[In January 2003 I accompanied an expedition that was conducting a survey of river dolphins on a stretch of the Mekong River in Cambodia. The expedition was led by Isabel Beasley, who was then a PhD student specializing on Orcaella brevirostris: also known as the ‘Irrawaddy Dolphin’ this species is found in many Asian river systems and deltas. The journal I kept during the expedition will appear on this site as a continuous series of posts. This is part 5 of the series.]
While speaking of Pilleri’s experiments with Indus dolphins (the animals he took to Switzerland) I mentioned one of his findings* – which was that he’d found the dolphins to be very sensitive to atmospheric pressure, to the point where they would respond to storms even before they had actually struck the area around the laboratory. Isabel says that this is widely reported also of orcaella. The local people says that the dolphins can be observed to behave differently before storms, jumping out of the water etc. This has been reported also of coastal orcaella, so it seems plausible that there is some kind of behavioural response to storms and atmospheric changes.
*see: Pilleri, G., 1970 b. The Capture and Transport to Switzerland of two live Platanista gangetica from the Indus River. Investigations on Cetacea,II.