Sensor:Radio Transmitter
Radio Transmitter
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Radio Transmitter
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radio-transmitter
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- Data packageData from: Ámbito de hogar y actividad circadiana del ocelote (Leopardus pardalis) en la Isla de Barro Colorado, Panamá(2020-07-03) Moreno, Ricardo; Mares, Rafael; Aliaga-Rossel, Enzo; Kays, RolandBecause ocelots (Leopardus pardalis) are elusive species in the wild, little is known of them. This study determines the home range and circadian activity of this feline in the Barro Colorado Island (BCI), Panama. This island has a wet tropical rainforest. Using wooden box traps and Tomahawk traps, between July 2001 and May 2004 15 ocelots were captured, and three other ocelots in 2009. Once captured, they were sedated and VHF collars were fitted, for the ones captured in 2009 we fitted GPS collars. Camera-traps were used to get additional information from individuals without collars and a more reliable data interpretation. The average home range of ocelots, obtained by radio-telemetry was 3.48 km2 (DE: 3.17) for males and 1.48 km2 (DE: 0.65) for females, although an adult male used an area of 9 km2. Males traveled on average 1.15 km per day and females 0.7 km. Through telemetry and camera traps, we found that ocelots were primarily nocturnal (Night = 63.2%; Day = 36.8%). Our results are similar to other studies; however, they suggest that BCI ocelots have smaller home ranges due to the high availability of food and also by the high density of females within the home ranges of males.
- Data packageData from: Large-range movements of neotropical orchid bees observed via radio telemetry(2020-07-03) Wikelski, Martin; Moxley, Jerry; Eaton-Mordas, Alexander; López-Uribe, Margarita M.; Holland, Richard A.; Moskowitz, David; Roubik, David W.; Kays, RolandNeotropical orchid bees (Euglossini) are often cited as classic examples of trapline-foragers with potentially extensive foraging ranges. If long-distance movements are habitual, rare plants in widely scattered locations may benefit from euglossine pollination services. Here we report the first successful use of micro radio telemetry to track the movement of an insect pollinator in a complex and forested environment. Our results indicate that individual male orchid bees (Exaerete frontalis) habitually use large rainforest areas (at least 42–115 ha) on a daily basis. Aerial telemetry located individuals up to 5 km away from their core areas, and bees were often stationary, for variable periods, between flights to successive localities. These data suggest a higher degree of site fidelity than what may be expected in a free living male bee, and has implications for our understanding of biological activity patterns and the evolution of forest pollinators.
- Data packageData from: Ecological impact of inside/outside house cats around a suburban nature preserve(2020-07-02) Kays, Roland; DeWan, Amielle A.While subsidised populations of feral cats are known to impact their prey populations, little is known about the ecological impact of inside/outside hunting cats (IOHC). We studied IOHC around a suburban nature preserve. Mail surveys indicated an average of 0.275 IOHC/house, leading to a regional density estimate of 0.32 IOHC/ha. A geographical model of cat density was created based on local house density and distance from forest/neighbourhood edge. IOHC hunted mostly small mammals, averaging 1.67 prey brought home/cat/month and a kill rate of 13%. Predation rates based on kills brought home was lower than the estimate from observing hunting cats (5.54 kills/cat/month). IOHC spent most outside time in their or their immediate neighbours' garden/yard, or in the nearby forest edge; 80% of observed hunts occurred in a garden/yard or in the first 10 m of forest. Radio‐tracked IOHC averaged 0.24 ha in home‐range size (95% minimum convex polygon (MCP)) and rarely entered forest. Confirming this, scent stations detected cats more often near the edge and more cats were detected in smaller forest fragments. There was no relationship between the number of cats detected in an area and the local small mammal abundance or rodent seed predation rates. Cold weather and healthy cat predator populations are speculated to minimise the ecological impact of IOHC on this area.
- 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.
- Data packageData from: The social organization of the kinkajou Potos flavus (Procyonidae)(2020-11-30) Kays, RolandThe social organization of the kinkajou Potos flavus is described from 380 h of observations on habituated, free-ranging animals. Individuals were most often alone while feeding at night, yet they regularly interacted in stable social groups. Four social groups were observed, each consisting of a single adult female, two adult males, one sub-adult and one juvenile. At least one breeding female was solitary and did not reside within a group. Social groups were consolidated primarily at denning sites and large fruiting trees by group feeding, allogrooming and scent marking. However, kinkajous were most often observed solitarily, as social feeding only occurred in 19.6 of total feeding bouts (mainly among males) and individuals rarely travelled together. Although the composition of social groups was polyandrous, males also copulated with non-group females which suggests a promiscuous mating system. Female-biased dispersal and patterns of male association seem to be patrilineal and based on resource defence. The evolution of social organization in the kinkajou is discussed in relation to predation risk, resource availability, and convergence with primates of similar fission–fusion socioecology.
- Data packageData from: Thieving rodents as substitute dispersers of megafaunal seeds(2012-06-27) Jansen, Patrick A.; Hirsch, Ben T.; Emsens, Willem-Jan; Zamora-Gutierrez, Veronica; Wikelski, Martin; Kays, RolandThe Neotropics have many plant species that seem to be adapted for seed dispersal by megafauna that went extinct in the late Pleistocene. Given the crucial importance of seed dispersal for plant persistence, it remains a mystery how these plants have survived more than 10,000 y without their mutualist dispersers. Here we present support for the hypothesis that secondary seed dispersal by scatter-hoarding rodents has facilitated the persistence of these large-seeded species. We used miniature radio transmitters to track the dispersal of reputedly megafaunal seeds by Central American agoutis, which scatter-hoard seeds in shallow caches in the soil throughout the forest. We found that seeds were initially cached at mostly short distances and then quickly dug up again. However, rather than eating the recovered seeds, agoutis continued to move and recache the seeds, up to 36 times. Agoutis dispersed an estimated 35% of seeds for >100 m. An estimated 14% of the cached seeds survived to the next year, when a new fruit crop became available to the rodents. Serial video-monitoring of cached seeds revealed that the stepwise dispersal was caused by agoutis repeatedly stealing and recaching each other’s buried seeds. Although previous studies suggest that rodents are poor dispersers, we demonstrate that communities of rodents can in fact provide highly effective long-distance seed dispersal. Our findings suggest that thieving scatter-hoarding rodents could substitute for extinct megafaunal seed dispersers of tropical large-seeded trees.