Sensor:Radio Transmitter
Radio Transmitter
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Radio Transmitter
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radio-transmitter
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- Data packageData from: Modelling landscape connectivity for greater horseshoe bat using an empirical quantification of resistance(2018-07-09) Pinaud, David; Claireau, Fabien; Leuchtmann, Maxime; Kerbiriou, Christian(1) Habitat fragmentation and isolation as a result of human activities have been recognized as great threats to population viability. Evaluating landscape connectivity in order to identify and protect linkages has therefore become a key challenge in applied ecology and conservation. (2) One useful approach to evaluate connectivity is Least‐Cost Path (LCP) analysis. However, several studies have highlighted importance of parameterization with empirical, biologically‐relevant proxies of factors affecting movements, as well as the need to validate the LCP model with an independent dataset. (3) We used LCP analysis incorporating quantitative, empirical data about behaviour of the greater horseshoe bat Rhinolophus ferrumequinum to build up a model of functional connectivity in relation to landscape connecting features. We then validated the accumulated costs surface from the LCP model with two independent datasets; one at an individual level with radio tracking data and one at a population level with acoustic data. (4) When defining resistance, we found that the probability of bat presence in a hedgerow is higher when the distance between hedgerows is below 38 m, and decrease rapidly when gaps are larger than 50 m. The LCP model was validated by both datasets: the independent acoustic data showed that the probability of bat presence was significantly higher in areas with lower accumulated costs, and the radio tracking data showed that foraging was more likely in areas where accumulated costs were significantly lower. (5) Synthesis and applications. Through our modelling approach, we recommend a maximum of 38m (and no more than 50m) between connecting features around colonies of greater horseshoe bats. Our quantitative study highlights the value of this framework for conservation: results are directly applicable in the field and the framework can be applied to other species sensitive to habitat loss, including other bats. Provided that it is parameterized with empirical, biologically‐relevant data, this modelling approach can be used for restoring and evaluating green networks in agri‐environmental schemes and management plans.
- Data packageData from: Foraging and roosting behaviour of the fringe-lipped bat, Trachops cirrhosus, on Barro Colorado Island, Panamá(2017-12-18) Hämsch, Frank; O'Mara, M. Teague; Jones, Patricia L.The Neotropical fringe-lipped bat, Trachops cirrhosus, is a generalist predator that hunts frogs and insects by homing in on their mating calls. Although research has examined cognition and prey preferences of bats in captivity, little is known of the foraging or roosting behaviour of this species in the wild. We radio tracked six T. cirrhosus individuals on Barro Colorado Island, Panamá. Bat day roosts were all in hollow cashew trees, Anacardium excelsum, in mixed sex groups of three to five T. cirrhosus individuals, with frequent roost switching. Radio tracked individuals flew an average of 218 ± 227 m from their day roosts to 12.0 ± 10.17 ha foraging areas (50% utilization distribution [UD] kernels = area where bats spent 50% of their time as estimated from a probability distribution). These 50% UD kernels were less than 10% of their average total range use, but larger than previously reported for T. cirrhosus. Radio tracked individuals overlapped in 50% UD kernel foraging areas by only 2.1 ± 5.9 % on average. Foraging behaviour consisted predominantly of short sally flights of less than one minute, indicating bats were likely perch hunting. Bats were more frequently in flight, and had longer flight durations, at the beginning of the night and just before dawn than throughout the rest of the night. These data provide insight into the foraging behaviour of T. cirrhosus in the wild that is a species fast becoming a model system of cognition in captivity.
- Data packageData from: Spatial ecology of the water opossum Chironectes minimus in Atlantic Forest streams(2016-06-13) Leite, Melina de Souza; Galliez, Maron; Queiroz, Thiago Lopes; Pinto de Mendonça, Patrícia; Fernandez, Fernando A.S.The water opossum Chironectes minimus is the world’s only semi-aquatic marsupial. It is considered rare, and it is reported on several regional conservation lists of species as either endangered or data deficient. Given its uniqueness and the poor knowledge of its ecology, we aimed to investigate home range size and overlap and habitat selection of the water opossum in Atlantic Forest streams in southeastern Brazil. We radio tracked water opossums and collected information about their habitats and behaviour from October 2004 to April 2010. We combined common home range estimators for animals living in linear habitats with the synoptic model of home range and habitat selection. For the 10 individuals monitored, the home ranges varied between 0.80 and 9.66 km of watercourses; none of them had exclusive home ranges. The home range size for males was, on average, three times larger than for females. The overlap data showed that, on average, one male could encompass the home ranges of up to five females simultaneously, but more than one male could have access to the same female. For habitat selection at the individual level, we could not find any strong influence of habitat features on water opossum preferences because individuals selected different sets of habitat variables. However, at the population level, we found a negative relationship between home range size and river size. The water opossum seems to prefer shallow and narrow watercourses to establish its home ranges. Here, we present valuable information to advance our knowledge of the water opossum and its ecology, which is urgent for conservation purposes.
