How can you tell a male and female humpback whale apart?

In many animals, different sexes have different appearances, with males often being larger, showier, or both: think of brightly colored male songbirds or male lions with their luscious manes. For humpback whales, however, this is not the case. Apart from females being slightly larger than males on average, humpback whale males and females look very similar to each other, making it very difficult to visually determine sex. Adding to this, all reproductive organs in both females and males are neatly tucked away behind a genital slit to help them be more hydrodynamic and sleek in the water.

Luckily for us researchers, though, we have a few tricks up our sleeves to tell the difference between the sexes, allowing us to collect additional data for our photo-identification catalog.

The easiest way to determine a female humpback whale is a close association with a calf. Mothers and calves maintain a strong bond throughout the first year of the calf’s life, so when we see an adult whale closely accompanied by a calf, we can safely assume that she is the mother of that calf.

In the absence of a calf, though, things become trickier. If the whales roll over onto their backs, often we can see the genital slit on their abdomen. The relative location of the genital slit offers some clues: For males, the genital slit is located closer to the whale’s belly, while the females’ genital slit is closer to their tail flukes. Immediately towards the tail from the genital slit, females have a grapefruit-sized lump known as a hemispherical lobe. No one knows what exactly this structure does, but we do know that it is only present on females. Females also have two mammary slits, one on either side of the genital slit, which they will use when nursing their calves.

Click through the photos in this gallery and our researchers will explain how we were able to identify the sex of these humpback whales

When we are able to determine the sex of a whale, this information is included along with the animal’s fluke photo when it is added to the catalog. Knowing the sex of different individuals enables us to more accurately determine calving rate and sex ratios of different habitat areas.

Southern right whales in Hervey Bay

This season, humpback whales haven’t been the only large baleen whale sighted in Hervey Bay. We have also had several sightings of mother-calf pairs of southern right whales, a rare species for this area. The first pair was seen in July, and there have been many additional sightings over the past several weeks, much to the surprise and delight of passengers and staff onboard Ocean Defender.

All right whales have white patches of rough skin on their heads called callosities. The pattern of callosities is unique to each individual whale, and researchers use these patterns to identify right whales much in the same way that we use fluke patterns to identify humpback whales. Using the patterns of callosities, we have been able to recognize at least three different mothers that have been sighted this season.

These mothers belong to the southeast Australia population, which is more commonly seen farther south in Victoria and New South Wales. Similar to humpback whales, southern right whales prefer relatively warmer, calmer waters for their calves, but they do not typically travel all the way to tropical areas. In fact, Hervey Bay is considered the extreme northern extent of their range. Southern right whales were hunted extensively since their slow swimming speeds and thick blubber made them the “right” whale to kill, particularly before the industrial era of whaling. The populations are recovering, though, and it is encouraging to see these mothers and calves along the east coast of Australia.

Looking back through the past several years of data from Hervey Bay, Pacific Whale Foundation researchers have only seen right whales in the area in 2006, 2007, 2009, and 2012 prior to this year. In those years, there were also fewer sightings: 2009 and 2012 each had sightings on two days, but our team only saw right whales a single time in 2007 and 2009. Although we can’t say for sure why these mothers and calves decided to visit Hervey Bay for such an extended time this season, it will certainly be interesting to see what future years bring for sightings of this amazing species.

Although Pacific Whale Foundation does not currently study southern right whales, our research team is collecting data and submitting all sightings and identification photos to the Australian Marine Mammal Centre which maintains a catalog of this population.

 

Pilot whale encounters 30 miles offshore

Our Research Team has begun surveying the deeper waters southwest of Maui as part of our new false killer whale study. The first day of research took us ~30 nautical miles off the coast of Maui in waters >2,500 feet. Although we didn’t see any false killer whales, we did have two encounters with short-finned pilot whales, a species we do not typically observe in the near-shore waters of the Maui 4-island region. This species has distinctive bulbous heads, wide dorsal fins, and sleek black bodies. Short-finned pilot whales are sexually dimorphic, which means that males and females look different. Males typically grow to 18 ft long compared to females who grow to an average length of 12 ft. The dorsal fins on males are also larger and wider than females, making it easy to tell the two apart.

During our encounter with short-finned pilot whales, two researchers were taking above water photographs of the whale’s dorsal fins, another researcher was collecting underwater footage using a pole-mounted camera, while a fourth research was collecting detailed observations on pod behavior and composition. We observed two mother-calf pairs, two subadults, and the rest were adults, spread out into smaller sub-groups of 2-3 individuals. During the encounters we observed the pod feeding and resting at the surface of the water.

The majority of our research takes place after our field work ends, because the data we collected in the field must be processed. This involved looking through 520 pictures of dorsal fins, assessing each image’s quality, and matching each image within the encounter to see how many different individuals we saw. After data processing was completed, we had photographically identified 19 different animals. These individuals were then compared to our existing catalog of 133 short-finned pilot whales to see if any have been previously sighted. One individual matched to our catalog and was sighted back in September 2002. The other 18 animals had never been seen before and were added as new individuals, increasing our catalog size to 152 individuals. Since we do not often see this species, it was expected that there would be many new individuals to add, as the estimated population size for the entire Hawaiian Islands EEZ is 12,422 whales (Bradford et al. 2013).

