Bedfordshire Bird Club Field Trip: 8 December 2013

Since moving to Henlow my local patch has been an area 2km x 1km around Henlow Grange, stretching from the A507 in the south to Langford in the north, lying to the west of the East Coast main line and either side of the River Ivel. The patch comprises a variety of habitats including worked-out gravel, now fishing lakes, alongside the River Ivel and its tributary the River Hiz; some woodland and parkland around the Grange plus farmland, mainly arable, between the rivers and the railway but including some paddocks for horse, sheep and cattle. This mix of habitats attracts a wide range of species and in eleven years I have noted about 120 species. In 2013, I participated in the Patchwork Challenge (http://patchworkchallenge.blogspot.co.uk/) and recorded 111 species for my patch.

On 8 December 2013, the Bedfordshire Bird Club (BBC) came visiting. Starting from Henlow Bridge Fishing Lakes, where we had been given permission to park, my plan was to walk round the Lakes, then north past Henlow Grange following the footpath over the River Ivel towards Langford, checking out the Poppy Hill gravel pits before doing a circuit of the fields to the east and then heading back the way we had come (just about all in tetrad TL13Z for atlassers). Shortly after 08:30 thirteen BBC members had gathered.

The walk got off to a good start with a Sparrowhawk flying fast and low through the car park scattering a small flock of Goldfinches. The fishing lakes were sadly devoid of waterfowl save for a few Mallards and Moorhens but a male Great Spotted Woodpecker landed in a lakeside tree and posed in full view. Those at the back of the party added a female Bullfinch as we approached the Grange while those at the front saw a Black Squirrel (probably one-in-three of the local squirrel population are this black form).  

The bridge over the River Ivel has been a reliable site for Kingfisher and we were not disappointed, one landing just downstream and sitting long enough for a scope to be  set up and good views had by all. A new footpath/cycle track, replacing the previous narrow footpath, has only recently been completed along the east side of Poppy Hill fishing lakes. From the track we viewed the pits, the duck flock was much reduced from the numbers in the autumn, but included 32 Tufted Duck, two Pochards and a female Gadwall and still represented a good haul for these lakes. A Mute Swan family of two adults and two immatures were on the northernmost pit.  

Up until this point we had been largely sheltered from the south-westerly wind, somewhat abated from the gale force winds of the previous week but still quite brisk. Heading east across the fields we were more exposed to the wind and this probably contributed to the small numbers of bird noted. We did find a small flock of Linnets and Meadow Pipits plus, the highlight for many, a couple of Corn Buntings sang from the overhead wires.

We recorded 44 species (full list below) on our walk which is about average for this time of year.

Special thanks to Dave Curson of Henlow Bridge Fishing Lakes for allowing us to use their car park.

Species List:

Cormorant, Grey Heron, Mute Swan, Mallard, Gadwall, Tufted Duck, Pochard, Sparrowhawk, Buzzard, Kestrel, Coot, Moorhen, Black-headed Gull, Common Gull, Wood Pigeon, Stock Dove, Kingfisher, Great Spotted Woodpecker, Green Woodpecker, Skylark, Meadow Pipit, Pied Wagtail, Grey Wagtail, Wren, Dunnock, Robin, Blackbird, Fieldfare, Mistle Thrush, Blue Tit, Great Tit, Coal Tit, Long-tailed Tit, Starling, Jay, Magpie, Jackdaw, Carrion Crow, Rook, Chaffinch, Goldfinch, Linnet, Bullfinch, Corn Bunting.

Originally published in The Hobby 132:3-4

Redwing Passage: 10 October 2013

I saw my first Redwing Turdus iliacus of the autumn on 7 October when 20 flew west over Henlow. The following few days were mild, at times warm, sunny, clear and calm; no further Redwings were seen or heard. Then the weather changed overnight and the Indian summer gave way to a cold blast from the north.

A few Redwings were noted flying over the school as I headed out on my usual walk around the fields north and east of Henlow Grange. In contrast to previous days, there was much less bird activity in the cold, blowy conditions and I had only a few Blackbirds and a couple of Mistle Thrush sightings to add to the BTO Winter Thrush Survey. Skylarks were more in evidence than recently with each stubble field seeming to hold a small flock, some numbering more than 40 birds but no Redwings were noted east of the River Ivel.

As I returned to Henlow, a flock of 103 Redwing flew over, heading west. At the time I thought they had probably come out of a roost in trees alongside the river. Continuing homewards along the drive to Henlow Grange more and more flocks of Redwing, each flock numbering between 50 and 150 birds, flew over, all heading west. In the twenty minutes it took me to walk home (from 09:00 – 09:20) more than 2000 must have passed by, all heading west at about tree top height.

Since December 2011, I have worked from home, converting one of the bedrooms into an office. This was quickly dubbed the Little Back Bedroom Bird Observatory by Jenny, my wife, who reckoned I spent more time looking out of the window than at the computer screen. On 10 October, she would have been right! By the time I had got a cup of coffee and checked my emails it was 09:50 and flocks of Redwings were still going over.

