Neonate Bottlenose dolphin stranded in Co Clare

4th Dec 2010 A newborn bottlenose dolphin calf was washed up in Doolin, Co Clare. The calf was likely live-stranded soon after birth.

On Wednesday lunchtime (2 December) I got a call from Jamie Storer on the beach at Doolin, Co Clare. Jamie said he had found a very small bottlenose dolphin. Usually I would expect this was mis-identified and was really a common or striped dolphin, but Jamie is thorough and has yet to get a species id wrong so I swung around to Doolin on my way home.

Jamie said local fisherman "The Dog" had found the dolphin that morning and from the haemorrhaging around its head it had live stranded. It was fresh and very clearly a newly born (neonate) bottlenose dolphin. The dolphins neonatal folds are clearly visible and its trailing umbilical cord.

The dolphins teeth had not erupted and the end of its tongue was crenulated, these papillae are used to form a seal on its mothers teat if it had the chance to suckle. Note also the vibrassae on the dolphins beak - a remnant of its terrestrial ancestry and often seen on foetus and newborn calves but soon disappear.

The dolphin measured 1.2m in length and weighed 21kg. This is by far the smallest bottlenose dolphin recorded stranded in Ireland. Bottlenose dolphins are typically born at 0.8-1.4m in length and from 9-30kg. From the bent dorsal fin and curled tail flukes we can confidently say this dolphin was only just born and live-stranded. We can only speculate as to what happened. Maybe it was separated from its mother on birth, maybe she was unable to help it to the surface to take its first breath, maybe the mother was alone and did not have the support of a maternal group to assist at birth.

Bottlenose dolphins in the Shannon Estuary, just 60km south of Doolin give birth from May to October but peak in July and August when sea temperatures are at their highest. Maybe the sea was too cold (around 11C at present) and the calf had thermal shock ! we will never know but this stranding provides valuable information on bottlenose dolphin reproductive behaviour in Ireland.

Thanks to Jamie Storer of Doolin, Co Clare for yet another interesting record.

Simon Berrow

IWDG Co-ordinator