Tuesday, 5 July 2011

BTO Atlas in Lincs - Number of species required to achieve 75% confirmed breeding

Many Atlas supporters have been hard at work since the breeding season commenced and the ttv coverage for the county is now virtually completed. The key task left is to confirm as many species breeding in each 10km square as possible. 

So how are we doing in this respect in Lincs? Here is a graphic showing those square in yellow where we have yet to reach the 75% target for breeding species confirmed. The number in each square is the number of species that need to be confirmed to hit the 75% target. We are doing pretty well compared to adjacent counties and 36 of our 79 squares are already over 75%. A further 12 are within 5 species.

We are now getting down to the wire with only a few weeks left to confirm breeding. Please check out what species are missing in your local squares by clicking on "My local gaps" on the the BTO Atlas homepage and then chase down the missing species. Its great fun and will add an extra enjoyable dimension to your birding. There are still many unconfirmed common birds, particularly warblers and now is a great time to confirm most species. If you need any guidance on using the website and adding records please contact your BTO regional representative (http://btolincs.blogspot.com/).

Heres to some good birding and some excellent coverage for Lincs when the Atlas book is published in just udner 2 years time."

Monday, 6 June 2011

Some tips on confirming breeding by birds of prey

In this last summer of the BTO Atlas, we are trying to confirm breeding by as many species as possible. The main atlas period ends on 31st July, but we can continue to confirm breeding into the autumn. This is especially relevant to birds of prey, several of which don't fledge until July or August.

The tips below for three species – all now widespread in the county – are based closely on guidance prepared by Rob Clements for Kent but are equally applicable here. So why not take the opportunity for some relaxed late summer birding and give it a go? Bear in mind that you should avoid disturbing the birds, especially important for Hobby, which is a Schedule 1 species for which disturbance at the nest (without a licence) is an offence. Having said that I saw my first newly fledged Common Buzzard today. Most species seem to have advance their breeding by at least a couple of weeks this year so please keep that in mind.

Common Buzzard

Confirming breeding for Common Buzzard is not difficult! These are large and noisy birds; the adults can be seen carrying food items back towards a nest-site through-out the day, and newly-fledged young are almost continuously noisy, plaintively calling for food from hedgerow trees and woodland edge. Look for areas of mixed woodland and farmland. Find a good viewpoint on a sunny morning in July or August. Scan the horizon for Buzzards, listen for their calls. If all the activity is distant, move nearer, preferably without disturbing the birds. Juvenile Buzzards are much whiter than adults, and lack the clearly defined dark terminal bands on tail and under-wings.


Best looked for in July/August. Most blocks of mature conifers hold breeding Sparrow-hawk Walk around quietly, listening for young Sparrowhawks plaintive begging calls, or the chattering alarm calls from the adults. The successful nest is quite obvious, with thousands of white down feathers, all over the nest and surrounding branches. The woodland floor below is splattered with white droppings, as if some-one had been flicking white paint all around an area of 100 sq yds or more. Watching from a viewpoint, the adult Sparrowhawks can be seen approaching the wood carrying bird prey, often diving in from high up.


Look for successful breeding Hobby in the period from 1st August to 20th September. Start off from a viewpoint giving a good view over an area of woodland edge and hedgerow trees. Choose sunny weather between 9.00am to 4.00pm. Look for family groups of Hobby hawking insects or chasing each other around in spectacular play. Closer up, you can hear a young Hobby keeping up almost continual calling, a higher pitched version of Peregrine begging calls. Juvenile Hobbies are easily identified, with buff edging to the feathering on the upper-parts and an absence of reddish "trousers." Adult Hobbies regularly visit the fledged juveniles, bringing bird prey and chasing off intruding Sparrowhawks and Crows. If you've not seen anything after an hours watching, move on and try somewhere else. Hobby nests are often approx. two miles apart in open farmland in southern England, though it may well be more in parts of Lincolnshire.

Thursday, 14 April 2011

Time to start confirming the early birds

We are now 2 weeks into the summer atlas period and we still have a lot to do. One of our key tasks this summer is to confirm as many breeding species as possible in each 10k square and enter breeding evidence into the atlas database either through roving records or a timed tetrad visit.

So what should we be looking for? Well many of our commoner residents are already in full swing gathering nest material and building nests (code B , probable breeding) and starting to lay (code ON, confirmed) but some breed earlier than others and April is a good time to look for them. Please note you don't have to actually check the nest to see if there are eggs there. Just observing behaviour that indicates the bird is sitting is sufficient.

Take Rook for instance. Birds are now sitting on eggs and they'll be easy to confirm as ON over the next week before the already sprouting tree leaves make them less visible. Rookeries are easy to spot driving around. Over the last week I've cleaned up on Rooks in East Lincs confirming them in the last 3 missing squares TF44 Benington Seas End, TF55 East Wainfleet and TF58 Trusthorpe. Please check if they are missing in your square by looking at "Any square summary" and if they are get them now.

