While rummaging through files to prepare for an upcoming presentation, I made an exciting discovery.
Tucked away in the clutter of my digital archives were photos of this female humpback and her calf:
The photos are from August 2005, before I started my calf ID efforts, so basically, I never really noticed the relevance of this female humpback + her male calf until now.
I know this humpback whale.
With this (and related) photos, I've now documented this female visiting the Vava'u island group in Tonga with calves in five seasons: 2002, 2005, 2008, 2009, and 2012.
Yes, she's a 5x mommy!
The last time I wrote about her was in December 2012, when I ID-ed her with a baby after watching a NatGeo documentary while I was staying at my friend Ron's house in Palau (read blog post).
Yup, as head-smacking preposterous as it might sound, I recognised her on TV. It's actually not too difficult, because the markings on her body are easy to remember: stripe with a dot. There's a slight difference between the left and right sides of her body, but basically both sides have the stripe-with-a-dot pattern (which isn't all that common among the whales that visit Vava'u).
Which brings me to the point of this post...If you find yourself in Vava'u later this year or in future seasons, please keep an eye out for this female. If you see her, please take photos and let me know. Irrespective of whether she has a baby at the time or not, it'll be interesting to record additional sightings.
Several people have contributed photos and information to date to help establish the baby-timeline for this female...Nonie Silver, Karen Stone, Kirsty Bowe, Michele Hall. Thank you!!!
Here is a PDF summary of confirmed sightings to date (about 1MB): Female humpback whale with multiple calves in Vava'u, Tonga. (Please excuse the amateurish formatting. I'm a bit too overwhelmed with work at the moment to worry about making the file pretty!)
A bit of speculation: The female humpback seems to be on a 3-year cycle, with the exception of 2008-2009, when she had babies two years in a row. I've documented another female that had babies in 2008 and 2009 as well.
My guess is that both babies in 2008 didn't make it. Perhaps both babies died relatively early on in the season/ rearing process, leaving the females sufficient time and metabolic reserves to mate again and have a calf the following year.
My calf-density count for 2008 was low (0.24 calves/ boat-day, the lowest I've recorded since 2007), so maybe there was something about that season that affected survival rates. (See this blog post for chart of calves/ boat-day)
This could be sheer coincidence of course, but I'm particularly keen to see if she shows back up with another baby in 2015.