibling bat species by DNA metabarcoding

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 R. 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 (Ojk = 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

Relationship between body length (cm) and body mass (g) of the eastern mosquitofish <i>Gambusia holbrooki</i>.

<p>Relationship between body length (cm) and body mass (g) of the eastern mosquitofish <i>Gambusia holbrooki</i>.</p

Sagittae otoliths of cyprinodontiform species in Dénia.

<p>(A) <i>Aphanius iberus</i>, (B) <i>Valencia hispanica</i>, (C) <i>Gambusia holbrooki</i>. (D–E) Sample of otoliths in <i>Myotis capaccinii</i> feces. All images are at the same scale.</p

Relationship between length of otoliths (µm) and body length (cm) of the eastern mosquitofish <i>Gambusia holbrooki</i>.

<p>Relationship between length of otoliths (µm) and body length (cm) of the eastern mosquitofish <i>Gambusia holbrooki</i>.</p

Bat individuals' data

Data about the traits of each bat individual