Female dietary bias towards large migratory moths in the European free-tailed bat ( Tadarida teniotis )

Abstract

In bats, sexual segregation has been described in relation to differential use of roosting and foraging habitats. It is possible that variation may also exist between genders in the use of different prey types. However, until recently this idea was difficult to test owing to poorly resolved taxonomy of dietary studies. Here, we use high-throughput sequencing to describe gender-related variation in diet composition of the European free-tailed bat (Tadarida teniotis), while controlling for effects of age and season. We analysed guano pellets collected from 143 individuals mist-netted from April to October 2012 and 2013, in northeast Portugal. Moths (Lepidoptera; mainly Noctuidae and Geometridae) were by far the most frequently recorded prey, occurring in nearly all samples and accounting for 96 out of 115 prey taxa. There were significant dietary differences between males and females, irrespective of age and season. Compared to males, females tended to consume larger moths and more moths of migratory behaviour (e.g. Autographa gamma). Our study provides the first example of gender-related dietary variation in bats, illustrating the value of novel molecular tools for revealing intraspecific variation in food resource use in bats and other insectivores.

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

“…Although an increase in sequencing depth generally improves the results gained (Smith & Peay, ), sequencing depth alone cannot counteract presequencing technical distortions such as PCR stochasticity and primer biases (Alberdi et al, ). In addition, increasing sequencing depth also increases the amount of artifactual sequences, thus the measures to get rid of artifactual sequences should be modified accordingly, by setting relative copy number thresholds (e.g., 0.01%) rather than removing just singletons (Mata et al, ). Ultimately, it can be hoped that such distortion will decrease as sequencing technologies improve with regard to overall cost (thus output that can be afforded), coupled with decreased error rates and increased maximum sequence length.…”

How much is enough? Effects of technical and biological replication on metabarcoding dietary analysis

“…Another problem is the imperfect correlation between the proportions of sequencing reads and biomass, making it hard to establish the contribution of each prey item to the overall diet (Deagle, Thomas, Shaffer, Trites, & Jarman, ; Elbrecht & Leese, ; Piñol, Mir, Gomez‐Polo, & Agustí, ). Because of this, metabarcoding studies generally quantify diet in terms of frequency of occurrence (e.g., Biffi et al., ; Kartzinel & Pringle, ; Mata et al., ), although this does not necessarily reflect the relative dietary intake of different prey items in terms of numbers, biomass or energy (e.g., Foster, Harmsen, & Doncaster, ; Greenstone et al., ; Sheppard et al., ).…”

“…In this study, we evaluate how variability among (a) individual bats, (b) faecal pellets of each bat and (c) PCRs of each pellet affect estimates of diet diversity and composition and on the frequency of occurrence of the prey items. Also, we tested the effects of analysing pools of samples vs. separate samples per individual, as these two variants are often used in dietary studies (e.g., pools : Burgar et al., ; Clare et al., 2014a, 2014b; Krauel, Brown, Westbrook, & McCracken, ; individuals : Hope et al., ; Mata et al., ; Vesterinen, Lilley, Laine, & Wahlberg, ). Our results were used to analyse the level of replication required to obtain accurate descriptions of predator diets using metabarcoding.…”

Does sex matter? Gender‐specific responses to forest fragmentation in Neotropical bats

“…However, gender‐specific differences in attributes such as aggressiveness toward conspecifics (Ancillotto & Russo ), prey composition (Mata et al . ), and selection of roosting and foraging areas (Downs et al . , Istvanko et al .…”