This was a very successful day offshore! Stay tuned for other research updates from this exciting new study.

What’s it like to do a research internship at PWF?

On the first field day for our two summer interns, you could sense the excitement as we set out on our research vessel, Ocean Protector, to survey for dolphins. Pacific Whale Foundation Research Department offers internships that give individuals the opportunity to get hands on experience in collecting and analyzing field data on marine mammals.

During our survey the interns were overjoyed when we came across a pod of Hawaiian spinner dolphins, as it was the first time ever seeing this species of dolphin for both young researchers. Spinner dolphins are named for their acrobatic spinning leaps that are unique to this species. These dolphins can spin up to seven times when they propel themselves out of the water. Scientists do not know for certain why they spin, but believe the dolphins may use the aerial spinning behavior as a form of communication or as a way to remove parasites.

As the interns took turns on the research camera, trying to capture photos of individual dorsal fins, they made several important observations about the group of around 80 spinner dolphins that we encountered.  They were first struck by the sheer size of the group. Spinner dolphins are usually sighted in large groups of 100-1000 individuals. The interns quickly learned that it can be very overwhelming to take photographs and get an accurate group count of the animals since multiple dolphins will surface at the same time. Due to these difficulties, we also use underwater footage captured on a GoPro to help us gather data on group size. As we continued following the pod and collect data, one of the interns asked why the animals were not spinning. We explained to the interns that spinner dolphins here in Hawaii typically rest during the day time, and feed in large groups offshore at night. Spinner dolphins’ resting behavior usually involves slow swimming, but spins and leaps can also be observed on occasion and can be a sign that the pod has been disturbed. After spending a memorable hour collecting the data and photos needed, we continued on with our field day.

Once back in the office, the interns got the chance to process the data that was collected in the field.  This involves looking through the photos that were taken, finding the best photo of each individual, and matching the individuals to our existing spinner dolphin catalog. The interns matched the photos to our spinner dolphin catalog that currently has 438 individuals, and found 27 matches. The current population of Hawaiian spinner dolphins in the Maui 4-island region is unknown; our catalog will to help us estimate the number of individuals and look at their distribution and movements. These valuable data will help us protect these dolphins, which are facing increasing disturbances and threats from human interactions.

Meet our new adoption whales!

Pacific Whale Foundation has two new humpback whales from our North Pacific Humpback Whale Catalog that are available for a symbolic adoption.

Makena is an adoption humpback whale that was named in honor of Greg Kaufman, the Founder of Pacific Whale Foundation.  This whale represents the long-term research Greg did to promote ocean conservation and his effort to be a voice for protecting whales. Makena was first seen in Maui waters as an adult in 1997.  During this first sighting, Pacific Whale Foundation researchers photographed Makena in a surface active pod with five other whales, including a calf.  In 2014, Makena was sighted again in the 4-island region and a photograph of its tail flukes was taken by a member of the public and donated to the research department.  The story of this whale perfectly encapsulates Greg Kaufman’s legacy;  combining our dedicated research study with a citizen scientist program, and promoting marine education and conservation through our animal adoption program.

Sally is a female humpback whale that has become famous in the Maui area thanks to her unique “fluke-up” behavior.  The “fluke-up” behavior is rarely seen in Hawaiian waters, and is referred to by some as “sailing”. Sally was first observed by our researchers exhibiting the “fluke-up” behavior with her calf nearby in 2016.  No one fully understands the purpose of this behavior, but in 2018, this whale once again had a calf and several times throughout the season was seen displaying the same posture. Photos of Sally were donated to the research department from one of our Keiki Whalewatches, and from Naturalist Josh Wittmer aboard PacWhale Eco-Adventures whalewatch.

 

Want to know more about these amazing individuals? When you adopt a marine mammal through our adoption program you get the chance to learn more about the specific animal’s story and get updates on any re-sightings of the individual.  By adopting one of these animals, you will be able to learn more about Makena the whale, or Sally and her unique “fluke-up” behavior.  Check out our website to learn how to adopt one of these magnificent whales, or any of our other marine mammals that are available for adoption from our catalogs.

And remember, when adopting a dolphin or whale you are supporting PWF’s ongoing research, education, and conservation efforts to protect marine life. Thank you for your support!

Nala the Famous Humpback Whale

One very special humpback whale and her calf made the news this whalewatch season, and it isn’t the first time. Not only is Nala a celebrity in the Hervey Bay whalewatching community and a frequent visitor to the area, she is also a long-time mother and a real-life example of how our research at Pacific Whale Foundation is making a difference.

Ask anyone in the Hervey Bay whalewatching community who Nala is, and almost anyone will have  heard of the famous whale. Her name was given to her in 1996 by a group of students at Hervey Bay High school who, going along with a Lion King theme, named her calf that year Simba. She has since been dubbed the “icon” whale of Hervey Bay and over the years, Nala has earned the respect and admiration of many.

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