The use of genetic data to separate species of bats has really gained momentum in the late 1990. In Europe, the first case of genetic data were used to demonstrate the presence of cryptic species is that of pipistrelle bats (Pipistrellus pipistrellus and P. pygmaeus). Since, over 10 new cryptic species were discovered and described through the genetic data (Pine & Veith 2001; Mayer & Von Helversen 2001; von Helversen et al. 2001; Pine et al. 2002; Ibañez et al. 2006; Mayer et al. 2007). This tendency was particularly true for bats on islands like Sardinia (Mucedda et al. 2002), the Azores (Willow et al. 2004; Willow et al. 2007) and Corsica (Castella et al. 2000), but has also been shown in recent years on the continent (Ibañez et al. 2006; Mayer et al. 2007).
Two recent genetic studies have shown that a significant number of species of bats in Europe accounted for probably another two species 'cryptic' or more(Ibañez et al. 2006; Mayer et al. 2007). The case of Myotis nattereri is a good example of the usefulness of genetic data. In their study, Ibañez et al. (2006) showed that this species was divided into three groups genetically very distinct separated there are several million years. These groups represent potential species but the analysis of a larger number of samples from different sources is necessary before concluding. Otherwise, the study of Mayer et al. (2007) shows two Myotis sp. (identified as Myotis nattereri according to morphological criteria) from Austria and northern Italy who are genetically very divergent M. nattereri Central Europe. These individuals represent a potentially new cryptic species within the 'complex' M. nattereri. Clearly, this species deserves special attention. Other species such as Eptesicus serotinus, Plecotus auritus, Pipistrellus kuhlii or Hypsugo savii are also suspected of harboring cryptic species (Mayer & Von Helversen 2001; Ibañez et al. 2006). These cryptic species are however sometimes impossible to identify because of the morphological characters on the ground (Dietz & Von Helversen 2004). That's why these species are so far gone unnoticed or use of genetic data to discover possible. In this case, the use of genetic assign individuals to one species is very direct and effective (Clare et al. 2007; Mayer et al. 2007).
If the studies cited above do not mention the presence of cryptic species for some species, this does not mean they do not exist. As all species have not been a comprehensive geographic sampling, it is impossible to deny the presence of new cryptic species, even among the most common species. A effet, result of acoustic analysis of pipistrelle bats in the south of France, it is not impossible that behind the names Pipistrellus pipistrellus or Pipistrellus pygmaeus, still lurks an undescribed species. In France, new species described since the late 1990 are four in number, Pipistrellus pygmaeus, Plecotus macrobullaris, Myotis alcathoe and Myotis escalerai. Field, these species are not always easy to differentiate from their species 'sister', morphologically very similar. Harvesting joint morphological data, Genetic and echolocation is an essential step towards a better understanding and recognition of the species present on our territory. While recognition of two species among pipistrelles communes (Pipistrellus pipistrellus and Pipistrellus pygmaeus) dates back over 10 years, discrimination morphological of both species is not always obvious, see sometimes even difficult. Numerous criteria morphological allowing discrimination between two species were deferred ('Y' alar, ratio of phalanges, hump between the nostrils, etc.) but it seems that none of them does either reliable to 100% in the whole of the range of both species (obs. pers.). It is therefore very important to watch and record the maximum of morphological characters to increase the reliability of the identification. Otherwise, it is essential to place the species in a regional context rather than rely on morphological criteria from other regions or countries (sometimes unreliable). This emphasizes the need to make the results of morphological studies available regional, either through publications, either through websites.
In France, species that may pose problems of identification are as follows:
1- Myotis mystacinus/M. alcathoe (secondarily, M. brandtii). Some dental criteria reported in the literature do not prove reliable 100% (And. Le Bris & A. The Houédec, with. pers., obs. pers.). We will try to write an article suitable for this problem soon.
2- Pipistrellus pipistrellus/P. pygmaeus. Several morphological criteria discriminating the two species have been proposed but very few data are available on their reliability and validity in different regions. An article summarizing these criteria and their validity / reliability would be welcome.
3- Myotis nattereri/M. escalerai. To date, knowledge about M. escalerai remain scant, and apart from the fact that it is a priori a species exclusively cave during the breeding, there is no publication describing the morphological differences between the two species (Ibanez et al. merely mention that M. escalerai differs from M. nattereri by its distinct hairs on the fringe of the tail membrane [… these bats can be distinguished by distinct fringing hairs in the tail membrane], data not used in the absence of more detailed). It remains to verify the description of Cabrera 1904 in which certain criteria could be given (This does not seem the case that Ibanez et al. not mention anything). Research this topic and a review of the data currently available to us would be very useful for correctly identifying individuals in the field without having to go through genetic analysis, present only way to discriminate the two species reliably.
If you are interested to write an article about cryptic species listed below, feel free to get started. If you think of other species present problems of identification, see these problems so we can discuss.
Castella, In., Ruedi, M., Excoffier, The., Ibañez, C., Arlettaz, R. & Increase, J. 2000. Is the Gibraltar Strait a barrier to gene flow for the bat Myotis myotis (Chiroptera: Vespertilionidae)? Molecular Ecology 9: 1761-1772.
Clare, E.L., Lim, B.K., Engstrom, M.D., Eger, J.L.. and Hebert, P.D.N. (2007). DNA barcoding of Neotropical bats: species identification and discovery within Guyana. Molecular Ecology Notes 7: 184-190.
Dietz, C. From Helversen and, The. (2004). Illustrated identification key to the bats of Europe.
Ibañez, C., Garcia-Mudarra, J.L., Ruedi, M., Stadelmann, B. and Juste, J. (2006). The Iberian contribution to cryptic diversity in European bats. Acta Chiropterologica 8(2): 277-297.
Pine, A., Mayer, F., Kosuch, J., Helversen, O.v. and Veith, M. (2002). Conflicting molecular phylogenies of Eurpean long-eared bats (Plecotus) can be explained by criptic divesity. Molecular Phylogenetics and Evolution 25: 557-566.
Pine, A. and Veith, M. (2001). A new species of long-eared bat from Europe (Chiroptera: Verspertilionidae). Myotis 39: 5-16.
Mayer, F., Dietz, C. and Kiefer, A. (2007). Molecular species identification boosts bat diversity. Frontiers in Zoology 4: 4.
Mayer, F. From Helversen and, The. (2001). Cryptic diversity in European bats. Proceedings of the Royal Society of London, B 268: 1825-1832.
Mucedda, M., Pine, A., Pidinchedda, It. and Veith, M. (2002). A new species of long-eared bat (Chiroptera, Vespertilionidae) from Sardinia (Italy). Acta Chiropterologica 4(2): 121-135.
Willow, P., Rabbit, M.M., Palmerin, J.M. and Ruedi, M. (2004). Mitochondrial DNA variation and population structure of the island endemic Azorean bat (Nyctalus azoreum). Molecular Ecology 13: 3357-3366.
Willow, P., Ruedi, M., Rabbit, M.M. and Palmeirim, J.M. (2007). Genetic divergence and phylogeography in the genus Nyctalus (Mammalia, Chiroptera): implications for population history of the insular bat Nyctalus azoreum. Genetics 130(2): 169-181.
von Helversen, O., Heller, K.-G., Mayer, F., Nemeth, A., Volleth, M. and Gombkötö, P. (2001). Cryptic mammalian species: a new species of whiskered bat (Myotis alcathoe n. sp.) in Europe. Natural sciences 88: 217-223.