• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Upton Warren (17 Viewers)

By the time I left late morning a further five species (in capitals) had been added the reserve's year list, bringing it to 66. A combination of the various sightings is as follows:

FLASHES
3 Lesser Redpoll, Treecreeper, 3 LINNET, Meadow Pipit, 1 Grey Heron, 24 Teal, GOLDCREST by the steps.

SAILING POOL
19 Greylag Geese (+ another 5 over), 25 Canada Geese, 1 Coot, 1 GC Grebe, 7 SISKIN on southern boundary.

EDUCATION RESERVE
Chiffchaff, 2 Siskin, 10 Lesser Redpoll, Green and GS Woodpecker, many tits (not just you Mike!).
MOORS POOL
1 Little Grebe, 2 GC Grebe, 17 Curlew, 200 Lapwing, 8 Snipe, no Gadwall or Pochard, 11 Shoveler, 2 Grey Heron, 1 Canada Goose, 30 Cormorant, 29 Teal, 93 Coot, 17 Tufted Duck, 3 Siskin, 2 Lesser Redpoll, BUZZARD, KINGFISHER.

Charming! Nothing further to add to the list.
 
  • Hirundines, Acrocephalus warblers, Little Ringed Plovers and Common Terns have shown highly significant shifts towards earlier spring arrival at UW.
  • There is no evidence to suggest that Willow Warblers, Sylvia warblers, Cuckoos, Grasshopper Warblers, Wagtails, Chats, Spotted Flycatchers, Black Terns or Hobbies are being recorded earlier (or later) in the spring at Upton Warren compared to earlier decades.
  • Garganey is being recorded later in the spring compared to earlier sample periods. In fact it has ceased being a regular spring migrant in the recent couple of years.
    .

  • A great article Dave but a bit out of my league mate. Thankfully after reading the Bird Migration by Ian Newton, I knew a few of the bigger words (obligate afrotropical-european migrants and facultative migrants)8-P
    I also think that the previous years successful breeding facilitates an early return, especially with non passerines. We have noted this with LRP, Avocet and Common tern which are easy to record. Passerines are more difficult to locate, but there is no doubt that warblers are arriving and singing in suitable habitat much earlier than they used to.
    The whole concept of migration is so fascinating and interesting that even the scientific fraternity haven't got all the answers and use conjecture as a tool for many aspects of it.
    Roll on the spring now just 10 weeks away. Iv'e just thought they have already had 9 weeks to build the flashes hide:eek!:...better have a word with some one:t:
 
Roll on the spring now just 10 weeks away. Iv'e just thought they have already had 9 weeks to build the flashes hide:eek!:...better have a word with some one:t:

Given that the first Avocet arrived on the 13th Feb last year, I would say that the Trust has less than 6 weeks to get the whole work programme at the Flashes finished, including snagging (of which I suspect there may be a fair bit).
 
TUESDSAY WORK PARTY at MOORS

Tomorrow Tuesday 3rd January is the first work party of the year.
We are continuing the coppicing and management of the north east woodland at the Moors pool.
Come along and work off that Christmas excess:t:
B :)John
 
A great article Dave but a bit out of my league mate. Thankfully after reading the Bird Migration by Ian Newton, I knew a few of the bigger words (obligate afrotropical-european migrants and facultative migrants)8-P
I also think that the previous years successful breeding facilitates an early return, especially with non passerines. We have noted this with LRP, Avocet and Common tern which are easy to record. Passerines are more difficult to locate, but there is no doubt that warblers are arriving and singing in suitable habitat much earlier than they used to.
The whole concept of migration is so fascinating and interesting that even the scientific fraternity haven't got all the answers and use conjecture as a tool for many aspects of it.
Roll on the spring now just 10 weeks away. Iv'e just thought they have already had 9 weeks to build the flashes hide:eek!:...better have a word with some one:t:

John,

You're right that there is often unsubstantiated conjecture bandied about and I've been careful to avoid it - the above is based only on the data available. We may assume that all warblers are getting earlier, for instance, but the objective truth revealed by these statistics is that many are not being recorded significantly earlier at UW in the spring, only really the Acros are. There is no objective evidence that the Sylvias and Phylloscs are being recorded earlier (ignoring Blackcap and Chiff problem due to possible overlap with wintering birds). These results were certainly a surprise to me. In fact it is probably because wintering Chiffchaffs are quite rare at Upton, they are easy to disregard and the first arrival of migrant Chiffs is signified by territorial singing birds, the recorded arrival dates are actually quite consistent over the years, since the first available data starting in 1974: t (18) = 1.483, p = 0.156. This shows that migrant Chiffs are not being recorded significantly earlier at UW and this may be surprising but is based on actual recorded data rather than perception.

