Flat-headed Bats Research Articles

Impact of external odor on self-grooming of lesser flat-headed bats, Tylonycteris pachypus.

Grooming is a common behavior of some mammals. Previous studies have shown that grooming is a means by which animals clean themselves, remove ectoparasites, and lower their body temperature. It is also involved in olfactory communication. Bats belong to the order Chiroptera and, like most mammals, are the natural host of many ectoparasites. Bat grooming, including licking and scratching, is one of the ways to reduce the adverse effects caused by ectoparasites. Bat grooming may also be induced by exogenous odor. In this study, we used lesser flat‐headed bats (Tylonycteris pachypus) to test the hypothesis that exogenous odor affects the self‐grooming behavior of bats. Results showed that external odor from distantly related species caused lesser flat‐headed bats to spend more time in self‐grooming. Lesser flat‐headed bats that received odor from humans spent the longest time in self‐grooming, followed by those that received odor from a different species of bats (T. robustula). Lesser flat‐headed bats that received odor form the same species of bats, either from the same or a different colony, spent the least amount of time in self‐grooming. These results suggest that bats can recognize conspecific and heterospecific through body scent.

Tylonycteris pachypus(Chiroptera: Vespertilionidae)

Tylonycteris pachypus (Temminck, 1840) is a small vespertilionid bat known as the lesser bamboo bat, club-footed bat, or the lesser flat-headed bat. The head of this species is dorsoventrally flattened, which is characteristic of this genus. Fleshy pads are present on the pollex and heel in members of this genus and are used in positioning the body inside the internodes of bamboo stalks. T. pachypus is intermediate in size between the larger T. robustula and the smaller T. pygmaeus. These species are sympatric throughout much of their ranges, which include South China, India, Bangladesh, Myanmar, Thailand, Laos, Cambodia, Vietnam, Malaysia, Indonesia, Borneo, and the Philippines.

Dispersal, mating events and fine-scale genetic structure in the lesser flat-headed bats.

Population genetic structure has important consequences in evolutionary processes and conservation genetics in animals. Fine-scale population genetic structure depends on the pattern of landscape, the permanent movement of individuals, and the dispersal of their genes during temporary mating events. The lesser flat-headed bat (Tylonycteris pachypus) is a nonmigratory Asian bat species that roosts in small groups within the internodes of bamboo stems and the habitats are fragmented. Our previous parentage analyses revealed considerable extra-group mating in this species. To assess the spatial limits and sex-biased nature of gene flow in the same population, we used 20 microsatellite loci and mtDNA sequencing of the ND2 gene to quantify genetic structure among 54 groups of adult flat-headed bats, at nine localities in South China. AMOVA and F ST estimates revealed significant genetic differentiation among localities. Alternatively, the pairwise F ST values among roosting groups appeared to be related to the incidence of associated extra-group breeding, suggesting the impact of mating events on fine-scale genetic structure. Global spatial autocorrelation analyses showed positive genetic correlation for up to 3 km, indicating the role of fragmented habitat and the specialized social organization as a barrier in the movement of individuals among bamboo forests. The male-biased dispersal pattern resulted in weaker spatial genetic structure between localities among males than among females, and fine-scale analyses supported that relatedness levels within internodes were higher among females than among males. Finally, only females were more related to their same sex roost mates than to individuals from neighbouring roosts, suggestive of natal philopatry in females.

Hierarchical polygyny in multiparous lesser flat-headed bats

How males gain access to mates and the potential for female choice will determine whether polygyny can operate at several levels, from within litters and groups to the wider population. Female lesser flat-headed bats (Tylonycteris pachypus) form maternity groups in bamboo stems. Unusually for bats, they are multiparous, providing the opportunity to test whether multi-level polygyny differs among males depending on whether they roost with females, with males or are solitary. We genotyped 662 individuals from 54 internodes and analysed parentage of 165 litters. Our results revealed 170 sets of paternal twins/triplets, of which 96 were full-sibs and 74 were half-sibs. We found that males captured roosting with females typically sired more offspring overall than did other males and also showed a greater tendency to monopolize paternity within both litters and roosting groups. In comparison, males that sired fewer full-sibs were assigned more maternal half-sibs. These latter individuals, which included solitary males and those from all-male groups, might gain copulations either via roaming with furtive mating or during visits by females. Indeed, female lesser flat-headed bats store sperm, so could benefit from multiple mating to reduce genetic incompatibilities. At the same time, however, we found no evidence of outbreeding. Finally, relatedness and mtDNA analyses revealed that polygyny also operated within matrilineal kin, suggesting a system that might promote social cohesiveness. Future studies of individual movements will help to determine the extent to which mixed paternities in litters, matrilines and groups are driven by male or female behaviour.

