Sunday, 12 July 2015

Gorgeous Grebes - Lake Wanaka

If you’ve been following my blog you’ll know that the Australasian Crested Grebe/Kamana has been a bird we’ve been seeking out on many of the high country lakes we’ve explored in the last few months. Initially we didn’t have much luck in getting close to the ones we did locate, that was until we stayed at the Ohau Canal near Twizel and I managed to get a lovely close up shot.

I knew that if I hadn’t have managed to get a good shot, there was one more lake that had grebes at close quarters; Lake Wanaka. The grebes at Lake Wanaka are well known locals, not only because they have made their home along the town waterfront but they’ve also increased their numbers tenfold because of the work of one dedicated man, John Darby. More on his work later.

Not long after arriving at the Outlet Campground, David went down to the river to check it out for fish. It was a big surprise when he came back to the van to tell me there was a juvenile grebe swimming along the river bank just below us. Being a juvenile he had probably been chased out of his parent’s territory further on around the lake.

At the first opportunity I drove around to the Wanaka town's waterfront to check for grebes and I was not to be disappointed. Within 20 minutes, along the lake front past the marina to the sailing club (around 400 metres), I saw seven grebes; 3 adult pairs & one juvenile. They were all still a little way out from the shore and wary but I managed to get a few shots before they headed out to the moored boats on the otherside of the marina. (Click on the photos to enlarge)


A couple of days later when I returned, I noticed that one pair of grebes had laid claim to the floating platform in front of the marina. I had seen it previous with just a few twigs on it but no birds nearby. Now they were steadily building up a mound of weed and twigs, and one was staying put on the pile- making sure another pair didn’t steal it. These are man-made floating platforms, there are four or five around the marina  and they have been made by John Darby.

One on the platform and one floating off to the side.
Two years ago only one pair of grebes lived in the Roys Bay area of the lake, now there are seven breeding pairs who have produced over 30 chicks. Just to show how significant this is, grebes once inhabited over 100 South Island lakes but numbers have been declining mainly due to introduced predators and habitat loss through wetlands drainage and the establishment of hydro schemes. Now the grebe is one of New Zealand’s rarest birds, only around 600 remain in the South Island.

Grebes nest on floating rafts of vegetation that they build themselves and Lake Wanaka’s fluctuating levels meant their nests either flooded or were left high and dry. Once their nests were no longer floating the eggs and chicks also become vulnerable to predators. The grebes even tried to build a nest on the transom board of a boat one year.


John designed a floating wooden nesting platform that has had a few modifications to cope with the lake’s strong north-westerly storms. The platform in my photos is anchored to the lake bed, others are tethered by chain and bolts to the marina piles. Apparently the grebes made instant use of the first platform which was installed around 9pm one night. By 7am the next morning it had been claimed by a pair of grebes.

While the birds keep a wary eye onshore, the comings and goings of boats around the marina does not seem to disturb them.


Over the next week I returned to the waterfront a number of times to see the progress the birds were making on the platform. It was fascinating watching them carry a wide range of vegetation back to the raft and then try to manoeuvre it on-board. Prodding and poking it until it fitted just right. One partner would sometimes disagree with the placement and pull it off, swim around to the other side and try and poke it in there.


Unfortunately a very large tree shaded the site in the late afternoon when most of the activity happened so my shots aren't so great. And oh how I wish I had that 600mm lens!


The handsome grebe belongs to an ancient order of diving water birds found on every continent in the world. It is renowned for its courtship displays and the way the young grebes ride among plumage on the back of their swimming parents- that’s my next mission but I guess I’ll have to wait until the spring and a return visit to Wanaka, to catch that.

I did capture some of the elaborate greeting displays and saw another pair mating (they were on one of the platforms attached to the marina- no photos though, although I can say it looked rather awkward- when you see the size of their feet you'll understand)

Grebes have a range of loud growling, grunting and barking calls that travel far across water but here my pair are calling to each other with soft grunts before greeting each other after one had left the platform.


And here’s a series of shots at the ‘changing of the guard’- after this, the one that had been sitting on the nest swam off out into the lake to feed, I presume. I liked the way they swam like synchronised swimmers, side by side (4th shot) quite fast for a short distance before pulling up and crossing bills together again.


