Phylosc's, Acro's and lovely lady Sylvia

Adam Homer writes:

The numbers of warblers ringed at Stanford Reservoir, Northants has increased significantly over the last 5 years. An annual habitat management plan allows us to control tall scrub which then allows low scrub and vegetation such as Brambles, Hawthorn, Sedge and Phragmites to regenerate. This as we all know is very important habitat for breeding birds such as warblers.

A site that is as far inland from any coastal observatory that you could get, Stanford Ringing Group prides itself on the numbers of warblers caught annually. Over 3,600 warblers were ringed in 2014 and already this year we have ringed nearly 3,800 and we still have October to catch a few more Blackcap and Chiffchaff.



With all these warblers ringed and eventually setting off on their migration we do receive a few reports of birds controlled (caught by another ringer >5km from ringing site) and we occasionally control birds ringed at other sites. Every spring we also retrap some of our returning warblers and to me that is what bird ringing is all about. That a small bird such as a Garden Warbler or Willow Warbler can fly a round trip of 3,000 miles and return to the site it has been breeding at for 10 years in a row is amazing!

Garden Warbler taken by Lee Barber (tail obscured)

One of these record-breakers was once again retrapped this year. It was a Garden Warbler that was ringed as an adult female on 2 July 2005. She then disappeared for two years, returning in 2008 and retrapped every year since. I was on holiday when she returned this year and was caught during two of our CES sessions. On 8 August she became the longest known BTO-ringed Garden Warbler at 10yrs and 37 days, breaking the longevity record for this species by 7 days*.

			Year
	2011	2012	2013	2014	2015
Garden Warbler	84	42	66	108	116
Blackcap	710	205	402	1665	1608
Lesser Whitethroat	50	26	56	81	109
Whitethroat	491	261	480	455	469
Sedge Warbler	259	67	145	140	190
Grasshopper Warbler	17	3	2	1	1
Reed Warbler	287	87	242	246	314
Willow Warbler	192	224	178	215	215
Chiffchaff	379	178	388	717	741

 

As you can see from the table above, the numbers of warblers, particularly Blackcap and Chiffchaff, have increased significantly with Garden Warbler and Lesser Whitethroat also showing a positive upward trend.

*Eds - The longevity records will be updated when all the 2015 data has been sent to the Ringing Scheme and fully processed. This longevity record will then replace the previous longevity record... unless another ringer catches an older bird or Stanford Ringing Group catch this Garden Warbler again a few days older.

Predictable migration - not!

The great Chris Mead described bird migration as "a regular movement between areas inhabited at different times of the year", but perhaps a more complete description might be "movements occurring at predictable times of each year, between breeding and one or more non-breeding areas, and therefore involving flights in predictable directions." But life isn't always quite so simple and there will always be birds that break (or rewrite) the rules. Lesser Redpolls are being caught with increasing frequency at feeders and some of the movements they make are... interesting!

Two birds ringed within a couple of days of each other in early April 2013 in New Clipstone, Nottinghamshire (in red below), were then recaught by ringers in early November, but at rather opposite compass points. One made it a short way south to Stanford Reservoir, Northamptonshire, whilst another made a rather lengthier trip up to Barra, Western Isles (both in blue below).

View Unusual migrations in a larger map

Whilst this is a little unusual, Stanford Reservoir seems to be the centre of such unusual movements, with two birds ringed there on 6th October 2012 making equally diverse movements. Both of these birds were recaught on 27th April 2013, but one in Lockerbie, Dumfries & Galloway, and the other in Brandon, Suffolk (both shown in green above).

So answers on a postcard please as to what these birds are up to!

World's oldest Whitethroat!

When ringers at Stanford Reservoir, Northants, caught Whitethroat ring number P774799 on 2 August 2009 they didn't think much of it. It was only later they realised that it had been originally ringed at the same site on 3 August 2002. Since then it was a regular at the site, though did go missing in 2007.

Seven years old might not seem like much, but P774799 is now the oldest recorded Whitethroat in Europe (and presumably the world?), beating a six year old Lincolnshire bird found dead back in 1992.

What is more amazing is that just in migrations alone, it will have made the 7,000 mile return trip to/from Africa seven times, crossing the Sahara 14 times!

Thanks to Adam Homer at Stanford Ringing Group for letting us know about this amazing bird.