Tuesday, 16 December 2014

Beer Head 2014 Ringing Review

It was in 2013 that I was suddenly struck by the bird ringing potential Beer Head had to offer. Beer Head is our Portland Bill when it comes to birds, we only get a tiny fraction of the birds that Portland do, but it is certainly our best spot for grounded passerine migrants in spring and autumn, especially warblers and chats.  There was a small area in particular where I felt the habitat suited mist netting and over the years many migrants have been seen there, so during the winter of 2013/2014 I got in touch with the farmer to see if he'd let me give it a go.  The reply was very favourable, and made me wonder why I hadn't asked several years before!  April 2014 couldn't come round soon enough...

For those who don't know Beer Head, here's an overview...

That's Portland in the bottom right corner - Beer Head is nothing in comparison but it is a headland nonetheless.

A closer view of Beer Head. The area outlined in red is the usual area I bird when I go up here, although sometimes do wander further west along the cliff top towards Branscombe. The area circled in blue is my ringing site.

So as you can see from the above photo it really is just a small section that I've been ringing in.  There are plenty of other hedgerows and fence lines for migrants to filter along and completely bypass me and my nets, so my numbers are just a fraction of what Beer Head gets as a whole.  Looking at my ringing site in a bit more detail, I used four different net rides...

I never used all four nets at once, three was the most but I usually operated with just two.

During the year I managed to get up here on 20 mornings, seven during April, two in May, five in August,  five in September and one in October.  All sessions were over by 11am at the latest usually due to work commitments and as I said most times I was operating just two nets (often one 60 foot and one 40 foot). I was happy with the coverage I gave it in spring, but felt I could have done more in the autumn. Although I must say, it was a poor autumn for grounded passerine migrants on patch, Aug-Sep was much quieter than usual, and during October birding up Beer Head was very hard work indeed. I knew it would be the kind of ringing site that would vary day to day during migration time, being completely dependent on grounded migrants, and this was true, but thankfully I had more good days than bad - especially during the spring.  My worse day was the October session, it only lasted one and a half hours but I caught no birds at all.  My best for numbers was 22nd April, with 52 birds trapped, though 29th September wasn't far behind with 50 birds trapped.  In all I trapped and ringed 347 birds, and controlled one (the Blackcap mentioned in the previous blog post). And the 347 birds were...



Species Full grown Retraps/ Recoveries Total

Swallow 1 0 1

Meadow Pipit 2 0 2

Wren 6 3 9

Dunnock 14 0 14

Robin 16 3 19

Redstart 7 0 7

Wheatear 1 0 1

Blackbird 10 1 11

Sedge Warbler 1 0 1

Whitethroat 9 0 9

Garden Warbler 1 0 1

Blackcap 43 3 46

Chiffchaff 50 0 50

Willow Warbler 134 0 134

Goldcrest 9 0 9

Firecrest 1 0 1

Spotted Flycatcher 1 0 1

Long-tailed Tit 9 0 9

Blue Tit 8 2 10

Great Tit 4 1 5

Chaffinch 5 0 5

Greenfinch 8 0 8

Goldfinch 1 0 1

Linnet 6 0 6

Total 347 13 360


And there you have it.  As I expected from the start, mostly migrant birds. Even the Robins I'd say at least 14 of them were true migrants, with just one or two being resident birds. Same with Blackbirds, but the Dunnocks and Wrens were probably all local birds along with some of the tits and finches.  At the start of the season I said to myself I would be very happy to have ringed 100 Willow Warblers by the end of the year, and as you can see I smashed that.  Interestingly out of the 134, 103 were in the spring with just 31 in the autumn - summing up perfectly how poor the autumn was for us in terms of grounded migrant numbers.  

Here's a few pics of some of the oddities that wound up in my nets...

Female Firecrest on 4/4/14
My first Redstart caught here, a cracking male on 14/4/14
With my first female Redstart not far behind on 17/4/14
Male Greenland Wheatear on 2/5/14
Garden Warbler on 14/5/14
Spotted Flycatcher on 14/5/14
Sedge Warbler on 18/8/14

So what did I learn, and what were the surprises? Well quite a lot of both to be honest!  I've found it really fascinating ringing at a site that I and others have birded for many years. It has completely changed my thoughts about Beer Head, and birding during spring and autumn. 

My best days in the spring were on clear and bright mornings, not the cloudy overcast weather that is often associated with good spring falls. The important factor was the wind direction though, with the northerly element being key in grounding migrants. The bad news is although these weather conditions were the best for grounding birds, wind along with clear blue skies aren't great for mist netting. I probably would have caught many more birds if there were clouds in the sky. 

I also found that during these good conditions birds were arriving/passing throughout the morning, they clearly hadn't all arrived at dawn as is often thought. In fact the first half hour after dawn was often very very quiet, and on a couple of occasions it looked like the morning was going to be a complete waste of time based on how it started, but suddenly it would get busy. Whether the birds had arrived but just hadn't started moving around I don't know, but this was a big surprise to me, I was convinced dawn was going to be the busiest time of the morning.

There were several days in the spring that I know if I was birding around Beer Head I would have said it was quiet, but the nets proved otherwise.  In fact I remember one day in particular that both my Dad and Ian M were birding and reported the bushes were quiet, but I'd caught over thirty Willow Warblers, a couple of Redstarts, etc... And I can safely say over the years of birding Beer Head we have all been under counting - and this probably happens everywhere.  Even on the quiet days when there was just a light trickle of phylloscs, each time I went to the nets there would be a few new ones, and none of the ones I had already ringed.  Clearly in the spring birds often move through really quite rapidly with few lingering.  Birds often flew into the nets in small groups as well, I expected this in the autumn but not so much in the spring, but it certainly was the case.

Sylvia Warblers were a surprise too, being surprisingly scarce in the spring. Over the year I caught 43 Blackcaps, 9 Whitethroats and a Garden Warbler.  Well just three of those Blackcaps and the Garden Warbler were in the spring. So odd as Blackcaps were singing throughout the spring from just down the slope!  It's obvious why I caught the number I did in the autumn because there was a lot of food about where I net, but why so few in the spring?  I think the most obvious answer is that they stay lower down the headland, either in the under cliff below Beer Head or in the thicker bushes just down the slope to the east of where I ring.  Like I said, Blackcaps were always singing from here, so maybe the singing birds lure in all the passing migrants?  Whatever the reason I found it quite odd though, the ratio of phylloscs to sylvia just wasn't right - and it's not like the habitat isn't suitable!

And although we know this with birding anyway, just because it's quiet doesn't mean it's not worth it.  Both the Firecrest and Greenland Wheatear were caught on quiet days....

Right - I think this post is long enough. I want to end by saying I cannot wait for next year to start up here, and really look forward to seeing what else I learn. And also, I would like to thank Peter, Doug, Richard, James and my Dad who all helped out at some time or the other, whether it was ringing, writing, or kit carrying. It all helped and some of it was crucial to the success of the site.  Lastly of course, thanks to the land owner for being so helpful and generous.

2 comments:

  1. Interesting Steve, after 30 years of watching the headlands I would concur that good numbers of migrants can arrive after a clear night with northerly wind, we don't always need mist and south-easterlies to get good numbers to drop in. I think clear nights are safer for migration and easier for birds to navigate. Dave Cope

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  2. Hi Dave, glad you agree. The northerly wind is the importand thing I reckon, anything blowing from the south means the birds go straight over us without stopping, but it's surprising how little wind from the north they need to ground.

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