Saturday, 24 September 2022

Tern, tern, tern. To every thing there is a season....

With apologies to the Byrds (performers) and Pete Seeger (composer).   The purpose under heaven in this case was to check for a Bird of the Day, with a specific hope for a White-fronted Tern (before they return to New Zealand for procreative activities.

I have looked for them many times recently with no luck.  Indeed there have been few terns of any species around Mallacoota recently.  That changed today with a very large flock on a sandbank.

A member of BLEG who worked as a microbiologist spent a lot of working time counting bacteria in petri dishes.  He has transferred that skill to counting flocks of birds through a telescope and has expressed the view that most people's ad hoc estimates are usually a significant undercount.  My guestimate of this flock was 500 birds.  What do readers estimate?  (NB the birds in the water are mainly Godwits and Knots, not terns.)

I will note that Rob Clay reported (a few back) a similar phenomenon at Marlo/Cape Conran.  I have no idea why they have returned to Mallacoota today: perhaps going to the pub to watch the Grand Final?  I did note that quite a few of them seemed to be flying in from the direction of the Goodwin Sands.

Of course I hadn't expected this so had had left camera at home.  The image above is straight off my iPhone.  I also didn't have the phone adapter for my telescope but I was able - with a little fiddling about and a lot of muttered obscenities - to get a digiscoped image of 2 of the 5 White-fronted Terns I saw.

I returned with camera and too a couple of shots of the flock of terns and after loading them to my computer counted the terns by putting a dot on each bird.  I changed colour every 100 birds to make it easier to keep track of where I was up to.  I used the formation of terns in the water as a reference point to avoid duplication.


My total count was 1099 birds which I suggest is within +/- 20 of the actual number.

When I first arrived (sans camera) the waders were in 2 groups with 48 Bar-tailed Godwits in one group and 27 Red Knot in another.  By the time I returned the two species had mingled.  Here is part of the mixture.  (I did check for Black-tailed Godwits but no luck.)  I will be submitting this to Crap Bird Photography in due course.



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