Swimmer-whale/dolphin in-water encounters (2012-2014)
Field study news on in-water encounters with free-ranging cetaceans.
Wildlife encounters of humans diving, swimming and wading in the vicinity of cetaceans in open water environments have increased worldwide. At the same time, the quality and quantity of close-up or interactive cetacean behaviors addressed towards humans appear to vary widely. In the past, free-ranging cetaceans were reported to avoid, aggressively interact with, injure or even kill humans. Further indirect effects threatening the health status of target species such as entanglements, boat strikes or alterations of behavior have been reported as negative by-products. From the management perspective, encounters have to be directed in order to reduce the likelihood of detrimental outcomes for both sides. It has been proposed to conduct studies on the quality of behavioral interactions to facilitate a comparative perspective between species and locations, as well as to conduct research before commercial programs are implemented. However, self-initiated cetacean behaviors addressed towards humans still have received little attention, hence their structure and function largely remain unclear.
In a collaborative effort, researchers from Brazil (Luiz Cláudio Pinto de Sá Alves, Alexandre de Freitas Azevedo and Artur Andriolo) and Germany (Fabian Ritter and Michael Scheer) currently catalogue self-initiated behaviors of two cetacean species. The study will compare behaviors addressed towards human feeders and swimmers which occur during encounters with food-provisioned Amazon botos (Inia geoffrensis) and non-habituated short-finned pilot whales (Globicephala macrorhynchus) in the Canary Islands, respectively.
During the majority of encounters, short-finned pilot whales addressed affiliative behaviors towards swimmers. Neutral or avoidance behavior occurred less and intraspecific agonistic behaviors occurred rarely. In contrast, botos did not show avoidance reactions to human feeders but were permanently attracted to them. Risky behaviors occurred during all encounters and botos additionally addressed agonistic behaviors towards conspecifics. Nearly all risky interspecific behaviors remained constant or increased and all agonistic intraspecific behaviors increased between seasons. Thus, humans are permanently exposed to health risks, and these increased between consecutive seasons.
First results will be published in 2014 (...here…).
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Food-provisioning of Amazon botos
Swim encounters with short-finned pilot whales
Click ...here... to see a group of short-finned pilot whales underwater in close range to the swimmer (.mov file with 7.2 MB). Several times the whales echolocate towards the swimmer.
Click ...here... to see and mainly hear a group of short-finned pilot whales communicating (.mov file with 6.4 MB). The whales emit a variety of sounds such as clicks, whistles, grunts and calls.
Click ...here... to see two pilot whales encircling
two human swimmers (.mov file with 5 MB)
Click ...here... to see a pilot whale frontally approaching
a human swimmer (.mov file with 1.9 MB)
Click ...here... to see a large pilot
whale group (.mov file with 18.2 MB)
(Video: Fabian Ritter)
Click ...here... to see human snorkelers swimming
with a large pilot whale group (.mov file with 10.4 MB)
(Video: Roland Gockel)
Click ...here... to see a human swimmer approaching
a pilot whale underwater (.mov file with 9.9 MB)
(Video: Roland Gockel)
Field study news
Encounters of humans with free-ranging marine mammals have quantitatively increased worldwide, mainly in the context of commercial whale watching activities. In addition to observations of free-ranging animals from land, air or boat, for many humans it has become a life-dream to encounter a whale, dolphin or pinniped directly in its natural habitat and during swim encounters. Next to short-finned pilot whales (...here...) more than 20 free-ranging whale and dolphin species were reported to be encountered by human swimmers, snorkelers, divers and waders.
As for short-finned pilot whales (...here...), cetacean individuals or groups self-initiate a variety of behaviors which they address towards humans. Own research showed (...here...) that these behaviors can be affiliative, aggressive-threatening and sexual in nature. Though most interactive behaviors were affiliative, food-provisioned and solitary dolphins were reported to self-initiate -next to affiliative- aggressive-threatening and even sexual behaviors. It is believed that these behaviors are responses to inappropriate human behaviors.
Research is authorized by the Ministerio de Agricultura, Alimentación y Medio Ambiente, Madrid, Spain. Commercial or private swim encounters with wild cetaceans in Canary Island waters are prohibited by law.