Bat Attacks Research Articles

Tiger beetles produce anti-bat ultrasound and are probable Batesian moth mimics.

Echolocating bats and their eared insect prey are in an acoustic evolutionary war. Moths produce anti-bat sounds that startle bat predators, signal noxiousness, mimic unpalatable models and jam bat sonar. Tiger beetles (Cicindelidae) also purportedly produce ultrasound in response to bat attacks. Here we tested 19 tiger beetle species from seven genera and showed that they produce anti-bat signals to playback of authentic bat echolocation. The dominant frequency of beetle sounds substantially overlaps the sonar calls of sympatric bats. As tiger beetles are known to produce defensive chemicals such as benzaldehyde and hydrogen cyanide, we hypothesized that tiger beetle sounds are acoustically advertising their unpalatability. We presented captive big brown bats (Eptesicus fuscus) with seven different tiger beetle species and found that 90 out of 94 beetles were completely consumed, indicating that these tiger beetle species are not aposematically signalling. Instead, we show that the primary temporal and spectral characteristics of beetle warning sounds overlap with sympatric unpalatable tiger moth (Arctinae) sounds and that tiger beetles are probably Batesian mimics of noxious moth models. We predict that many insect taxa produce anti-bat sounds and that the acoustic mimicry rings of the night sky are hyperdiverse.

Resting posture drives the evolution of agonistic displays in bats.

Agonistic displays are one of the most diverse social behaviors that have important functions in animal's life history. However, their origin and driving factors have largely been unexplored. Here, we evaluated agonistic displays of 71 bat species across 10 families and classified these displays into two categories: (a) boxing displays where a bat attacks its opponent with its wrist and thumb and (b) pushing displays where a bat uses its head or body to hit a rival. We estimated the strength of the phylogenetic signal of the agonistic displays, revealed their origin, and tested the potential evolutionary relationships between agonistic behaviors and body size or resting posture (free hanging vs. contact hanging where the bat is in contact with some surface). We found that agonistic displays were phylogenetically conserved and that boxing displays are the ancestral state. Moreover, we found that bats with a free-hanging resting posture were more likely to exhibit boxing displays than pushing displays. In addition, bats with longer forearms do not have a higher propensity for boxing displays. This study expands our limited knowledge of the evolution of agonistic displays and highlights the importance of resting posture as a driving force in the diversity of agonistic displays.

Testing bird-driven diurnal trade-offs of the moon moth's anti-bat tail.

Traits are often caught in a dynamic tension of countervailing evolutionary pressures. Trade-offs can be imposed by predators evolutionarily curtailing the conspicuousness of a sexually selected trait, or acting in opposition to another natural selection pressure, for instance, a different predator with a divergent hunting strategy. Some moon moths (Saturniidae) have long hindwing tails that thwart echolocating bat attacks at night, allowing the moth to escape. These long tails may come at a cost, however, if they make the moth's roosting form more conspicuous to visually foraging predators during the day. To test this potential trade-off, we offered wild-caught Carolina wrens (Thryothorus ludovicianus) pastry dough models with real Actias luna wings that were either intact or had tails experimentally removed. We video recorded wrens foraging on models and found that moth models with tails did not experience increased detection and attack by birds. Thus, this elaborate trait, while obvious to human observers, does not seem to come at a cost of increased avian predator attention. The evolution of long hindwing tails, likely driven by echolocating predators at night, does not seem to be limited by opposing diurnal constraints. This study demonstrates the importance of testing presumed trade-offs and provides hypotheses for future testing.

High duty cycle moth sounds jam bat echolocation: bats counter with compensatory changes in buzz duration.

