Tuesday, 6 June 2017

Bega River Entrance Tathra NSW

The Bega River discharges to the Tasman Sea just north of Tathra (near the Tathra-Bermagui Road bridge. A large sand spit blocks most of the river entrance and this provides ideal habitat for shorebirds and seabirds to rest, nest and forage. So this area is another good location on the NSW south coast (the Sapphire Coast) to look for birds. We spent an hour or so there in late May and captured all these photos there.

The sand spit has a good amount of debris deposited on the sand bar by floods and sparse patches of tussocky vegetation all providing cover for small shorebirds such as Red-capped Plovers and Double-banded Plovers. We found seven and six of these plovers respectively on the sand spit. The Red-caps are resident Australians however the Double-banded Plovers are migrants from the South Island of NZ – an east-west shorebird migrant which is rare – all the other shorebirds migrate north – south. They spend winter in SE Australia including along the coast and on inland water and breed in NZ, so we mostly see them in their drab winter non-breeding plumage. It is possible to see birds in breeding plumage in Australia late in the season before they migrate back east to NZ.

Please click on photos to enlarge.

Double-banded Plover in non-breeding plumage.
Same bird as above – different pose.
This Double-banded Plover standing among flood debris is still showing some breeding plumage on the breast.
Adult Red-capped Plover. The red cap is missing from the top of this bird’s head?

There were about 60 Crested Terns and a similar number of Silver Gulls resting on the estuary shoreline of the spit and with them two Pied Oystercatchers. I moved closer to them to see if they were flagged.

Both PO's were resting so I had to approach a little closer to get them to stand so I could see if they were flagged. 
One of the birds stood and moved to the left and this bird then stood to follow. As it did it hunched up and called.

To my surprise the following bird suddenly mounted the other bird.
Presumably the male is now standing on the back of the female.
The birds are clearly copulating or attempting to.
They continued to copulate.
The male stands up a little and she continues to stand for him.

Is this for real? 
The amorous encounter ends with the male toppling off to the left.

I did not expect to see Pied Oystercatchers copulating as I thought late May, just one day short of the official start to winter, was well outside their normal breeding season. In the south, the breeding season is from August to January though the Morcombe field guide says breeding can occur as early 
as June. As this encounter was observed on the 30th of May it is possible this pair are breeding.


 As you can see in the photos neither of the PO’s were flagged or banded.

Apparently PO’s are monogamous – they mate for life.

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