- Data packageData from: Defensive fruit metabolites obstruct seed dispersal by altering bat behavior and physiology at multiple temporal scales(2019-11-25) Baldwin, Justin W.; Dechmann, Dina K.N.; Thies, Wibke; Whitehead, Susan R.The paradoxical presence of toxic chemical compounds in ripe fruits represents a balance between plant enemies and allies: chemical traits can defend seeds against antagonistic herbivores, seed predators or fungal pathogens, but also can impose costs by repelling mutualistic seed dispersers, although the costs are often difficult to quantify. Seeds gain fitness benefits from travelling far from the parent plant, as they can escape from parental competition and elude specialized herbivores as well as pathogens that accumulate on adult plants. However, seeds are difficult to follow from their parent plant to their final destination. Thus, little is known about the factors that determine seed dispersal distance. We investigated this potential cost of fruit secondary compounds – reduced seed dispersal distance ‐ by combining two datasets from previous work on a Neotropical bat‐plant dispersal system (bats in the genus Carollia and plants in the genus Piper). We used data from captive behavioral experiments, which show how amides in ripe fruits of Piper decrease the retention time of seeds and alter food choices. With new analyses, we show that these defensive secondary compounds also delay the time of fruit removal. Next, with a behaviorally annotated bat telemetry dataset, we quantified post‐feeding movements (i.e. seed dispersal distances). Using generalized additive mixed models we found that seed dispersal distances varied nonlinearly with gut retention times as well as with the time of fruit removal. By interrogating the model predictions, we identified two novel mechanisms by which fruit secondary compounds can impose costs in terms of decreased seed dispersal distances: 1) small scale reductions in gut retention time and 2) causing fruits to forgo advantageous bat activity peaks that confer high seed dispersal distances.
- Data packageData from: Science update for the South Peace Northern Caribou (Rangifer tarandus caribou pop. 15) in British Columbia(2019-08-27) Seip, Dale R.; Price, ElenaAll caribou in British Columbia belong to the woodland subspecies (Rangifer tarandus caribou) and are further classified into three ecotypes based on differences in habitat use, behaviour and migration patterns. Approximately 17,000 northern ecotype Woodland Caribou reside in the province. This document focuses on seven herds belonging to this population found in the southern Peace region of BC (South Peace Northern Caribou, SPNC). These herds are referred to as the Graham, Moberly, Scott, Burnt Pine, Kennedy Siding, Quintette and Narraway. There are approximately 1,000 SPNC in BC The following summarizes the designations that apply to SPNC, which are designated as Threatened by the Committee on the Status of Endangered Wildlife in Canada. They are listed as Threatened in Canada on Schedule 1 of the Species at Risk Act. In BC, the SPNC are ranked S3 (special concern, vulnerable to extirpation or extinction) by the Conservation Data Centre and are on the provincial Blue list. The BC Conservation Framework ranks the SPNC as a priority 2 under goal 2 (prevent species and ecosystems from becoming at risk). They are protected from capture and killing, under the BC Wildlife Act. Caribou are also listed as a “Category of Ungulate Species” for which an Ungulate Winter Range (UWR) may be legally established under Section 11(3) of the Government Actions Regulation of the Forest and Range Practices Act (FRPA). UWRs contain habitat necessary to meet the winter habitat requirements of an ungulate species. Caribou are also listed as a "Category of Species at Risk" for which a Wildlife Habitat Area (WHA) may be legally established under Section 11(1) of the Government Actions Regulation. WHAs for caribou may be established to protect habitat required for calving, rutting, matrix/connectivity and mineral licks. UWRs and WHAs established under FRPA are also recognized under the Oil and Gas Activities Act. Recovery is considered to be biologically and technically feasible. The seasonal habitat use patterns of SPNC vary among herds, but generally in winter, they will select low-elevation forests (low-elevation winter habitat) and/or windswept alpine ridges (high-elevation winter habitat). In summer, certain herds use and select alpine and subalpine habitat, while other herds may use low-elevation boreal forest habitat. Use of high-elevation habitat provides some spatial separation between SPNC and predators such as grey wolves (Canis lupus) because these wolves primarily use low-elevation forest where the density of other ungulate species is higher. The primary cause of known adult mortality of SPNC is predation, primarily wolf predation. Other species including bears, wolverines (Gulo gulo) and eagles can be significant predators, particularly on calves. Any habitat change that compromises the spatial separation between caribou and their predators can compound this threat by increasing the risk of predation. Forestry-related activities have impacted SPNC and their habitat and are expected to do so into the future. Present-day energy production and mining are the most imminent industry-related threats to SPNC and their habitat. Impacts associated with forestry activities and energy and mining development include habitat loss, alteration and fragmentation and displacement of caribou from preferred habitats. Alteration of habitat may include the reduction of the availability of forage and/or the facilitation of habitat into early-seral forest, which supports more abundant early-seral ungulates (e.g., moose) and their predators. Most linear corridors such as access roads, seismic lines, pipelines and all- weather roads associated with energy production into the alpine increase SPNC risk to predation and have the potential to displace caribou from preferred habitats. Effluents and pollutants associated with energy production may also pose a risk to SPNC. The overall calculated and assigned threat impact that is observed, inferred, or suspected to be directly or indirectly effecting the ecology of SPNC over the next 10 years is very high (75% population declines).
