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.  

In the beginning.......there were LRP's

 As December ticks away, I eventually get to the task of sorting out the years records from the notebook.  If only I was a little more organised.  This week’s task was to complete the analysis of one of my regular breeding bird surveys; at Amwell Quarry (now nature reserve).  The run of data on breeding birds for this site now extends back to the late 1970s when mineral extraction began.  Why have I done this for 35 years?  Who knows, it just happened.

Eighty species have bred at Amwell over those years, 46 of them managing to enter the ‘scoresheet’ for 2012.  This is somewhat below the 53 species in the best year; 2001.  These 46 species amounted to a total of 327 pairs of birds, again somewhat below the peak of 410 pairs in 2002.  So the headline story is somewhat of a rise and fall.  However, as you would expect, these figures hide the many changes over the years.  A number of species, such as Willow Warbler, Yellow Wagtail (5 pairs in 1983), Turtle Dove, Linnet and Tree Sparrow, have all declined more or less in line with national trends.  But without doubt, the major influence has been successional changes in the habitats, with meadow, marsh and mud being replaced by reed and willows. 

These changes have, of course, produced a number of winners: Grey Herons and Cormorants in the trees, recently joined by Little Egrets, and Reed Warblers, Cetti’s Warblers and Blackcaps in the reed and scrub.  In addition, Black-headed Gulls and Common Terns have used the rafts provided.  The losers have been the grassland birds of the old meadows and more significantly the variety of wildfowl and waders.  Tufted Ducks peaked at a massive 62 broods in 1987 but have since dropped away to low single figures.  Likewise, Gadwall rose to a peak of 12 broods before dropping to just one and after peaking at 53 pairs, Sedge Warblers have dwindled to just 14 as habitats have changed.

Wading birds, particularly the Little Ringed Plover, have always been a key feature of the site since the mineral extraction began.  LRPs peaked at 8 pairs but with numbers rising and falling in relation to the amount of habitat.  Despite the recent addition of Oystercatcher in recent years, LRPs and waders in general, are now teetering on the edge of disappearing as breeding birds.   The problem is that the relentless march of reed and other vegetation across the formerly open areas outpaces the management effort.  What is needed, what most old gravel pits need, is a bit of Localised Intermittent Catastrophe.  A combination of controlled vandalism with a large digger and some dynamic water management should help knock selected areas back to an earlier stage in the succession so the process can start again.  We gathered on site this autumn, umm-ed and arr-ed a bit, and some good work was subsequently undertaken, but on reflection, much more of the same will be required if LRPs are to remain until the end.

Below - Amwell 1987 (8 prs of LRP), Amwell 2012 (none).

 

Ria Lagartos - shear magic

No sooner had we checked into the hotel, gone up to the room and stepped out onto the balcony when the words "Meester White?" came from down below. "Yes, how did you know we had arrived?" I replied.  "This is a very small place and you are the only gringos in town". We had arrived in Rio Lagartos, at the northern end of the Yucatan peninsula and entrance town to the Ria Lagartos Biosphere Reserve.

We had booked a couple of days to be guided by the excellent Diego Nunez around Ria Lagartos  http://www.riolagartosnaturetours.com. The first day by boat amongst the creeks and mangroves, the second on land amongst the scrubby transition zones.  The reserve holds large numbers of waterbirds as well as Yucatan specialities such as Mexican Sheartail and Yucatan Wren.   The boat took us through mudflat channels, mangrove creeks and out to the sea.  Waders whirled around in numbers; Willet, Yellowlegs, Semi-p, Western and Least Sandpipers, Long-billed Curlew and Short-billed Dowitcher.  Black Skimmers, Roseate Spoonbill, Belted Kingfisher, Lineated Woodpecker, Wood Stork and hundreds of herons added to the mix.  Diego attracted a Black Hawk close to the boat by throwing out fish and whistling up a Ferruginous Pygmy Owl lured out a Blue-crowned Motmot.

