Common Vampire Bat Desmodus Rotundus Research Articles

Human cat borne rabies as the new epidemiology of the disease in the Andes mountains.

Rabies virus (RABV) is the etiologic agent of rabies, a fatal brain disease in mammals. Rabies circulation has historically involved the dog has the main source of human rabies worldwide. Nevertheless, in Colombia, cats (Felis catus) have become a relevant species in the epidemiology of rabies. To characterize rabies cases in humans in Colombia in the last three decades in the context of the epidemiology of the aggressor animal. We conducted a retrospective longitudinal epidemiological study of human rabies caused by cats' aggression, collecting primary and secondary information. Variables considered included the demography of the patient, symptoms, information about the aggressor animal as the source of infection and the viral variant identified. We found that the distribution of rabies incidence over the years has been constant in Colombia. Nevertheless, between 2003 and 2012 a peak of cases occurred in rural Colombia where cats were the most frequent aggressor animal reported. Most cats involved in aggression were unvaccinated against rabies. Cat's clinical signs at the time of the report of the human cases included hypersalivation and changes in behaviour. Human patients were mostly children and female and the exposure primarily corresponded to bite and puncture lacerations in hands. The RABV lineage detected in most cases corresponded to variant 3, linked to the common vampire bat (Desmodus rotundus). The geographical presentation of cat borne RABV in humans occurred along the Andes mountains, epidemiologically known as the rabies red Andean corridor. By finding cats as the primary source of rabies spillover transmission in Colombia, this report highlights the importance of revising national rabies control and prevention protocol in countries in the Andes region. Our results demonstrate that rabies vaccination for outdoor cats needs to prioritize to reduce the number of rabies-related human deaths.

Hierarchically embedded scales of movement shape the social networks of vampire bats.

Social structure can emerge from hierarchically embedded scales of movement, where movement at one scale is constrained within a larger scale (e.g. among branches, trees, forests). In most studies of animal social networks, some scales of movement are not observed, and the relative importance of the observed scales of movement is unclear. Here, we asked: how does individual variation in movement, at multiple nested spatial scales, influence each individual's social connectedness? Using existing data from common vampire bats (Desmodus rotundus), we created an agent-based model of how three nested scales of movement-among roosts, clusters and grooming partners-each influence a bat's grooming network centrality. In each of 10 simulations, virtual bats lacking social and spatial preferences moved at each scale at empirically derived rates that were either fixed or individually variable and either independent or correlated across scales. We found that numbers of partners groomed per bat were driven more by within-roost movements than by roost switching, highlighting that co-roosting networks do not fully capture bat social structure. Simulations revealed how individual variation in movement at nested spatial scales can cause false discovery and misidentification of preferred social relationships. Our model provides several insights into how nonsocial factors shape social networks.

Bat cellular immunity varies by year and dietary habit amidst land conversion.

Monitoring the health of wildlife populations is essential in the face of increased agricultural expansion and forest fragmentation. Loss of habitat and habitat degradation can negatively affect an animal's physiological state, possibly resulting in immunosuppression and increased morbidity or mortality. We sought to determine how land conversion may differentially impact cellular immunity and infection risk in Neotropical bats species regularly infected with bloodborne pathogens, and to evaluate how effects may vary over time and by dietary habit. We studied common vampire bats (Desmodus rotundus), northern yellow-shouldered bats (Sturnira parvidens) and Mesoamerican mustached bats (Pteronotus mesoamericanus), representing the dietary habits of sanguivory, frugivory and insectivory respectively, in northern Belize. We compared estimated total white blood cell count, leukocyte differentials, neutrophil to lymphocyte ratio and infection status with two bloodborne bacterial pathogens (Bartonella spp. and hemoplasmas) of 118 bats captured in a broadleaf, secondary forest over three years (2017-2019). During this period, tree cover decreased by 14.5% while rangeland expanded by 14.3%, indicating increasing habitat loss and fragmentation. We found evidence for bat species-specific responses of cellular immunity between years, with neutrophil counts significantly decreasing in S. parvidens from 2017 to 2018, but marginally increasing in D. rotundus. However, the odds of infection with Bartonella spp. and hemoplasmas between 2017 and 2019 did not differ between bat species, contrary to our prediction that pathogen prevalence may increase with land conversion. We conclude that each bat species invested differently in cellular immunity in ways that changed over years of increasing habitat loss and fragmentation. We recommend further research on the interactions between land conversion, immunity and infection across dietary habits of Neotropical bats for informed management and conservation.