That is an interesting possibility re the LRP breeding success etc. leading to earlier arrival in the subsequent year. We certainly have seen an apparent trend in avocet appearing earlier and that could be a possible explaination. However, we have only 8 years to judge that assumption on and this is insufficient to draw any statistically rigorous conclusions from. It would certainly make for a good study in about 20 years time. This would allow us to gauge the dispersion (i.e.variance, standard deviation) of the data and it might be interesting to correlate arrival date against breeding success in the previous year, by way of simple linear regression. I guess we could do that now on LRP and Common Tern to test your theory. There probably is enough of an historic record for this to be done - over to Phil, perhaps (I'm sure he'll be the man with all the raw numbers).:t:

As for the hide not being ready when the Avos turn up - you already know my concerns about that. Best have a few words with you know who. Cheers

Edit: Chiffchaff percentile plots attached. Both data sets are of very similar variance (relative dispersion indicated by slopes) and normally-distributed (indicated by linearity) - although the historic data-set deviates from normal more than the more recent one. The separation of the data sets is insufficient for there to be statistical significant difference. The bisection with the 50th percentile (dashed line) indicates the relative locations of the median dates. These are separated by 5 days (13th March versus 18th March) - this might sound like a significant shift but the standard deviations for each data set are ~7 days. It is because of this inherent variability within the groups of data that the difference is not statistically significant (z-score ~0.7 i.e.the difference is less than one sigma).

The t-test is a pretty robust method but is most valid when the data sets are normally distibuted (Gaussian) and homogeneous (equal variance). Both of these conditions are substantially met in the Chiffchaff data, as presented below.
 

Attachments

  • Chiffchaff Spring Arrival at UW.jpg
    Chiffchaff Spring Arrival at UW.jpg
    21.8 KB · Views: 49
Last edited:
John,

That is an interesting possibility re the LRP breeding success etc. leading to earlier arrival in the subsequent year. We certainly have seen an apparent trend in avocet appearing earlier and that could be a possible explaination. However, we have only 8 years to judge that assumption on and this is insufficient to draw any statistically rigorous conclusions from. It would certainly make for a good study in about 20 years time. This would allow us to gauge the dispersion (i.e.variance, standard deviation) of the data and it might be interesting to correlate arrival date against breeding success in the previous year, by way of simple linear regression. I guess we could do that now on LRP and Common Tern to test your theory. There probably is enough of an historic record for this to be done - over to Phil, perhaps (I'm sure he'll be the man with all the raw numbers).:t:

Dave,

Could probably break this down into three categories -(1) no breeding ever on site (2) unsuccessful breeding the previous year and (3) successful breeding the previous year - and see if there is any substantial variation between them (albeit we may be working with fairly small sample sizes for each category). If I send you that stats can you do the analysis?
 
Dave,

Could probably break this down into three categories -(1) no breeding ever on site (2) unsuccessful breeding the previous year and (3) successful breeding the previous year - and see if there is any substantial variation between them (albeit we may be working with fairly small sample sizes for each category). If I send you that stats can you do the analysis?

Yep send them over - I'll see what I can do. Might require a different approach though if some of the variables are discrete.
 
Water Levels

Hi Folks, Happy New Year

Given the extreme weather last year, how are the water levels now reading in terms of what you expect or wish them to be on the 2 sites ?
 
Hi Folks, Happy New Year

Given the extreme weather last year, how are the water levels now reading in terms of what you expect or wish them to be on the 2 sites ?

Hi Mark,

The flashes water level was reading 0.4 the other day. IIRC this time last year the level was hovering around 0.50. Therefore, about 10 cm lower this year. We would normally expect some flooding over winter and some overflow from the sluice into the hen brook. this hasn't yet happened this winter.

To me, the levels on the moors look more like you'd normally expect. :t:
 
Hi Mark,

The flashes water level was reading 0.4 the other day. IIRC this time last year the level was hovering around 0.50. Therefore, about 10 cm lower this year. We would normally expect some flooding over winter and some overflow from the sluice into the hen brook. this hasn't yet happened this winter.

