Woodcock on the wane

 

A long wander through my local Wormley Woods coincided with the arrival of the latest BTO newsletter. Woodcock was the connecting factor.  I saw 2 Woodcock; one flushed by me and one by a dog.  Wormley Woods are very popular with dog walkers and cyclists. Even the remote corner I explored had an off-the-leash labrador tearing through it. I doubt I could find any significant area of the wood without a squidgy tyre print or a doggy do.  I later flicked through the BTO newsletter and settled on the feature on the forthcoming Woodcock survey before shifting to the BTO website.  Woodcock have declined significantly in recent decades. The old CBC recorded a 74% decline between 1968 and 1999.  A quick look at the recent Atlas results appear to show that Woodcock in Hertfordshire in particular have dropped away sharply between the last two atlases, with the Broxbourne Woods complex remaining a very small and tenuous toehold in the county.  No-one really knows why they are declining but, low and behold, recreational disturbance, the drying out of woodland, overgrazing by deer and declining woodland management have been put forward as possible causes.  All four could apply to Wormley Woods.  No doubt the Woodland Trust and Natural England are actively considering these issues at this very moment.

It is undoubtedly good that people get out and enjoy wildlife-rich areas, including nature reserves, as human indifference to wildlife is arguably its greatest threat.  Yet disturbance to the very wildlife that we are encouraging people to visit and enjoy is a real issue that can be subtle in its effects.   Research has shown that disturbance can affect settling rates and patterns of breeding birds, lower their productivity, and can result in reduced densities and delayed breeding.

Studies of Nightjar (formerly present in the local woods but now gone) have found a reduction in breeding densities on sites heavily used by people and dogs.  Increased nest failure due to daytime egg predation was found to be the cause, particularly where nests are close to paths.  The theory goes that as sitting birds are flushed from nests, the eggs are exposed to predation, with the main predator suspected to be crows.

The distribution of Woodlarks on Dorset heaths was also found to be significantly affected by the presence of people and dogs.  Within sites with recreational access, the probability of suitable habitat being colonized was lower in those areas with greater disturbance; this was reduced to below 50% at around eight disturbance events per hour. However, there was no effect of disturbance on daily nest survival rates.  Birds on sites with higher levels of disturbance fledged more chicks (per pair) owing to a strong density-dependent increase in reproductive output.  However, in the absence of disturbance, overall productivity would be 34% higher.

Further afield, a fascinating study on the island of Ouessant in France showed that visitors had a detrimental impact on the survival of juvenile Chough simply by scaring them away from feeding sites.  Annual survival rates of juveniles were found to be negatively correlated with the number of visitors during August.  The time spent foraging by juveniles was 50% less than expected during this peak tourist month.  Food for thought.  Or not, if it happens to be August.

The Chase

A gloomy view of The Chase Local Nature Reserve in Dagenham, in more ways than one.  A colleague recently drew my attention to the current plight of The Chase and as I was in the area, I dropped in to refresh my memory of the site.  One of East London's largest nature reserves is under severe threat due to Government and Council cuts. Barking and Dagenham Council plans to cut its Ranger Service from 12 to just 5 staff, and to close the environmental education programme for 3000 primary school children taught annually at The Chase.  The reserve will be left unmanaged and the state of the art environmental centre moth-balled.  

The site is 260 ha of lakes, reedbeds, seasonal pools and flashes, acid grassland (horse-grazed and ungrazed), scrub and river with floodplain, notably with some Black Poplars.  Being slightly off from my regular beat, I have only visited the site a dozen or so times, but I briefly reminisced at the spots where Pine Bunting and Great Snipe were added to my London list.  The Chase is an excellent local birding patch but on the evidence of my visit is also very popular with local people for walking, dog-walking, angling etc. 

So at a time of growing realization of the value of green spaces for human health and increasing concerns over childrens ‘dis-connect’ with the natural world and wildlife, the Council decides to cut its service. 

Evidence shows that the proportion of children playing out in natural spaces has dropped by as much as 75 per cent over the last thirty to forty years. This is despite the proven positive effects that contact with the natural world has on children’s physical and mental health, personal and social development, and even academic achievements and life chances.   There is a petition here that can be signed to register opposition to these cuts and although rather late in the day there is surely no reason why these cuts can’t be reversed.  The Council has a meaningless sign at the site: ‘Barking and Dagenham’s building for the future’.   Clearly not a better future.

