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

Pied Wagtail Feeding in a Silver Birch Tree

In our front garden we have a weeping silver birch Betula pendula, which stands about 4m tall. The crown of the tree is a matted tangle of branches and twigs, which by early November was mostly devoid of leaves while the ‘weeping’ branches still retained many.

Remembrance Sunday 2012 was a fine autumnal day, starting frosty with clear blue skies and almost no wind. At 09:10, by which time the frost had mostly melted, I noticed a winter plumaged Pied Wagtail Motacilla alba yarrellii walking about on the crown of the silver birch. It stopped often to peck at branches and more frequently at the remaining leaves, sometimes pecking five or six times at a single leaf. BWP categorises this type of foraging as ‘picking’ (Cramp 1988). The Pied Wagtail foraged in the tree for more than five minutes, only leaving when two juveniles flew over, calling. The adult bird followed them to a nearby flat roof where they stood, each calling. After a brief while the juveniles flew off and the adult returned to the crown of the silver birch and resumed foraging. At this point I went to get a camera, but when I returned the Pied Wagtail had disappeared. Blue Tits Cyanistes caeruleus and Great Tits Parus major were present in the silver birch at the same time, moving through and apparently feeding from the ‘weeping’ branches.

I was away from home on 12-14 November 2012. Subsequently, a Pied Wagtail was noted foraging in the crown of the silver birch on two further occasions. On 15 November, it was first observed, already in the tree, at 13:30 and stayed for about 30 minutes. During this time it briefly flew off and returned three times. Once it was accompanied by a second, winter-plumaged Pied Wagtail but this bird did not stay long and did not forage. On 17 November it was first observed at 11:57, again already in the tree and it remained until 12:24 when it was disturbed by a car passing by. For six minutes, between 12:03 and 12:09, it perched on a branch at the top of the tree. During this time it was mostly still, not even wagging its tail. For the remainder it was actively foraging on the crown of the silver birch.

Photographs were taken of the wagtail on both 15 and 17 November. Comparison of the images suggests it is the same bird foraging on the crown of the silver birch.

Although less than 10m from where I was watching with 10x binoculars, I could not see what the Pied Wagtails were feeding on. Nor could I find any obvious prey items on closer inspection of the leaves.

I had previously recorded both Pied Wagtails and Yellow Wagtails Motacilla flava flavissima perching in the silver birch but this is the first time I have noticed foraging activity. Various other species have been recorded foraging in the tree, e.g. Blue Tit, Great Tit and Goldcrest Regulus regulus but these were usually on the ‘weeping’ branches. Starlings Sturnus vulgaris are the only other species noted foraging on the crown, when in the summer months, they feed on aphids.

BWP records Pied Wagtails foraging on the ground, floating vegetation and on the backs of pigs but does not record them foraging in trees (Cramp 1988).

Cramp, S. (ed.). 1988. The Birds of the Western Palaearctic. Vol 5.

Originally published in The Hobby 126: 17-18

Clerical Oversight and Elusive Ton

On 26 September 2012 I noted a lone Lapwing flying north over the fields near Poppy Hill Farm. I did not realise at the time that this was the first I had seen on my local patch this year and did not add it to my Self Found Year List (SFYL).

When the Self Found Year List (SFYL) challenge was made in March 2012 I decided I would concentrate on my local patch of Henlow Grange as I knew I did not have the time nor, possibly more importantly, the energy to compete with the big boys. By the time the challenge was issued, I had already recorded 70 species, of which 52 species had been found on New Year’s Day. I quietly set myself the target of 100 species, a target I hoped to reach by the end of the spring migration.

