Why are Dartford Warblers so rare in the UK? (1 Viewer)

[Richard Ford]

Frensham Common in on the A287 at ……….. O thanks Michael ;-)

And is an all round good inland spot, two large ponds with Great Crested Grebes and other waterfowl in Winter. Also has a habit of turning up good passage birds, Waders, Osprey… Great Grey Shrike in Winter.
Well worth a look at any time of year..

A bit early to plan it but I am sure I will remember (remind me ;-) and we will arrange a Surrey Heath bird finding mission in the spring..



Rich :t:

 

[PaulAshton]

I live near Cannoch Chase staffs and can comment on the temperature issue.

While on Dartmoor one February day I visited a heath (quire high up) which is noted for it's Dartfords.

it was blooooody freezing.. and much colder than Cannock Chase at the same time of year (which is pretty cold).

So if they can take Dartmoor then Cannock Chase is easy.

 

[Michael Frankis]

Hi Paul,

It may be a bit more complex than that - on Dartmoor, they have the option to indulge in some altitudinal migration to get to somewhere a bit warmer for the duration of a cold snap; at Cannock, they wouldn't be able to do that.

Also while Dartmoor may feel colder to us due to wind chill, Cannock is probably colder in °C, and it is °C cold that kills their insect food, not windchill.

Michael

 

[scampo]

I live near Cannoch Chase staffs and can comment on the temperature issue.

While on Dartmoor one February day I visited a heath (quire high up) which is noted for it's Dartfords.

it was blooooody freezing.. and much colder than Cannock Chase at the same time of year (which is pretty cold).

So if they can take Dartmoor then Cannock Chase is easy.

It would be a surprise if they didn't move north - but they may have a particualr food requirement, like the nightjar. They are now quite common in Suffolk, but this could well be a different population than that in Hampshire, for instance - indeed it may be from the Continent.

With generally warmer seasons, I should expect Cannock to see its first DW soon.

 

[Ruby]

Thanks for putting that link in Birdman - do you just cut'n'paste the URL??

Trip in Spring sounds great.... Nightjar and Woodlark would bother be lifers for me....!!


Rgds... Ruby

 

[andythomas]

Actually Dartford Warbler is on the Staffordshire list, due to breeding records from Cannock Chase of an unknown date. Probably mid-late 1800s. No records since. The last one seen in Warwickshire was in October 1914. However, in Worcestershire there were no records at all until the early 1990s, but then single winter visitors in five of the ten years up to 2001.

Worcestershire is therefore favourite for a return of breeding birds to the West Midlands region, and I would think that Castlemorton Common would be the most likely site.

As for breeding populations, the last Atlas in 1992 gave a maximum of 950 pairs. According to Holloway in his Historical Atlas this figure had probably not occurred since the early 20th century. He mentions cold winters in 1880/81 and 1886/87 which severely affected the population, particularly as their proximity gave little time for recovery. So I would guess the last time we had a population as high as today's was in 1880.

--
Andy

 

[HH75]

Hi all,
While winters are generally mild enough over most of Ireland to support Dartford Warblers,two factors would seem to mitigate against the establishment of a breeding population:
1)the absence of lowland heath
2)Dartford Warblers are essentially resident,and don't make it across here that often(ticked sp.here this year,and that was only the 10th Irish record)
Nevertheless,the two most recent Irish records were in spring(the previous 8 had been in autumn),and it is conceivable that they could adapt to gorse-covered headlands?
Harry H

 

[birdman]

do you just cut'n'paste the URL??

That's the way I do it!

:t:

 

[scampo]

Hi all,
While winters are generally mild enough over most over Ireland to support Dartford Warblers,two factors would seem to mitigate against the establishment of a breeding population:
1)the absence of lowland heath
2)Dartford Warblers are essentially resident,and don't make it across here that often(ticked sp.here this year,and that was only the 10th Irish record)
Nevertheless,the two most recent Irish records were in spring(the previous 8 had been in autumn),and it is conceivable that they could adapt to gorse-covered headlands?
Harry H

Well, the population on Dunwich Heath is, effectively, on a 'gorse covered headland', so the possibility exists. As you say, though, DWs are generally sedentary - yet there seems evidence, I have been told, that the Suffolk population is a Continental race.

 

[Michael Frankis]

Hi Steve,

I have been told, that the Suffolk population is a Continental race.

This is highly improbable - the continental / mediterranean race (nominate undata) doesn't breed anywhere closer that southeast France. The atlantic race (dartfordiensis) includes not only the UK birds but also those in N&W France, NW Spain and N Portugal.

Michael

 

[gordon hamlett]

In his excellent book, The State of the Nation's Birds, the late, lamented Chris Meads writes that DW is 'seriously increasing and expanding.'