Big Garden Birdwatch

Okay, maybe it’s an age thing, but I did the Big Garden Birdwatch this year.  Well, it takes me an hour to walk from the house to the car these days (poor feet not big garden), so I might as well do something useful on the way to somewhere better.  I recorded a total of 25 species feeding in the garden during the hour.   I have 3 large seed feeders (nyger/sunflower), fat ball feeders and lots of ‘apple trees’ (half apples spiked onto branches).  Tits dominate by far, Great and Blue Tits are near impossible to count but there are easily 25-30 of each at any one time.  Several Coal Tits are regular and a single Marsh Tit has been visiting frequently all month and duly put in an appearance. 

The ‘apple trees’ are a great hit.  Jays, Jackdaws and thrushes love them.  Even the Blue Tits regularly feed from them.  Single Mistle Thrush and Fieldfare have each ‘guarded’ an area of apples during the cold spell.  The local Sparrowhawk regularly raids the feeders about twice a day.  It deters the tits for a minute or two, but then the flight-line resumes.  It’s a bit like a speeded up arrival at Heathrow; look into the garden and Blue or Great Tits are descending from the large tree to the feeders every few seconds, one after another.  Unlike Heathrow, they increase their arrival rate in the snow.  A quick wait on the arrival branch, onto a spare perch on the feeder, and then away.

I’ve been in this house for about 9 months now.  The commonest bird in my last garden was Redpoll, with up to 40 on and around the nyger.  Greenfinches were the commonest birds on the sunflower feeders.  Just 11 miles away, the avifauna of my new garden has a very different feel.  No Redpolls, very few Greenfinches and zero House Sparrows or Starlings.  Although both gardens are located close to woodland (then Epping Forest, now Broxbourne Woods) the current garden has far more woodland birds, with Nuthatches, Green and Great Spotted Woodpeckers all visiting daily.  However, the highlight of the new garden has been the occasional visits of up to three Hawfinches over the last month. One briefly appeared in a tree at the end of the garden yesterday, but they have failed to come down for seed so far.

Count completed, I did then sneak out for a quick look at the nearby Caspian Gull.  Oooo don’t you just love those tertials?  Hmmm maybe not that much.

Pics above: Marsh Tit, Nuthatch, a busy day on the feeders, Blue Tit on 'apple tree'.

Rejuvenation

 

Reedbeds under conservation management have traditionally been managed by rotational cutting, with the objective of slowing natural succession. Even on a small site, such an objective is questionable, but with a site of over 200 ha, this is not a feasible option. So Ham Wall in Somerset is the focus of a larger scale ‘reedbed rejuvenation’ project, a trial of a new form of reedbed management.  Compartments of up to 20 ha will be held at a lower water level for a number of years and reverted to grassland by a combination of cutting, burning and grazing. After maybe five years, the ground will be re-flooded to create shallow open water and reeds will slowly re-colonise.  Compartments will be 'rejuvenated' on rotation in order to maintain a range of successional states within the reedbed.

I returned to Ham Wall last week to look at the first compartment to be managed in this way and recently re-flooded after several years of drier conditions.  So what will happen next?  Well, we expect the newly flooded habitat will provide good feeding opportunities for a range of reedbed and wetland birds as the reeds regain dominance over a number of years.  In the short-term, it should attract large numbers of waders, wildfowl, egrets and herons over the next year or so as water levels fluctuate, particularly as they drop in late summer.  The land will be allowed to revert to reedbed, with higher water levels, and continue through its succession to old, littered reedbed, before the process is repeated.

Although early days, the first signs are promising.  Large numbers of duck, including Teal, Wigeon, Gadwall and Shoveler are already using the area, with Lapwing and up to 200 Snipe around the margins.  A dozen Water Pipits flitted around the margins.  A couple of Great White Egrets were in the area and it is hoped they will find the area to their liking.

New Year thrash

Although a dry and sunny day boded well for the traditional New Year thrash through the Lee Valley, the broken rib (a Christmas present from the log-pile) somewhat slowed me down and it was more of a crawl than a thrash.   A rough tot-up showed a vaguely possible 100 species but in the end I settled for a reasonable 86 seen on the day.

High water level was the theme of the day, with brimming lakes and flooded fields. The Girling Reservoir was as full as I can remember it and typically, once the gulls had departed at dawn, there were very few birds left.   Most of the Black-necked Grebes also seem to have departed, with only 6 noted.  A Chiffchaff along the Girling fence was an unexpected bonus.  Further up the valley, just 5 Smew are around this winter so far, but Bittern number 6-7, of which I managed a couple – at Cheshunt and Amwell.