Tiger moth species vary greatly in the number of clicks they produce and the resultant duty cycle. Signals with higher duty cycles are expected to more effectively interfere with bat sonar. However, little is known about the minimum duty cycle of tiger moth signals for sonar jamming. Is there a threshold that allows us to classify moths as acoustically aposematic versus sonar jammers based on their duty cycles? We performed playback experiments with three wild-caught adult male bats, Eptesicus fuscus. Bat attacks on tethered moths were challenged using acoustic signals of Bertholdia trigona with modified duty cycles ranging from 0 to 46%. We did not find evidence for a duty cycle threshold; rather, the ability to jam the bat's sonar was a continuous function of duty cycle consistent with a steady increase in the number of clicks arriving during a critical signal processing time window just prior to the arrival of an echo. The proportion of successful captures significantly decreased as the moth duty cycle increased. Our findings suggest that moths cannot be unambiguously classified as acoustically aposematic or sonar jammers based solely on duty cycle. Bats appear to compensate for sonar jamming by lengthening the duration of their terminal buzz and they are more successful in capturing moths when they do so. In contrast to previous findings for bats performing difficult spatial tasks, the number of sonar sound groups decreased in response to high duty cycles and did not affect capture success.

Common vampire bat (Desmodus rotundus) abundance and frequency of attacks to cattle in landscapes of Yucatan, Mexico.

Desmodus rotundus is one of the wild animal species that has benefitted by habitat alteration and its population has increased due to livestock activities. Common vampire bat population management has been implemented across Mexico due to the economic losses to livestock production, inflicted by vampire bat attacks and rabies transmission. Yucatan is one of the seven most impacted states in Mexico by the number of cattle rabies cases per year. However, there is little research on D. rotundus populations such as the frequency and attack patterns to cattle. This study's objective was to analyze the relationship between D. rotundus abundance and number of bovines attacked in livestock landscapes in Yucatan. The study used data gathered by the State Committee for Protection and Promotion of Livestock in Yucatan through the National Campaign for Common Vampire Bat Population Control. Data collected from January 2014 to December 2017 was analyzed using Pearson correlation. Distribution maps on Desmodus rotundusabundance and number of bovines attacked were also created. Higher abundance of Desmodus rotundus and number of cattle attacks were observed in the central region of Yucatan, particularly in Izamal municipality. Positive correlations were found between (1) abundance of Desmodus rotundusand number of cattle in the region, (2) total number of cattle and number of cattle attacked, and (3) abundance ofDesmodus rotundusand number of cattle attacked. We can conclude that there is a relationship betweenDesmodus rotundusabundance and frequency of cattle attacks in most municipalities across Yucatan. Some outstanding exceptions were observed, which require further detailed investigations.

Turning the rationale of cattle rabies surveillance and control in Latin America: from rabies case to vampire bat aggression-based program

In Brazil and in most of the Latin America countries, the control of the cattle rabies relies upon the indiscriminate culling of the Desmodus rotundus inside a radius of 12 km around an outbreak. The culling is performed by applying warfarin paste in the back of the bats, in the hope that when it returns to its roost after foraging, its conspecifics would ingest the paste during social grooming and die of hemorrhage. This control approach is performed in absentia with the surveillance effort, since if bats die indiscriminately, the effects in the social structure of the colonies are unknown. It is believed that the indiscriminate culling helps the rabies virus spread among bats and consequently, the spillover to livestock. For this reason, any sampling effort in bats and even the identification of cattle rabies outbreaks transmitted by bats is useless to predict future outbreaks or even mitigate current outbreaks. Even though the tendency of the cattle rabies outbreaks is decreasing in Brazil, this should be carefully considered, since rabies surveillance efforts are heterogeneous and decreasing. Even so, the nationwide space-time cattle rabies outbreak shows a wave pattern, increasing the urge of the revision of the current surveillance and control actions. The present work proposes a new approach aiming at decreasing the spillover to livestock by incorporating ecological features of the D. rotundus, most importantly turning the surveillance-control rationale which is currently reactive to livestock rabies cases to a surveillance system reactive to changes in the incidence of vampire bat attacks on the livestock and selective bat population control. For example, estimating the roosts' carrying capacity and contact networks allows the interruption of rabies virus spread by reducing the bat population of target individuals in selected roosts or roost communities. Moreover, the terrain slope dependency of the bat foraging behavior allows to find more efficiently the roost from which bats are attacking a farm or conversely, to find attacked farms if an occupied bat roost is known. These practices could increase the efficiency of the surveillance and control and the cost-effectiveness of the current cattle rabies control program.

