Opportunistic visitors: long-term behavioural response of bull sharks to food provisioning in Fiji

Shark-based tourism that uses bait to reliably attract certain species to specific sites so that divers can view them is a growing industry globally, but remains a controversial issue. We evaluate multi-year (2004–2011) underwater visual (n = 48 individuals) and acoustic tracking data (n = 82 transmitters; array of up to 16 receivers) of bull sharks Carcharhinus leucas from a long-term shark feeding site at the Shark Reef Marine Reserve and reefs along the Beqa Channel on the southern coast of Viti Levu, Fiji. Individual C. leucas showed varying degrees of site fidelity. Determined from acoustic tagging, the majority of C. leucas had site fidelity indexes >0.5 for the marine reserve (including the feeding site) and neighbouring reefs. However, during the time of the day (09:00–12:00) when feeding takes place, sharks mainly had site fidelity indexes <0.5 for the feeding site, regardless of feeding or non-feeding days. Site fidelity indexes determined by direct diver observation of sharks at the feeding site were lower compared to such values determined by acoustic tagging. The overall pattern for C. leucas is that, if present in the area, they are attracted to the feeding site regardless of whether feeding or non-feeding days, but they remain for longer periods of time (consecutive hours) on feeding days. The overall diel patterns in movement are for C. leucas to use the area around the feeding site in the morning before spreading out over Shark Reef throughout the day and dispersing over the entire array at night. Both focal observation and acoustic monitoring show that C. leucas intermittently leave the area for a few consecutive days throughout the year, and for longer time periods (weeks to months) at the end of the calendar year before returning to the feeding site

Vigilance of mustached tamarins in single-species and mixed-species groups—the influence of group composition

Species that participate in mixed-species groups (MSG) may have complementary roles in antipredator strategies. We studied vigilance in mustached tamarins (Saguinus mystax), small arboreal primates that form stable mixed-species groups with saddleback tamarins (Saguinus fuscicollis), in order to examine how the direction of vigilance changes with different species group compositions and whether the division of labor between the two species can be confirmed. We did so by comparing quantitative and qualitative differences in vigilance behavior between same individuals in and out of association (case A); MSG and single-species groups of the same total group size from two different populations (case B); and MSG of the same group size but with a different ratio of conspecifics to heterospecifics (case C). We predicted that individuals would increase downward scanning when heterospecifics are absent or their percentage is low, but total vigilance would increase only in case A due to the group size effect. However, mustached tamarins increased total vigilance due to horizontal scanning in cases A and C, and the predictions were confirmed only in small-sized groups in case B. Thus, we found indications that associating tamarin species in MSG might complement each other in the direction of vigilance, but the division of labor alone does not satisfactorily explain all the findings. There appear to be other mechanisms at work that define how direction of vigilance changes with group size and species composition. Complementarity of species probably occurs due to species vertical stratification rather than differences in the direction of vigilance

Dog-walking behaviours affect gastrointestinal parasitism in park-attending dogs.

Background: In urban parks, dogs, wildlife and humans can be sympatric, introducing the potential for inter- and intra-specific transmission of pathogens among hosts. This study was conducted to determine the prevalence of zoonotic and non-zoonotic gastrointestinal parasites in dogs in Calgary city parks, and assess if dog-walking behaviour, park management, history of veterinary care, and dog demographics were associated with parasitism in dogs Methods: From June to September 2010, 645 questionnaires were administered to dog owners in nine city parks to determine behavioural and demographic factors, and corresponding feces from 355 dogs were collected. Dog feces were analyzed for helminth and some protozoan species using a modified sugar flotation technique and microscopic examination, a subsample was analyzed for Giardia spp. and Cryptosporidium spp. using a direct immunofluorescence assay. Descriptive and multivariate statistics were conducted to determine associations among behaviours, demographics, and parasite prevalence and infection intensities Results: Parasite prevalence was 50.2%. Giardia spp. (24.7%), Cryptosporidium spp. (14.7%), and Cystoisospora spp. (16.8%) were the most prevalent parasites. Helminth prevalence was low (4.1%). Presence of Giardia spp. was more likely in intact and young dogs; and infection with any parasite and Giardia spp. intensity were both positively associated with dogs visiting multiple parks coupled with a high frequency of park use and off-leash activity, and with being intact and young. Cryptosporidium spp. intensity was associated with being intact and young, and having visited the veterinarian within the previous year Conclusions: Our results indicate a higher overall prevalence of protozoa in dogs than previously found in Calgary. The zoonotic potential of some parasites found in park-attending dogs may be of interest for public health. These results are relevant for informing park managers, the public health sector, and veterinarians

Grey Nurse Shark (Carcharias taurus) Diving Tourism: Tourist Compliance and Shark Behaviour at Fish Rock, Australia

Humans can dive with critically endangered grey nurse sharks (Carcharias taurus) along the east coast of Australia. This study investigated both compliance of tourist divers to a code of conduct and legislation and the behaviour of grey nurse sharks in the presence of divers. A total of 25 data collection dives were conducted from December 2008 to January 2009. Grey nurse shark and diver behaviour were documented using 2-min scan samples and continuous observation. The proportion of time spent observing human–shark interactions was 9.4% of total field time and mean human–shark interaction time was 15.0 min. Results were used to gauge the effectiveness of current management practices for the grey nurse shark dive industry at Fish Rock in New South Wales, Australia. Grey nurse shark dive tourists were compliant to stipulations in the code of conduct and legislation (compliance ranged from 88 to 100%). The research detailed factors that may promote compliance in wildlife tourism operations such as the clarity of the stipulations, locality of the target species and diver perceptions of sharks. Results indicated that grey nurse sharks spent the majority of their time milling (85%) followed by active swimming (15%). Milling behaviour significantly decreased in the presence of more than six divers. Distance between sharks and divers, interaction time and number of sharks were not significantly correlated with grey nurse shark school behaviour. Jaw gaping, rapid withdrawal and stiff or jerky movement were the specific behaviours of grey nurse sharks that occurred most frequently and were associated with distance between divers and sharks and the presence of six or more divers. Revision of the number of divers allowed per interaction with a school of grey nurse sharks and further research on the potential impacts that shark-diving tourism may pose to grey nurse sharks is recommended