We ran several cruises over the weekend, so here are just a few highlights:
- After we finished snorkeling on Saturday’s Private Snorkel Cruise, we saw 2 whales breaching simultaneously. As we headed out to see them, we encountered another Humpback duo who were soon joined by 2 more Humpbacks. This pod of 4 had something to work out between themselves because as we watched them, we saw multiple head lunges, peduncle throws and pec slaps. These whales were heading south at a pretty good clip, but the trade winds were blowing, and we were able to parallel them and watch the action for at least 40 minutes.
- Guests on Saturday’s Pau Hana Sunset Cruise spent considerable time with a Mom/Calf/Escort pod. Both Mom and that Escort were huge whales and all 3 of them apparently decided our boat was worth a look. We watched them surface just about 20 yards off our port rails before spouting several times and sounding. And when that Escort lifted his flukes so close to us, not only did some of us get some great photos, but all of us were able to appreciate just how big he really was.
- On Sunday’s Private Sunset Whale Watch Cruise, we got to see a couple different Mom/Calf/Escort pods. The first pod was composed of some pretty huge whales — and they ventured close by to take a look at us. After watching pod (1), we saw some more spouts, so went over to look at a Mom/calf pod — who we’ll call “pod (2)”. Pod 2’s whales were notably smaller than pod (1)’s whales, and after watching them for awhile, we turned the boat and encountered pod (1) again. This time, we watched another male whale try to make a play for pod (1)’s Mom, but her Escort wasn’t having it, and he chased this second male away. We watched as the unsuccessful male headed over to try his luck with our pod (2) Mom/Calf. But pod (2) Mom didn’t seem too interested either, and she and her calf headed over to where we were. For a few moments pod (1) and pod (2) were pretty close together right around our boat before pod (2) Mom and her calf continued their journey up the coast.
Ocean Sports Whale Fact of the Day: Why do we keep commenting on the relative sizes of female Humpbacks and their escorts? Research published in 2012 documents that the largest female humpbacks associate and show a significant preference for the largest male humpbacks. This same preference didn’t seem to be as important to the males, as they’d associate with any size female (though the smaller males were more often seen with smaller females).
This “assortative paring” has rarely been documented in mammals – so why would female Humpbacks use size as a determining factor for mate choice? Since males aren’t involved in taking care of their calves, and since research demonstrates that a bigger calf is much more likely to survive, the size of her mate seems to be very important to a female Humpback. The sex differences in size preference by mature whales probably reflects the relatively high costs for big females to mate with small or immature males, compared to the lower costs of big males mating with small or immature females.
Body size appears to influence the adoption of mating tactics by the younger and smaller males too – but in a converse fashion. Smaller males avoid the costs of competing for the highest-quality (a.k.a “biggest”) females since they probably won’t be successful, instead focusing their attentions on smaller females that may or may not be mature, but at least will allow association.
And if it would help sum all that up in layman’s terms…for female Humpbacks, size matters.