Wingtip folds and ripples on saturniid moths create decoy echoes against bat biosonar

Sensory coevolution has equipped certain moth species with passive acoustic defenses to counter predation by echolocating bats.1,2 Some large silkmoths (Saturniidae) possess curved and twisted biosonar decoys at the tip of elongated hindwing tails.3,4 These are thought to create strong echoes that deflect biosonar-guided bat attacks away from the moth's body to less essential parts of their anatomy. We found that closely related silkmoths lacking such hindwing decoys instead often possess intriguing ripples and folds on the conspicuously lobed tips of their forewings. The striking analogy of twisted shapes displayed far from the body suggests these forewing structures might function as alternative acoustic decoys. Here we reveal that acoustic reflectivity and hence detectability of such wingtips is higher than that of the body at ultrasonic frequencies used by hunting bats. Wingtip reflectivity is higher the more elaborate the structure and the further from the body. Importantly, wingtip reflectivity is often considerably higher than in a well-studied functional hindwing decoy. Such increased reflectivity would misdirect the bat's sonar-guided attack toward the wingtip, resulting in similar fitness benefits to hindwing acoustic decoys. Structurally, folded wingtips present echo-generating surfaces to many directions, and folds and ripples can act as retroreflectors that together create conspicuous targets. Phylogenetically, folds and ripples at wingtips have evolved multiple times independently within silkmoths and always as alternatives to hindwing decoys. We conclude that they function as acoustic wingtip decoys against bat biosonar. VIDEO ABSTRACT.

Assessment of crab fishermen's exposure to rabies virus in a typical Amazonian community.

Outbreaks of human rabies transmitted by hematophagous bats occurred in 2018 in Pará state, Brazil, eastern Amazon, after 12years of no record of the disease. Thus, it is necessary to understand the epidemiological characteristics of these attacks to protect the local population. This study aimed to characterize the bat bite populations in the municipality of São João da Ponta, Pará State, Brazil, in 2013-2015. The Notifiable Diseases Information System (SINAN) database was used to identify the five individuals who sought medical care during the study period (seeds). Other individuals who were attacked during the same period but did not seek medical care (n=61) were reached by snowball sampling, and a descriptive analysis was performed based on information obtained from questionnaires. Majority of the interviewees were men (92.4%; 61/66) and adults aged 20-50years (69.9%; 46/66) and had <4years of formal school education (86.3%; 57/66). Additionally, most of them were rural residents (92.4%; 61/66) and crab fishermen (79.3%; 53/66). The interviewees (92.4%; 61/66) identified mangroves of the Mãe Grande de Curuçá extractive reserve, where groups of fishermen sometimes gather for several days for crab fishing, often living in improvised dwellings without walls and covered by tarps or straw (88.8%; 56/66), conducive to attacks by vampire bats. Overall, 42.4% (28/66) of the participants had been bitten more than four times throughout their life. The median number of attacks over the participant's lifetime was 3.11 (range, 1-23). Participants were unaware of the risk of contracting rabies from the bite (95.4%; 65/66). These results suggest that vampire bat attacks are essentially an occupational hazard in the study region. Moreover, for each reported attack, there were at least 12.2 unreported cases. Thus, the study highlights the need to develop strategies for prophylactic treatment of this population.

