False Killer Whales of Maui NuiLatest update May 3, 2019 Started on May 16, 2018
Since 1980, Pacific Whale Foundation has been leading the charge in advocacy, research and education to promote ocean conservation and the protection of whales, dolphins, turtles and other marine animals living wild in their natural habitat. Today, our research efforts will be applied towards the endangered main Hawaiian Islands insular population of false killer whales.
In early March, the PWF research team was able to successfully respond to two reports of false killer whales sighted in the Maui Nui region!
The first sighting occurred on a Saturday morning, when researchers received a call about false killer whales near Molokini. Within an hour of the report, a response team was formed and able to launch the research vessel from Ma’alaea harbor. Once the false killer whales were sighted, we discovered that the pod of ~20 animals were very spread out and traveling fast. In addition, the wind was picking up and it was difficult to spot the animals and track them through the water. We were still able to launch an unmanned aerial vehicle (UAV) to collect calibrated aerial measurements of individuals, while also collecting photo-ID data, behavioral observations and underwater footage at the same time. Despite the difficulties of weather conditions and the animals’ behavior, we were able to obtain some valuable aerial footage for measurement of two adult false killer whales.
The second sighting occurred during a field day when our researchers were on the water conducting humpback whale surveys aboard the R/V Ocean Protector. The team received a call from a collaborating research group about a pod of false killer whales off the island of Lanai. We quickly changed course and set off to locate the group, and after about an hour of transit, saw the first black dorsal fin. We were then able to successfully launch the UAV and conduct seven flights over the animals to collect data. The false killer whales were traveling and diving repeatedly during this encounter, but with the UAV flying overhead we had a perfect vantage point for keeping up with the animals. The UAV also gave us the opportunity to observe the behaviors of the group from a different perspective, including a feeding event, where we were able to watch one of the false killer whales with a fish in its mouth. It was a tremendously successful and eventful encounter, and we were able to get aerial footage from the UAV and photo-ID data of all 18 of the animals in the group, including two mother-calf pairs and two juveniles.
Encounters such as these are crucial for researchers in order to better understanding this endangered population. Specifically, this aerial footage will be used to measure body size, body condition and assess potential pregnancy in individuals. These measurements will let us examine the health and growth rate of individuals, and can be used to develop age-structured population models to determine the population growth rate. We could not do this research without the continued help from the Maui on-water community who help us by reporting false killer whales in Maui Nui waters. We are excited to advance our research efforts and use our findings to help protect and conserve this population.
Research activities authorized under NMFS Research Permit #21321. All UAV activities were conducted by an FAA Part 107 certified pilot.
Our research involves locating false killer whales in the Maui Nui region and collecting identification and photogrammetry photos to determine population parameters and use underwater footage to record behaviors and assess scar patterns. We also use unmanned aerial vehicles (UAVs) to measure body size and condition as well as assess potential pregnancy status. Check out this short video showcasing our field work in 2018!
On January 11th, the research team set out on board R/V Ocean Protector, in search of the dolphins that are resident to Maui County. The calm weather permitted us to go nearly 30 nautical miles offshore, where we had our first sighting of a target species; we found a small group of short-finned pilot whales. While continuing our search efforts towards Lahaina, we unexpectedly spotted a whale shark. The researchers onboard were ecstatic; this was the first time some of them had ever seen a whale shark in Maui, making it a particularly special encounter.
However, the day was not over…
While fueling up in Lahaina, the captain of another vessel told us that they had just seen false killer whales off the southeast coast of Lanai. They did not have a specific GPS location but described the general area where they saw the pod traveling. With our tanks full, we set off in search of the false killer whales. In the midst of our search, we received a phone call reporting a sighting of false killer whales approximately 5 miles off the northwest coast of Maui, near Kaanapali. We suspected this was the pod we were in search of. We quickly changed course and headed north to continue our search, with the help of another vessel, Ocean Discovery, standing by to keep eyes on the pod. Around 4 pm, we spotted the telltale large black dorsal fins and were able to begin our sighting.
Upon initial approach, we saw a mom traveling along with her calf. This was a great sign of recovery - it's very encouraging to see this population reproducing. We collected both above-water photo identification data and underwater video using a pole-mounted GoPro. Not too far away from the mother and calf were two humpback whales slapping their pectoral flippers on the surface of the water. The distraction of the humpback whales was a good one because while watching them, we saw another false killer whale nearby. We maneuvered our boat closer to this new individual to take pictures of its dorsal fin. While waiting for the animal to come to the surface of the water to breathe, we were all caught off guard when the false killer whale suddenly leaped out of the water no further than 20 yards from our research vessel!
As we wondered what had caused this acrobatic display we noticed a lone mahi-mahi, one of the preferred prey fish of false killer whales, swimming near the surface of the water. The fish swam so close to our vessel that we could even see teeth marks on the side of its body. We realized that we were in the middle of two false killer whales feeding. False killer whales are known to play with their food, and this looked like a prime example of them doing so.
As the sun began to set, we headed back to the harbor. We had traveled 110 nautical miles and had an extremely successful day. We were very fortunate to be out surveying that day, allowing us to quickly respond to the calls reporting false killer whales. This rapid response program enables us to maximize our data collection so that we can learn more about this endangered population and we are greatly appreciative to all ocean users who report sightings and help us with our mission. The research team is looking forward to the next time we sight this incredible species again.
We started our rapid response program in the summer of 2018 and it's been incredibly successful! With one research vessel surveying our study area we have a relatively low likelihood of encountering false killer whales, so we turned to the community for help. More eyes and ears on the water will benefit our research, which will, in turn, provide the science needed to assist managers in protecting and conserving this endangered population. We are also working collaboratively with other researchers to share data and expand our body of knowledge.
We are asking all water users in Maui Nui to please notify our researchers immediately when false killer whales are sighted by calling/texting: (808) 990-5544. If weather conditions permit, we will launch a rapid response so we can get to the animals as quickly as possible and collect valuable data. Our researchers collect identification photographs, aerial footage, underwater footage, and behavioral observations.
Due to the reporting network and our rapid response program, we have had 6 encounters with false killer whales this year! As we expand our reporting network, we are excited to learn more about these special animals.
We have purchased a laser photogrammetry system and are testing it out in the office. Two green dot lasers will be mounted onto the telephoto camera lens and be used to project a calibrated scale on the animal's fin or body. We then use these laser points to obtain measurements of each false killer whale. We will also fly our UAV (drone) over these animals to take calibrated aerial photographs, which provide another set of measurements.
These measurements will be used to estimate the age and size of individual false killer whales, which is important for examining the growth and health of individuals. Age and size also determine maturity and influence reproductive success; these measurements can help researchers to develop age-structured population models and determine if the population is recovering or continuing to decline.
False killer whales (Pseudorca crassidens) are a large species of dolphin and one of a group of dolphins known as the “blackfish”. Their name originates from their discovery: they were first described based on fossils and were thought to be extinct. Their skull and teeth resemble that of killer whales, so they were named the false killer whales. In Hawaii, there are three populations of false killer whales: an offshore (pelagic) population, the Northwest Hawaiian Islands population, and the Main Hawaiian Islands insular population. Our research focuses on the Main Hawaiian Islands insular population which has fewer than 200 individuals, of which very few are females capable of breeding. Due to its extremely small population size and limited range, the insular population was listed as endangered under the U.S. Endangered Species Act in 2012. Our research involves locating false killer whales in the Maui Nui region and collecting identification and photogrammetry photos to determine population parameters and use underwater footage to record behaviors and assess scar patterns. We also use unmanned aerial vehicles (UAVs) to measure body size and condition as well as assess potential pregnancy status.
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