Climate change linked to vampire bat expansion and rabies virus spillover

Bat‐borne pathogens are a threat to global health and in recent history have had major impacts on human morbidity and mortality. Examples include diseases such as rabies, Nipah virus encephalitis, and severe acute respiratory syndrome (SARS). Climate change may exacerbate the emergence of bat‐borne pathogens by affecting the ecology of bats in tropical ecosystems. Here, we report the impacts of climate change on the distributional ecology of the common vampire bat Desmodus rotundus across the last century. Our retrospective analysis revealed a positive relationship between changes in climate and the northern expansion of the distribution of D. rotundus in North America. Furthermore, we also found a reduction in the standard deviation of temperatures at D. rotundus capture locations during the last century, expressed as more consistent, less‐seasonal climate in recent years. These results elucidate an association between D. rotundus range expansion and a continental‐level rise in rabies virus spillover transmission from D. rotundus to cattle in the last 50 years of the 120‐year study period. This correlative study, based on field observations, offers empirical evidence supporting previous statistical and mathematical simulation‐based studies reporting a likely increase of bat‐borne diseases in response to climate change. We conclude that the D. rotundus rabies system exemplifies the consequences of climate change augmentation at the wildlife–livestock–human interface, demonstrating how global change acts upon these complex and interconnected systems to drive increased disease emergence.

Gut microbial shifts in vampire bats linked to immunity due to changed diet in human disturbed landscapes

Anthropogenic land-use change alters wildlife habitats and modifies species composition, diversity, and contacts among wildlife, livestock, and humans. Such human-modified ecosystems have been associated with emerging infectious diseases, threatening human and animal health. However, human disturbance also creates new resources that some species can exploit. Common vampire bats (Desmodus rotundus) in Latin America constitute an important example, as their adaptation to human-modified habitats and livestock blood-feeding has implications for e.g., rabies transmission. Despite the well-known links between habitat degradation and disease emergence, few studies have explored how human-induced disturbance influences wildlife behavioural ecology and health, which can alter disease dynamics. To evaluate links among habitat disturbance, diet shifts, gut microbiota, and immunity, we quantified disturbance around roosting caves of common vampire bats in Costa Rica, measured their long-term diet preferences (livestock or wildlife blood) using stable isotopes of carbon and nitrogen, evaluated innate and adaptive immune markers, and characterized their gut microbiota. We observed that bats from roosting caves with more cattle farming nearby fed more on cattle blood. Moreover, gut microbial richness and the abundance of specific gut microbes differed according to feeding preferences. Interestingly, bats feeding primarily on wildlife blood harboured a higher abundance of the bacteria Edwardsiella sp., which tended to be associated with higher immunoglobulin G levels. Our results highlight how human land-use change may indirectly affect wildlife health and emerging infectious diseases through diet-induced shifts in microbiota, with implications for host immunity and potential consequences for susceptibility to pathogens.

A review of the diet of the common vampire bat (Desmodus rotundus) in the context of anthropogenic change.

The online version contains supplementary material available at 10.1007/s42991-023-00358-3.

