Unmanned Aerial Vehicle Reveals Killer Whales in Striking Detail

UAV Reveals Killer Whales in Striking Detail

Transcript: UAV Reveals Killer Whales in Striking Detail

Rich Press: There’s a population of killer whales that spends part of the year around the San Juan Islands north of Seattle. They’re called the Southern Resident Killer Whales and they’re very endangered. There are only 81 of them left in the wild. That’s the bad news, but the good news is that 81 is five more than there were last year. There was a baby boom among the Southern Residents recently that added five to their number and for a population of this size, five new individuals is a very big deal.

Today we’re going to look at some amazing photographs that will give us a glimpse not only of some of the new calves, but also of the family lives of these whales. The photos were taken with an unmanned aerial vehicle and to help us understand the photos we have one of the scientists who took them here with us today. John Durban is a marine mammal biologist with NOAA Fisheries and he recently got back from the research expedition that yielded these incredible pictures.

John, thanks for taking my call.

John Durban: Oh, no problem, Rich. I’m happy to talk to you.

Rich Press: So you recently returned from several weeks of fieldwork where you and your colleagues were using an unmanned aerial vehicle to photograph killer whales from above. I’m told that you were photographing the Southern Residents and also the Northern Residents that live across the border in Canada. What were you trying to accomplish?

John Durban: Well, we’re really answering a very simple question. Are these killer whales getting enough to eat? Both these populations of killer whales are specialists in preying on salmon, particularly Chinook Salmon, and several stocks of Chinook Salmon are themselves endangered, which makes these whales vulnerable, because there’s concern about their prey supply. Are they getting enough to eat?

So what we’re trying to do with the hexacopter is simply to get a camera above the whales and measure their length, so we can monitor growth, and to look at their width profile so we can see how fat they are. We do that by taking pictures and taking measurements from the pictures.

Rich Press: Got you. So you can get very precise measurements from these pictures, is that right?

John Durban: We can. A small hexacopter has an onboard pressure altimeter, so with every photograph we get a measure of altitude, so we can scale for measurements and pixels on the photograph to measurements in centimeters on the scale of the whale. From 100 feet up we’re typically accurate to just a few centimeters, so we can get very precise measurements.

Rich Press: Cool. I want to mention that you and your NOAA colleagues took these pictures with our research partners at the Vancouver Aquarium. So what I’d like to do is to take a look at some of these pictures and maybe you could tell me what you see in them. Does that sound okay?

John Durban: Sure. That sounds fun.

Rich Press: Okay. Great. So the first photo I have here has two whales in the frame. They look like they’re speeding along in tandem. What’s going on here?

John Durban: Yeah, they do. What it shows are two adult females. The whale on the top is L-47, a female who’s 40 years old or just a little over 40. The whale below her is her adult offspring, L-91, who now is about 20 years old. They’re traveling together, which isn’t unusual in the killer whale society. The offspring often stay with their mothers for their whole lives.

But what’s interesting about these two whales is their difference in shape. You can see the L-91, the whale at the bottom is really quite fat, but she’s fat as you move backwards down the body, so if you look around the dorsal fin, or a good marker is that gray saddle patch around the dorsal fin, you can see she’s really wide there and very wide in comparison to her mother if you look above her; around the saddle patch the mother is quite lean there. And that’s because we think L-91 was heavily pregnant at this time. We didn’t actually notice it at the time, because we didn’t have much time to review the pictures, but just five days later we had cause to go back and have a look, because this whale, L-91, was seen with a brand new calf just a few days later.

Rich Press: Cool. I think, actually, I have a photo of that, so another photo I have here is of a whale. I think you’re going to tell me it’s L-91, and a calf swimming just on her right.

John Durban: That’s right. This is L-91 now, now not looking quite as fat. If you look at that saddle patch she looks more like a normal killer whale, and the reason is she’s given birth to this tiny little guy, the newest member of the Southern Resident population, L-122. So we’re within a few days of the birth of this calf. This is the smallest calf we’ve ever photographed from the air.

I think what I love about the picture is the kind of nurturing you see here. That calf is swimming up by its mother’s head. In fact, the white on the side of the mother’s head, that’s her eye patch, so it shows you her eye is just in the front of those, so the calf is up by its eye. She’s keeping an eye on it. It just shows the kind of level of care and close nurturing that’s going to go on and really persist throughout this calf’s life. Its mom is its ticket to growing and making it and it’s great to see this close bond in the early days of life.

Rich Press: Great. Then the next picture I have is also of an adult and I believe it’s the same calf, and they’re no longer moving forward together. They’re kind of looking at each other. What’s going on here?

John Durban: Yeah. You can see here that L-91 now has something in her mouth and actually that’s a big part of a salmon. You can see some of the fish is actually beneath her and sinking. What we were able to see as we were flying the hexacopter is that two of the members of this family group actually came over towards the mother and brought a salmon to her. They dropped it and she picked it up. I think it’s a great example of how the whole family are involved in rearing this calf.

But as L-91 is now nursing the calf that’s very energetically costly to produce this energy rich milk and particularly in the early days of the calf’s life, she probably doesn’t have much time to dive down and collect fish on her own. So we can see these related family members are helping feed the mother and, therefore, helping to raise the calf. I think it is a great example of how society and group living is really important to these whales. They do family better than we do. They stay in their family their whole lives and they’ll help care for this newest member of the family. It's a great reminder of that.

Rich Press: Speaking of newest members of the family, here’s another picture of a mother and calf, a different picture of a mother and calf, a different pair this time. This picture is super-clear.

