Hello there! Florence here, signing in from Newport. We had a fantastic trip south to Port Orford, and tracked another 53 whales bringing our season total up to 117 so far! This morning, we were back out at Boiler Bay and spent 5 hours staring at empty water – in keeping with the theme of this post, field work does not always go as planned.
Our two study areas couldn’t be more different. At the Boiler Bay State Wayside, we are approximately 18 meters off the water. In Port Orford, we are perched on the side of a 63 meter tall cliff. This extra height greatly increases our range and accuracy as well as changing the angle of our photography and the type of photo analysis we can do. We’re quite excited to have a top down view of our whales, because the photos we are capturing will allow us to use certain photogrammetry techniques to measure the length and girth of the individuals. With luck, when we compare the photos from the beginning of the season (now) to the end of our study (September) we may be able to see a change in the height of the post-cranial fat deposit, which would indicate a successful foraging season. Gray whales do not eat from the beginning of their southward migration, through the breeding and calving season, until they reach productive foraging grounds at the end of their northward migration. This means that all their sustenance for 6+ months is derived from their summer foraging success. Did you know that they even generate their own water through an oxidation reaction which creates ‘metabolic water’ from their blubber stores? So it will be rather fantastic if we manage to measure the change in whale body condition over the course of the summer – particularly if we are able to spot any mother-calf pairs who will have had an especially grueling journey north.
So, while our photo database is advancing nicely, technical difficulties are to be expected when you’re in the field, and sometimes, troubleshooting takes longer than you would like it to. This evening, let me introduce you to the elusive species known as ‘the Chinese land whale.’ It is a very rare breed which spontaneously generates itself from misaligned computer files.
When the theodolite beeps as we ‘mark’ a whale, a pair of horizontal and vertical angles are getting sent from the machine to a program called ‘Pythagoras’ on the laptop. Given our starting coordinates and a few other variables, the program auto-calculates for us the latitude and longitude of that whale. While we hoped it would be a simple matter to upload these coordinates to Google Earth to visualize the tracklines, it turns out that Pythagoras stores the East/West hemisphere information in a separate column, so if we just plot the raw numbers, our whale tracks end up in the middle of a field in rural China! Hence, the rare ‘Chinese land whale’. Now that we know the trick, it is not so difficult to fix, but we were quite surprised the first time it happened!
Of course, that is not the only thing that has gone wrong with visualizing the tracklines. When we first got to Graveyard Point survey site, it turns out that we had set our azimuth (our reference angle) the wrong direction from true north, so all our whales seemed to be foraging near the fish and chips restaurant in the middle of town.
After discovering that in order to rotate something 180degrees, you simply need to alter the azimuth angle by 90degrees, (we’re still not sure why this is working), the whales left the fish and chips to us and returned to the harbor. Anyways, now that we’ve figured out these glitches, we can focus on identifying individual whales, and figuring out which track-lines might be repeat visitors.
In other outreach news, the OSU media department came out to the field and interviewed us a few weeks ago (on a day that the theodolite and computer were refusing to talk to each other due to a faulty connector cable – which is always delightful when one is trying to showcase research in progress). The resulting article has been posted should you wish to take a look:
Until next time,
Team Ro”buff”stus