Bat blunders

Bat blunders

Reducing conflict between the common vampire bat Desmodus rotundus and cattle ranching in Neotropical landscapes

AbstractIncreased cattle ranching in Neotropical landscapes has led to human–wildlife conflicts that complicate the relationship between agricultural production and biodiversity conservation. We review the literature related to conflicts between livestock production and the common vampire bat Desmodus rotundus, specifically, the factors that influence the incidence of problems caused by bites to cattle. We summarise the strategies proposed to reduce these problems and propose actions from the perspectives of cattle management, landscape ecology and the biology of the common vampire bat. The literature shows that free‐range extensive management systems, where cattle graze in areas with forest cover, near riparian zones, caves, secondary vegetation (generally shrublands and immature trees), and vegetation fragments and edges, increase the implications and the severity of the conflict. As a result of different selection forces, the wing morphology and echolocation characteristics of the common vampire bat facilitate its movement under these landscape conditions, thus favouring a scenario of greater interaction with cattle. We propose the establishment of a ‘buffer zone’ to separate the cattle as far as possible (at least 1 km) from the elements of the landscape that are key for the movement patterns of common vampire bats in cattle ranching areas. The feeding events of this species are positively associated with host availability and landscape elements that provide habitat and connectivity, which shows that the cause of this conflict originates from the process of cattle production and the invasion of the habitat of the common vampire bat. Anti‐rabies vaccination programmes in cattle and forest–cattle separation are the most important strategies to minimise conflict and prevent rabies outbreaks.

Social effects of rabies infection in male vampire bats (Desmodus rotundus).

Rabies virus (RABV) transmitted by the common vampire bat (Desmodus rotundus) poses a threat to agricultural development and public health throughout the Neotropics. The ecology and evolution of rabies host-pathogen dynamics are influenced by two infection-induced behavioural changes. RABV-infected hosts often exhibit increased aggression which facilitates transmission, and rabies also leads to reduced activity and paralysis prior to death. Although several studies document rabies-induced behavioural changes in rodents and other dead-end hosts, surprisingly few studies have measured these changes in vampire bats, the key natural reservoir throughout Latin America. Taking advantage of an experiment designed to test an oral rabies vaccine in captive male vampire bats, we quantify for the first time, to our knowledge, how rabies affects allogrooming and aggressive behaviours in this species. Compared to non-rabid vampire bats, rabid individuals reduced their allogrooming prior to death, but we did not detect increases in aggression among bats. To put our results in context, we review what is known and what remains unclear about behavioural changes of rabid vampire bats (resumen en español, electronic supplementary material, S1).

A recombinant rabies vaccine that prevents viral shedding in rabid common vampire bats (Desmodus rotundus).

Vampire bat transmitted rabies (VBR) is a continuing burden to public health and agricultural sectors in Latin America, despite decades-long efforts to control the disease by culling bat populations. Culling has been shown to disperse bats, leading to an increased spread of rabies. Thus, non-lethal strategies to control VBR, such as vaccination, are desired. Here, we evaluated the safety and efficacy of a viral-vectored recombinant mosaic glycoprotein rabies vaccine candidate (RCN-MoG) in vampire bats (Desmodus rotundus) of unknown history of rabies exposure captured in México and transported to the United States. Vaccination with RCN-MoG was demonstrated to be safe, even in pregnant females, as no evidence of lesions or adverse effects were observed. We detected rabies neutralizing antibodies in 28% (8/29) of seronegative bats post-vaccination. Survival proportions of adult bats after rabies virus (RABV) challenge ranged from 55–100% and were not significantly different among treatments, pre- or post-vaccination serostatus, and route of vaccination, while eight pups (1–2.5 months of age) used as naïve controls all succumbed to challenge (P<0.0001). Importantly, we found that vaccination with RCN-MoG appeared to block viral shedding, even when infection proved lethal. Using real-time PCR, we did not detect RABV nucleic acid in the saliva samples of 9/10 vaccinated bats that succumbed to rabies after challenge (one was inconclusive). In contrast, RABV nucleic acid was detected in saliva samples from 71% of unvaccinated bats (10/14 sampled, plus one inconclusive) that died of the disease, including pups. Low seroconversion rates post-vaccination and high survival of non-vaccinated bats, perhaps due to earlier natural exposure, limited our conclusions regarding vaccine efficacy. However, our findings suggest a potential transmission-blocking effect of vaccination with RCN-MoG that could provide a promising strategy for controlling VBR in Latin America beyond longstanding culling programs.