Landscape and cattle management attributes associated with the incidence of Desmodus rotundus attacks on cattle

Bovine paralytic rabies, transmitted by Desmodus rotundus, causes economic losses for Latin American livestock producers. Although the total number of reported cases has decreased markedly due to vaccination campaigns, economic losses can be significant for smallholders. Identifying risk factors for vampire bat attacks on cattle could help guide preventive control efforts in specific areas. The objective of this study was to analyze the relationship between the incidence of D. rotundus attacks on cattle and various landscape features and cattle management practices in northeastern Puebla, Mexico. We visited 61 properties with cattle between May and October 2011, in which we quantified the incidence of attacks on cattle and described landscape and cattle management attributes. The following features were described within a 200-m radius around the nightly resting site of cattle: topography, percent forest cover, and number of forest fragments, rivers and streams, tree lines, buildings, roads and highways. With these variables, we built models that were assumed to describe the levels of human interference, prey availability, and movement facilitation for bats. The human interference model (number of buildings plus number of roads) best explained the incidence of attacks on cattle. According to our results, the cattle with the highest vulnerability to attacks by vampire bats are those resting at night in less confined sites, far away from human activity. Results of this study suggest that rabies vaccination campaigns on cattle should focus on fragmented areas with few livestock management practices.

Wild pig (Sus scrofa) as prey of the Common Vampire Bat (Desmodus rotundus)

The common vampire bat (Desmodus rotundus), is the hematophagous bat with the broadest distribution and the only one that preys on wild mammals. However, when the abundance of domestic species increases, D. rotundus tends to feed on horses, domestic pigs, and poultry. The presence of Wild pigs in Laguna de Terminos, Campeche, represents an increase in prey availability, a factor that fosters the growth of bat populations in the region. Records were obtained with camera traps in the area of influence of the Laguna de Terminos Flora and Fauna Protection Area, Campeche. Camera traps were placed on trees at the edge of trails for the recording of Wild pigs (Sus scrofa) and collared peccaries (Pecari tajacu). The photo trapping period ranged from January 25 to August 16, 2018 with a sampling effort of 1,428 trap days. We recorded 18 species of mammals in the five locations studied. Predation of the common vampire bat on Wild pigs was recorded in a single camera trap located in an oil palm plantation (Elaeis guineensis) surrounded by livestock areas and secondary forest fragments. Wild pigs were the only species recorded as being attacked by the common vampire bat. Of all separate records of Wild pigs, 11.7 % (n = 22) corresponded to photographs and videos of interactions between Wild pigs and bats. Vampire bat attacks were recorded between 20:00 and 5:00 h, with a peak of activity around 23:21 h. The increased availability of Wild pigs, together with changes in land use, seemingly foster the growth and expansion of vampire bat populations and, therefore, contribute to a higher incidence of attacks on domestic species. In addition to the negative ecological effects, the presence of Wild pigs involves increasingly important epidemiological implications. Studies on the interaction between common vampire bats and Wild pigs are necessary to assess the risk of disease transmission in the region.

Deaf moths employ acoustic M\xfcllerian mimicry against bats using wingbeat-powered tymbals

Emitting ultrasound upon hearing an attacking bat is an effective defence strategy used by several moth taxa. Here we reveal how Yponomeuta moths acquire sophisticated acoustic protection despite being deaf themselves and hence unable to respond to bat attacks. Instead, flying Yponomeuta produce bursts of ultrasonic clicks perpetually; a striated patch in their hind wing clicks as the beating wing rotates and bends. This wing structure is strikingly similar to the thorax tymbals with which arctiine moths produce their anti-bat sounds. And indeed, Yponomeuta sounds closely mimic such arctiine signals, revealing convergence in form and function. Because both moth taxa contain noxious compounds, we conclude they are mutual Müllerian acoustic mimics. Yponomeuta’s perpetual clicking would however also attract bat predators. In response, their click amplitude is reduced and affords acoustic protection just as far as required, matching the distance over which bat biosonar would pick up Yponomeuta echoes anyway – advanced acoustic defences for a deaf moth.