Henlow Grange is in east Bedfordshire, immediately east of Henlow village. My local patch includes the area around the Grange, stretching from the A507 in the south to Langford village in the north. The East Coast Main Line forms the eastern boundary while Henlow village and the River Ivel are on the western edge.. This area falls in atlas tetrad TL13Z and comprises two 1km squares TL1838 and TL1839. The River Ivel and its tributary the Hiz flow from south to north with disused gravel pits, now converted to fishing lakes, alongside. Sadly, none seem particularly attractive to waterfowl. There is some woodland in the grounds of Henlow Grange, not open to the public, and along the banks of the river including small conifer and poplar plantations. The fields east of the river are mostly arable, growing oil seed rape, wheat and barley with some areas of set aside and a few remnant hedges. This area supports a reasonable population of farmland species, including Corn Buntings, Yellow Hammers, Linnets and Yellow Wagtails.  Alongside the railway are some horse paddocks with short cropped grass which are favoured by thrushes and Starlings during the winter months and Wheatears and wagtails on passage. It is possible to walk a loop round Henlow Bridge Lakes in the south and another loop round the fields in the north, but there is only the one bridge over the River Ivel. I usually walk either the southern loop or the northern loop, preferring the latter as there is less disturbance from the traffic noise generated by the A507.

NERVOUS NINETIES: By early May I had recorded 90 species including most of the common summer migrants and was looking forward to notching the elusive ton. Another five species, Garden Warbler, Lesser Whitethroat, Cuckoo, Sedge Warbler and Hobby were added in mid-May, all summer migrants that had been recorded elsewhere in the county up to 10-days earlier. A pair of Shelduck flying over and a single Spotted Flycatcher in the lime tree avenue leading to the Grange were the only additions in June. And then nothing new until the end of September. I tried hard to turn fly over gulls into the Yellow-legged variety but lacked the conviction to make a confident id. I scoured the remaining hedgerows hoping to turn up a migrating Redstart but to no avail. A pair of Ravens, cronking as they flew west took the tally to 98 or so I thought.   

Only when extracting data from BirdTrack to write an article titled ‘Nervous Nineties’ did I realise that the lone Lapwing had not been includied in my local patch total. This clerical oversight meant that the adult Mediterranean Gull seen on 25 October, which I originally thought was number 99 became number 100. Not a bad way to bring up the ton!

Highlights of the hundred have been the Woodcock flushed from beside the track on a snowy morning; the male Merlin perched on the wires, which I originally thought was a Mistle Thrush until I lifted my binoculars (my excuse is my glasses were misted with the rain); the spring passage of Wheatears on the horse paddocks with associated Whinchats and the pair of Kingfishers nesting along the River Ivel.

There are a few species recorded in previous years that I have yet to see this year, so hopefully still a few more for the list.

Sparrows Eat Beetroot

Only during the breeding season do House Sparrows Passer domesticus visit our Henlow garden in numbers. At this time of year family parties appear, usually comprising one adult, either male or female, and their brood. This year the first family, a female with three young was first noted on 14 June 2012, a couple of weeks later than in previous years. Subsequently, numbers have risen to a maximum of three males, three females and 12 young, presumed to be three broods of four chicks. At first the fledglings hide in the shrubbery only noisily appearing with wings quivering when the parent approaches with food, but perch more in the open as they become bolder.

On 14 June 2012 a female House Sparrow flew to our vegetable patch rather than the seed feeders and pecked at the leaves of beetroot. I assumed she had been picking an insect from the leaf. That evening while watering the garden, I checked the beetroot. I could find no insects on any of the beetroot leaves but small pieces had been torn from the leaves on one plant. The following day, I watched more carefully, and a female House Sparrow was seen to nip out pieces of beetroot leaf and, apparently eat them. Over the following four days, the leaves were stripped from this beetroot plant. The female House Sparrow fed at least one of the fledglings immediately after nipping out a piece of leaf and later the young birds were also seen feeding on the beetroot leaves. I could not tell if only one female and brood were involved. No males were recorded feeding on the beetroot leaves. Only one plant in the row of beetroots was attacked this severely although the leaves of other plants had been nibbled.

BWP (Cramp & Perrins 1994) records that House Sparrow regularly attack flowers and green leaves, but is not certain these are eaten.

Cramp, S & C.M.Perrins (eds) (1994). The Birds of the Western Palearctic Vol VIII.

 

Originally published in The Hobby 124: 11

SPRING EQUINOX

Spring is sprung the grass is riz, I wonder where the birdies iz?