1600 pairs in 1994 and likely to be many more now though this population is always likely to crash if we get a severe winter.

Gordon

 

[jayhunter]

We have a few gorse inhabited hillsides up here in Cheshire, which would be ideal breeding grounds if it wasn't for the winter temperatures. Frensham is one of my old stamping grounds as a lad from Hampshire, must try to get a visit in next time I am down visiting my Mother.

 

[scampo]

Hi Steve,



This is highly improbable - the continental / mediterranean race (nominate undata) doesn't breed anywhere closer that southeast France. The atlantic race (dartfordiensis) includes not only the UK birds but also those in N&W France, NW Spain and N Portugal.

Michael

I didn't mean to use the word 'race' - my apologies. But it was suggested to me that the Suffolk population were not necessarily from Hampshire.

 

[Cuckoo-shrike]

Yes, as Harry says, Dartfords are generally resident and sedentary. But over the years, we've had a few March records here on the south Cornish coast in areas where they don't breed. These birds have often been associated with incoming Chiffchaffs, leading to suspicion that they may be Continental migrants.
The population on the Lizard peninsula has burgeoned in the last few years. I don't think there were any here in the mid 1980's.

 

[Michael Frankis]

Hi Aquila,

They are not quite so sedentary as often stated in (particularly older) books, apparently a proportion are short-distance migrants, either just moving from inland heaths to nearby coasts, or crossing the Channel to France at least. So the ones arriving with Chiffchaffs are probably returning migrants, not new immigrants.

Michael

 

[ColinD]

While winters are generally mild enough over most of Ireland to support Dartford Warblers ...........

Perhaps there is a third reason why Dartford Warblers are not in Ireland. Rainfall.

Mild winters have been mentioned a few times during this discussion, and it seems to be assumed that this is one positive of Global warming which will help the Dartford Warbler.

However, lets assume that the doomsday scenario of the gulf stream changing course does not happen, and that winters do indeed become milder, it is still not neccessarily true that global warming will benefit the species, in my opinion.

Yes we may get milder winters, but if the breeding season is very wet, perhaps that will adversly effect the species. Perhaps the species also requires hot sunny periods during the spring and summer, (and that is why they are not in Ireland).

One of the possibilities of global warming is that temperatures will generally rise, but we will have more cloud cover and rain, and less sun. If that happens (and it does seem to be happening if recent years are anything to go by), maybe, rather than see them increase, we will lose Dartford Warblers as a breeding species, along with many other species which you might assume would benefit from global warming, such as some species of dragonflies and butterflies.

Colin

 

[Michael Frankis]

Hi Colin,

Good point, that could well be true for the wetter areas, though I would suspect lowland southeast Ireland is less cloudy & wet than Dartmoor (except that I don't know where on Dartmoor the Dartfords are). Personally, I'd suspect high rainfall is more of a barrier to any potential Cirl Bunting spread, than to Dartfords.

This year's summer doesn't follow your suggested trend (!!); as far as I'm aware, the most widely suggested global warming scenario shows Britain becoming drier in the south, and wetter only in the northern Atlantic fringe (western Ireland, western Scotland, perhaps also north Wales and Cumbria)

Michael

 

[CJW]

wetter only in the northern Atlantic fringe (western Ireland, western Scotland, perhaps also north Wales and Cumbria)

Michael

And guess who's stuck in the middle of that lot!

 

[jayhunter]

The Greater Manchester area within which I fall, seems to be getting more than enough of its share of annual rainfall. I think that Colin's location must be quite close to me, my lawn is always green and lush, but travel 100 miles south and my friend's lawns resemble brown withered tufts and inch wide cracks in the earth. We did have a couple of good weeks in March/April this year.

 

[Bertram Bree]

Dartford Warbler in Jersey

Hi there,
Dartford Warblers in Jersey fluctuate in numbers quite dramatically, although at present there are over a hundred pairs on Jersey covering most of the suitable habitat on an island only 120 square km in size, many pairs a couple of hundred metres above sea level. I find Les Landes common on the north-west tip of Jersey a good spot for the species, particularly near the model aircraft runway, where they follow Stonechats so often that if you find a Stonechat you can often find a Dartford Warbler chasing it out of its territory. The call is a give away when trying to locate a Dartford Warbler and the song is also an easy way to detect it if you play a recording birds are sure to get interested in the 'Top of the Dartford Warbler Tops'. There should be no problem in finding a Dartford Warbler in the breeding season in Jersey if you get help from a local birder who knows the specias well.
Ouaisne is also a good spot for Dartford Warbler as wellas for Agile Frogs, Green Lizards and European Serins. Cirl Buntings used to be found here easily in the past but there numbers are decling here in Jersey now for some strange reason probably due to loss of habitat and disturbance.Regards from sunny Jersey.
Nice birding.Bertram BREE