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All By Him/Her Self

Humpback Gender ID

March 29, 2024

Aloha,

It’s the “End of Season” countdown. With just a few dedicated Whale Watch Cruises left this season, we’re still seeing and hearing Humpbacks.

Guests on Thursday’s Mid-Morning Whale Watch Cruise spent most of the cruise watching a lone (and perhaps lonely) small-ish Humpback. This whale was definitely not a calf (too big) but definitely not a mature whale either (too small). Our Humpback wasn’t doing too much — mostly surfacing, spouting a few times, and then sounding, but while he (she?) was underwater our whale wasn’t swimming far, so it was also easy to keep track of her. We got a lot of good views of this whale on the surface, and a lot of good views of her flukes.

When we deployed our hydrophone we were shocked at the clarity of two whale’s voices (one was really low in pitch and the other really high in pitch). It sounded like they were right below the boat — but if they were, they never surfaced — at least while we were there.

Guests on our Pau Hana Sunset Cruise got a real treat. While sipping on refreshing beverages, we got to witness two very active Mom/Calf pods. Mom in that first pod started tail lobbing, which seemed to excite her calf, who then breached at least 6 times. After they quieted down, we decided to head over to see the second Mom/calf pod. After waiting around for a bit in the area where we thought they might be, Mom breached twice about 100 yards from us — and her baby started breaching too. Interestingly, there was a pod of spinner dolphins hanging around both of these Humpback pods, and we wondered whether their presence might have spurred all that surface activity.

Mahalo,

Claire

Ocean Sports Whale Fact of the Day: Throughout the season, I’ve been using the pronouns “he” and “she” almost randomly when referring to Humpbacks in these blog posts. And that’s because unless there’s a calf around, it’s pretty much impossible to identify the gender of a Humpback from our vantage point. If there is a calf, the whale closest to the baby is usually “Mom”, and any other whales joining the pod are males. So how do researchers figure it out? If you’re underneath the whale…or if the whale rolls over close to your boat and you know exactly what you’re looking for, you may be able to distinguish between the genders. A female Humpback’s genital slit is almost adjacent to her anus, separated only by a small lump called a “Hemispherical Lobe”. She also has two visible mammary grooves located on either side of her genital opening. A male Humpback’s genital slit on the other hand, is about midway between his umbilicus and anus (so, they’re much further apart than a female’s), and he lacks that “hemispherical lobe”.