Risk Factors Associated with Attacks of Hematophagous Bats (Desmodus rotundus) on Cattle in Ecuador.

In recent years, there has been an increasing risk of hematophagous bat attacks in Latin America, where livestock production is a basic source of food for local populations. In Ecuador, livestock represented an important part of agricultural output. Some cases of cattle bitten by bats in the province of Santa Elena have been reported; however, no previous studies have been conducted to determine the magnitude of the attacks and the associated risk factors. In this research, a cross-sectional descriptive study was performed recording attacks of hematophagous bats (Desmodus rotundus) through visual inspection of livestock and the capture of specimens by mist nets. Generally, the prevalence of D. rotundus attacks on farms was 69%, whereas attacks on bovine had 24% of prevalence. From the captured specimens, 93% were identified as D. rotundus and within the 30% of the captured D. rotundus, no infections for rabies virus were diagnosed. The univariable analysis used for estimating the risk factors associated with bat attacks showed that corrals away from populated centers present the highest risk (odds ratio [OR] = 19.864; p = 0.0004), followed by tree density >30 per hectare (OR = 16.313; p < 0.0001) and predatory birds of bats (OR = 15.375; p < 0.0001); a binary logistic regression model showed "corrals away from populated centers" (OR = 23.47; p = 0.006) as the main risk factor. Linear regression analysis showed good correlation between the number of bovines attacked and the number of bites (R2 = 0.977; p < 0.0001) suggesting some feeding patterns of D. rotundus. This study could be used as a starting point for understanding the feeding habits of D. rotundus and factors governing their attacks in coastal regions of Ecuador, and potential occurrences of rabies infections. With this knowledge, surveillance and control programs can be supported to improve rabies transmission monitoring.

Can the elongated hindwing tails of fluttering moths serve as false sonar targets to divert bat attacks?

It has long been postulated that the elongated hindwing tails of many saturniid moths have evolved to create false sonar targets to divert the attack of echolocation-guided bat predators. However, rigorous echo-acoustic evidence to support this hypothesis has been lacking. In this study, fluttering luna moths (Actias luna), a species with elongated hindwing tails, were ensonified with frequency modulated chirp signals from all angles of orientation and across the wingbeat cycle. High-speed stereo videography was combined with pulse compression sonar processing to characterize the echo information available to foraging bats. Contrary to previous suggestions, the results show that the tail echoes are weak and do not dominate the sonar returns, compared to the large, planar wings and the moth body. However, the distinctive twisted morphology of the tails create persistent echoes across all angles of orientation, which may induce erroneous sonar target localization and disrupt accurate tracking by echolocating bats. These findings thus suggest a refinement of the false target hypothesis to emphasize sonar localization errors induced by the twisted tails, and highlight the importance of physics-based approaches to study the sensory information involved in the evolutionary arms race between moths and their bat predators.

Acoustic Aposematism and Evasive Action in Select Chemically Defended Arctiine (Lepidoptera: Erebidae) Species: Nonchalant or Not?

Tiger moths (Erebidae: Arctiinae) have experienced intense selective pressure from echolocating, insectivorous bats for over 65 million years. One outcome has been the evolution of acoustic signals that advertise the presence of toxins sequestered from the moths’ larval host plants, i.e. acoustic aposematism. Little is known about the effectiveness of tiger moth anti-bat sounds in their natural environments. We used multiple infrared cameras to reconstruct bat-moth interactions in three-dimensional (3-D) space to examine how functional sound-producing organs called tymbals affect predation of two chemically defended tiger moth species: Pygarctia roseicapitis (Arctiini) and Cisthene martini (Lithosiini). P. roseicapitis and C. martini with intact tymbals were 1.8 and 1.6 times less likely to be captured by bats relative to those rendered silent. 3-D flight path and acoustic analyses indicated that bats actively avoided capturing sound-producing moths. Clicking behavior differed between the two tiger moth species, with P. roseicapitis responding in an earlier phase of bat attack. Evasive flight behavior in response to bat attacks was markedly different between the two tiger moth species. P. roseicapitis frequently paired evasive dives with aposematic sound production. C. martini were considerably more nonchalant and employed evasion in fewer interactions. Our results show that acoustic aposematism is effective at deterring bat predation in a natural context and that this strategy is likely to be the ancestral function of tymbal organs within the Arctiinae.