The long-staying drake Scaup and Long-tailed Duck may seem to be the highlights of the day but they were probably eclipsed by Hawfinch and Lesser Spotted Woodpecker, the first time I have seen both species locally on a day count for many a year.  Pleasingly, the Hawfinch was added in my valley-side garden during a breakfast stopover, with up to three being noted in recent days.

Although water birds are generally in good numbers in the valley, it is the dearth of seed-eating farmland birds that is a problem.   There seems to be virtually no flocks of finches in the valley any more, but given that weedy areas on farmland or around mineral workings have all but disappeared this is not surprising. So while Red Kite, Little Egret and Peregrine now almost put themselves on the list, partridges, linnets and Yellowhammers take some searching out.

Don't tell him Pike

I saw my first Bittern in Nightingale Wood in 1972.  The London Bird Report has it as:  Cheshunt GP, one on Mar 4^th (GJW).  Hmm, rather brief for what I seem to remember was a good find at the time.   However, over the years this has become a regular haunt for wintering bitterns.  So why do Bitterns return to this spot year after year?

Nightingale Wood is a wonderfully scruffy few acres of wet self–set woodland on the edge of a badly restored gravel pit.  It’s landform is varied to say the least: hollows, holes, slopes, cliffs, pools and piles of reject gravels.  Initially colonised by Hawthorn and willow scrub but now succeeding to Ash and Alder, with masses of dead wood. The modern mineral planning officer would never allow it.  They would smooth everything out, cover in top soil and insist on regimented rows of planted trees, and in doing so would eliminate any decent habitat.

Nightingale Wood? I hear you say.  Well yes, once upon a time in the scrubby days, 2 or 3 pairs were to be found.  I found my first Nightingale nest in this wood and watched the youngsters fledge.  Many a Willow Tit nest was also noted.  Over the years the wood has provided regular Woodcock, Water Rails, Siskins and Redpolls , but also 3 Golden Orioles, 2 Firecrests, 2 Wood Warblers, Pied Flycatcher, Great Grey Shrike, Bearded Tits and a roost of 9,000 Fieldfares one night.  The edge of the wood grades into the water-filled pit through tumble-down wet woodland and marshy spits to a reedbed fringe of about an acre.

This is where the Bitterns come in. So why do Bitterns return to this spot? The varied topography of the wood continues out under the water with deeper pools interspersed with reedy shallows.  Research papers will tell you that Rudd and Eels are the preferred prey of breeding birds in the UK, but Perch and Pike aplenty tuck into these watery hollows in the reedbed during the winter and form the main prey for Lee Valley Bitterns in the lean months. Good feeding at this time of year is crucial for getting the birds through the winter and into good condition for breeding.

I returned to Nightingale Wood yesterday for an hour or so at dusk and a couple of Bitterns were on show.  There are currently 7 or 8 Bitterns wintering in the Lee Valley, with 5 in the Cheshunt pits complex.  The reedbed now has excellent viewing rides cut into it by the Lee Valley Park Authority.  One Bittern duly appeared on the edge of a reedy ride no more than a dozen paces from my original sighting in ‘72.   It caught a nice stripey Jack Pike and soon dispatched it.  At dusk both birds moved with just a brief few wing-beats from the feeding spots to the safe roosting areas on the edge of the reedbed.   That’s why they come back here.

Cranes

One frosty morning last week, I was out in the Fens again looking at Cranes.  The nesting pair were back on territory, after some weeks of touring the Fens.  Last year’s youngster was still in tow but will surely be given the boot as spring approaches. Cranes have had their most successful year in the UK since returning as a breeding bird, with up to 24 pairs rearing at least 13 youngsters.  The Fens offshoot of the Broads population now seems well established

The winter food of these birds is a mix of agricultural remains and more natural foods from wet grasslands.  The Cranes had been feeding extensively on beet tops earlier in the winter.  One family party were feeding in a maize strip, picking cobs off the standing crop.  Spuds seem to be a good food also.  Spuds left in the ground after harvest may be favoured as they are fresher, but good farming practice usually leaves few available for the birds.  Piles of dumped spuds have been used to attract birds but it appears Cranes prefer them fresh, so replenishing stocks may be the best approach.  The birds I was watching were feeding on waste grain put out for them.

Winter roost sites are important, with birds favouring shallow flooded areas. Ideally they will be close to feeding areas but birds will frequently fly some distance to a suitable roost.

So if we want to attract Cranes, or keep them in a particular area for viewing, why not grow small areas of sacrificial crops - spuds or maize, adjacent to wet grassland etc.   Also, ensure that suitable winter roost sites are present.   Shallow flooding of some cropped land would be beneficial.    These techniques are well known to attract cranes and geese in the USA and such management would also benefit other farmland birds.