scholarly journals Evaluation of a satellite telemetry system for monitoring movements of caribou

Rangifer ◽  
1986 ◽  
Vol 6 (2) ◽  
pp. 73 ◽  
Author(s):  
James A. Curatolo

A cow caribou from the Central Arctic Herd was collared with a satellite-monitored radio transmitter in the Kuparuk Oilfield, Alaska, in 1984. From 19 June to 17 August, the radio transmitted 18 hours per day. A total of 346 locations were recorded, for a mean of 5.8 locations per day or one location every 3.1 hours of transmission time. The location of 13 direct observations of the radio-collared cow averaged less than 1 km from the nearest satellite-fixed location. The satellite-fixed locations of the radio-collared cow provided detailed data on movement patterns during the three seasons studied. The cow traveled an average of 8 km day1, 23 km1, and 14 km day1 during the post-calving season, mosquito season, and oestrid fly season, respectively.

2001 ◽  
Vol 28 (3) ◽  
pp. 283 ◽  
Author(s):  
Glenn P. Edwards ◽  
Stephen R. Eldridge ◽  
David Wurst ◽  
David M. Berman ◽  
Vanessa Garbin

Movement patterns of female feral camels were studied over four years (February 1993 to December 1996) in central and northern Australia using satellite telemetry. Areas used over 12-month periods (calculated using the fixed kernel method) were large (449–4933 km 2 ) and increased with increasing aridity as measured by long-term mean annual rainfall. No consistent pattern of variation was detected in movement rates of camels across seasons. Data collected over several years are needed to classify movements in feral camels. The only telemetered camel that has been monitored for longer than two years (this study) appeared to move within a large home range over the concluding 3.5 years that it was tracked. Because the areas used are large, extensive buffer zones will be needed in arid regions to protect environmentally sensitive areas from the impacts of feral camels.


Author(s):  
Sandra Bessudo ◽  
Germán A. Soler ◽  
Peter A. Klimley ◽  
James Ketchum ◽  
Randall Arauz ◽  
...  

Understanding distribution ranges and the daily movement patterns of pelagic fishes are key aspects for the establishment and planning of protected areas for their conservation. In this study the vertical and horizontal movements of scalloped hammerhead sharks, Sphyrna lewini, were recorded in Malpelo and Cocos Island using satellite telemetry. Nine sharks were tagged with satellite transmitters during March 2006, 2007 and 2008 at Malpelo Island, and three hammerhead sharks were tagged at Cocos Island in June 2008. The sharks moved between islands in the Tropical Eastern Pacific and made regional movements from Malpelo to the south of Cocos and around the Malpelo ridge. When away from the island, sharks made infrequent nocturnal short dives down to 1000 m where temperatures were as low as 4 °C. For a shark that was tracked for five months, results indicated significant differences between the time spent at different depth ranges, as well as an interaction between depth, water layers, and the time of the day. The shark swam mostly at surface waters (0-10 m) during the cold water season, and spent more time at the deepest depth range (>100 m) during nigh time. Further long-term studies on shark movement patterns are required for a better management of this highly mobile and vulnerable species.


Koedoe ◽  
2015 ◽  
Vol 57 (1) ◽  
Author(s):  
Peter M. Calverley ◽  
Colleen T. Downs