The early morning ‘bush-bash’ produced five species of hummers, with excellent views of Mexican Sheartail and two nests found.  Diego 'called in' a Laughing Falcon, with the cameras rat tat tat-ting away.  Lesser Roadrunner, Vermillion Flycatcher, Squirrel Cuckoo and Yucatan Bobwhite all gave excellent views.  With stomachs rumbling, the freshly caught Lobster, cooked by Diego's wife, was washed down by a few bottles of Sol.  With not a single all-inclusive buffet bar in sight, this was a simple pleasure.  Jabiru and Crested Caracara drifting over as we left was a perfect ending.

 

Above; Mexican Sheartail, Skimmers and others.

Below: Black Hawk, Yucatan Wren, Laughing Falcon and elsewhere, a Cozumel Island Racoon.

 

Mexican rave

 

I swore I would never return to an all-inclusive hotel. Well, family politics dictated that I attended a wedding near Cancun in Mexico; the grim prospect of a minimal birding foreign trip loomed.  Luckily the hotel was located in a mosquito and crocodile infested swamp, and you can never knock out the urge to go birding can you?

21 species during a wedding ceremony didn't seem too bad. Laughing Gull, Brown Pelican, Least Sandpiper, Double-crested Cormorant and Royal Tern on the beach. Ospreys drifting overhead. Yellow-throated Warbler and Northern Waterthrush in the nearby bush. The service got under way. “Will you tick this Magnificent Frigatebird?” “I will.”

The hotel golf course was the saviour; plenty of lakes and swampy scrub, if rather over-manicured in the American style. An early morning walk each day soon developed a reasonable list.  Even better, take a buggy around and just get out the 'scope instead of the clubs. The golf going on around me was somewhat lacking in quality. Anything that went vaguely straight and over 20 metres prompted highly enthusiastic shouts of "Gee, good golf" and "Go on Tiger". Therefore, the safest place to stand on the course was somewhere in a straight line between tee and hole.

The bushes held plenty of warblers and a good selection of vireos. Parula, Yellow and Magnolia Warblers were all numerous, as were Waterthrushes, Yellowthroat and Ovenbird. Then add in a few of the local specialities such as Yucatan and Mangrove Vireos, and Black-headed Trogon. Meanwhile, the lakes had Killdeers, Spotted Sandpipers, American Black Terns a selection of herons and numerous technicolour Grey-necked Wood Rails.

By 10.00am the increasingly wayward golfers, and the heat, drive you to the 19th for a margarita. Then on to the beach, more margarita’s, and close study of the American Sandwich Terns and Semipalmated Sandpipers. Could be worse I suppose.  Wedding over, we may be able to escape into the surrounding countryside....

Below: American Sandwich Tern: The bill is slightly shorter and thicker than Sandwich. The moulting adult shows darker unmoulted primaries and some new primaries which have a narrower (1-1.5 mm) white fringe than Sandwich (2-4 mm). The black rear crown and nape feathers are longer, blacker and more greasy looking than Sandwich.

Scilly 1979 – a blast from the past

As usual, we cruised across to the islands on the Scillonian, a reasonably smooth crossing for once, dumped the bags and then tried to find out the latest bird news by the usual methods – the blackboards and semaphore. We quickly joined a stream of birders heading towards Higher Moors where a Subalpine Warbler was on show. Around 250 birders funnelled down a narrow muddy track, jostling and pushing to see the bird, tempers flared, some chap ended up in the ditch on his backside.   A great start.  A Rustic Bunting provided the next stop towards the north of the island and the rest of the day was made up with standard Scilly ‘fillers’ of the time: 2 Short-toed Larks, Pink Stink and a Tawny Pipit.  The following day a quick trot saw us down on Lower Moors looking for a Sibe Stonechat.  Viewing was tricky with the old ‘brass and glass’ scope, I wish they would hurry up and invent the tripod.

