More Essex

Scarce Emerald (Lestes dryas) and getting down to the hard-grasses, looking at the diminutive anthers of Curved hard-grass (Parapholis incurva - left) next to Hard-grass (P. strigosa - right).

Following the Essex theme, last week provided the opportunity to look around a rarely visited south-east corner of the county.  The seawalls and borrow-dykes provide the habitat for some local botanical specialities; Slender Hare’-s-ear, Sea Barley, Stiff Saltmarsh-grass and Curved Hard-grass were all duly noted.  The saline borrow-dykes supported Spiral Tasselweed and the specialist lagoonal isopod Idotea chelipes, whilst the more brackish pools had Scarce Emerald Damselfly and Hairy Dragonfly.  The bird highlights included 5 Short-eared Owls and 6 Whimbrel, as well as breeding Redshanks and Shelduck.

A Little Sterner

Beauty and the beast: the problems for the Little Tern.

The two-day tour of the Essex coast was primarily to look at the fortunes of the Little Tern.  By the time we had finished, and understood the problems, we were all a little sterner.  Little Terns have not been doing well recently; in Essex or further afield in the south-east.  They suffer from disturbance by humans, competition from gulls and flooding from high tides.  And everything seems to like to eat them; from Foxes, Stoats and Hedgehogs, to Kestrels and owls.  Much of this comes down to an increasing lack of safe nesting sites on our over-crowded coastlines.

Whilst the beaches clearly have disturbance issues, the Essex coast has many small saltmarsh islands amongst its estuaries and creeks.  We found 3,500+ pairs of Black-headed Gull, 100+ pairs of Herring Gull, 56 pairs of Common Tern, 30+ pairs of Oystercatcher and 8 pairs of Ringed Plover.  More surprisingly, a total of 29 Mediterranean Gulls were noted, including at least 6 on nests.  Little Terns amounted to 41 nesting pairs, with 20 or so additional birds.

The islands perhaps provide an answer for the Little Terns.  Many of the nesting pairs are on areas of dumped dredging or shellfish remains.  The saltmarsh islands are not attractive nor very accessible to people or ground predators.  A partnership with harbourmasters and fishery interests might bring about the regular recharging of small areas of suitable nesting habitat for the terns.

Elsewhere in East Anglia, news is of mixed fortunes for Little Terns, with the usual problems of flooding out and predation.  However, up to 200 pairs near Winterton is excellent and North Norfolk may still have 400 active nests. A spell of calm weather might be helpful!

Red-breasted Devaluation

Geese in Essex - Red-breasted last winter and broods of Barnacles yesterday.

Just to remind you, here’s a photo of a Red-breasted Goose in Essex from last winter.  I saw it again yesterday, or did I? I certainly saw a Red-breasted Goose; holding territory on an Essex coastal marsh, with a female tucked away on a nest.  Last year this pair raised four young.

I was visiting an area of coastal marshland at the invitation of the landowner during a two-day tour of sites on the Essex coast.  The landowner is a farmer who ‘likes his birds’.  The most obvious thing about this well-managed land was that it was teeming with young birds; waders, geese and duck.  There were around 70 pairs of Avocets (many with well-grown young), 5 pair of Ringed Plover, 20 pairs of Little Terns, 1,000 pairs of Black-headed Gulls and many Redshank.  I saw broods of Gadwall, Tufted Duck and Shoveler.  The landowner operates a minimal disturbance policy and ‘discourages’ ground predators such as Foxes and Stoats. There were also many geese, including about 80 pairs of Barnacles and the pair of Red-breasted.  I saw around 20 broods of Barnacle Geese.  A fascinating site, but somewhat alarming if you want to think the Red-breasted Goose you are chasing is wild.

Northern snippets

Choughs, The Oa and a fat, juicy tipulid larva.

A welcome change of scenery last week looking at reserve issues on Islay, with The Oa and Loch Gruinart being the main sites visited.  An Otter in the bay below the campsite at Port Charlotte was a good start.  Management for Chough was one focus of the visit.  They prefer places with short, grazed pasture, less than 5 cm in height, and soft soils where they can probe to find food.  A specialist feeder on invertebrates, they will take beetles and their larvae, fly larvae (especially tipulid (Cranefly) larvae), ants, their grubs and pupae, and spiders.  Dung invertebrates are an important source of food.   Such food resources can be patchily distributed, as we found by sampling various areas of turf but we did turn up some particularly juicy tipulids in a key feeding area.

Marsh Fritillary butterflies are locally frequent on Islay. Attack by parasitoid wasps appears to have an important effect on the population dynamics of the butterfly and may help to explain its requirement for large habitat patches. Two parasitiod wasp species, Cotesia bignellii and C. melitaearum, are present in the UK  and are of conservation importance in their own right, one being specific to the Marsh Fritillary. Studies suggest that the parasitoid and its host may have a shifting metapopulation distribution, with the butterfly 'escaping' parasitism in some areas by dispersal and colonisation, with local extinctions occurring in other areas.

A Marsh Frit caterpillar with cocoons of emerged parasitiod wasp larvae.

Highlights of the trip included 30+ Chough, 6 crekking Corncrakes, 4 Golden Eagles, Hen Harrier, Tystie and Great Northern Diver.  Loch Grunart produced Corncrake and Quail calling together in front of a pair of Whooper Swans.  As well as an approachable flock of 20+ Chough, Ardnave Point also produced a typically tame migrant Dotterel.  And all this sandwiched between a daily menu of various local delicacies; from full Scottish breakfast with ‘square’ sausage and tattie scone through to sampling the local whiskies.