Spatial and Temporal Analysis of Attacks by Common Vampire Bats (Desmodus rotundus) on Humans in the Rural Brazilian Amazon Basin

This article attempts to investigate the effects of the notification of wounds caused by Desmodus rotundus in humans in the rural zone of the eastern Brazilian Amazon basin. We analyzed data on bat attacks for the period between 2007 and 2012, provided by the Para State Secretariat for Municipal Public Health (SMS) and the Para State Agricultural Defense Agency (ADEPARA). We recorded 121 attacks in humans in the municipality of Pacaja, in 28 localities, including both rural and urban areas. Urban cases accounted for almost a fifth (19.8%) of all records. No significant variation was found in the number of cases recorded each year (H = 7.28, d.f. = 5, P = 0.20), although significant variation was found in the spatial distribution of the reports (Q = 17.08, d.f. = 5, P < 0.01), reflecting the heterogeneity of the occurrence of attacks. Our conclusion is that the major reduction in the number of reported attacks on humans by hematophagous bats in the municipality of Pacaja is a positive result of the notific...

Multimodal cues improve prey localization under complex environmental conditions.

Predators often eavesdrop on sexual displays of their prey. These displays can provide multimodal cues that aid predators, but the benefits in attending to them should depend on the environmental sensory conditions under which they forage. We assessed whether bats hunting for frogs use multimodal cues to locate their prey and whether their use varies with ambient conditions. We used a robotic set-up mimicking the sexual display of a male túngara frog (Physalaemus pustulosus) to test prey assessment by fringe-lipped bats (Trachops cirrhosus). These predatory bats primarily use sound of the frog's call to find their prey, but the bats also use echolocation cues returning from the frog's dynamically moving vocal sac. In the first experiment, we show that multimodal cues affect attack behaviour: bats made narrower flank attack angles on multimodal trials compared with unimodal trials during which they could only rely on the sound of the frog. In the second experiment, we explored the bat's use of prey cues in an acoustically more complex environment. Túngara frogs often form mixed-species choruses with other frogs, including the hourglass frog (Dendropsophus ebraccatus). Using a multi-speaker set-up, we tested bat approaches and attacks on the robofrog under three different levels of acoustic complexity: no calling D. ebraccatus males, two calling D. ebraccatus males and five D. ebraccatus males. We found that bats are more directional in their approach to the robofrog when more D. ebraccatus males were calling. Thus, bats seemed to benefit more from multimodal cues when confronted with increased levels of acoustic complexity in their foraging environments. Our data have important consequences for our understanding of the evolution of multimodal sexual displays as they reveal how environmental conditions can alter the natural selection pressures acting on them.

Moth tails divert bat attack: Evolution of acoustic deflection

Adaptations to divert the attacks of visually guided predators have evolved repeatedly in animals. Using high-speed infrared videography, we show that luna moths (Actias luna) generate an acoustic diversion with spinning hindwing tails to deflect echolocating bat attacks away from their body and toward these nonessential appendages. We pit luna moths against big brown bats (Eptesicus fuscus) and demonstrate a survival advantage of ∼ 47% for moths with tails versus those that had their tails removed. The benefit of hindwing tails is equivalent to the advantage conferred to moths by bat-detecting ears. Moth tails lured bat attacks to these wing regions during 55% of interactions between bats and intact luna moths. We analyzed flight kinematics of moths with and without hindwing tails and suggest that tails have a minimal role in flight performance. Using a robust phylogeny, we find that long spatulate tails have independently evolved four times in saturniid moths, further supporting the selective advantage of this anti-bat strategy. Diversionary tactics are perhaps more common than appreciated in predator-prey interactions. Our finding suggests that focusing on the sensory ecologies of key predators will reveal such countermeasures in prey.