Geographic Distribution of Common Vampire Bat Desmodus rotundus (Chiroptera: Phyllostomidae) Shelters: Implications for the Spread of Rabies Virus to Cattle in Southeastern Brazil.

Desmodus rotundus bats show a complex social structure and developed adaptive characteristics, considered key features of a pathogen disseminator, such as the rabies virus, among bats and other mammals, including cattle and humans. Our aim was to understand the correlation between the environment and the ecological features of these bats in bovine rabies outbreaks. Geostatistical analyses were performed, covering 104 cattle positives for rabies, between 2016 and 2018, in 25 municipalities, in addition to the characteristics of D. rotundus colonies mapped during this period in the state of São Paulo, Brazil. Data from the shelters showed that 86.15% were artificial, mainly abandoned houses (36.10%) and manholes (23.87%), in addition to demonstrating a correlation between these shelters and a higher concentration of bovine rabies cases. Due to their adaptive capacity, these bats choose shelters close to the food source, such as livestock. In Brazil, D. rotundus is the main transmitter of rabies and the cause of outbreaks in cattle and deaths in humans, considering the advance of humans in previously preserved ecosystems. There seems to be a correlation between the impact of anthropic changes on the environment, mainly for the expansion of pasture for cattle and the outbreaks of bovine rabies in this area.

How to Make a Vampire: Part II. Getting Ready to Feed

The mammalian feeding system is made up of multiple components that influence facial variation, including the masticatory muscles, bony jaw apparatus, and teeth. However, it is not fully understood how the development of these components are coordinated and are impacted by life history and diet.Bats are the only mammals that continue to nurse until they are almost adult size, and often after they become volant. Common vampire bats (Desmodus rotundus) have a relatively prolonged juvenile period among bats, can nurse up to nine months, and later solely subsist off of blood. Feeding system maturity may therefore be delayed in bats, and particularly delayed in Desmodus, as a result of their lengthy juvenile period and liquid diet. In this study, we examine the developmental maturity of the cranium and feeding apparatus in the late fetus of a common vampire bat (Desmodus rotundus) relative to an adult (its mother).The heads of each specimen were microCT scanned twice. Conventional microCT was used to image mineralized tissues. Diffusible iodine‐based contrast‐enhanced CT (diceCT) imaging was used to image soft tissues. Cranial length and palate length measurements were acquired from unstained scans to evaluate size and jaw apparatus development. Masticatory muscles (e.g., medial pterygoid, zygomaticomandibularis) and permanent tooth crypt volumes were acquired from stained tissue scans to evaluate masticatory muscle and tooth development. Developmental maturity of these structures was assessed by calculating a percentage of the growth completed (i.e., [fetal muscle volume/adult muscle volume]*100).In the fetus, permanent tooth crypt volume is already comparable to the adult condition despite cranial length and palate length being &lt;75% of adult size. Masticatory muscle volume maturity is highest in the lateral pterygoid muscle (~35%), whereas other masticatory muscles are far less developed (e.g., medial pterygoid volume maturity, ~20%; temporalis profundus volume maturity, ~20%; temporalis medius volume maturity, ~6%).These results reveal highly precocious permanent tooth development in Desmodus. Although this may facilitate transition to hematophagy, Desmodus do not fly until eight to ten weeks, so the precocious incisors may primarily aid the infant to grip its mother’s skin. Differential development of the masticatory muscles may also be influenced by the need for young bats to use their mouths to help anchor themselves to their mother early in life. This may explain the advanced maturity of the lateral pterygoid muscle, which would protrude the jaw and help to facilitate a more secure grip.