Variation in the abundance of ectoparasitic mites of flat-headed bats

Variation in the abundance of ectoparasitic mites of flat-headed bats

Variation in the abundance of ectoparasitic mites of flat-headed bats

We investigated the ectoparasitic mite loads (Macronyssus: Macronyssidae: Acarina) on 2 species of flat-headed bats, Tylonycteris pachypus and T. robustula (Mammalia: Chiroptera: Vespertilionidae) in 2 counties of Guangxi Province, southern China, from 2002 to 2005. In Longzhou County both species of bat occur sympatrically, but only T. pachypus occurs in Ningming County. Individuals of the smaller species (T. pachypus) harbored significantly more mites than did those of T. robustula. In both species males harbored more mites than nonreproductive females, pregnant females had more mites than lactating and nonreproductive females, and juveniles harbored more mites than adults. Mite load on both species of bats showed significant seasonal variation, declining from spring to winter. No correlation was found between mite load and size of the host colony. We discuss our findings in relation to the ecology and biology of both hosts and parasites.

Brains of Vespertilionids II. Vespertilioninae with special reference to Tylonycteris

As shown in Part I, the Vespertilioninae have on the average the lowest encephalization index (EI) of all the Vespertilionid subfamilies available, and the average size indices (Sis) of most of their brain parts are also lowest. There are, however, clear differences between the genera. The highest indices for the total brain and for many brain parts (OBL, DIE, TEL, PAL, SEP, STR, SCH) were found in Myotis, the highest Sis for NEG and MES in Scotophilus, for CER in Lasiurus, for BOL in Rhogeessa, and for HIP in Cbalinolobus. The lowest values for all brain parts except BOL were found in Tylonycteris (for BOL in Glauconycteris). The average EI of the flat-headed bamboo bats Tylonycteris pachypus and T. robustula was 60, i. e., 2/5 less than that of the non-Tylonycteris Vespertilionids, which, as the reference group, have an average EI of 100. The brain size reduction may well be related to the adaptation to extreme flat-headedness. The amount of reduction in the various brain parts differs: it is strongest (about 1/2) in higher but more dispensable brain parts (STR, HIP, NEO) and distinctly lower (about 1/4) in structures closely involved in the fundamental vegetative functions (OBL, MES). Genera with conservative skull characteristics may have derivative characteristics of the brains, and vice versa.

Development and characterization of 13 novel microsatellite loci from the flat-headed bat (Tylonycteris pachypus) with cross-species amplification in closely related taxa

13 novel microsatellite loci was isolated using the enriched library method from genomic DNA of the flat-headed bat (Tylonycteris pachypus). These loci showed high levels of genetic polymorphism testing on 54 individuals sampled from Guangxi province, China. The number of observed alleles per locus ranged from 2 to 15. The expected and observed heterozygosity values ranged from 0.170 to 0.900 and from 0.185 to 0.944, respectively. One loci departed significantly from Hardy-Weinberg equilibrium (HWE) after Bonferroni correction and no Linkage disequilibrium was found between any pairs of loci. In addition, these loci were tested in the sister species, Tylonycteris robustula, seven loci amplified successfully and were also polymorphic.

Rediscovery of the Mexican flat-headed bat Myotis planiceps (Vespertilionidae)

The insectivorous flat-headed bat Myotis planiceps (Vespertilionidae) is an endemic species apparently restricted to a very small area, known only from three specimens collected between 1952 and 1970 in Madrean pine-oak woodland in three adjacent states in north-central Mexico: Coahuila, Nuevo Leon, and Zacatecas (Matson, 1975). Myotis planiceps was once considered extinct by IUCN (Baillie and Groombridge, 1996), but more recently its status was changed to Critically Endangered (IUCN, 2004). The first objective of our study was to determine if we could find a living population or populations of this species. If extant populations were discovered, then further investigations were warranted, including detailed distribution, habitat requirements, dietary habits, and roosting behavior, to define the species’ current conservation status in accordance with standards proposed by IUCN (2004).

