Tethys Research Institute - Ionian Dolphin Project
Agony and death of a newborn bottlenose dolphin calf in the Amvrakikos Gulf, Greece
On July 3rd, 2008, we observed and filmed the agony of a newborn bottlenose dolphin in the semi-closed waters of the Amvrakikos Gulf, western Greece.
The newborn eventually died and sunk in the murky waters of the Gulf, disappearing from view.
The
observations were documented by a video and 104 digital photos (see a selection of 33 photographs).
Please report any comment, observation or literature to Joan
Gonzalvo.
Report of the observation
By Joan Gonzalvo, Elisa Malevolti and Giovanni Bearzi
Chronology |
Local time |
Notes |
0:00 |
10:10 |
Dolphins sighted. |
0:02 |
10:12 |
Arrival to dolphin position. Initial group: 2 adults and 1 newborn (NB). Other dolphins visible at a distance. The NB has apparent swimming difficulties and awkwardly flaps its fluke out of the water. Both adults keep surfacing close to him and regularly touch or push him. |
0:18 |
10:28 |
Other 2 adults and 1 calf join the initial group. One of the adults and the calf approach the NB surfacing very close, almost touching him. After a couple of minutes they leave. The second adult stays. The group is now composed of 3 adults and the NB. All three adults keep surfacing close to the NB, who swims with increasing difficulty. |
0:26 |
10:36 |
Other dolphins join the focal group, which now includes 6-7 adults and the NB. One of the two adults who were with the NB at the beginning of the sighting leaves. |
0:32 |
10:42 |
Twice the NB gets close (up to about 6 m) to the motionless research boat. In both occasions the adult who has been with him since the beginning of the sighting (the presumed mother) positions herself between the NB and the boat and pushes him away from the boat. The NB shows increasing signs of distress and frequently keeps his head out of the water. Various adults surround him and occasionally push or support him from below in an apparent attempt to help him stay afloat. |
0:40 |
10:50 |
Focal group now composed of five adults and the NB. On his frantic struggle to stay afloat the NB occasionally looses his balance and falls on his back. Adult dolphins keep supporting him. |
0:42 |
10:52 |
The NB shows increasing difficulties and continuously tries to keep his head out of the water. Adults staying close to the NB occasionally produce large bubbles of air and strike their flukes energetically underwater. |
0:45 |
10:55 |
Three adults have left. Now only the presumed mother and another adult assists the NB. Both of them keep him at the surface by swimming below him and pushing him up. |
0:48 |
10:58 |
The NB freezes and in a few seconds he sinks, disappearing from sight in the murky waters of the Amvrakikos Gulf, at a depth of about 20 m. The two dolphins who had been assisting him dive and disappear from sight for about 5 min. |
0:55 |
11:05 |
Dolphins seem to have merged in a single group composed of 7-8 adults, progressively moving away from the location where the NB was last seen. |
1:00 |
11:10 |
The group is now composed of 9 adults and 1 calf. Although they do not show a clear directionality they keep moving away from the spot where the NB was last seen. Three adults occasionally display social interactions. |
1:05 |
11:15 |
The group splits and we stay with 5 adults that keep moving away. The presumed mother of the dead NB is present. |
1:11 |
11:21 |
End of sighting. We leave the dolphin group about 500 m away from the area were the NB was last seen. |
Additional notes
While only one adult (the presumed mother) consistently stayed with the NB and was the one interacting with him more often, several other adults also interacted with the NB throughout the observation, touching him and apparently trying to help him stay afloat.
The presumed mother of the NB is a known female first identified in 2004. Gender was determined previously through photographs of the genital area during aerial behaviour. This female was encountered several times since 2004, but she was never seen with an offspring before. This suggests that the NB could have been her first calf.
Photographs of the NB showed that he had a series of large spots and irregular pigmentation on its back and head. While the origin and nature of these skin marks are presently unknown, they may be external evidence of disease. Alternatively, this abnormal pigmentation may be a result of increased exposure to sunlight (sun hits particularly hard in Greece at this time of the year) resulting from prolonged permanence near the surface.
Why we did not try to "save" the newborn dolphin
By Giovanni Bearzi
I wasn't on board when Joan and Elisa found the dying newborn, but I support their choice of documenting the event without trying to intervene.
I'm quite sure that they would have done their best to help the baby, should there be any space for meaningful action. But I agree with them that there wasn't any.
Below, I try to explain why.
---
The fate of the baby dolphin was rather unpredictable. While he obviously had problems, these were of unknown origin and they could have been of temporary nature. We did not know whether the newborn could recover and what was going to happen next. Only towards the end of the observation it became apparent that he was going to die.
Capturing a dolphin in deep open waters cannot be expected to be easy, also considering that adult dolphins were consistently preventing the baby from approaching the resarchers' boat too closely. The likely reaction by the newborn to approaching human swimmers under those circumstances could be avoidance and increased distress.
The researchers on boat had no veterinary experience and carried no medical equipment. The best they could do (provided that they managed to capture the bay dolphin) was keeping him at the surface. This, however, was expected to result in additional stress and overheating, thus increasing rather than decreasing the risk of mortality. Wild dolphins have been reported to die of stress when handled and the risk may be particularly high if the handled animal is already distressed or ill.
Attempts to capture the newborn may have elicited aggressive behaviours by its presumed mother and/or by other adult dolphins, exposing humans to unknown but potentially significant risks, particularly in deep and murky waters. The presence of swimmers was also likely to disrupt the behaviour of the whole group, possibly jeopardizing the repeated and obvious attempts by other dolphins to assist the newborn. This, again, was thought to increase rather than decrease the risk of a potentially fatal outcome.
For additional information on bottlenose dolphins in the Amvrakikos Gulf see: