Wood Warblers (1 Viewer)

[occasional]

There seem to be an exceptionally large number of wood warblers about in my part of Argyll this year, which seems to follow a sudden increase in blackcaps a few years ago. Anyone else noticed a similar increase ?

 

[Nutcracker]

In continuing terminal decline to extinction in Northumbs.

 

[kb57]

In continuing terminal decline to extinction in Northumbs.

Although I came across a nesting pair over the border in Co. Durham this year, so all not lost quite yet...

 

[jogresh]

My gut feeling "on the ground" (having done a couple of contracts in woodlands in the hills of N Wales), is that they are declining/shrinking in range, particularly woods on the fringes of their ranges. One wood where I've had them previously - Coed Dinorwic, Llanberis - we surveyed 4 times between mid April and late June, and didn't get a single Wood Warbler. It would be tempting to assume that any increase in Argyll corresponds to the decline in SE Britain. I should say, I haven't done any statistical analysis on the data I've generated.

 

[Nutcracker]

My gut feeling "on the ground" (having done a couple of contracts in woodlands in the hills of N Wales), is that they are declining/shrinking in range, particularly woods on the fringes of their ranges. One wood where I've had them previously - Coed Dinorwic, Llanberis - we surveyed 4 times between mid April and late June, and didn't get a single Wood Warbler. It would be tempting to assume that any increase in Argyll corresponds to the decline in SE Britain. I should say, I haven't done any statistical analysis on the data I've generated.

Dinorwic is surely core range, rather than fringes?

One thing I've noticed with Northumbs is that they disappeared earlier from sites with heavy people, and particularly dog-walker pressure; the remaining likely breeding site isn't in their original core area in the county, but is noticeably less infested with dog walkers.

But otherwise the clear trend is for the numbers to be doing best in Scotland, so climate warming may well be important too. Milder winters in particular may allow increased competition for food resources from resident species.

 

[jogresh]

Dinorwic is surely core range, rather than fringes?

One thing I've noticed with Northumbs is that they disappeared earlier from sites with heavy people, and particularly dog-walker pressure; the remaining likely breeding site isn't in their original core area in the county, but is noticeably less infested with dog walkers.

But otherwise the clear trend is for the numbers to be doing best in Scotland, so climate warming may well be important too. Milder winters in particular may allow increased competition for food resources from resident species.

What was on my mind was that in my area, it seems to me like they are retreating from the woodlands around the fringes of their local range, by which I meant the ones which are lower in altitude. So for Coed Dinorwic, in the past I've had them at 350 feet ASL, whereas now there are none. There were other "lower" woods we surveyed in the areas round Maentwrog and downstream from Nantmor which also seemed to lack Wood Warblers in prime habitat.
2 yrs ago, I was surveying the large NT Ysbyty Ifan estate, which is on quite a high plateau - decent areas around 900 feet and there were really good numbers of Wood Warblers. While doing this, I was asking 2 friends doing nestbox schemes several miles further downstream if there were the usual numbers of Wood Warblers in their woods, and it seems there weren't. There is, of course, always the danger of confirmation bias.
The points about disturbance and mild winters are interesting ones. They can be extremely confiding birds, singing within close proximity, sometimes coming close to check me out, then carrying on their business.

 

[Nutcracker]

They can be extremely confiding birds, singing within close proximity, sometimes coming close to check me out, then carrying on their business.

Yep, I know, hence my emphasis on dogs, more than people. If they (through being confiding) nest close to paths, the nests will be sniffed out by dogs and the chicks eaten :-C

 

[kb57]

Yep, I know, hence my emphasis on dogs, more than people. If they (through being confiding) nest close to paths, the nests will be sniffed out by dogs and the chicks eaten :-C

The pair I found in Co. Durham this year were nesting on the ground just a few metres from a public path, fortunately not one that appeared very well walked.