John Durban: Another beautiful picture. This is J-16, the mum, with one of the calves born this year just swimming over her back there. It’s a great example of the kind of nurturing and close care that goes on between a mother and a calf. And this is a great photogrammetry image because we can really see the edges of the whales and you can see the resolution we can get of the calf. We’ll be able to monitor this calf’s growth in years to come and make sure it’s getting enough food.

Rich Press: The next picture I wanted to talk about is a great one. It's actually my favorite one. I see a picture of a killer whale and there is a youngster coming up behind her to nurse. Tell me about this picture.

John Durban: Yeah, this is a stunning picture. The female here is L-94. She’s a 20-year-old female, and this is another of the calves that was born over this last year, and the calf is nursing. It's getting milk from the female’s mammary slits and it will nurse that way for a year or two, probably up to two years, after which time it will start to take solid food, but still be largely fed by its mother and helped in feeding by its mother. It's a great image.

Rich Press: Yeah. I love it in part because it’s just a beautiful, graceful, image, but also, I’ve never seen a picture like this. I’ve seen pictures of killer whales nursing in captivity. I’ve never seen a picture of this happening in the wild. Is this the first time you’ve witnessed this?

John Durban: It certainly is the first time we’ve seen it with this clarity. Previous attempts to photograph from the air, we’ve been in manned aircraft, like helicopters, so we’ve been a lot higher, so we’re getting this kind of detail. So this is the first time we’ve seen this kind of behavior in this kind of clarity.

Rich Press: Great. This is the second year you’ve photographed these whales from a hexacopter. In fact, we had a conversation much like this one just about a year ago and I’ve got here one of the pictures you took last year. It's – I guess it’s from the Northern Residents, so this is the group that lives up to the north. Tell me a bit about these guys and tell me about the picture you got of them this year.

John Durban: Yeah. This is one of the stunning pictures we obtained last year. In fact, one of the first pictures we ever obtained of killer whales with the hexacopter. We were blown away by the quality of it.

So this shows the I-16 matriline of Northern Resident Killer Whales. If we look closely in the middle there we see a small, little grey calf. That’s I-44 that was a young of the year last year and he’s swimming just below his mother, so the whale above him is I-51. The whale above her is its sibling. That’s I-129 that was five years old.

This year we were able to photograph the same group, so if we look at the picture we obtained from this year, now we’re just looking at three whales. The bottom is the mother, I-51. In the middle, that’s the new little calf from last year, I-144, and above is its older sibling. We can see it now looks like a normal killer whale. The calf is no longer small and mottled. This shows our ability to monitor growth one year to the next. We’ll take these measurements and use our altitude and our focal length and convert them into real quantitative measurements to see how that growth compares to other calves. To me it’s a great graphic example of what we’re trying to do with this photogrammetry of monitoring both shape change and growth over the long-term.

Rich Press: This year we’ve looked at a bunch of photos of killer whales that are in relatively good shape. Their bodies are robust. They don’t seem undernourished, as some of them did last year. There were also a number of newborns in the Southern Resident group this year, so the population seems to have had a good year. I know that part of the reason you’re doing this research is to correlate their condition with salmon runs, so salmon is the main food. I suppose the hypothesis might be that if there are large salmon returns in a given year they have a lot to eat, perhaps they’re doing better.

Are you able to make any conclusions as to why the whales seem to be doing well this year?

John Durban: Well, yeah, I think it’s a bit too early to make conclusions, just because we’ve only got a couple of years for comparison, but in the long-term that’s exactly what we want to do is to compare year in, year out how the whales are doing compared to the salmon returns. Even, we want to go beyond that and look at this seasonally, how they’re doing in the spring compared to the fall. I think it’s fair to say that this year we saw a lot more robust whales than last year, and you’re right, the Southern Resident Killer Whales have had a number of new calves, in fact, 5 over the last 12 months or so. So I think it is a sign that feeding has been okay for them and pretty good in the last few months. But you know, future monitoring is going to tell us whether those calves survive and grow to recruit to the adult population. So I think the success of our study is being measured in longevity, whether we can keep this going to track growth, and changes in condition, changes in reproduction, and see if we can link it to not only salmon returns, but specific runs of salmon or times of the year when salmon are important. By doing that we can help to guide management actions to perhaps help, you know, enable these whales in lean times to make sure they get an adequate food supply.

Rich Press: Yeah. So, John, listen, I know you’re really busy, so forgive me for taking up so much of your time, but I want to thank you for taking the time to talk with us. I think these pictures are really beautiful and I think that people are going to enjoy seeing them, so thank you.

John Durban: Thanks, Rich. It's really exciting to not only be part of taking the pictures, but to help talk about them too.

Rich Press: That was NOAA Fisheries Biologist, John Durban. John asked me to make sure to tell you that they keep the hexacopter at least 90 feet above the whales at all times, high enough that the vehicle doesn’t disturb the animals, and also to tell you that they have permits, both, from NOAA Fisheries to fly the hexacopter near these animals, which are protected, and from the FAA for flight clearance.

I had a similar conversation with John following the first expedition to photograph killer whales last year. A number of the whales appeared undernourished last year, so that conversation was a little less optimistic, but it was really interesting. So if you haven’t listened to that yet, you can find a link on our podcast page, that’s www.fisheries.noaa.gov/podcasts. If you go there, you’ll also be able to download the photographs we just spoke about. And, there’s a link to guidelines from NOAA Fisheries about how to use UAVs responsibly to view wildlife. If this is something you’re going to do, please read these guidelines first.

Thanks for listening. Join us again next time for more stories about ocean life and ocean science. I’m Rich Press and you’re listening to On the Line.

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