Search

Moonlight intensity influences the activity patterns of bats. Some bat species reduce their activity levels during brighter nights, a phenomenon known as “lunar phobia.” While lunar phobia of bats has been extensively studied in tropical regions, the same is not the case of bats in temperate regions. By using acoustic detectors, we examined differences in the activity of insectivorous bats on nights with different moonlight intensity in an agricultural landscape of central Chile. We also examined the hourly activity patterns throughout the night and how these varied between full and new moon nights. All bat species modified their activity based on the moonlight intensity; however, their effects were species-specific. The activity of Lasiurus varius, L. villosissimus, Myotis chiloensis, and Histiotus montanus was lower during bright nights, while Tadarida brasiliensis was the only species whose activity was higher during bright nights. Hourly activity throughout the night differed between full moon nights and new moon nights in most bat species. During full moon, bats concentrated their activities in the early hours of the nights; a more homogeneous activity pattern was exhibited during new moon night. Our study demonstrates that moonlight affects the activity of bats in Chile, a factor that should be considered when studying bats.

The Atacama Myotis is an endangered and poorly studied bat species, endemic from Peru and Chile. Using mist nets and ultrasonic recordings we release new information on activity patterns and roost ...

Conversion of natural land covers to agriculture is a major cause of the global biodiversity decline. Bats are an important component of biodiversity in agricultural landscapes because they provide pest control services. Although management recommendations towards the enhancement of insectivorous bat populations in agro-ecosystems have previously been highlighted, little information is available for promoting bat conservation within viticultural landscapes. In the present study, we examined the role of the adjacent habitat on bat activity in vineyards of central Chile. We also evaluated differences in bat activity between the edges and the interiors of the vineyards in relation to the type of adjacent habitat. To accomplish this, we conducted acoustic surveys along edge and the interior of 16 vineyards bordering different adjacent habitats. Overall bat activity in vineyards was not influenced by the adjacent habitat type, but it was by the location within the vineyard; edges showed significant higher activity than the interior of the vineyards. Vineyards adjacent to native vegetation showed the highest levels of activity for Lasiurus varius, Lasiurus villosissimus and Myotis chiloensis compared to those adjacent to monoculture or urban areas. All bat species were most active at the edges of the vineyards as compared to the interior, which increase the probability of this group providing ecosystem services in vineyards. Therefore, vineyard edges, in particular those adjacent to native vegetation, should be considered as part of agricultural management in order to promote bat diversity and abundance in this crop.

Bat populations are threatened in many regions of the world, partly due to the loss of foraging and commuting habitats in farmland and declines in insect prey populations caused by agricultural intensification. Given that bats play an important role as bioindicators and in suppressing crop pests, it is crucial to mitigate negative impacts that arise from these threats. In this study we evaluated the richness, quantified at family level, and abundance of bat prey insects in organic vineyards surrounded by three types of adjacent habitat: urban/semi-urban areas, exotic tree plantations, and remnants of native vegetation. The relationship between the abundance of prey and the foraging activity of bats in the vineyards was also examined. Insects were sampled using ultraviolet light traps, located both inside and at the edge of the vineyards. Bat activity was monitored at each site using acoustic recorders. The insect richness was unaffected by the type of adjacent habitat and did not differ between the edge and the interior of the vineyards. In contrast, insect abundance was significantly influenced by the type of adjacent habitat. Vineyards adjacent to native vegetation and exotic tree plantations showed the highest abundances for most insect orders present in the bat diet compared to urban areas. Bat activity was significantly correlated with the abundance of Coleoptera and Lepidoptera, with mixed effects between bat species (negative for Tadarida brasiliensis, positive for Lasiurus varius, Lasiurus villosissimus and Myotis chiloensis). Crop edges adjacent to native vegetation provides important foraging habitat for bats and should therefore be considered in agricultural management. Locating vineyards close to these habitats may promote bat conservation via increased prey insects and may also benefit winegrowers through the ecosystem services provided by insectivorous bats in this crop.

