Carlos Ayora Ibáñez

Screening of Active Lyssavirus Infection in Wild Bat Populations by Viral RNA Detection on Oropharyngeal Swabs

ABSTRACT Brain analysis cannot be used for the investigation of active lyssavirus infection in healthy bats because most bat species are protected by conservation directives. Consequently, serology remains the only tool for performing virological studies on natural bat populations; however, the presence of antibodies merely reflects past exposure to the virus and is not a valid marker of active infection. This work describes a new nested reverse transcription (RT)-PCR technique specifically designed for the detection of the European bat virus 1 on oropharyngeal swabs obtained from bats but also able to amplify RNA from the remaining rabies-related lyssaviruses in brain samples. The technique was successfully used for surveillance of a serotine bat (Eptesicus serotinus) colony involved in a case of human exposure, in which 15 out of 71 oropharyngeal swabs were positive. Lyssavirus infection was detected on 13 oropharyngeal swabs but in only 5 brains out of the 34 animals from which simultaneous brain and oropharyngeal samples had been taken. The lyssavirus involved could be rapidly identified by automatic sequencing of the RT-PCR products obtained from 14 brains and three bat oropharyngeal swabs. In conclusion, RT-PCR using oropharyngeal swabs will permit screening of wild bat populations for active lyssavirus infection, for research or epidemiological purposes, in line not only with conservation policies but also in a more efficient manner than classical detection techniques used on the brain.

Bat predation on nocturnally migrating birds

Bat predation on birds is a very rare phenomenon in nature. Most documented reports of bird-eating bats refer to tropical bats that occasionally capture resting birds. Millions of small birds concentrate and cross over the worlds temperate regions during migration, mainly at night, but no nocturnal predators are known to benefit from this enormous food resource. An analysis of 14,000 fecal pellets of the greater noctule bat (Nyctalus lasiopterus) reveals that this species captures and eats large numbers of migrating passerines, making it the only bat species so far known that regularly preys on birds. The echolocation characteristics and wing morphology of this species strongly suggest that it captures birds in flight.

Endemic Circulation of European Bat Lyssavirus Type 1 in Serotine Bats, Spain

To determine the presence of European bat lyssavirus type 1 in southern Spain, we studied 19 colonies of serotine bats (Eptesicus isabellinus), its main reservoir, during 1998–2003. Viral genome and antibodies were detected in healthy bats, which suggests subclinical infection. The different temporal patterns of circulation found in each colony indicate independent endemic circulation.

Mitochondrial DNA signatures at different spatial scales: from the effects of the Straits of Gibraltar to population structure in the meridional serotine bat ( Eptesicus isabellinus )

The meridional serotine bat Eptesicus isabellinus is found in North Africa and the Iberian Peninsula. We analyzed the genetic structure of E. isabellinus at two different geographic scales to reveal the historical and ecological patterns that have shaped its populations. The role of the Straits of Gibraltar as an isolating barrier between African and Iberian populations is evaluated and the degree of genetic structure and female-mediated gene flow was assessed at a local scale between neighboring colonies. Populations of E. isabellinus from Iberia and northern Morocco show little genetic divergence and share mtDNA haplotypes, indicating that the Straits of Gibraltar are neither an impediment to dispersal nor a cause of genetic differentiation. Our results also suggest that E. isabellinus may have dispersed from western Andalusia into northern Morocco after the last glacial period. At a smaller geographic scale, the colonies studied showed high variation in genetic variability and structure, indicating that no female-mediated gene flow is present. This pattern is consistent with a described pattern of independent endemic viral circulation of the bat rabies virus EBLV-1, which was found when studying rabies dynamics in the same serotine bat colonies.

Phylogeny of European Bat Lyssavirus 1 in Eptesicus isabellinus Bats, Spain

To better understand the epidemiology of European bat lyssavirus 1 (EBLV-1) in Europe, we phylogenetically characterized Lyssavirus from Eptesicus isabellinus bats in Spain. An independent cluster of EBLV-1 possibly resulted from geographic isolation and association with a different reservoir from other European strains. EBLV-1 phylogeny is complex and probably associated with host evolutionary history.

