title: Food provisioning increases the risk of injury in a long-lived marine top predator.
abstract: Food provisioning of wildlife is a major concern for management and conservation agencies worldwide because it encourages unnatural behaviours in wild animals and increases each individual's risk for injury and death. Here we investigate the contributing factors and potential fitness consequences of a recent increase in the frequency of human interactions with common bottlenose dolphins (Tursiops truncatus) in Sarasota Bay, Florida. A rising proportion of the local long-term resident dolphin community is becoming conditioned to human interactions through direct and indirect food provisioning. We investigate variables that are affecting conditioning and if the presence of human-induced injuries is higher for conditioned versus unconditioned dolphins. Using the most comprehensive long-term dataset available for a free-ranging bottlenose dolphin population (more than 45 years; more than 32 000 dolphin group sightings; more than 1100 individuals), we found that the association with already conditioned animals strongly affected the probability of dolphins becoming conditioned to human interactions, confirming earlier findings that conditioning is partly a learned behaviour. More importantly, we found that conditioned dolphins were more likely to be injured by human interactions when compared with unconditioned animals. This is alarming, as conditioning could lead to a decrease in survival, which could have population-level consequences. We did not find a significant relationship between human exposure or natural prey availability and the probability of dolphins becoming conditioned. This could be due to low sample size or insufficient spatio-temporal resolution in the available data. Our findings show that wildlife provisioning may lead to a decrease in survival, which could ultimately affect population dynamics.
authors.affiliation: Cetacean Research Unit, School of Veterinary and Life Sciences , Murdoch University , Murdoch, Western Australia 6150 , Australia.
authors.forename: Fredrik
authors.identifier: 0000-0001-9090-8458
authors.initials: F
authors.lastname: Christiansen
authors.affiliation: Sarasota Dolphin Research Program, Chicago Zoological Society, c/o Mote Marine Laboratory , Sarasota, FL , USA.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: McHugh
authors.affiliation: Cetacean Research Unit, School of Veterinary and Life Sciences , Murdoch University , Murdoch, Western Australia 6150 , Australia.
authors.forename: Lars
authors.identifier: 0000-0001-8138-8606
authors.initials: L
authors.lastname: Bejder
authors.affiliation: Institute of Biological and Environmental Sciences , University of Aberdeen , Aberdeen AB24 2TZ , UK.
authors.forename: Eilidh M
authors.initials: EM
authors.lastname: Siegal
authors.affiliation: Institute of Biological and Environmental Sciences , University of Aberdeen , Aberdeen AB24 2TZ , UK.
authors.forename: David
authors.initials: D
authors.lastname: Lusseau
authors.affiliation: Sarasota Dolphin Research Program, Chicago Zoological Society, c/o Mote Marine Laboratory , Sarasota, FL , USA.
authors.forename: Elizabeth Berens
authors.initials: EB
authors.lastname: McCabe
authors.affiliation: Mote Marine Laboratory , Sarasota, FL , USA.
authors.forename: Gretchen
authors.initials: G
authors.lastname: Lovewell
authors.affiliation: Sarasota Dolphin Research Program, Chicago Zoological Society, c/o Mote Marine Laboratory , Sarasota, FL , USA.
authors.forename: Randall S
authors.initials: RS
authors.lastname: Wells
keywords: Sarasota; anthropogenic disturbance; behaviour; dolphin; human exposure; wildlife management