A few days later and the compost pile is getting higher, of course it’s a Catch 22, the more they pile on, the more the raft sinks. The more the raft sinks, the more they pile on, trying to keep it out of the water.


Here's another courtship display- now you can see those weird legs ‘hinged’ on to rear end (in case you haven’t been following the blog- the legs are set well back to help with diving, these birds spend 99% of their time in water, only coming out to nest). The one on the left has brought part of the nest material with it.




With the greeting over, the returning bird swims over to the platform. And wouldn’t you know it, I was caught on the hop. I was expecting the bird to start collecting nest material again, like they had before, when instead, it launched itself most awkwardly out of the water and flopped onto the platform.  I didn’t have my shutter speed high enough to catch it clearly.

Mind you he does look rather funny, like Roadrunner perhaps?


Once up on top it’s a bit of a struggle to move about….


…and you can see why! With feet like this wouldn’t you? They are the strangest looking things I have ever seen. Like some alien growth, I think I’ve seen some sort of seaweed that looks similar.


Great for swimming no doubt, but just about useless on land, no wonder they spend all their time in the water.


Finally after much moving about, and tucking in of those ginormous feet, this beautiful crested grebe settles in for the afternoon. There are no eggs in the nest, it’s far too early for that, they are just making sure no one else takes over their renovations and nest preparations.


A few days later- the pile is still growing and there’s water lapping at the front door….




12 comments:

  1. John Darby and Shellie deserve medals for Grebe duties.

    ReplyDelete
    Replies
    1. Well John Darby certainly does Jimu, not so sure about me. Still got to get the chicks riding on the back to close this chapter.

      Delete
  2. Love your gorgeous shots of the Grebes Shellie.

    ReplyDelete
    Replies
    1. Thanks Lena, I was pretty pleased with them too. Love the courtship series.

      Delete
  3. Oh wow - well done Shellie. What beautiful birds - well done. Good on John Darby, such a simple thing really to make a predator-resistant nesting platform, but it is obviously making a big difference. Will definitely look out for them next time down that way. As rats & stoats can swim well it would be great to see the locals set up some traps along the shoreline during nesting season to help out even more. I am not sure how long the chicks stay in the nest before they get on the adult's back. I'd do it if I lived there. Look forward to "chicks on backs" photos!
    Melanie from Tauranga

    ReplyDelete
    Replies
    1. Thanks Melanie, I too wondered about swimming rats & stoats and how the grebes would cope. I know during the season John and a few volunteers kayak around the nests each day and also keep an eye on visitors and boat traffic. It's a very busy area where they are and even while I was there watching I became concerned about a few larger dogs bounding along in the shallow water. But I guess they have things under control, I think the chicks leave on their parent's back soon after hatching because I read about John opening an abandoned egg that was left after the first chick hatched- it had a dead (obviously) close to full term chick in it. Doesn't explain about pests swimming out to the eggs though.

      Delete
  4. Lovely shots Shellie. Might need to take a springtime trip to Wanaka with my new 150-600mm, I think I've been bitten by the birding bug!
    Regards, Lisa

    ReplyDelete
    Replies
    1. Oh you rat-bag, how lucky are you! :) How are you finding it? I dearly want one but think I'll not use it enough to warrant the expense. Perhaps if I had dedicated photo shoots rather than racing here, there and everywhere I'd use it more. 99% of the time my 18-300mm is my carry round lens and that's heavy enough. But then again........watch this space :) Great you've joined the club....just don't becomes one of those twitchers ;)

      Delete
    2. I love the reach on it and I got a free Manfrotto monopod on a promotion when I bought it. The monopod hadn't arrived in time for my trip but my tripod's central pole is a monopod too. At nearly 2 kg it definitely needs support!
      I think I had more misses than hits with it on my trip so it will take a bit of practice to get used to. Looking forward to some more settled weather and some spare time.

      Delete
    3. I'll look forward to seeing some great shots soon then! :)

      Delete

Thanks for taking the time to comment, it's much appreciated.