Preferential prey selection by Desmodus rotundus (E. Geoffroy, 1810, Chiroptera, Phyllostomidae) feeding on domestic herbivores in the municipality of São Pedro--SP.

In order to verify possible preferential prey selection by Desmodus rotundus feeding on domestic herbivores in the Municipality of São Pedro (São Paulo, Brazil), vampire bat attacks were surveyed at rural properties where domestic herbivores were being raised and attack frequencies of D. rotundus on the total herd and on different species were calculated. The analysis found that the most frequently attacked herbivores were cattle and horses. The chi-square test (χ2), with a significance level of 5% corroborated the comparative analysis of attack frequency in properties that had these two species. Of the two, horses were attacked more frequently, which could be a sign that D. rotundus exhibits preferential prey selection when attacking domestic herbivores. This evidence is also supported by the Optimal Foraging Theory, in which the net rate of energy consumed is higher for horses than it is for cattle. Additionally, we propose that the thinner integument of horses (relative to that of cattle) may facilitate bites by D. rotundus and thus contribute to the observed prey preference.

Haematophagous bat bites in Ecuadorian Amazon: characterisation and implications for sylvatic rabies prevention.

To characterise the risk factors of haematophagous bat bites and to provide information to contribute to the prevention of rabies in Ecuador. Cross-sectional study based on interviews with 3518 individuals, from which two sets of variables were generated: characteristics of haematophagous bat attacks in the previous year among humans and risk factors for being bitten. Data were analysed using multivariate logistic regression models, taking history of bat bites in the previous year as the response variable. In the previous year 723 (20.6%, 95%CI 19.3-21.9) of the participants declared having received haematophagous bat bites and 50.4% in the previous month, giving an incidence rate of 10.4% (95%CI 9.6-11.6) per month. Sleeping on the floor or in a hammock (adjusted odds ratio [aOR] 1.58, 95%CI 1.21-2.06), not using a protective bed net (aOR 1.25, 95%CI 1.03-1.50) and living in a dwelling with permanent openings in the structure (aOR 1.49, 95%CI 1.12-1.95) were associated with a higher probability of bat bites. Those most affected were the group aged ≤12 years (age 13-19 years, aOR 0.39, 95%CI 0.32-0.48; age ≥20 years, aOR 0.67, 95%CI 0.50-0.90). Primary prevention based on pre-exposure vaccination would be justifiable given the high dispersion of the population and the high incidence of bat bites. As a secondary protective measure, communities should work towards increasing the use of protective measures and putting barriers in permanent openings in their dwellings.

Riqueza de Especies y Variabilidad Trófica de Murciélagos en Zonas de Riesgo de Rabia de Origen Silvestre en Izabal, Guatemala

Izabal, Guatemala, is considered a high-risk region of bovine paralytic rabies and also has documented cases of common vampire bat attacks to humans in villages in marginal conditions. Measures to control vampire bat populations are commonly undertaken, however, when not properly supervised, they often ignore selective techniques and result in the killing of harmless species. In order to document species richness and to compare the proportion of other guilds, bats were captured using mist nets in farms with cattle that were recurrently injured by common vampire bats. A total of 280 bats belonging to 13 genera and 18 species were documented, with Artibeus , Sturnira , Desmodus and Glossophaga being the most common genera in order of abundance. For a sample size of 40 individuals a variation of seven to 11 species was calculated for all sites. The proportion of common vampire bats in contrast to other guilds present was significantly lower (x2 = 18.379, d. f. = 3, P = 0.0004). The bats documented along with the common vampire bat might be providing important ecosystem services that can be suppressed as a consequence of their decreasing population sizes or the disappearance of their colonies.