Excitement! a putative Blyth’s Reed Warbler had been found on St Agnes.  Unfortunately it was in a small private field.   Queuing for the 300 birders boating over to Aggy was the order of the day, with ten birders in the field for 15 minutes, tough if you don’t see it.  All progressed relatively well and in good humour as the bird performed well.  However, gentle mumbling increased to severe doubt and eventually the Guru of the day, Pete Grant, declared it was just a Marsh Warbler.  Trouble was, nobody knew what a Blyth’s Reed looked like.  My book gave some guidance; Brownish. Difficult to distinguish. See Marsh Warbler.  I checked Marsh Warbler; Brownish. Difficult to distinguish. See Blyth’s Reed Warbler.  Hmmm, crystal.

Stress set in over the next couple of days as we were led a merry dance by a Rose-breasted Grosbeak that would appear in front of birders, then vanish, then appear again in another part of the island.  The grapevine was not quick enough for this sort of thing.  We moped around in obvious places waiting for news and while checking around the airfield, where a Cory’s Shearwater off Giant’s Castle was an unexpected bonus, my eye was attracted to a vibrant orange thing up on Porth Hellick down.  A quick look through bins revealed a birder with striking orange hair jumping up and down waving madly (a standard communication method of the day).  He had the Grosser!  We legged it up there and enjoyed our first tick of the week. Stress subsided, a good bird at last.   ‘Beacon bonce’, as the orange-haired one became known, was our hero. 

A routine check of Aggy again turned up trumps as a Radde’s Warbler was discovered in a garden off the main road as we were passing.  Another tight squeeze ensued as there were few available gaps in the hedge.  An amused local provided some step ladders for personal, if somewhat wobbly, additional viewing.  This was quickly followed back on Mary’s by a proper dash up towards the golf course for a Swainson’s Thrush, another tick!  A trip over to Tesco’s added the regular Black Duck, a Ring-necked Duck and the usual Bob-white Quail.

The week ended quietly with the usual fodder of a Lesser Golden Plover (or American GP as you call them now), Spotted Crake, Little Bunting, another Rustic Bunting, R-b Fly, Yellow-broweds, a couple of Dickie Pips  and the obligatory ‘small dark wheatear’ – yes, it rained one day.  But a 2-tick week was not to be scoffed at and we departed happily enough.

Pics.  Top:  Grosser!, Above: team member Tim Andrews finds a Yellow-browed (note all the 'brass and glass').  Below: Radde's on Aggy, my turn for the steps! (whats that new-fangled metal thing with 3 legs?, Bottom: the best dressed birders today have Swift Audobons and a handbag (Beacon bonce takes a nap).

Scilly enough?

The bloke who used to run the disco on the quay with an Aladdin Sane style painted face was looking past his best. He probably thought the same of me. "You still do the disco on the quay" I enquired. "Blimey, you've been coming here a long while" he replied. But let's hope he now has more than 5 records in his collection, I like Siouxsie and the Banshees but not every 15 minutes.  After visiting the Isles of Scilly every year from 1975 until 1995, we had not been back for 17 years. This was the 'old gits return' tour, one last hurrah. First impressions were that not much had changed other than there were virtually no birders, a few more posh houses had appeared and everything was a lot more expensive. We set out to find birds.

The Aquatic Warbler was typically ground hugging and elusive as it grovelled amongst the iris by Porthloo Pond. A couple of flight views was the best on offer. By contrast, the Ortolan was best mate with the sparrows on Porthcressa beach and behaved in a similarly approachable fashion. A couple of Yellow-browed 'sweeeet'ed and showed briefly in Lower Moors and a Lapland Bunting rattled and rolled over the golf course. Just as I remembered it. Peninnis never seemed that far in the past but it felt like a long slog this time. A scattering of pipits including the Buff-bellied lurked around the lighthouse but the old lookout pole seemed to have gone. I was looking forward to climbing that again.

The fact was, everywhere seemed further than it was before. Did we really walk twice around St Mary's everyday? Anyway, no problem, now they have introduced electric carts for the old gits.  However, there are significant changes; the birders are not only far fewer in number but on average much older and probably only a handful with much experience. Fewer birders out there, fewer birds being found. On one day, we were the only birders on the boat over to Tesco's. Scilly has become like an extended episode of Dad's Army; all the old dodderers holding forth whilst the young guns are away at new frontlines.