The study of movement patterns and home range is fundamental in understanding the spatial requirements of animals and is important in generating information for the conservation and management of threatened species. Ndumo Game Reserve, in north-eastern KwaZulu-Natal, bordering Mozambique, has the third largest Nile crocodile (Crocodylus niloticus) population in South Africa. Movement patterns of 50 Nile crocodiles with a total length of between 202 cm and 472 cm were followed over a period of 18 months, using mark-resight, radio and satellite telemetry. The duration of radio transmitter attachment (131 ± 11.4 days) was significantly and negatively related to total length and reproductive status. Satellite transmitters failed after an average of 15 ± 12.5 days. Home range was calculated for individuals with 10 or more radio locations, spanning a period of at least 6 months. There was a significant relationship between home range size and total length, with sub-adults (1.5 m – 2.5 m) occupying smaller, more localised home ranges than adults (> 2.5 m). The largest home ranges were for adults (> 2.5 m). Home ranges overlapped extensively, suggesting that territoriality, if present, does not result in spatially discrete home ranges of Nile crocodiles in Ndumo Game Reserve during the dry season. Larger crocodiles moved farther and more frequently than smaller crocodiles. The reserve acts as a winter refuge and spring breeding site for an estimated 846 crocodiles, which also inhabit the Rio Maputo during the summer months. Nile crocodile movement out of the reserve and into the Rio Maputo starts in November and crocodiles return to the reserve as water levels in the floodplain recede in May.Conservation implications: Movement patterns of Nile crocodiles show the important role the reserve plays in the conservation of Nile crocodile populations within the greater Ndumo Game Reserve–Rio Maputo area.


Author(s):  
D. Hughes ◽  
T. P. Lynch ◽  
L. Pender ◽  
M. Sherlock

2019 ◽  
Author(s):  
Tiziana A. Gelmi-Candusso ◽  
Ronald Bialozyt ◽  
Darja Slana ◽  
Ricardo Zárate Gómez ◽  
Eckhard W. Heymann ◽  
...  

AbstractSeed dispersal distances (SDD) critically influence the survival of seedlings, spatial patterns of genetic diversity within plant populations and gene flow among plant populations. In tropical forests, a large percentage of seeds is dispersed by animals, and their foraging behaviour and movement patterns determine SDD. Direct observations of seed dispersal events by animals in natural plant populations are mostly constrained by the high mobility and low visibility of their vectors. Therefore, diverse alternative methods are used to estimate SDD, but direct comparisons of these approaches within the same seed dispersal system are mostly missing.In this study, we take advantage of two plant species with different life history traits, Leonia cymosa and Parkia panurensis that are exclusively dispersed by two tamarin species, Saguinus mystax and Leontocebus nigrifrons (Callitrichidae) at our study site in the Peruvian Amazon. We compare SDD estimates obtained from direct observations, genetic identification of mother plants from seed coats, parentage analysis of seedlings, and modelling approaches, including the combination of movement data and gut passage times and individual-based modelling.We detect differences between SDD estimates that can be linked to the processes relevant at different phases of the seed dispersal loop covered by the respective approaches. Despite these differences, SDD estimates for P. panurensis are consistently lower than for L. cymosa which is likely related to differences in fruit characteristics and fruit abundance, factors that influence gut passage time, foraging behaviour and movement patterns of the tamarins.Our comparisons allow setting SDD estimates from studies using different methodological approaches into the seed dispersal loop context, thus improving comparability of methodologically different studies and method applicability.


2020 ◽  
Vol 16 (12) ◽  
pp. 20200645
Author(s):  
Jefferson T. Hinke ◽  
George M. Watters ◽  
Christian S. Reiss ◽  
Jarrod A. Santora ◽  
M. Mercedes Santos

Estimating when and where survival bottlenecks occur in free-ranging marine predators is critical for effective demographic monitoring and spatial planning. This is particularly relevant to juvenile stages of long-lived species for which direct observations of death are typically not possible. We used satellite telemetry data from fledgling Adélie, chinstrap and gentoo penguins near the Antarctic Peninsula to estimate the spatio-temporal scale of a bottleneck after fledging. Fledglings were tracked up to 106 days over distances of up to 2140 km. Cumulative losses of tags increased to 73% within 16 days of deployment, followed by an order-of-magnitude reduction in loss rates thereafter. The timing and location of tag losses were consistent with at-sea observations of penguin carcasses and bioenergetics simulations of mass loss to thresholds associated with low recruitment probability. A bootstrapping procedure is used to assess tag loss owing to death versus other factors. Results suggest insensitivity in the timing of the bottleneck and quantify plausible ranges of mortality rates within the bottleneck. The weight of evidence indicates that a survival bottleneck for fledgling penguins is acute, attributable to predation and starvation, and may account for at least 33% of juvenile mortality.


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