Teasing apart cryptic species groups: Nutritional ecology and its implications for species‐specific conservation of the Myotis mystacinus group

Abstract

The increasing loss of biodiversity and the need to delay the sixth mass extinction on earth resulted in several international conventions aiming at protecting threatened species. Protection improves with increasing knowledge of the biology and ecology of these species. However, species numbers rapidly increase with the ongoing description of cryptic species, resulting in a lack of ecological knowledge for each of these species. We studied the nutritional ecology of three cryptic bat species of the Myotis mystacinus group using stable isotope analysis and molecular fecal analysis. Inter-and intraspecific variations were compared by calculating the isotopic and dietary niches for each species. We hypothesized (a) that all three species are generalists, but (b) that M. mystacinus and Myotis brandtii are more similar to each other than to Myotis alcathoe. Third we assumed that the occupied niches are intraspecifically more similar than interspecifically. We could show that the members of the M. mystacinus group differ in their nutritional ecology. Our data suggest that M. alcathoe is the most specialized species of the group, occupying a more distinct ecological niche compared to the other two species. Interestingly, the dietary and isotopic niche overlap was higher interspecifically than intraspecifically. Furthermore, considering our findings and those from other studies we illustrate implications for the conservation of these cryptic species. K E Y W O R D S ecological niche, insectivorous bats, molecular diet analysis, δ 13 C, δ 15 N

Food for everyone: Differential feeding habits of cryptic bat species inferred from DNA metabarcoding

“…This seasonal constraint probably applies more generally to all insectivorous bats from temperate regions exploiting insects with strongly marked seasonal phenologies. Such seasonal niche partitioning can only be detected if the sampling regime covers most of the life cycle of these bats, whereas it could be overlooked with designs focusing on narrower time scales, as has been done in many comparative studies (Arrizabalaga‐Escudero et al, 2018 ; Roswag, Becker, Drangusch, et al, 2018 ).…”

“…However, such ecological indices consider each prey species as a simple resource type, and do not account for information derived from the ecology of the prey itself (Spitz et al, 2014 ). Some authors relied on informal considerations about major prey groups or singular prey species hunted by co‐occurring bats (Chang et al, 2019 ; Salinas‐Ramos et al, 2015 ; Vesterinen et al, 2018 ), while others used comparative tests to assess habitat preferences of pairs of predators based on prey species assigned to different ecological categories (Razgour et al, 2011 ; Roswag, Becker, Drangusch, et al, 2018 ; Vallejo et al, 2019 ). More sophisticated approaches aiming to relate characteristics of multiple consumers to habitat or functional traits of their prey with RLQ approaches (Quéméré et al, 2013 ; Spitz et al, 2014 ) offer a promising analytical development.…”

Urban tolerance is phylogenetically constrained and mediated by pre‐adaptations in African bats

“…We then determined whether these species were present in urban (including suburban or peri-urban) areas within their range (personal communication P. Webala, I. Tanshi and M.C. Schoeman;Andreani et al, 2019;Dekker et al, 2013;Fenton et al, 2002;Geldenhuys et al, 2013;Hoye & Spence, 2004;Jacobs & Barclay, 2009;Kurek et al, 2020;Lane et al, 2022;Legakis et al, 2000;O'Malley et al, 2020;Roswag et al, 2019;Schoeman, 2016;Schoeman & Waddington, 2011;Taylor et al, 1999;Wojtaszyn et al, 2013) and recorded this information as presence (1) or absence (0) in urban areas. We categorized roost specificity for each species as: utilizing 1 roost type = high, 2 roost types = medium, and ≥3 roost types = low.…”

Food for everyone: differential feeding habits of cryptic bat species inferred from DNA metabarcoding

“…We suggest this seasonal constraint probably applies more generally to all insectivorous bats from temperate regions with strongly marked seasonal insect phenologies. Such seasonal niche partitioning can only be detected if the sampling regime covers most of the life cycle of these bats, whereas it could be overlooked with designs focusing on narrower time scales, as has been done in many comparative studies (e.g., Arrizabalaga-Escuderoet al, 2018;Roswag et al, 2018b).…”