The protozoan Trypanosoma cruzi, the causative agent of Chagas disease, is transmitted by infected feces or consumption of blood-sucking triatomine insects to several mammalian orders including Chiroptera. In Chile, the distribution of several insectivorous and one hematophagous bat species overlaps with those of triatomine vectors, but the T. cruzi infection status of local chiropterans is unknown. In 2018, we live-captured bats from two protected areas in Chile to collect plagiopatagium tissue, feces and perianal swab samples, in search for T. cruzi-DNA by real time PCR assays using species-specific primers. In Pan de Azucar island (∼26°S), we examined a roost of Desmodus rotundus (common vampire bat) and sampled tissue from 17 individuals, detecting T. cruzi-DNA in five of them. In Las Chinchillas National Reserve (∼31°S), we examined two roosts of Histiotus montanus (small big-eared brown bat), collecting feces or perianal swab samples from eight individuals, detecting T. cruzi-DNA in four of them. This is the first report of T. cruzi-DNA evidence in bat species from Chile. Both vector-borne and oral transmission are potential infection routes that can explain our results. Further investigation is needed for a better understanding of the role of bats in the T. cruzi transmission cycle.

Davison's Mastiff Bat Promops davisoni is a poorly studied species, only present in Ecuador, Peru, and more recently in Chile, where its known geographic distribution is supported by very few records from the extreme north of the country. Using ultrasonic recordings, we reported new records of P. davisoni in northern Chile, extending its distribution range ca. 60 km southward to the Chaca and Camarones valleys in the province of Arica. Additionally, using Species Distribution Models, we predicted its potential distribution in the north of the country based on similar suitable habitats. The high number of recordings obtained in our study suggest a wide distribution and relative abundance of P. davisoni in the coastal valleys of the Arica province and surrounding urban areas, with a remarkable habitat diversity for populations of this species. In addition, our potential distribution models suggest its presence in other arid environments within the Atacama Desert. These data provide additional information on the current and potential distribution of P. davisoni and can be useful for further studies to better understand the biology and population dynamics of the species, as well as the design of conservation and management strategies.

We recorded and characterized the echolocation calls emitted by the common vampire bat Desmodus rotundus during foraging in natural habitats in Chile. Signal design typically shows multiple harmonics consisting of a brief quasi-constant frequency (QCF) component at the beginning of the pulse followed by a downward frequency modulated component. Calls are characterized by long durations (5.5 ms) and emitted as single pulses or in groups of 2–3 pulses at a repetition rate of 29 Hz. The higher frequency ranges (85–35 kHz) and the unusual QCF component that characterized multiharmonic signals of free-flying D. rotundus in Chile is a remarkable feature for acoustic identification with other Chilean bats.

Myotis chiloensis (Waterhouse, 1838), the Chilean myotis, is found only in Argentina and Chile, where it is the most common bat species in the southern part of Chile. It is a small insectivorous bat and differs from other members of the genus because of its darker pelage. It uses human buildings and caves to establish colonies, and forages in dense forests of Nothofagus to capture insects, thereby providing ecosystem services to agriculture and forestry. M. chiloensis is considered of “Least Concern” by the International Union for Conservation of Nature and Natural Resources.

Disentangling the relative effects of forest loss versus fragmentation on species distribution and abundance is crucial for adopting efficient biodiversity conservation actions, which could change with the nature of the landscape matrix. We tested the moderating effect of landscape matrix on insectivorous bats response to forest loss and fragmentation. We conducted acoustic surveys at forest patches surrounded by either an agricultural-dominated matrix or a pine-dominated matrix. We related bat activity to forest amount and the number of forest patches at multiple spatial scales, and compared their effects between landscape matrices. Bat activity was associated with both predictors, however their effects varied with the matrix type. In agricultural landscapes, as the amount of forest increased, the activity of Histiotus montanus, Lasiurus cinereus and Tadarida brasiliensis increased, while activity of Myotis chiloensis decreased. Similarly, as fragmentation increased, the activity of Lasiurus varius and M. chiloensis increased, while activity of H. montanus decreased. In production-forest landscapes, only H. montanus decreased its activity with increasing forest amount. In contrast, activity of L. cinereus, M. chiloensis and T. brasiliensis increased with increasing fragmentation. Forest amount was a stronger predictor for agricultural landscapes than for production-forest landscapes, suggesting that low contrast matrices can mitigate the effects of forest loss. Fragmented landscapes with native forest patches surrounded by a low contrast matrix may support a higher activity of insectivorous bats. Management efforts in fragmented landscapes should aim to decrease the patch-matrix contrast, which will mitigate the effects of forest loss on bats.