- Data packageData from: Airplane tracking documents the fastest flight speeds recorded for bats(2016-10-31) McCracken, Gary; Safi, Kamran; Kunz, Thomas; Dechmann, Dina K.N.; Swartz, Sharon; Wikelski, MartinThe performance capabilities of flying animals reflect the interplay of biomechanical and physiological constraints and evolutionary innovation. Of the two extant groups of vertebrates that are capable of powered flight, birds are thought to fly more efficiently and faster than bats. However, fast-flying bat species that are adapted for flight in open airspace are similar in wing shape and appear to be similar in flight dynamics to fast-flying birds that exploit the same aerial niche. Here, we investigate flight behaviour in seven free-flying Brazilian free-tailed bats (Tadarida brasiliensis) and report that the maximum ground speeds achieved exceed speeds previously documented for any bat. Regional wind modelling indicates that bats adjusted flight speeds in response to winds by flying more slowly as wind support increased and flying faster when confronted with crosswinds, as demonstrated for insects, birds and other bats. Increased frequency of pauses in wing beats at faster speeds suggests that flap-gliding assists the bats’ rapid flight. Our results suggest that flight performance in bats has been underappreciated and that functional differences in the flight abilities of birds and bats require re-evaluation.
- Data packageData from: Eastern coyote home range, habitat selection and survival in the Albany pine bush landscape(2019-12-10) Bogan, Daniel A.; Kays, RolandIn the northeast USA, top mammalian predators were extirpated through persecution and habitat loss. The coyote (Canis latrans) expanded into the northeast taking advantage of this vacant predator niche. Since 1970, coyotes have been widespread across all of mainland New York, yet no study has examined how well coyotes survive in suburban areas in this region and little is known of their ecological roles or potential to conflict with people. This information is important because in western states coyotes have high survival rates, a high degree of urban association and cause conflict with people. I studied survivorship and correlates of cause-specific mortality of coyotes using radio telemetry. The annual survival rate was 0.20 ± 0.14. There were no differences in survival rates between sexes, age classes, home range location, or capture methods. Collisions with vehicles (n = 7) and shooting (n = 6) accounted for the 2 major mortality factors. Coyotes that were killed by vehicles crossed roads more often than all other coyotes, though they did not have more roads within their home ranges. Coyotes that were shot had a larger mean and maximum open habitat patch size within their home ranges. High exploitation of the local coyote population may cause coyotes to avoid human-developed lands thus reducing the potential for negative interactions with people. I concurrently studied home range and habitat selection of coyotes in the suburban Albany Pine Bush landscape. Fixed kernel and minimum convex polygon (95%) home ranges (n = 17) averaged 6.81 km2 and 5.75 km2, respectively. Habitat analysis revealed that coyotes selected for natural habitat and avoided residential and commercial lands when locating a home range area and moving within the home range. Compositional analysis additionally ranked natural habitat as the most selected habitat at 2 spatial scales of selection (62.3% and 74.5%). Coyotes lived in small home ranges and primarily used the remaining natural lands in the suburban landscape. These results indicate that local coyotes maintain a natural ecological role and under existing conditions do not currently pose a threat to people and pets living adjacent to natural lands.