Taxonomy of little bent-winged bats (Miniopterus, Miniopteridae) from the African islands of São Tomé, Grand Comoro and Madagascar, based on mtDNA

ABSTRACT Due to a morphological uniformity typically shown by bent-winged bats, the taxonomic recognition of species and subspecies within the sole genus Miniopterus has been much questioned and revised. The situation and definition of the African species M. minor is particularly confused. This species is known from scattered and discontinuous records on both mainland coasts, Madagascar, São Tomé and Grand Comoro islands. The island forms have been included either within M. minor or considered as endemic species. To clarify their taxonomy, we compare mitochondrial DNA sequences of all the island forms with other related African Miniopterus. The genetic distances found in this study support a taxonomic recognition of the island forms at species level and the phylogenetic reconstructions based on these data suggest that the M. minor, as considered traditionally, is not a monophyletic group. The morphological similarities between the Miniopterus from São Tomé (West Africa) and Grand Comoro (East Africa) may reflect convergent evolution rather than a common ancestry.

Plasticity in the echolocation inventory of Mormopterus minutus (Chiroptera, Molossidae)

We recorded the echolocation behavior of the molossid bat Mormopterus minutus, a species that uses a plastic call inventory. During its foraging activity, M. minutus searches for insects emitting rather long and narrow-band echolocation calls. Search call design however, can vary noticeably even in a continuous foraging pass. While echolocating in different flying conditions M. minutus uses several other call designs such as short CF, QCF, FM/QCF, FM and multi-harmonic FM, with or without harmonic overlap, and QCF/FM. Call plasticity characterizes most echolocation sequences, particularly in bats flying in open spaces. Call variation was also influenced by the presence of conspecifics. In those sequences containing echolocation calls from more than one bat, signals from different individuals were reliably identified. In contrast to other small molossids, the call designs in the echolocation inventory of M. minutus show a high level of plasticity. Our results suggest that M. minutus has combined the advantages of emitting several call designs, as shown by molossids, with the advantages of manipulating one signal design as shown by vespertilionids within the same sonar inventory.

Phylogeography of Barbastelle bats (Barbastella barbastellus) in the western Mediterranean and the Canary Islands

We use two mitochondrial DNA fragments with different substitution rates (cytochrome b gene and the control region) to address the following phylogeographic questions about western Palaearctic populations of the barbastelle bat (Barbastella barbastellus): 1) Do the Iberian populations of barbastelles show any genetic discontinuity associated with its present fragmented distribution?, 2) Is the Gibraltar Strait an effective barrier to gene flow for barbastelles? and 3) Is the subspecies from the Canary Islands genetically distinct from continental barbastelles? Our molecular survey shows that there is only a shallow genetic structure among populations of the Iberian Peninsula and Morocco, and probably, even across Europe until Thrace, although this last point needs to be confirmed. The Gibraltar Strait has not played any significant role as a biogeographic barrier to prevent the recent passage of European barbastelles to Morocco (or vice versa). Our phylogenetic reconstructions also confirm the taxonomic distinction of B. barbastellus guanchae as an endemic subspecies confined to the Canary Islands. The precise origin of this Canarian taxon is, nevertheless, still unclear as its mitochondrial lineage is distinct from any lineage found so far in Morocco and Iberia. This important genetic distinctness suggests either a relatively ancient colonization of the Canary Islands or that the source population of the founders have not yet been identified.

Presence of Myotis alcathoe Helversen & Heller, 2001 (Chiroptera: Vespertilionidae) in the Iberian Peninsula

In a survey of bats from La Rioja (Spain), several specimens of the mystacinus group were captured at different mountain localities. Genetic and morphologic analyses have revealed the presence of two lineages within this group in La Rioja. The lineages have been identified as corresponding to two different species: Myotis mystacinus sensu stricto and the recently described M. alcathoe. Both species were found using the same nocturnal refugia (caves) and the same forest habitats. This study extends the distribution of M. alcathoe west and southwards and adds a new mammal species to the Iberian fauna.

Echolocation calls and a noteworthy record of Pteronotus gymnonotus (Chiroptera, Mormoopidae) from Tabasco, Mexico

Echolocation calls of the big naked-backed bat, Pteronotus gymnonotus, are poorly known. At present, only the predominant frequencies have been described from calls emitted by indoor or hand held specimens (Griffin and Novick, 1955; Grinnell, 1970; Simmons, 1973) and a single sonogram (Pye, 1980). We present the first description of echolocation characteristics of P gymnonotus, recorded from a freeflying specimen from Tabasco, Mexico. Distributional implications of this record also are discussed.