Captain Mainwaring is everywhere, pompously standing guard with his radio/CB and spouting. "Don't stand there you stupid boy, I've been coming to Scilly for 6 years now".  Privates Fraser and Godfrey were dipping down at the shy Aquatic. "We are doomed" said Fraser, "there are more birds on Shetland". Godfrey shuffled up, "I had to be excused, but my sister Dolly says there are two Buff-breasts on the airfield now". "No you old duffer" says the Verger "one's a Dotterel". Meanwhile, Private Walker was down the Scillonian Club selling dodgy videos of the glory days.
Corporal Jones came charging up "Don't panic, don't panic. I've looked at the Snipe at Porth Hellick. They're all Wilson's". And so it went on.

We eventually added Pink Stink, R-b Fly, Barred and Bonelli's, with Yellow-broweds everywhere. No modern day mega's, but still a lovely place, and once upon a time that might have seemed like a reasonable haul.

Below: Ortolan, Buff-breast, Dotterel, R-b Fly and old gits twitch-cart.
 

Black-head squeeze continues

The remarkable increase of breeding Black-headed Gulls in the Lee Valley has continued this year, nearly all of them nesting on rafts provided for Common Terns.  This year’s total amounted to 107 pairs spread across four sites, with good numbers of young birds fledged.   By contrast, the Common Terns have had a very poor year.  The total of 52 pairs is the lowest in the valley for some 30 years.  Not only that, but productivity has been equally poor.  But are these two stories linked?

Terns in general appear to have had a very mixed year, both between and within species.  The poor summer, with a high proportion of windy days preventing fishing and the downpours chilling eggs and chicks, has been a major problem.  In the valley, many terns failed to settle until very late this year, with limited success.  In general, productivity at inland colonies is frequently better than the average.  Common Terns nesting on freshwater sites have been shown to make shorter feeding forays than coastal birds, allowing for better colony protection as birds are away from the nest less. 

Although the Black-headed Gull is over ten times as numerous as the Common Tern as a breeding bird, both species have shown an interesting similarity in trend in distribution and abundance in recent decades.  Although there have been declines in the north and west of the UK, increases have taken place in inland areas of southern England, much linked to the spread of flooded gravel pits in river valleys.  In recent years, Black-headed Gulls have spread rapidly along the Thames valleys and its tributaries, in many cases nesting on rafts provided for Common Terns.  The reasons for the declines in the north are unclear but an increase in predation, particularly by Mink, and unfavourable land-use changes have been suggested as the cause.  

With the Black-heads increasing rapidly in recent years, the general feeling is that the terns are being squeezed out.  Despite this, all the local colonies had available space on the rafts.  In recent years, the delaying of the positioning of rafts has shown some limited benefits for the later nesting terns.  Perhaps the time has come to vary the design of the standard tern raft to better accommodate both species as they seem to have subtle differences in nest location.  Around the world you can find examples of a very different approach.  Look at the 22,000 m² floating island designed for Caspian Terns in Oregon, USA for example (below).  Some trials next summer at a number of sites may begin to show the way.

 

Rush conundrum

 

Phew!  A twitchable Baillon’s arrives at Rainham Marsh in a perfect viewing position.  Not unexpected, given the influx this summer (but I would guess this may be a Dutch bred bird). However, a relief after the necessary news blackout of territorial birds. At least the North London birding press should be able to report this one correctly without relying on various blogs and adding a dollop of speculation.  Journalists, pah!

I joined the assembled crowds at dawn on Saturday and marvelled at the ability of the little critter to find this particular little patch of suitable rushy habitat.  Having received some photos of Baillon’s Crake habitat in The Netherlands back in June, I noted the swamps of Flowering Rush and Bur-reed and initially thought they had sent me a picture of Rainham as a joke.  A quick e-mail to Rainham ensured they were crake surveying at night but to no avail.  Anyway, this shortish, open-structured wet vegetation appears to be just what they like.  Okay, I saw the ‘89 Sunderland bird but that clearly had a dodgy radar.