Intraspecific variability in echolocation calls could be an important factor hampering the accurate acoustic identification of species in the field. We studied variations in the echolocation behavior of Lasiurus varius in relation to habitat structure. Echolocation calls of L. varius reflected the degree of clutter present in its foraging areas. Bats foraging in an uncluttered habitat emitted longer and lower-bandwidth calls, with the lowest frequency values, whereas bats foraging in a cluttered habitat broadcast shorter and broadband signals, showing an increase in frequency content of their calls. Discriminant function analysis gave an overall classification of 76% of the calls emitted in the different flight situations. Our results highlight the need for independent recordings at each study area or habitat type to circumvent potential echolocation call variations, particularly in fragmented landscapes.

The current trend toward simplification of agricultural landscapes, as well as the associated loss of perennial cover types, can decrease landscape heterogeneity and also natural enemy abundance and diversity, favouring exotic species. We evaluated the effects of agricultural landscape composition and heterogeneity at two different spatial scales (radii of 250 and 1000 m), on the diversity and abundance of native and exotic coccinellids, associated with alfalfa fields located in two regions of Central Chile. Data were analyzed using partial least square regressions, considering the whole coccinellid assemblage and the three most abundant species. In both regions, coccinellid diversity and the abundance and proportion of native coccinellids in alfalfa responded differentially from total abundance and the abundance of exotic coccinellids. The diversity and abundance of coccinellids in alfalfa increased with the compositional and configurational heterogeneity of the landscape. The abundance of both native and exotic coccinellids in alfalfa fields decreased as the area covered by cultivated lands, such as annual crops and orchards, increased. Nevertheless, the responses of native and exotic coccinellids were not consistent among regions, which may be explained by responses of the dominant species in each region. The results of the present study suggest that variables related to a higher intensification of agricultural landscapes (lower compositional and configurational heterogeneity, as well as more annual crops) reduce coccinellid diversity and abundance in alfalfa fields. To maintain a higher abundance and diversity of these natural enemies in alfalfa, more heterogeneous landscapes with less annual crops should be promoted.

Forestry plantations supporting native species exhibit a dense understory, which might reduce bat activity within plantations. We compared bat activity in Monterrey pine plantations with and without an understory in central Chile. Total activity did not differ between plantations with a developed understory and those without it, being higher on-track than off-tracks sites. Trails provide commuting areas for bats within plantations allowing its use regardless of their degree of structural clutter. Promoting understory in plantations provides habitats for bats and might enhance their conservation in human-modified landscapes.

Myotis atacamensis is a poorly known bat species endemic to the central portion of the pacific coast of South America, where it is known from the province of Lambayeque, Peru (latitude 5° S), to the province of Elqui (latitude 30° S), Chile. Here, we report the first record of M. atacamensis for the province of Choapa (latitude 31° S, Coquimbo Region) in Chile. This is the southernmost record of the species within Chile and South America, extending its geographic range ca. 200 km southward.

Te southern Big-Eared Brown Bat, Histiotus magellanicus, is a poorly known vespertilionid occurring only in southern Chile and Argentina, where it appears to be restricted to Valdivian Temperate Forests and Magellanic Subpolar Forests. Here we report the frst record of H. magellanicus in the Maulino Temperate Forest of central Chile, a Mediterranean-climate ecosystem, suggesting that the species might not be exclusive to subantarctic forests, as previously thought. Tis constitutes the northernmost continental record for the species, extending its range ca. 400 km the previous known northern locality. Fil: San Pedro, Annia Rodríguez. Universidad de Chile; Chile Fil: Barquez, Ruben Marcos. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Programa de Investigación de Biodiversidad Argentina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Simonetti, Javier A.. Universidad de Chile; Chile

We assessed foraging activity of insectivorous bats in a fragmented landscape of central Chile including native temperate forest, forest fragments, commercial pine plantations and local human settlements. Overall bat activity was noticeably greater along adult pine plantation edges, local human settlements and the edge of continuous forest than over interior habitats and unplanted forest plantation clear-cuts. Tadarida brasiliensis foraged mostly above human settlements and edges of adult pine plantations but avoided interior habitats. Lasiurus cinereus was more active along edges of both adult pine plantations and continuous forest than in clearcuts and interior habitats of forest fragments. In contrast, Lasiurus varius, Histiotus montanus and Myotis chiloensis occurred not only along vegetation edges but also within the interior habitats of adult pine plantations. The high activity levels suggest that bats not only pass through exotic pine plantations, but that they are active in these habitats commuting and feeding, thus enhancing their capacity to persist in landscapes modified by humans in which exotic forestry plantations are an important component.