Come schnell and high water

'Er indoors said she enjoyed last year’s trip down to Seville and Donana; must be the Lynx effect.  So a return trip was in order. Aha, a chance to check out Baillon's Crake habitat and gauge possibilities of northward movement this year.

Arriving at El Rocio on the western edge of the Donana National Park, it was clear that this was no drought year: it was wet, very wet.  Water levels were very high.  A heavy storm forced us into the local restaurant to debate the finer qualities of Coquinas verses Almejas, accompanied by some fried anchovies, and a little octopus of course.  With full bellies and the rain easing, we ventured out to look over the lagoon.  At the tail end of the storm, Sand Martins and Swallows were moving in numbers. An estimated 10,000 passed through over the next hour, the naked eye view appearing as a mass of midges swarming over the water and all moving northwards with purpose.  Slowly the sun broke through and temperatures rose.  The soft rolling ‘prruup’ noises from above broke into the consciousness as dozens of Bee-eaters streamed through.  Now concentrating upwards, Black Kites, Booted Eagles and Red-rumped Swallows dotted the sky in a steady movement. The odd Monty’s and Purple Heron added interest.  Warm sun on the bones and birds on the move; what could be better?

Early next morning we were out looking around the marshes; they were wet.  Spotted Crakes, Baillon’s Crake and Water Rails crept around the flooded swamps.  Not much chance of a major northward push of Baillon’s this year.  In last year’s drought conditions, Baillon’s, Stilts and Glossy Ibis all moved northwards searching for better conditions.  It also delayed the onward passage of Spoonbills due to poor feeding.  No such problems this year.  Feeding groups of Spoonbills, several colour-ringed, were swishing energetically, belly-deep in water and frequently flicking up and gulping down small fish.

There were many birders around and most seemed to be Germans. A beckoning "Come, schnell" provided me with close views of Purple Gallinule.  Savi’s reeled from every swampy hollow, Subalpine Warblers disappeared around every patch of scrub and Woodchats dotted the tops of bushes.  Nightingales sang and Redstarts flitted.  As lunch time approached, the baby lamb chops needed some consideration (oh the flavour!) and after several glasses of rioja, we were surprised to see a Lynx run right through the restaurant.

Below - Lynx in pine wood

Oil platform

A day out this week on the Essex coast at Wallasea with colleagues from Buglife looking for Oil Beetles.  As luck would have it, we hit a warm sunny morning,  with singing Corn Buntings everywhere.  And plenty of the target species; Black Oil Beetles Meloe proscarabaeus, along the seawall, mostly doing what Oil Beetles need to do in the spring..  The name derives from their habit of releasing oily droplets from their joints when disturbed; this contains cantharidin, a chemical apparently causing blistering of the skin and painful swelling.

The life cycle is fascinating.  The female beetle lays up to 1,000 eggs in burrows close to the burrows of mining bees. The larvae, known as triungulins, climb up into flowers and wait for a passing bee collecting pollen.  They then hitch a lift on the bee back to the bee’s nest where they munch their way through the bee’s eggs and pollen supplies.  The adult beetles emerge from the bee burrows after overwintering.  More on the Buglife website here.

Comings and goings

Despite the reluctance of winter to give way to spring, comings and goings have been evident in the last few days.  Today at Hall Marsh, where some excellent management has been undertaken by the Lee Valley Park, a Little Ringed Plover was back on territory, a Sand Martin headed north and a Chiffchaff sang from nearby bushes.

A few days earlier I had waited in vain at Amwell for a Great White Egret to return to the roost, but luckily witnessed a far more interesting event.  At dusk a Bittern drifted headed across the lake and dropped into its usual reedbed roost site. Nothing unusual there.   However, 15 minutes later, in the gathering gloom it rose out of the reedbed to begin circling up into the sky giving the little known ‘gull call’.  Within a minute or two a second bird had risen out of the reeds to join it, both dark shapes now just visible circling over the lake.  As they rose and drifted northwards, a third calling bird appeared from the south to circle the lake.  This bird disappeared high into the gloom back southwards with its far carrying call audible long after the gloom had swallowed up it’s shape. 