A two-step metagenomics approach for the identification and mitochondrial DNA contig assembly of vertebrate prey from the blood meals of common vampire bats (Desmodus rotundus)

The feeding behaviour of the sanguivorous common vampire bat (Desmodus rotundus) facilitates the transmission of pathogens that can impact both human and animal health. To formulate effective strategies in controlling the spread of diseases, there is a need to obtain information on which animals they feed on. One DNA-based approach, shotgun sequencing, can be used to obtain such information. Even though it is costly, shotgun sequencing can be used to simultaneously retrieve prey and vampire bat mitochondrial DNA for population studies within one round of sequencing. However, due to the challenges of analysing shotgun sequenced metagenomic data such as false negatives/positives and typically low proportion of reads mapped to diet items, shotgun sequencing has not been used for the identification of prey from common vampire bat blood meals. To overcome these challenges and generate longer mitochondrial contigs which could be useful for prey population studies, we shotgun sequenced common vampire bat blood meal samples (n = 8) and utilised a two-step metagenomic approach based on combining existing bioinformatic workflows (alignment and mtDNA contig assembly) to identify prey. After validating our results from detections made through metabarcoding, we accurately identified the common vampire bats’ prey in six out of eight samples without any false positives. We also generated prey mitochondrial contig lengths between 138 bp to 3231 bp (median = 770 bp, Q1 = 262 bp, Q3 = 1766 bp). This opens the potential to conduct phylogenetic and phylogeographic monitoring of elusive prey species in future studies, through the analyses of blood meal metagenomic data.

Forced proximity promotes the formation of enduring cooperative relationships in vampire bats.

Spatial assortment can be both a cause and a consequence of cooperation. Proximity promotes cooperation when individuals preferentially help nearby partners, and conversely, cooperation drives proximity when individuals move towards more cooperative partners. However, these two causal directions are difficult to distinguish with observational data. Here, we experimentally test if forcing randomly selected pairs of equally familiar female common vampire bats (Desmodus rotundus) into close spatial proximity promotes the formation of enduring cooperative relationships. Over 114 days, we sampled 682 h of interactions among 21 females captured from three distant sites to track daily allogrooming rates over time. We compared these rates before, during and after a one-week period, during which we caged random triads of previously unfamiliar and unrelated vampire bats in proximity. After the week of proximity when all bats could again freely associate, the allogrooming rates of pairs forced into proximity increased more than those of the 126 control pairs. This work is the first to experimentally demonstrate the causal effect of repeated interactions on cooperative investments in vampire bats. Future work should determine the relative importance of mere association versus interactions (e.g. reciprocal allogrooming) in shaping social preferences.

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.

A database of common vampire bat reports

The common vampire bat (Desmodus rotundus) is a sanguivorous (i.e., blood-eating) bat species distributed in the Americas from northern Mexico southwards to central Chile and Argentina. Desmodus rotundus is one of only three mammal species known to feed exclusively on blood, mainly from domestic mammals, although large wildlife and occasionally humans can also serve as a food source. Blood feeding makes D. rotundus an effective transmissor of pathogens to its prey. Consequently, this species is a common target of culling efforts by various individuals and organizations. Nevertheless, little is known about the historical distribution of D. rotundus. Detailed occurrence data are critical for the accurate assessment of past and current distributions of D. rotundus as part of ecological, biogeographical, and epidemiological research. This article presents a dataset of D. rotundus historical occurrence reports, including >39,000 locality reports across the Americas to facilitate the development of spatiotemporal studies of the species. Data are available at https://doi.org/10.6084/m9.figshare.15025296.

Habituation of common vampire bats to biologgers.

Rapid advancements in biologging technology have led to unprecedented insights into animal behaviour, but testing the effects of biologgers on tagged animals is necessary for both scientific and ethical reasons. Here, we measured how quickly 13 wild-caught and captively isolated common vampire bats (Desmodus rotundus) habituated to mock proximity sensors glued to their dorsal fur. To assess habituation, we scored video-recorded behaviours every minute from 18.00 to 06.00 for 3 days, then compared the rates of grooming directed to the sensor tag versus to their own body. During the first hour, the mean tag-grooming rate declined dramatically from 53% of sampled time (95% CI = 36–65%, n = 6) to 16% (8–24%, n = 9), and down to 4% by hour 5 (1–6%, n = 13), while grooming of the bat's own body did not decline. When tags are firmly attached, isolated individual vampire bats mostly habituate within an hour of tag attachment. In two cases, however, tags became loose before falling off causing the bats to dishabituate. For tags glued to fur, behavioural data are likely to be impacted immediately after the tag is attached and when it is loose before it falls off.

