A large reef manta ray (Manta alfredi) aggregation has been observed off the north Sudanese Red Sea coast since the 1950s. Sightings have been predominantly within the boundaries of a marine protected area (MPA), which was designated a UNESCO World Heritage Site in July 2016. Contrasting economic development trajectories have been proposed for the area (small-scale ecotourism and large-scale island development). To examine space-use, Wildlife Computers® SPOT 5 tags were secured to three manta rays. A two-state switching Bayesian state space model (BSSM), that allowed movement parameters to switch between resident and travelling, was fit to the recorded locations, and 50% and 95% kernel utilization distributions (KUD) home ranges calculated. A total of 682 BSSM locations were recorded between 30 October 2012 and 6 November 2013. Of these, 98.5% fell within the MPA boundaries; 99.5% for manta 1, 91.5% for manta 2, and 100% for manta 3. The BSSM identified that all three mantas were resident during 99% of transmissions, with 50% and 95% KUD home ranges falling mainly within the MPA boundaries. For all three mantas combined (88.4%), and all individuals (manta 1–92.4%, manta 2–64.9%, manta 3–91.9%), the majority of locations occurred within 15 km of the proposed large-scale island development. Results indicated that the MPA boundaries are spatially appropriate for manta rays in the region, however, a close association to the proposed large-scale development highlights the potential threat of disruption. Conversely, the focused nature of spatial use highlights the potential for reliable ecotourism opportunities.
Establishing baseline data on the abundance of threatened shark species is critical for monitoring site- and region-specific population tends over time. This is of particular importance for monitoring sharks at remote locations or in regions where there are no reliable data on shark numbers, fishing effort and current population status. Through establishing a standardized recreational SCUBA diver observation programme, this study examined the number, size and sex-composition of grey reef sharks, Carcharhinus amblyrhynchos, on a remote coral reef system off the Red Sea coast of Sudan. In addition, placard tags were attached to individual sharks to examine coarse scale residency and movement patterns and to determine the effectiveness of this technique. Over a 4.5 month period (December 2007–April 2008), a mean (±SE) of 5.9 ± 0.3 grey reef sharks were observed per diving day with peak numbers of sharks associated with temperatures of 26–26.9°C and strong currents. Estimated mean (±SE) total length of observed sharks was 1.9 ± 0.03 m identifying that most animals were mature. Female sharks were dominant on the site and pregnant females were recorded. Placard tagged sharks (N = 4) were observed by recreational SCUBA divers throughout the study period (23.1%, 20.0%, 16.9% and 3.1% of total observation diving days) indicating sporadic site attachment. The placard tags remained intact and were free of fouling for a total of 175 days. The numbers of grey reef sharks seen on this Red Sea coral complex suggest a healthy, relatively unexploited population. This study demonstrates that the recreational diver community, which forms a large pool of skilled volunteers, can generate baseline data on shark numbers at regularly dived sites and provide insights into the ecology of the observed species. Modification of placard tags, including attachment to the dorsal fin and time corrodible release systems may provide an inexpensive and accepted tool for monitoring individual shark residency and movement patterns. Engaging the recreational SCUBA diver community in a standardized scientific monitoring programme has the potential to monitor trends in shark populations over large spatial and temporal scales.
The movements of female moose, 14 in 1995 and 20 in 1996, were recorded by radio-tracking to examine the characteristics of calving sites in the centre of Quebec. Females were spotted by helicopter every 3 or 4 days mean = 3,5 ± 0,4; n = 15) between mid-May and early June (1995: May 17 - June 9; 1996: May 21 - June 6) so that the exact dates and sites of calving could be determined. Topography and vegetation at the sites were determined using topographic maps and terrestrial surveys and were compared with control sites chosen randomly within the home range of each female. Twenty-six calving sites were identified, 10 in 1995 and 16 in 1996. Calving sites were situated seven times more often at the top of hills (69%; n = 26) than control sites (10%). They were also situated more often (88%) on hills with less than 10% slopes than control sites (52%). Finally, distance to the nearest river was greater for calving sites mean = 543 m) than for control sites mean = 339 m). Canopy and food, altitude, distance to a road or a water source, drainage, and orientation did not differ between calving sites and control sites. Although this is not a formal test, the observed characteristics of calving sites support the hypothesis that calving females choose sites where the risks of fawn predation are lowest. As females do not repeatedly use the same calving sites and as the physical characteristics of the sites and nature of the forest at the sites are not limiting, we do not see any reason why moose calving sites should be submitted to particular protection or management measures.
Introductions of the rabbit flea, Spilopsyllus cuniculi (Dale), were made on an island (3.1 km2) of the Kerguelen subantarctic archipelago in January and December 1987. Despite a small founding population, the species succeeded in establishing itself. Three years after introduction, the rate of spread was 614 ± 133 m (between 1990 and 1993). Despite the subantarctic climate of Kerguelen, the burdens were similar to those noted in habitats favourable to this ectoparasite. The flea burden of adult rabbits after colonisation of the whole island was higher for pregnant females (182 ± 21, n = 98) than for non-pregnant ones (85 ± 16, n = 68) or males (20 ± 3, n = 116). The circulation of myxoma virus, present on this island for several decades, has been favoured by the flea. As a result, the proportion of rabbits with antibodies rose from 34% before introduction of the flea to 85% in 1998. Moreover, the introduction of fleas has changed the relative proportions of both adult males and females with antibodies. Those proportions were not different before the introduction but more males than females showed antibodies when the flea colonised the whole island. Finally, the prospects of the introduction of Spilopsyllus cuniculi on the main island of the archipelago are discussed.
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