Now the conundrum.  The marvellously crakey rush habitat at Rainham does not favour the usual fare of waders and gulls.  In fact, management is being undertaken to significantly reduce the amount of rushy edges to the pools in favour of muddy margins suitable for White-tailed Plovers and the like.  Okay, the rushy habitat could be shunted away into a corner away from prime hide viewing, but then who would see the next crake?  A conundrum to be pondered and not to be rushed.  What would you do?

 

Above - Flowering Rush and botanists closely studying it.  Below - Baillon's Crake habitat in The Netherlands (Ruud van Beusekom) and at Rainham, snap!

 

House of reed

Blundering around inside a reedbed is all in a normal day’s work for a Grumpy Ecologist, usually ending up thoroughly wet and ‘bloodied’ with reed-cuts.  The subtle variations of reed height and density, and the water depth, provide a guide to the location of the reedy constructions of some of the reedbed inhabitants.

Water Voles can be extremely common in wet reedbeds, with latrines and feeding stations every couple of metres.  One of the less frequently mentioned signs of Water Voles is the ‘Vole Mansion’ (above photo) but deep inside reedbeds these constructions can be very numerous.  The neat ball of woven reed strips is slung within a reed framework and under a loose reedy roof, the supporting reeds trimmed off with a typical Water Vole bite.  They are often provided with a reed ramp access down to an outside latrine.  The whole mansion is around 25 cm high and 20 cm in width.

The Water Rail nest is a neat cup, about 15 cm across, of woven reed.  Built just above water level, this one was in 35 cm of water depth and typically built just above water level.  Most Water Rail nests seem to have a covering reed ‘canopy’; this one (below) is open, however it was located in tall (240 cm) and dense reed (360 stems/m²).

 

Most Bittern nests also seem to be built just above water level with good, stout, reed stems bent over and folded in, before a woven platform around 40 cm in diameter is constructed on top.  A lining of finer material, other aquatic plants if present nearby, may be added.  One or two reed ramps lead down to the water.  The deepest water I have found a Bittern nest in is 115 cm.  The nest shown below is perched at an unusually high 110 cm on its scaffolding, above 62 cm of water, but remained above this spring’s rising water levels.  A scattering of downy feathers in and around the nest provides some pointers to the successful outcome.  She obviously had heard the weather forecast. 

 

Antlion antics

Antlion larva

With perfect timing some good weather at last arrived as we embarked on an assessment of invertebrate habitat at Minsmere this week.  Overall, there is a good diversity of habitat on this section of the Suffolk coast but the increasing numbers of Red Deer and the impact of their trampling and browsing is a concern in some areas. The trip turned into a bit of a general bio-blitz, with a good range of local specialities logged over a couple of days.

Antlions are one of those local specialities, with their characteristic larval pits even being found around the visitor centre walls.  We concentrated our search down at North Warren where a concentration of 1000+ pits had been counted earlier in the season.  Many had been washed away by recent heavy rain but a good number remained. The sand at the bottom of the pits conceals a ‘Doctor Who’ monster of a larva.  As soon as a couple of ants were ‘persuaded’ to wander around the pit edge, a deadly flick of sand knocked them down to the waiting jaws.

Plenty of Grayling and Silver-studded Blue butterflies were on the wing across the heathland, a long list of bees was steadily accumulated, and each gorse bush seemed to be home a few of the widespread Labyrinth Spider Agelena labyrinthica; their large sheet webs with a tubular retreat being very obvious.  Natterjack Toads have had a good year with thousands of tadpoles being seen earlier in the year despite the ponds being rather churned up by deer.  More by luck than skill we came across a toad posing nicely within a hollow.  Nearby we found the large Robber-fly Eutolmus rufibarbis.  This splendid beast is a scarce species of southern heathlands, especially Breckland.  It lays its eggs in slits in plant stems, with the emerging larvae entering the soil and predating dung beetle larvae.  A number of scarce plants were encountered, Red-tipped Cudweed, the diminuative Smooth Cat’s-ear, Mossy Stonecrop and two species of Catchfly: Sand and Small-flowered.  Both had just finished flowering but were still readily identifiable from the developing seed capsules.