Several other species will be on the nest in the next couple of weeks including Mute Swan, Lapwing, Long tailed Tit, Mistle Thrush, Song Thrush and Magpie. You might think these birds should be confirmed in every square in Lincs but they aren't yet so please check. Some species can be difficult to find on the nest but if you see them displaying now eg Lapwings ( code D, probable breeding)) note their location and keep checking for further evidence as summer progresses. Then look out for chicks in June (code FL, confirmed).

The easiest confirmation for Thrushes is carrying food to a probable nest site (code FF). Mistle Thrushes tend to fledge in early May so try not to miss them feeding. Song Thrushes have a longer season giving more opportunity to see them. At the moment in East Lincs we have Mistle Thrush unconfirmed in 3 squares, TF35 north of Boston, TF47 Alford and TF56 Skegness. Song Thrush is missing from TF58 Mablethorpe but someone has a stake out with a territorial bird in their back garden so fingers crossed.

It can be a lot of fun, absorbing and deepen your interest in birds to observe their breeding behaviour so please get stuck in and enjoy it. You can do it in your garden, town/village, local 10k square or anywhere in Lincs or the UK and Ireland. If you are going away for Easter think about checking your holiday square as you may well be able to add valuable records, particularly in remoter regions.

Friday, 1 April 2011

North Lincs Summer Bird Race

There will be a North Lincs Summer Race to record the number of breeding birds in a square during a 24 hour period between April and 2nd May inclusive.

To take part email donandchris@hotmail.co.uk to register the square of your choice go out for the day and record as many breeding
birds as possible enter your visit as Roving Records by Saturday 14th May.

Available squares: SE70, SE80, SE81, SE90, SE91, SK89, SK99, TA01, TA10. TA11, TA20, TA21, TA30, TA40, TF09, TF19, TF29, TF30, TF39, TF40
Do have a go and Good Luck

Monday, 21 March 2011

Which are the most important breeding species in Lincs: Insights from BBS

The Breeding Bird Survey (BBS) is an annual survey which monitors changes in bird populations from year to year and trends over longer periods. It started in 1994 and took over from the Common Bird Census. Its big virtue is that it is based on randomly selected 1 km squares across all counties of the UK. It therefore provides a more accurate estimate of populations. The BBS is used for important conservation purposes such as determining red, amber or green conservation status. In 2009 volunteers surveyed a total of 3,243 squares across the UK of which 51 were in Lincolnshire.

All the data is available to anyone who wants to access it by country, region or county at this link: http://www.bto.org/volunteer-surveys/bbs/latest-results

There are 2 sets of data: first the number of squares each species has been recorded in, by year in each geographic area, second, the total numbers of each species counted by year in each geographic area. You can copy and paste the data into excel and analyse it as you wish.
So I've been messing about with the data to answer the question above. From the conservation point of view; which are the relatively most important species of conservation concern in Lincolnshire compared to the rest of the UK? I took the data and computed the rate of occurrence for all species I believe have bred or probably bred in Lincolnshire in the last 10 years and expressed that as a percentage of the rate of occurrence across the UK as a whole. Species occurring at a rate of 50%greater than the rest of the UK were designated as important in Lincolnshire. The conservation status (red or amber) of each species was noted from the RSPB Birds of Conservation Concern 2010 Report (available on their website).

Birds of conservation concern status is determined by the rate of fall of populations as measured by BBS and the atlas from the early 70s to 2009. So some relatively abundant birds like Skylark and House Sparrow are red because they are much less abundant than they used to be because of pressures arising from our industrial civilisation. Here is the list of species generated from this analysis.

The general UK trend of population change is also shown. It is possible that if we had a larger sample of BBS squares in Lincolnshire there could well be more rarer species on the list.
But the point is these birds are the jewels in our crown and we can make a better contribution to the overall UK conservation of these species by our efforts in Lincolnshire.
How can we do that. First by making sure that we record these species as confirmed breeders in as many squares as possible in the final season of the breeding atlas. Second by contributing to BBS and helping monitor annual changes in the populations of these birds. Third by supporting and lobbying for measures that contribute to the breeding success of these species through schemes like habitat management on Lincolnshire nature reserves and in the wider countryside, and the provision of nest boxes for those species which use them.
If you'd like take part in BBS which is primarily conducted in April and May have a look at www.bto.org/bbs and the more atlas roving records you can submit that confirm breeding for the above species, where they've not been confirmed so far, the better.
Look out for more posts about these individual species over the next few months.