In the next hour (09:50 – 10:50), I counted 42 flocks of Redwings totalling 1447 birds flying west, roughly along the line of Coach Road, Henlow, at or just above roof top height. There were none high in the clear sky when I scanned with binoculars. Redwings were not constantly in view, flocks seemed to come through in pulses with two or three flocks in a minute followed by a lull. The longest period without any Redwings was 4-minutes. Flock size ranged from one singleton up to c.150 with most between 10 and 40 birds and an average flock size of 34 birds.

After a 30 minute break, I had to do some work, I returned to counting at 11:20 by which time the Redwing passage was much lighter. In the hour to 12:20 I only counted 9 flocks totalling c.200 birds. These seemed to track a bit further north-west than the earlier birds, flying across the Pyghtles rather than along the line of Coach Road. By 12:45 the movement seemed to have petered out and I recorded no further flocks of Redwing during the rest of the day.

Few other species seemed to be involved in the movement. Two flocks of Skylarks were noted, one passing directly over our garden at window height. The local finch flock, Goldfinches, Greenfinches and Chaffinches would often fly up and join a passing flock of Redwings, so it was difficult to determine if any finches noted were part of the passage.

Given the restricted view from my window, overlooking the backs of the houses along Coach Road and between the houses to the Pyghtles playing fields beyond, some of flocks passing over would only have been partially counted; anything flying directly over our house or to the south would have been missed. So, although these figures are undoubtedly underestimates for the number of Redwings moving over Henlow, they do give a snapshot of one of the most exciting migration movements I have ever witnessed.

And then came news from the vismiggers at the Pinnacle, Sandy where they counted 33082 Redwings in just under 5-hours watching!

Originally published in The Hobby 130:6

A Kick in the Rookeries!

Going back to my earliest notebooks, I have always kept a record of rookeries. Up to the end of 2012, I had recorded 96 rookeries in Bedfordshire since moving to the county in 2002. Most had been recorded on journeys around the county by car, so most are visible from a road. I have rarely visited the south-west or north of the county so had few rookeries from those areas. The national survey in 1975 found 201 rookeries in Bedfordshire (Trodd & Kramer 1991) while in fieldwork for the latest atlas (2007-2011) Rooks were confirmed breeding in 179 tetrads, meaning a minimum of 179 rookeries in the county. Several tetrads hold more than one rookery, e.g. TL04B, Stewartby Lake (North) and TL03G, Apsley End Shillington.

 

Prompted by an email on HOSList, the Hampshire equivalent of the BedsBirds email group, I created a google.maps map, plotting the approximate position of all Bedfordshire rookeries that were known to me, including those no longer in use. I included the following extra pieces of information: Ordnance Survey six-figure map reference, year first recorded, tree species, in which nests were built, and 2013 nest count.

 

Many rookeries occupy traditional sites, but for most Bedfordshire rookeries the year first recorded is since 2002 (the year I moved to the county) although many have, undoubtedly, been existence longer than that, e.g. a rookery at Reynold (for which I do not have a map reference, so it is not, yet, included on the google.map ) has been occupied for at least 40 years (Bedfordshire Bird Report 2007).

 

In 1975 48% of rookeries in Bedfordshire were in Elm trees but following the loss of these trees to Dutch Elm Disease rooks nested predominantly in oak, ash, sycamore, beech and horse chestnut (Trodd and Kramer 1991). Given the variety of diseases that seem to be afflicting various trees e.g. acute oak decline disease, poplar scab and ash tree die back, it seemed an opportune time to determine which trees are used by Rooks for their rookeries. However, I have found it more difficult to identify trees in their ‘winter plumage’ than I had anticipated and so will try and re-visit at least some of the rookeries once the trees are in leaf.

 

I published the google.map via the BedsBirds email group and subsequently, with the help of other BedsBirders have added another 30 or so rookeries. As of 09/04/2013, the locations of 128 rookeries have been mapped. Counts for all bar 11 of these have been received for this year, giving a total, so far,  of 2899 nests. Seven rookeries used in previous years seem to be unused this year. Rookeries have been recorded in 99 tetrads suggesting there are at least 80 rookeries so far unmapped. A copy of the map, as of 09/04/2013, is shown. The red pins are rookeries no longer in use.  The up-to-date version can be viewed at:

 

http://tinyurl.com/BedsRookeries2013

 

Bedfordshire Bird Reports since 1995 mention a further 28 rookeries for which I do not have an exact location, some of which may be duplicates for known rookeries.

If you would like to help identifying the location of the above rookeries, supplying details of new rookeries or adding extra details to rookeries on the map, please email me or BedsBirds.

 

Thanks to Dave Anderson, Bob Hook, Judith Knight, Dave Kramer, Darren Oakley-Martin for already supplying additional information and special thanks to Jenny Hicks for joining me on rookery patrols.

 

First published in The Hobby 127: 9 - 11