Thursday, 18 September 2008

Swamp Harrier

.....Circus approximans

Swamp Harrier's are migrants to Tasmania arriving in early spring. I saw my first for this year on the 19th August. Yesterday I noticed a pair near Table Cape which kept returning to the same spot on the ground. Perhaps they are preparing to nest as unlike many other birds of prey, the Swamp Harrier makes it nest on the ground, often among crops.

They will likely lay 4 to 5 eggs. Survival of the young will depend largely on the availability of food and any accidental run-ins with farm machinery. Their prey includes anything from insects to rabbits as well as carrion.

By around March next year almost all of our Swamp Harriers would have returned to the mainland with only a few choosing to spend the winter here in Tasmania. Robert Green records one bird that he banded at Antill Ponds in the Tasmanian Midlands. It was recovered the following winter at Goodwood Island at Chatsworth in northern New South Wales. According to Google Earth that's over 1,500 km's to the north (as the Harrier flies).

The photos below could be better but I'm happy in that they are the best I've managed for this species to date. Notice the loose feather on the head - perhaps the result of a dogfight with the local lapwings and ravens.


(Click Photos to Enlarge)

Swamp Harrier - Circus approximans


Swamp Harrier - Circus approximans


References:
  • Green. R. H. - 1995 - The Fauna of Tasmania - Birds , Potoroo Publishing, Launceston
  • Birds in Backyards - website


9 comments:

  1. Your shots show the diagnostic white rump nicely Alan.

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  2. Lower picture - underwing pattern - looks like a juvenile. Might be a learner lover. Were the two birds very diff in size?

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  3. Thanks Duncan - That's one advantage of an otherwise bad angle ;-)

    Thanks Tony - That's interesting. They were never right next to each other so a bit difficult to compare sizes. What particular feature of the underwing are you looking at?

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  4. Kind of like a female Marsh Harrier with the white rump of the Hen Harrier. I love watching any Harriers, they're superb aerial dancers!

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  5. Great photos. I don't think I have seen those birds up here at all. Wish I could take more photos of
    BIF but my old camera is so-o-o-o slow to focus!

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  6. Thanks Jenny - yes, in fact having been in Britain for so long I keep calling them Marsh Harriers instead of Swamp harriers.

    Thanks Mick - This lens is recommended by some for BIF. I still need a bit of practice though.

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  7. Juvenile underwing marked by strong dark(leading edge)light diagonal pattern.
    Pizzey&Knight good on this.

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  8. Thanks Tony - for the extra info. I must get myself a copy.

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