Thursday, 10 March 2011

Some musings on "citizen science" and rarities

Reading Wikipedia today I discovered that the BTO is regarded as one of the worlds leading "citizen science" organisations. I was looking at definitions of birder, twitcher and ornithologist and it came as a surprise to me to find a new label. I started out as a science student so it feels good to be involved in massive projects like the atlas and BBS which have direct benefits for UK bird populations. Not sure about the citizen scientist description though; I prefer birder.

As it was a cold windy day I decided to do a bit of citizen science on my laptop. Two data sets available on the net have grabbed my attention recently. The first is the BBS data from Lincs available at www.bto.org/bbs showing how common breeding bird numbers have changed since 1990. Its fascinating. The second is the Birdguides Online UK Rarity archive of current defined BBRC rarities. Since the latter is only available by subscription I thought I would share it first. I copied and pasted all Lincs rarity records into a spreadsheet, sorted it by date order and then assigned every record from 1960 to 2008 to its 10 km square. For those interested a total of 251 records averaging about 5 a year, with a max of 14 in 1990 which was a Parrot Crossbill invasion year. I then mapped the results onto this 10km square schematic map of Lincs.

This produces lots of questions and as in stock markets past performance is not always a good guide for the future. For instance that 16 in the bottom right hand corner is Wisbech Sewage Farm which hasn't had a BBRC bird since 1983. Two squares above it with 4 is Frampton Marsh, shaping up to be one of our top hotspots. What are the chances of a Black Winged Pratincole there in 2011, what a hat trick that would be.

No one will be shocked that Gib is the best spot, though Donna Nook/Rimac run it close and the whole coast from Cleethorpes to Gib is good. I always wonder to what extent observer coverage, local weather variations, habitat, length of coast and funneling effects affect where birds are turned up. My dream is an experiment which would involve a series of days in which randomly selected 1 km squares on the coast and inland could be simultaneously covered in timed visits by a big team of observers to try and get a handle on why migrants turn up where they do. It would have to be repeated a number of times to generate sufficient data to get meaningful results. Perhaps there will be a chance to discuss the value/feasibility of this with BTO's professional scientists at our local conference at Riseholme on 16 April. If you haven't booked yet get a move on you don't want to miss out.
Finally where is the best place to live if you want to go for/find rarities in Lincs?
The picture left takes the data above and looking at each 10km square in Lincs shows the number of rarities accessible in a 5 x 5 grid centred on that square. The best place to live with a score of 139 is TF57. The village of Huttoft in that square is half way between Gib and Donna Nook and a couple of miles from the sea. Interestingly no BTO member or other serious birder lives in TF57 but George Rutter in Sloothby (TF47) is closest to the ideal position. Ed Mackrill in Welton le Marsh in TF46 is pretty close to it too, perhaps partly explaining why he has the biggest Lincs green list. Half of the Lincs top 10 listers live in just 2 squares TF38 and TF48 which are at the top of the triangle that runs from Louth to Theddlethorpe to Gunby Corner.
By the way if anyone would like the spreadsheet of the raw data (which runs from 1800) email me and I'll send you it.
I'll do the Lincs BBS data next time.

Monday, 28 February 2011

Winter atlas: one race ends, another one begins

So here we are at the end of 4 years hard work winter atlasing and I thought it would be good to look at where we are on the last evening. As you can see by comparing this map to the one in the 21 Jan post below we've continued to add species over the last few weeks and all but a few squares have had well over 80 species recorded. In addition well over 99% of ttvs have been completed and data submitted; with a few stragglers still to come, our density maps will look pretty good when the atlas is published.
There is still alot of work to do flushing out more records and validating the ones we already have so the totals are bound to change but this is probably not far away from the final out turn.
This map represents thousands of hours of birding effort from well over 600 birders in Lincs and a very big thank you to everyone who has participated.
We now have a months rest and then we'll be into the final summer of breeding bird atlasing where the focus will be on confirming breeding records for as many species as possible. In fact if you are keen now is a good time to locate species like Tawny Owl and Long eared Owl which should be vocal at the moment. The latter seems to have declined substantially as a breeding species in Lincs but how many of us have been out listening for them? Not me so far I have to confess, but I'll be making a special effort during March.
Its also a good time to check out Rook nesting activity which is proceeding apace at the moment and can be easily seen before trees come into leaf. There are a few squares where Rooks are not yet confirmed. The 2 in East Lincs are Mablethorpe TF58 and Gib Pt TF55. I had the pleasure of seeing 2 pairs of Rooks nest building this morning in a new location in TF58 so I'll be keeping a close eye on them looking out for signs to confirm breeding.
Why not check out the atlas website to find out what species need confirming in squares where you live/have a patch or regularly bird. Click on the "Any Square Summary" Option, enter your square number and select breeding from the drop down menu and look for the species without the greenspot (confirmed breeding) next to their name. You may already have evidence that could confirm breeding, if not you may be the best person to get it so start planning how now!