The ‘gull call’ can be given by both male and female Bitterns and has mainly been associated with pre-migration behaviour when birds circle up into the sky at dusk.  This behaviour is well known on the continent, where groups of up to 20 birds are noted at key wintering or passage sites.  However, the ‘gull call’ may also be heard in aerial chases over breeding sites in early spring. 

Although many of our wintering Bitterns are assumed to come from the continent, there is little firm evidence of this.  However, satellite tagging birds in the Netherlands has produced some interesting results.  Check out Anneke on this page.    Anneke was ringed in the Netherlands in 2011.  In October she arrived in the UK over Hull, toured Wales and then settled at Slapton Ley in Devon from late November to the end of February. On February 26, she flew back to the Netherlands with a stopover in East London after a flight of 900 m above the city.  Then she returned to her natal site, crossing the North Sea at over 60 miles per hour.

So our Lee Valley birds may be heading back to distant breeding areas but there is plenty of Bittern breeding activity in the UK already this spring, with a remarkable 35 booming birds in Somerset, good numbers in the north of England and some new sites occupied. With Great White Egrets also getting jiggy on at least two sites, this spring will be interesting.

Goshawk snippets

Last week developed a Goshawk theme.  A day in the Brecks on one of the few warm spring-like days so far resulted in some opportunistic top-of-forest watching, with views of a displaying pair in a regular location. Largely a bird of big forests, Goshawk has a small but increasing population in Thetford Forest with eight pairs located by regular observers last year.  I then departed for a couple of days in deepest Wales, where despite deteriorating weather, I was lucky enough to see another couple of birds.  The first was a male flushed from a woodland ride early in the morning.  It weaved its way heavily between the trees carrying a lumpy prey item which appeared to be a crow.  Landing in a small copse ahead of us to pluck the bird, we crept forward hopeful of a reasonable view, but typically it vanished in a couple of wing-beats, taking its breakfast with it.  Later, it or another male was displaying over the woodland, pinpointing a possible nest site.  Two UK studies have shown that crows and pigeons make up the bulk (around 68%) of the diet of Goshawks during the breeding season.  This is similar to the diet of Dutch birds but different to those in Scandinavia where grouse make up a bigger percentage of the prey.  The Goshawk has little competition in the UK.  Peregrines are closest in diet but Goshawks are more versatile; taking prey in wooded landscapes and from the ground.

Locally in the Lee Valley area, I have only managed a paltry three birds in 40 years of birding, and one of those had jesses.  Even four years of living in a house overlooking Epping Forest, where they are regularly claimed, resulted in nil sightings. The aforementioned bird with jesses; at Amwell in 1988, memorably took a Wood Pigeon with some force in flight, turning the pigeon into a firework explosion of feathers in the sky, followed by the gently descending feathery sparkles after the birds had long gone.

Extreme gulling

Above: Klaus, Yellow-leg, Caspian, mattress and Med - can you find them all?

The perfect end to the week; standing on a huge pile of rubbish in a stiff north-easterly with horizontal sleet.  I booked on to the Rainham Marsh gull ID special, lead by Klaus Malling Olsen, author of Gulls of Europe, Asia and North America.  After a thorough health and safety presentation by Veolia, who kindly allowed access to the tip, we were fully briefed on the dangers of wayward bulldozers and sniffing hydrogen sulphide.  Fully PPE-ed we made our way to our prepared viewpoint for a fine view over east London. It was cold.  However, a 2-hour watch provided warming views of 1^st winter and 2^nd winter Caspian Gulls, 2^nd winter and adult Yellow-legged Gulls and 2 adult Mediterranean Gulls amongst the gully masses, mattresses and general trash.  A male Hen Harrier rounded off the watch nicely.

Back in the centre, Klaus took us through the finer points of gull identification, made Caspian’s easy (just think of up-lift bras), poo-poo-ed Azoreans and urged us to find Baltics.  Overall, an excellent afternoon organised and run by the Rainham staff and volunteers.  Thanks to you all.  Can you choose a warmer day next time.

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.