Development of vocalizations in the flat-headed bats, Tylonycteris pachypus and T. robustula (Chiroptera: Vespertilionidae)

The development of vocalizations during postnatal growth in the flat-headed bats, Tylonycteris pachypus and T. robustula in South China is described. Females of both species gave birth to twins at the end of May, and the infants flew in the last ten days of June. Vocalizations served as precursors to echolocation calls and as isolation calls (i-calls) used to attract mothers. As the infants grew, the frequency of i-calls and precursor calls increased. The duration of i-calls increased little before 6-day old and then decreased. At the same time, the duration of echolocation precursor calls decreased. The directive calls that the mother or the infant emitted when searching for each other are also described. Female directive calls are lower in frequency and longer in duration than their echolocation calls, and the duration of infant directive calls is longer than those of the i-calls and precursor calls.

Ecology, Reproductive Biology, and Systematics of Neoplatymops mattogrossensis (Chiroptera: Molossidae)

Neoplatymops mattogrossensis , the South American flat-headed bat, is a ground crevice-dwelling microhabitat specialist. Small holometabolous insects are the predominant prey that it consumed in the Caatingas of Northeast Brazil. Its external morphology results in aerodynamic attributes that are unlike those of many molossids and that are similar to those of vespertilionid bats. The species is sexually dimorphic for most morphometric characters, but the magnitude of the dimorphism is slight, probably moderated by the constraints of crevice dwelling. Significant geographic variability characterizes the species, but is neither consistent nor of sufficient magnitude to designate recognizable subspecies. Low gene flow and a mosaic genetic structure probably characterize the species.

A Second Brazilian Record of the South American Flat-Headed Bat, Neoplatymops mattogrossensis

A Second Brazilian Record of the South American Flat-Headed Bat, Neoplatymops mattogrossensis

Somatic chromosomes of the flat-headed bats (Tylonycteris spp)

Zwei sympatrische, nahverwandte Fledermausarten,Tylonycteris pachypus (Temminck) undT. robustula Thomas, besitzen 46 beziehungsweise 32 Chromosomen, was offenbar den Robertson'schen Translokationen zuzuschreiben ist.

The Ecology of Basilia hispida (Diptera:Nycteribiidae) in Malaysia

Basilia hispida Theodor, 1967 is the sole insectan ectoparasite of the flat-headed bats Tylonycteris pachypus (Temminck) and T. robustula Thomas (Microchiroptera, Vespertilionidae); these bats are confined to south and south-east Asia and both species are widely distributed and locally abundant in West Malaysia (Malaya). Basilia hispida has been recorded from a number of hosts other than Tylonycteris species (Theodor 1967) but it is likely that only Tylonycteris species, and possibly only T. pachypus, can be considered as true hosts. In order to understand the ecology of Basilia hispida it was necessary to study both its breeding biology and behaviour and the ecology of the hosts (see Marshall 1970; Medway & Marshall 1970 and unpublished). Our present knowledge of the life cycles of Nycteribiidae has been summarized by Marshall (1970). The outstanding feature of their biology is that the offspring are deposited as prepupae and thus the only stages found independently in the field are the inactive pupal instar and the wingless imago. Adult B. hispida become sexually mature within 5-6 days of their emergence from the puparium and thereafter the female deposits a single prepupa every 9 days. Copulation frequently occurs at the time of prepupal deposition and it is only at this time that these permanent ectoparasites leave their hosts. The prepupae are deposited at the top of the vertical wall of the bamboo internode in which the host is roosting and immediately pupate; the pupal instar lasts about 25 days, the presence of a host bat stimulating adults to emerge. Thus the total life cycle of B. hispida from the emergence of a female to the emergence of her first offspring takes about 39 (5 +9 + 25) days. Although pre-adult mortality could not be accurately ascertained it appears likely that the greater part of post-embryonic mortality occurs in the adult instar and is due to predation by the host.

LXVI.—A new flat-headed bat of the genus Platymops Thomas from S.E. Sudan

LXVI.—A new flat-headed bat of the genus <i>Platymops</i> Thomas from S.E. Sudan