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At the water's edge: Blakiston's fish-owl

Updated Thursday 1st April 2010

From a nature reserve in Japan, the Saving Species team is joined by experienced field ornithologist, Mark Brazil, in an extended interview as they observe some Blakiston's fish-owls and also spot some unexpected Steller's eagles.

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Blakiston fish-owl Creative commons image Icon Robert tdc under CC-BY-SA licence CreativeCommons miki //en.wikipedia.org/wiki/File:Bubo_blakistoni_-Kushiro_Zoo_-Japan-8a.jpg under Creative-Commons license
 

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Mark Brazil:
The amazing thing that’s happening behind us is all of these Steller’s eagles are gathering in the trees. I think the blizzard has brought them back in from the Nemuro Channel. They’re coming back in; they’ve given up on fishing. And one after another they’re just coming in and landing in these big trees on the slope above us.

Julian Hector:
There’s another one coming in.

Mark Brazil:
[Unclear] bird just coming in.

Julian Hector:
Oh look at that in the snow.

Mark Brazil:
Absolutely diamond shaped tail just dropping in to join five others. And in the next tree there are four more. Just landing on a thin branch, didn’t quite make it, the branch wasn’t strong enough to support it.

Julian Hector:
And we’re in strong snow. We’re in a wooded valley and 200 feet above us or so are rocky outcrops and trees sticking out at all angles, and the trees are beginning to get laden with big eagles. And you can really, you can really see this distinctive white triangular tail, big tail isn’t it as it flies in. One, two, three, four, five, six, seven, eight, nine, ten - I can see ten Steller’s eagles. Eleven! And you think this is, right, and they’re coming in. They’re piling in, another one coming in. And another one!

Mark Brazil:
You can faintly see the sun through the snow clouds and the eagles just coming in above the sun. So these are birds that will have been out over the Nemuro Channel fishing over the sea ice and have just given up because of the conditions. They come back to shore and they’ll sit it out, sit out the weather in a tree.

Julian Hector:
Now behind us we also have a stream, and the stream flows down this valley, and we’re actually here for another reason because we have to say for the last two nights at nighttime we’ve been trying to hear more than see the Blakiston’s fish owl. Now we’ve just been talking about the Steller’s eagle but we’re talking about an owl aren’t we of the same sort of proportions.

Mark Brazil:
Same proportions, yes, massive owl.

Julian Hector:
We’re towards the end of February now.

Mark Brazil:
Yes, it’s the very beginning of the breeding season, and at this time of the year the males and females are still calling together, still dueting. They have a wonderful, deep, sonorous duet. But if the female’s incubating then the male won’t succeed in calling the female out. At other times of year they would patrol through the territory together calling. So at this time of year the male will try to call the female out, early in the evening, soon after sunset, but she’s likely to want to stay put if she’s got eggs. And so after two or three duets then the male gives up and he then sets off around the territory, silently, while the female stays in the nest. So I think what we’ve been experiencing is the tantalising first one or two calls of the evening and then the male disappearing off into the territory without further calling.

Julian Hector:
And we’ve come here because it is their territory. As their name suggests, they eat fish, that they are linked to these streams.

Mark Brazil:
Yes, indeed, and the network of streams here on the Shiretoko Peninsula, probably most of these streams have a pair. They’re fishing along the sides of the rivers. They like to stand in the water or stand at the water’s edge waiting for fish to come by, and then they’ll jump down and catch fish. This time of the year they’re mostly taking fish. But they’ll also occasionally take small flying squirrels. In spring, when the snow’s melting, they take red bellied frogs. We’ve had a massive emergence of frogs, and so that becomes their main prey in the early part of the spring, and they’ll take some birds but primarily fish throughout the year.

Julian Hector:
I went to a visitor centre where they had one of these animals presented, a stuffed one, and I haven’t seen the real thing, but I was amazed by its size. They are eagle sized, a spectacular animal. But the way it was presented it looked a little like a creature with a very thick tweed cloak over its shoulders and it sort of crouched down. I mean is that a true image? I can imagine it on a stream looking for fish like a man of the woods sheltering from the weather.

Mark Brazil:
Absolutely, yes. Absolutely, sitting there hunched down on the ice at the side of the river or in the snow looking like a woodland troll with a great cloak and because the snow gathers on their feathers and every now and then they shake to shake off that snow. And they’ll wait for hours by the side of the stream. And then if they’re lucky a fish will swim close enough for them to pounce on it.

Julian Hector:
And do they need all those sort of owly things, you know, silent flight, amazing stereo hearing, that sort of thing which you associate with other owls?

Mark Brazil:
Very much so, the same characteristics. They’re virtually silent in flight despite their massive size. But they do have bare toes, very heavily feathered feet but bare toes, and then very roughened scales underneath for grasping fish, very, very sharp talons, massive talons.

Julian Hector:
Blakiston? Named after somebody?

Mark Brazil:
Yes, named after T W Blakiston. Thomas Wright Blakiston, who was a naturalist, a sea captain and became consul of Hakodate, a small town in South West Hokkaido, in the late 1800s, and he was an avid collector. Sent specimens back from all of his travels, including his time in Japan, back to Britain and was very influential in our early understanding of the distribution of species in Japan. Was a zoogeographical name, a line named after him which runs between the island of Hokkaido and Honshu. We now recognise a major faunal and avifaunal difference between the northern part of Japan and further south, and Blakiston’s fish owl, Ketupa blakistoni, is a species named for him.

