Underwater Footage of Whales and Dolphins Interacting

If two animals share the same environment, then at some point they are likely to meet. In the wild these meetings are often between predator and prey; however, nature isn’t always so cruel. Some such encounters, referred to as “interspecies interactions,” can be playful or social, where neither individual is threatened.

 

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Mother-Calf Dolphin Resight

On August 12, the research team went out on the water surveying for odontocetes and marine debris. At around 11 am, we sighted a pod of 17 bottlenose dolphins and began taking photographs, as per our protocol. We spent the maximum allowed hour with this pod, giving our interns a chance to try their photo-identification skills and collect as many dorsal fin photographs as possible, as the pod was milling about and not difficult to keep track of. While we were watching the dolphins, we noticed there were two distinct pairings in the pod.

Later that week when we were in the office cataloging and examining the photographs, our analyst Jens noticed that one of the pairs was already in our bottlenose dolphin catalog. The same two individuals had been photographed together as a mother-calf pair  in 2011.

This mother and calf pair was sighted on August 6, 2011 and again on August 12, 2014.

This mother and calf pair was sighted on August 6, 2011 and the pair was seen again on August 12, 2014.

This is pretty neat because using photo-identification we can track how long these two individuals stay together. Bottlenose dolphins have a complex social structure that is very different from odontocetes that live in stable groups like a pod of killer whales. They live in a fission-fusion society, meaning it is dynamic and always changing. However, the association between a mother and calf is one of the strongest bonds in the dolphin society. They will stay together on average for between three and six years, and we know that these two have been together for at least three years. It will be interesting to see what happens to these two individuals in the future.

FACT OF THE WEEK: The Name Game

FACT OF THE WEEK: Bottlenose dolphins may address each other by name!

MORE ON THIS: Recent research has suggested that bottlenose dolphins have individually unique signature whistles that are equivalent to human names. During the first few months of life, a dolphin will develop its own signature whistle made up of a series of sounds and notes. Dolphins will also adopt the signature whistle of other dolphins in the pod to identify and communicate with different individuals, specifically close associates or those with strong social bonds. When a dolphin emits its own signature whistle, a  dolphin that is a close associate will reply with a copied version of the whistle with a few subtle alterations that differentiates the signature whistle from the copied whistle. This allows the second dolphin to relay information back to the first dolphin; the alterations to the whistle may also give information about who the second dolphin is.

Signature whistles httpwww.cell.comcmsattachment20079513612030487757gr2.jpg

Image from: Janik, V.M. 2013. Cognitive skills in bottlenose dolphin communication. Trends in Cognitive Sciences 17(4): 157 – 159.

Many species of dolphins live in fission-fusion societies, this means that the size and composition of the pod will change as time passes. When pods merge together, vocal signatures are exchanged in order to learn about the identities of individual members of the new pod. These exchanges are generally repeated several times during the interaction to either improve the probability of correct identification, or provide additional information with each exchange.

FURTHER READING:

Written by Patrice Hostetter

Bottlenose dolphin in Maalaea Harbor

Dolphin in Maalaea Harbor

The research team did not have to go far on July 3rd to spot a dolphin. There was one swimming around Maalaea Harbor! It looked like a sub-adult, meaning it was not fully grown. We photographed it following our protocol, and this week searched for a match within our bottlenose dolphin catalog, but this individual had not been photographed previously by our researchers. When we were examining the photos, we noticed a lot of tooth rake scars on the posterior (back) half of its body – perhaps it was seeking shelter from another dolphin or predator, it was curious, or maybe it had simply gotten lost. The team watched for a while and eventually the dolphin followed another boat out of the harbor.  Teenagers are always getting into trouble!

Rake Marks Photoshopped