Sightings of baby spinner and spotted dolphins

Recently the research team set out towards the island of Lanaʻi to continue our odontocete and marine debris surveys. Around 9:30 am, we came across a pod of approximately 100 spinner dolphins, including five calves. Even better, two of the calves were neonates: newborn dolphins!

Neonates can be distinguished by their small size: only 75-80 centimeters long in spinner dolphins — about the length of a skateboard. They also have “fetal folds” on their sides. These vertical, lightly-colored “stripes” are the result of being folded up inside mom, and they fade with time as the calf grows.

After spending just under an hour with the spinner dolphin pod, we continued our survey and were rewarded again, this time with an active pod of approximately 45 pantropical spotted dolphins, including six calves.

Not only was it great to see so many calves in one day, but these sightings were also sources of valuable data. Photographs and behavioral data collected during the time we spent with these animals will help build our photo ID catalogs and further our understanding of the amazing dolphins living here.

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.


The research team was recently lucky enough to observe two such interactions while surveying humpback whales off the leeward coast of Maui. The first was between pantropical spotted dolphins and humpback whales and the second between bottlenose dolphins and two humpback whales. Humpback whales and dolphins are more often observed in pods consisting of their own species; however interspecies interactions have been documented before. One notable example was in 2010 when researchers Deakos et al. observed bottlenose dolphins and humpback whales engaging in a “lift and slide” type of game off the coast of Kauai; which was such a significant behavior that their findings were later published as a scientific paper.

In the video captured by the research team, one of the two humpback whales is observed swimming with a group of bottlenose dolphins. Some explanations for this behavior could be:

  • Dolphins hunting fish that associate with the whale
  • Dolphins riding the pressure wave created by the whale swimming, similar to bow-riding
  • Dolphins bullying the whale
  • Play behavior, such as the whale attempting to coax a dolphin onto its head for another game of “lift and slide the dolphin”

The PWF Research Team is excited to be able to share this special encounter with you.

Reference:
Deakos, Mark H., et al. “Two unusual interactions between a bottlenose dolphin (Tursiops truncatus) and a humpback whale (Megaptera novaeangliae) in Hawaiian waters.” Aquatic Mammals 36.2 (2010): 121-128.

Double Take: False Killer Whales and Pilot Whales in the Same Day

When the research team carries out odontocete transects, we are looking for all species of toothed whales, but most commonly we see bottlenose, spotted and spinner dolphins. On rare occasions we see false killer whales, of which the insular Hawaiian population is on the endangered species list, and short-finned pilot whales, which is a deeper water species not commonly found in the shallower waters of our survey area. We might see these two species a handful of days per year. Well, believe it or not, we were recently lucky enough to see them both on the same day!

We were surveying the area behind the island of Lana‘i and we had a feeling it was going to be a special day when we set off from Ma‘alaea Harbor. We had just arrived at the start of our first transect line when we saw a large black dorsal fin. We soon realized that this was a false killer whale. At first we only saw one solitary individual, but it soon swam and joined the rest of its pod, which we estimated at 15 individuals. We photographed them to obtain ID’s for our false killer whale catalog and collected behavioral data. When we were satisfied that we had photographed all the individuals present we returned to our transect line, excited that we had such an exciting experience so early in the day.

Less than 30 minutes later we spotted another dorsal fin, only this one was much larger than the other species. Could it be? A quick confirmation with binoculars told us that, yes, we had a pod of short-finned pilot whales right in front of us. The pod was milling at the surface and spyhopping to check us out. Once again we photographed them for our photo-ID catalog and collected behavioral data as per our protocol. This time we stayed the maximum 60 minutes, and then we had to leave and return to complete the transect line.

Later that month we cataloged the photographs taken that day and realized that not one of the pilot whales photographed that day was a match to our catalog.  This most likely means that this pod was an entirely new sighting for us; we have never photographed them before. We added 22 new individuals to our catalog; 0 were re-sights. Of the false killer whales photographed, 10 were new individuals to our catalog and 3 were re-sights.

It was really a very special day for all of us on board the Ocean Protector. We consider ourselves very lucky if we see one of these species and to see them both in a single day was so amazing.

Here is a map to show you where the research department has sighted these two species over the past few years:

Sightings Map Of False Killer Whales and Short-Finned Pilot Whales

Coral Reef Survey

Pacific Whale Foundation (PWF) was recently contacted by WHALE Environmental Services LLC and asked if we were interested in a collaboration, as this Oahu-based company was planning to undertake a pilot project to survey the West Maui coral reefs. PWF was very keen to take part, and so we made arrangements to take our research vessel, Ocean Protector, out as a diving vessel for a change.

Using a standardized method, we made very short dives at 14 coral reefs along the coast of West Maui, between Ma’alaea Harbor and Honolua Bay. While scuba diving, we took note of various factors which would be used to indicate reef health, such as:

  • the number of coral species observed
  • the number of fish species observed
  • signs of pollution
  • signs of erosion
  • signs of coral disease or bleaching
  • signs of fishing pressure
  • signs of stormwater entry at the site

It was interesting to see the stark differences between a healthy reef and an unhealthy reef. This project is a baseline study – meaning that we are recording the current state of these reefs so we have a measurable starting point and can monitor the reef and detect any changes in the future. In science it is very important to record a baseline so you know when changes are happening. You then have data on how fast or slow changes are occurring, or in what locations.

While we await the results of the report that is being prepared, the research department is back to its usual summer routine of carrying out transect surveys for dolphins and marine debris.

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.

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