Potential attack of the common vampire bat (Desmodus rotundus) on nine-banded armadillo (Dasypus novemcinctus) in northern Oaxaca, México

El murciélago vampiro común, Desmodus rotundus, es un depredador que de forma obligatoria, se alimenta de sangre de vertebrados de un grupo diverso de presas, pero con preferencia a los mamíferos, tanto nativos como exóticos. El presente registro documenta la primera depredación potencial de un armadillo de nueve bandas, Dasypus novemcinctus, por D. rotundus en vida silvestre. La observación se registró en una cámara trampa colocada en un fragmento de crecimiento secundario de un bosque tropical perennifolio en Oaxaca, México. En una grabación de 10 segundos, observamos a un individuo de D. rotundus acechando y persiguiendo a un individuo de D. novemcinctus que busca alimento en la hojarasca. La presente observación, junto con otro estudio realizado en Brasil, donde un murciélago vampiro persiguió a un armadillo gigante Priodontes maximus, sugiere que los armadillos podrían ser presas de D. rotundus, pero la interacción es difícil de registrar en vida silvestre.

Morphological adaptations during development of the kidneys in Vampire bats

Tissue changes during embryonic and postnatal development are critical for the success of physiological processes later in mammalian life. Dietary transition from milk to a variety of other food items is one of the factors inducing these changes in mammal species. Blood is utilized as food by only three species of vampire bats among all living mammals. Considering its high protein content, this unique diet is known to induce several metabolic changes, including fasting susceptibility. However, changes in the renal function to meet the excretory needs associated to the blood diet are unknown. Here we aimed at investigating morphological alterations in vampires’ kidneys during embryonic and post-natal development in order to better understand the evolutionary adaptations allowing sanguivory. Common vampire bats (Desmodus rotundus) were captured and had their kidneys removed for histological, morphometrical and stereological analysis. Our results showed increased glomerular area and higher glomerular and uriniferous tubules volumetric densities in adults compared to developing bats. These results, together with a higher Renal Somatic Index and a thicker inner medulla also reported for adults, support renal hypertrophy due to increased renal function in blood-feeding vampires as compared to the earlier life stages. We also report a lower foot process density and its different arrange inside the glomerular capsule in adults, indicating an adaptation to a larger extracellular volume formed by increased glomerular filtration. Taken together, kidney morphological changes reported here for vampire bats may reflect in adults’ adaptations to a monotrophic strategy.

Correction to: Abundance of the common vampire bat and feeding prevalence on cattle along a gradient of landscape disturbance in southeastern Mexico

Cattle ranching is one of the main production activities in the Neotropics that has unavoidably led to cattle exposure to the common vampire bat (Desmodus rotundus) and rabies virus. Although many studies have assessed this issue, the influence of environmental characteristics associated with land use and social and production constraints have received little attention. We used satellite imagery classification to identify a gradient of landscape disturbance and analyzed the effects of cattle management and landscape structure on common vampire bat abundance and feeding prevalence. Evidence of the common vampire bat feeding on cattle was common in the study area: 87.5% of the ranchers interviewed claimed to have experienced this problem. The abundance and feeding prevalence of the common vampire bat was lower in landscapes dominated by open fields, scarce forest cover, and agricultural land. Bat abundance was positively associated with the presence of streams in the proximity of grazing areas, whereas cave’s presence was associated with higher feeding prevalence. We suggest that cattle grazing should avoid the proximity of streams, caves, and forests as much as possible, as these conditions increase the exposure of cattle to the common vampire bat and the potential for feeding, which can increase the likelihood of rabies virus transmission.