We tried not to look for birds but managed to see a few Stone Curlews and it would have been rude not to watch the group of four Spoonbills that circled, landed and fed in front of us.  These were no doubt some of the 12 or more Spoonbills currently loafing on the Suffolk coast and includes a 2011 German-ringed nestling which spent last winter on the Essex coast.  Stone Curlews have had a moderate year.  Five chicks have so far fledged from the ten pairs in the Minsmere area.  These birds generally choose undisturbed areas well away from public access but this year one pair settled close to the visitor centre, with volunteers posted at a suitable vantage point to point them out to visitors.   

A tale of simple fisherfolk

Little Egrets have come a long way since I first twitched one at Walthamstow Reservoirs in 1972.   Locally, the first breeding of Little Egrets in the Lee Valley occurred in 2006 when a pair reared 4 young amongst the Grey Herons at Walthamstow Reservoirs.  The valley total for this year seems to be at least 26 pairs in three colonies, at Walthamstow, Amwell and Netherhall.  All are tucked rather unobtrusively into Grey Heron colonies but at least 20 broods have been seen to fledge.   Further afield, the UK breeding population is now getting close to 1,000 pairs at around 100 colonies.  One of the largest colonies is at Northward Hill in north Kent where numbers grew to a peak of 124 breeding pairs in 2009, equalling and then exceeding the numbers of Grey Heron, before dropping to 114 in 2010 and then 94 pairs in 2011 as a result of two successive cold winters.  So this mainly fish-eating bird is on the rise.

By contrast, breeding Cormorants peaked in the Lee Valley a few years back at a little under 400 pairs.  Since then total numbers have dropped despite an increase in the number of colonies.   This year the number of active nests in the Valley was around 250 and reflects a steady decline locally over recent years. 

Which brings us neatly to the recent call by angling groups to add Cormorant to the general licence, thus easing the restrictions on killing.  Now, I spent a lot of time ‘angling’, well electro-fishing to be accurate, and then I’m only the assistant, brought along to get wet and carry the boat.  In attempting to create new wetlands, much time is  and effort is spent enhancing the underwater ‘fish’ habitat.  Fish populations reaching a critical threshold is one of the trigger points for getting birds such as the Bittern to breed.   Many reserves support good fish populations and the key issue is habitat quality, notably underwater landform, structure and connectivity, the water quality and the diversity of aquatic vegetation.   Cormorants have never been implicated as a problem on reserves except in an isolated case where an isolated pool was over-stocked to try and create a specific feeding area for birds.  And there perhaps we hit the main issue.  Not only do angling clubs frequently stock way above natural densities but they often tend to have sites with poor habitat quality. Redundant gravel pits for example, which even if earmarked as an angling lake, have little or no attention paid to the underwater habitat in the restoration process.  So the recent outburst against Cormorants smells rather fishy.  Rather than a serious attempt to address the real problems this looks like another attempt to solve a perceived issue with a gun.   

Conservationists and anglers should be on the same side.  Wouldn’t it be great to develop partnerships on some sites where we both work to improve fish stocks through good habitat management?

Crakey! Change the record books.

Calling Baillon's in typically rushy habitat.

Last year, during a trip to The Netherlands, we speculated that Baillon’s Crake was being overlooked in the UK, both as a migrant and breeding bird.  With fortuitous timing, a national Spotted Crake survey has been undertaken this year and surveyors were asked to listen out for Baillon’s Crake.  And one was found!  A rapid e-mail to reserve managers to raise awareness of the possibility of Baillon’s resulted in at least 7 singing males at 3 sites across England and Wales, with a possible 2 more at 2 further sites.  Crakey!

