This time of year, when most humpback and minke whales that spend the summers feeding in BC are down in their winter breeding grounds, MERS researchers and educators are spending more time at our computers and less time out on the water. One of our focuses this winter has been to share the results of MERS research with people who spend time on and near the water with the goal of discussing how we can work together to better understand humpback whales and the threats that they face, for the sake of boater and whale safety. In addition, we have been working on humpback and minke whale publications for scientific journals (see our latest publications).
With the help of one of our experienced and dedicated volunteers, Alison Ogilvie, we have also been reviewing some older humpback whale data, getting our photo and sightings databases up to date. One of these older humpback whale photos has allowed us to learn something new about one of our best-known whales, “Freckles” (BCY0727). Freckles was first seen in 2009, and was named for the white, speckled markings on its body. Since then, Freckles has lost some of these markings, but has become one of the whales that shows very strong site fidelity to northern Vancouver Island, coming back to the same area to feed each year.
The photo in question allowed us to determine that Freckles is a female. Determining the sex of humpback whales is not as easy as it is for many other animals… there are no obvious physical characteristics that are reliably visible at the surface to distinguish males from females. MERS has documented several of the humpback whales that spend time off northeastern Vancouver Island come to the area with a calf, so we know that these whales – including Chunky (BCX0081), Ripple (BCX1063), and Slash (BCY0177) are females. However, the sex of the vast majority of the humpback whales in our catalogue is unknown. We were therefore very excited to see photos of Freckles tail-lobbing repeatedly, which made the underside of her body visible. In this photo, I was able to see a small feature on Freckles’ body, the hemispherical lobe, that allowed me to determine that she is female.
Only female humpback whales have a hemispherical lobe, a small round lobe between the whale’s umbilicus (belly button) and fluke. These diagrams from Glockner (1983) demonstrate the different features of male and female humpback whales.
Now that we know that Freckles is a female, we are very curious to see when she might bring her first calf to the northern Vancouver Island area. Knowing Freckles’ sex is also very valuable for better understanding humpback whale behaviour.