Julian Hector:
Now they’re not common anymore? I mean they were more ubiquitous in the past and things have changed?

Mark Brazil:
Very much so. It was a bird that was widespread across the island of Hokkaido. It was a very important bird for the Ainu. It was one of their panape of gods, kotan-kor kamuy.

Julian Hector:
They’re the indigenous population?

Mark Brazil:
Indigenous people of Hokkaido revered the owl as one of their gods, and the name meant the god that defends the village, or that protects the village. The fish owls would have occurred in situations like this near the mouths of rivers, in areas of good wetland. So these were areas that provided good hunting for Ainu. They also provided situations overlooking hillsides, overlooking water, where Ainu had their settlements, and so the owl and the people lived in the same places.

But, unfortunately, as river and forest have been felled through the development of Hokkaido, with the loss of lowland habitat, the owl has lost out. Furthermore, with the intensification of forestry, a loss of large trees, and this is a very large owl that needs very large cavities in old trees, the loss of those trees has meant that even where there’s good fishing for them, good habitat for them, there’s nowhere for them to nest.

Julian Hector:
And the loss of large trees is because we, man, have wanted those large trees and have selectively taken them out?

Mark Brazil:
Either selectively taken them out or have logged them out because they were dying or dead, and also those larger trees are very susceptible to heavy snowfalls, losing limbs or being felled completely during very heavy snowfalls. So there’s been a steady loss of the largest, oldest trees, and those are the trees that the owls need to nest in.

Julian Hector:
So what’s the way forward? Is it, as we have standing here at the edge of a national park, is it protection in that way, or is it more about woodland management?

Mark Brazil:
It’s a combination of protection of areas that are a suitable habitat for them, and that’s been ongoing, and since the late 1970s or early 1980s nest boxing has been very effective. Initially making wooden nest boxes, enormous nest boxes, and more recently and now fibre reinforced plastic, FRP boxes, which are much lighter, much easier to carry out into the woodland. And the owls were desperate for nesting sites, and where nesting boxes were supplied those birds that were occupying territory very quickly occupied the nest boxes and started breeding.

Julian Hector:
That’s an approach which I think people could recognise all over the world with owl conservation?

Mark Brazil:
Very much so. It’s a very important move where you’ve got good habitat but nowhere suitable for the birds to nest. Nest boxes worked very well for owls.

Julian Hector:
And is there any evidence that putting up nest boxes which I know you have done since the 80s, a few, have been helpful?

Mark Brazil:
Oh, very much so. The Ministry of the Environment here and various researchers have been very active in putting up nest boxes, and that is helping the population. Unfortunately we still have continuing losses from the population as a result of collisions with traffic. And many of these owls, as I mentioned, they come down the river systems, they come down to the coast to fish along the coast, and it’s on the coast that most of Japan’s roads are.

In mountainous areas the roads follow the coast. The owls have to cross those roads and, unfortunately, we have traffic accidents each year and we’re losing quite a few young owls. And so the population isn’t getting forward. It isn't making progress. We’re protecting them on the breeding grounds, but unfortunately we’re losing them in traffic accidents and so on.

Julian Hector:
Now presumably being big animals they’re presumably long lived?

Mark Brazil:
They are long lived. I don't know exactly how many years they live but I imagine somewhere between 15 and 20 years.

Julian Hector:
Yes, so it’s not a season or two is it?

Mark Brazil:
No.

Julian Hector:
And so road traffic accidents, it just nibbles away at the adult population?

Mark Brazil:
Indeed, yes.

Julian Hector:
So the recruitment into the population just isn’t balancing the kind of unusual loss of adults?

Mark Brazil:
That’s right, and also we think there’s probably some impacts of predators and concern too that the introduced North American racoon that is now in Hokkaido may be spreading into areas where there are fish owls, and they would be competing for the cavities that the owls depend on.

Julian Hector:
So how does this all fit together? Blakiston’s fish owl is obviously a very important part of the Hokkaido biodiversity. You’ve talked about various things impacting its survival including introduced species. How can it all be sort of brought into some sort of condition of what ecologists I think call favourable status?

Mark Brazil:
I think we’re looking at ecosystem level conservation, and where we are is the Shiretoko Peninsula, which is a national park, now a World Heritage site too and so there is an attempt made to address large scale issues in this environment. There are many issues to deal with and the increasing population of sea kadir, the issues with the population of the fish owl and so on, but these all come down ultimately to an understanding amongst the local population, through education, of the value of the natural resources that they have in this area.

Because this is a major, not only a major area for conservation but it’s a major attraction for eco-tourists and nature tourists, and so it all involves the education of the local people I feel, trying to get them to understand and value these natural resources.

Julian Hector:
So you could argue get it right for Blakiston’s fish owl probably get it right for everything else?

Mark Brazil:
When you protect large predators, these are kind of umbrella species for conservation really aren’t they? They help protect environments that hold many, many other species. So by just choosing key iconic species for particular protection we also protect all of the other species that live in the same habitat with them.

 

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