The 2009 spring equinox fell on a Friday. Friday was a day of work. Work was where I was headed. In the preceding week the weather in southern Britain had been dominated by a high pressure system. This gave rise to clear nights resulting in a light frost followed by fine, sunny and warm days. Friday 20th March 2009 was no different. I ate breakfast looking out over the garden from the warmth of the kitchen and watched the frost dissipate as the sun slowly rose higher in the sky. The garden looks lovely at this time of year with daffodils flowering in the borders and the shrubs coming into leaf. Further evidence of spring was provided by two Eurasian Collared Doves canoodling on the garden fence, a Common Starling collecting a beakful of dried grasses and a female Common Blackbird tearing green vegetation from a flowering Aubretia and carrying it to a neighbour’s garden. Great Tits and Eurasian Blue Tits have been prospecting at a couple of our nest boxes but have not begun building yet. A pair of Robins have completed their nest in another box and already laid five eggs, but sadly, I think they may have deserted as I have not seen birds near the nest for several days.

Home is the Bedfordshire village of Henlow, about 45 miles (72km) north of London. By the time I came to leave for work at about 07:15, the frost had melted and I did not have to scrape the car windows. Several of the resident birds, Common Blackbird, Dunnock and European Robin were singing while both Common Wood Pigeons and Collared Doves were performing their ‘roller-coaster’ display flights. My office lies some 30 miles (48km) to the south entailing a commute of about an hour (depending on the traffic) and often enlivened by birding en route. The rookeries at Shillington (15 nests), Apsley End (49 nests) and Shillington Manor (3 nests) were hives of activity with much coming and going although building now appears to be complete. Major nest building in the rookery seems to take place between 8th-14th March in this part of the world. South of Hexton, my route climbs the north-facing scarp of the Chiltern Hills to 500 feet (155m) above sea level, before following the Mimram valley south-eastwards. A Red Kite, part of the successful reintroduction scheme, was seen perched in a roadside tree near Kings Walden. I now regularly record this species on my way to and from work, but less than 30-years ago had to make special trips to central Wales for a chance to see them. The upper reaches of the Mimram are dry, the first water appearing in ponds at Bendish Lodge where there were some Mallard and Common Moorhen. Nearby a pair of Mandarin Duck, they breed locally in most years, flew across the road. Northern Ravens are still quite rare in this area, so it was very pleasing to see one fly over just outside the village of Whitwell. My first for the year. Until very recently they were, like the Red Kites, absent from much of lowland England but in the last decade they have spread into the lowland counties although without the help afforded the kites.

My office is one of several in a converted barn at Bricket Wood, on the northern edge of Watford. Despite its location, the setting is pleasantly rural surrounded by horse paddocks and woods although traffic noise from the M25, London’s orbital motorway which lies just to the north, can be heard. In the warm, sunny conditions the birds were quieter than usual. Great Tits, Dunnocks and Starlings visited our bird table but only the wheezing European Greenfinches and the singing of Blackbirds, Dunnocks, Chaffinches and Robins came through the open window. The ringing cries of a European Green Woodpecker were heard, but other regularly heard species, such as Great Spotted Woodpecker, Eurasian Nuthatch and Eurasian Jay were noticeable by their absence.

I headed home via an alternative route, seeing fewer birds than on my way to work. Pairs of Red-legged Partridge were on the chalk fields along Whiteway Bottom, Kimpton where a Kestrel surveyed the ground from its vantage point on top of a telegraph pole. Sadly, the pair of Little Owls were not perched in their usual place.

Full species list for the Spring Equinox 20/03/2009: Grey Heron, Mandarin Duck, Mallard, Red Kite, Common Kestrel, Common Pheasant, Red-legged Partridge, Grey Partridge, Common Moorhen, Black-headed Gull, Mew Gull, Common Pigeon, Stock Dove, Common Wood Pigeon, Eurasian Collared Dove, European Green Woodpecker, Pied Wagtail, Dunnock, European Robin, Common Blackbird, Song Thrush, Eurasian Blue Tit, Great Tit, Eurasian Magpie, Western Jackdaw, Rook, Carrion Crow, Northern Raven, Common Starling, Common Chaffinch, European Greenfinch, European Goldfinch, Yellow Hammer (33 species).