So is Baillon’s Crake a scarce migrant and rare breeder in the UK rather than a vagrant?  Probably, but it is likely that the drought conditions in the Donana region of Spain earlier this year will have prompted more birds to move north looking for favourable conditions.  The drought appears to have affected a range of species.  We have seen influxes of Glossy Ibis and Black-winged Stilts, as well as Baillon's Crakes, and impacts on the movements of other birds, such as Spoonbills.   At least 3 pairs of stilts have attempted to breed in the UK as predicted in an earlier blog.   The Netherlands is also having a good year for Baillon's Crakes with at least 30 singing males.   However, 2005 was also good in The Netherlands yet failed to produce a record in the UK.   Were they overlooked?

Baillon’s Crakes can breed in small areas of suitable habitat; wet, low, tussocky but often open vegetation such as flooded sedges, rushes and grasses.  They also seem to like the edges of pools if this year’s birds are anything to go on.  Calls are poorly understood.  Although the best known is the short Garganey-like rattle of the male, at least 4 different calls have been heard from birds this year.  However, calls can be hard to hear in many conditions and they may not call that often!   Singing birds appear to be best heard between 22.30 and midnight at least, and with birds in The Netherlands known to arrive late, they may be singing well into July.   How many of this year’s birds will return next year?

 

 

Typical Baillon's habitat in The Netherlands (Ruud van Beusekom)

Beaver!

If there’s anything likely to make the Grumpy Ecologist un-grumpy it’s the Beaver.  The Beaver highlight of a three-day trip to north-east Scotland began by creeping knee-deep in water through a remote section of a nature reserve on a gloomy evening, with steady drizzle of course.  A Spotted Crake briefly whipped from a fantastically crakey marsh, a Marsh Harrier flew by, and then there it was: an initially unrecognised turd deposited in a super-highway of a path out of the water. Suddenly we were at Beaver-central; fallen trees, dragged branches, pathways and a possible lodge.  Fantastic!

The day had begun at the Loch of Strathbeg; at the UK’s largest dune loch.  A brief search along the Loch shore for Creeping Spearwort (or its hybrid with Lesser Spearwort) always looked likely to fail due to unseasonably high water levels but a summer plumaged Slavonian Grebe, 35 Goldeneye and a flyby Bonxie kept us happy. The rushy Low Ground in front of the visitor centre, now grazed by a herd of Koniks held a couple of hundred Curlew and a summering pair of Whooper Swan, while botanical interest was provided by Lesser Butterfly Orchid and the remarkably insignificant, but scarce, Mudwort.  After some hours looking at the management of the reserve, the drive south took us past the disgraceful Trump’s Folly and down to Blackdog for the scoter and Eider flocks harbouring Black Scoter and Surf Scoter. All paled into insignificance compared with the soon-to-be new addition to my British wildlife poo collection (the first since Wallaby on the IOM).

Now if any extinct animal should be returned to the UK, it is the Beaver (and then the Lynx).  However, potential introductions have become bogged down in ridiculous controversy and ‘fence-sitting’. Meanwhile, Beavers have done it for themselves, escaping from captivity on the River Tay and spreading out over recent years.  Why is the Beaver so important? Well, the Beaver is an ‘ecosystem engineer’; one of the few species that can significantly change the geomorphology and hydrology of the landscape.  In doing so, Beavers have been shown to increase habitat and species diversity at the landscape scale.  By the beginning of the 20th century, hunting had reduced the European populations of Beaver to a low ebb of some 1,000 individuals.  Then, as recognition of its qualities grew, re-introductions progressed across Europe, beginning in Sweden as long ago as 1922.  Over the last 80 years, Beavers have been reintroduced to 27 countries on mainland Europe, with the UK being one of the few exceptions. Despite this, Scottish Natural Heritage embarrassingly tried to remove the Tay freedom fighters.  More can be found out about the Tay Beavers here.  Let’s hope they are here to stay.

At Loch of Strathbeg: Koniks, Whooper and Mudwort.