To me, the levels on the moors look more like you'd normally expect. :t:

Cheers Dave :t: (fair bit being added today to by the sound of things )
 
Work party called off today, due to the atrocious conditions. Thanks to the 9 that turned up anyway, from past experience the forecast is usually wrong -unfortunately today the BBC got it right:-C. Did manage to 'ring bark' a couple of trees in the NE woodland though.

Birding at the Moors
Little egret came in at 12.30ish and stayed around the islands, sheltering from the gale-force winds.
A pair of raven passed low over Amy's and 3 stock dove flew over.
The grazed meadow supported a flock of redwing (20) and a few blackbirds. At the chestnut tree / spindle bush area a small flock of thrushes including, fieldfare, redwing and blackbirds fed on the last of the sloe's. Also there were 4 Bullfinch, redpoll (2), chaffinch.
On the water and around the islands, totals were:
GCG 5, little grebe, cormorant 31, shoveler pr, Teal 71, Mallard c80, Tufted 15, Mute swan 4 ( the dominant male attempting to kill the rival in a battle that last 10 minutes or more.) Coot c100, water rail called. Snipe 14, Lapwing 120, curlew 18. Herring gull c20,
B :)John
I'll get back with water level comparisons
 
Last edited:
Water levels

This time last year all the pools were iced over to varying degrees so accurate water level readings were impossible to get.
When the thaw started the levels were as follows
Flashes 0.54 (13th January 2011) Dave's reading of 0.4 over the new year is 14cm (5and half inches) lower than last year. After today's rain I would expect it to rise rapidly. But it will probably drop again due to the water table still being low.
The Moors was 0.65 on the Amy's scrape marker (6th January 2011). Today it was 0.68 which is 3cm higher than last year. Thus no problem there.
The high water level and today's heavy rain saturated all the islands in Amy's marsh and the surrounding grassland, giving rise to a feeding frenzy by Teal, mallard, snipe and thrushes.
The north moors seasonal pool is now well flooded and the north moors pool itself is almost at its peak, just below the level when 'spillover' occurs.
B :)John
I hope the increased water level at the Flashes isn't used as an excuse, for you know what.:smoke:
 
Hi all

Happy New Year to everyone.
I have eight bird boxes that need erecting on Sunday's work party. I am happy to look after this, with John's help.
However, I now have eight bat boxes (cost us a tenner) as well. I'm going to have to lean on a far more knowledgeable team to sort this particular erection out!
Suffice to say, I'll bring 'em down on Sunday - you whack 'em up.
Nice to be back boys; thanks for your support... ;)
 
Hi all

Happy New Year to everyone.
I have eight bird boxes that need erecting on Sunday's work party. I am happy to look after this, with John's help.
However, I now have eight bat boxes (cost us a tenner) as well. I'm going to have to lean on a far more knowledgeable team to sort this particular erection out!
Suffice to say, I'll bring 'em down on Sunday - you whack 'em up.
Nice to be back boys; thanks for your support... ;)

Nice one Sy - see you on Sunday with your boxes.
 
Hi all

Happy New Year to everyone.
I have eight bird boxes that need erecting on Sunday's work party. I am happy to look after this, with John's help.
However, I now have eight bat boxes (cost us a tenner) as well. I'm going to have to lean on a far more knowledgeable team to sort this particular erection out!
Suffice to say, I'll bring 'em down on Sunday - you whack 'em up.
Nice to be back boys; thanks for your support... ;)

Sy's generous offer prompts a naive question: which species of birds can we reasonably expect, and want, to nest in the boxes at Upton apart from Blue Tits and, of course, Sand Martins? I am very ignorant about nesting practices and would welcome enlightenment.

Peter
 
Sy's generous offer prompts a naive question: which species of birds can we reasonably expect, and want, to nest in the boxes at Upton apart from Blue Tits and, of course, Sand Martins? I am very ignorant about nesting practices and would welcome enlightenment.

Peter

Hi Peter
Great and blue tits are the most common users of boxes on the reserve.
In the past we had a kestrel box near to the horse chestnut tree several years ago that was successful. A barn Owl has been erected at the edge of the reserve. There are many open fronted boxes scattered around as well. We have not really spent much time surveying the boxes, until last year. This fresh impetus might bring some rewards and more thorough monitoring of them will ensue from now on. We intend to number them and check regularly throughout the coming breeding season.
In the past we also put up tree sparrow 'colony' (a vertical cluster of boxes) and treecreeper boxes.
Andy Warr used to do the monitoring many years ago, when I next see him I will find out his findings, unless Mike knows.
B :)John
 

Users who are viewing this thread

Back
Top