Every cloud....

Black-tailed Godwit and Snipe

On balance, this spring is not shaping up to be a great one for the 50 or so pairs of breeding Black-tailed Godwits in the UK, with their primary locations on the Nene and Ouse Washes both flooded out by the heavy April rains...but every cloud has a silver lining so they say.   I visited the Nene this week; floodwaters are receding and although both Godwits and Snipe were busy displaying overhead, surely time is running out for the Godwits to produce many young this year.  There is an increasing urgency to attract them to new sites, either existing or created, that do not function as storage washlands for summer downpours.   So what do they require?

Godwits favour large, open wet grasslands and marshland.  A Dutch meadow-bird conference I attended some years back explained their dislike of ‘up-going structures’ as the Dutch liked to call them, and this included trees, hedges, buildings and the like.   They like to see in all directions.   After arrival on the breeding grounds, adult godwits require grasslands rich in soil invertebrates, probing for earthworms where high water tables push them close to the surface. They also seek out shallow pools as safe roosting sites.  The chicks have different requirements.  They seem to require longish (20cm) grass, often flower-rich but always with an abundance of invertebrates, particularly flies and beetles, amongst the vegetation. The density of the vegetation is important, with sparser swards preferred for the chicks to forage amongst.

A particular problem appears to be their attachment to natal locations and their slow colonisation of new sites.  So both the RSPB and WWT have been busy creating new habitat on ex-arable farmland adjacent to, but outside, the Ouse Washes to try and attract breeding Godwits.   After some years of ‘maturing’ habitat, an excited text from the site manager over the weekend brought the news that the first Black-tailed Godwit chicks had hatched on the new RSPB land.  Somewhat ironically, the heavy rain and resultant flood has pushed the few remaining Ouse Washes Godwits onto both the RSPB and WWT new habitat. Let’s hope they stay there.

The Baillon’s – my part in its finding

After a trip to The Netherlands last summer, I drafted a blog about finding Baillon’s Crake in the UK this year.  I never posted it as it seemed a bit extreme.  What do you know?

In The Netherlands, we looked at some sites created for Purple Herons.  Extensive, shallow wetlands that provide good feeding conditions and will slowly colonise with reed and other aquatic vegetation.   Such areas, of course, attract many other species.  In the early stages, Black-necked Grebes and Spoonbills are likely to appear, but of particular interest was the occurrence of Spotted and Baillon’s Crakes in grassy and rushy habitats after initial flooding.  Bailllons Crakes occur across the Netherlands in low numbers but are very easy to miss and are thought to be more numerous than the figures suggest.  Looking at one of the sites with Baillon’s Crake reminded me of the singing bird in 1999 at Grove Ferry in the early stages of the reedbed habitat creation there.   With only four UK breeding records, are we over-looking them?   Could we manage sites like Grove Ferry to attract more crakes?  A tenner says we could.

Anyway, we decided to add Baillon’s Crake to the national Spotted Crake survey this year. Everyone laughed of course.  Now a Baillon’s has been found on a Spotted Crake survey by Ian Hawkins at Malltraeth.  How many more are out there?

Baillon's typically turns up later in spring in The Netherlands than Spotted; from mid-May until the end of July.  They can breed very late in the season, and have been seen with small chicks in mid-August. The males rattling song, somewhat like a cross between a frog and a Garganey, is best heard during quiet, windless nights.  They may call during rather cold nights, when the Marsh Frogs keep quiet, which is a distinct advantage.  They occupy sometimes surprisingly small marshes with a water table of 10-20 cm, with a vegetation of narrow-leaved marsh plants (typically sedges and low rushes).  When they have young, they will give harsh Magpie-like calls like cha-cha-cha-cha but also loud Blackcap-like ‘tek’ calls.

The Dutch Baillon's site we looked at:

Frampton comes alive.

Will Frampton Marsh rock the world of scrapes?  I pondered this question as I sat through the rather dull indoors part of the reserve annual review and itching to get out and examine the wader potential of the scrapes in the field, especially as I had noticed the Wind of change had gone to the east.  Located on the south-west corner of The Wash, the site certainly has the potential to pull waders.  Hmmm  Penny for your thoughts.

Regular readers will know I have ranted about scrapes before. Food abundance and availability are the key issue.  These are, in turn, is affected by water regime, nutrient levels and predators.  New wetlands are generally highly productive in the first few years of existence as early colonising invertebrates benefit from high nutrient levels and reach high abundance levels.  Food!  As time passes, nutrients become locked up in the system in mud and decomposing material and invertebrate predators increase as a more balanced system develops.  Less food!

So the key is to dry out shallow water bodies to allow nutrients to be released to the system, to kill off predators and then to re-set the clock by allowing re-colonisation.  But how often should this be done? Some ‘food’ invertebrates may peak in year 1, others up to years 4-5.  The trouble is that birders then moan when a scrape is dry for a season and there are no birds.  Many reserves fail to manage scrapes correctly for fear of a visitor backlash when they are dry, but then end up with a visitor backlash for having few birds. It’s a plain shame.

So, Frampton was designed with three scrapes adjacent to each other, all around seven hectares in extent. The two hides each overlook two scrapes.  The aim is to rotationally manage the scrapes; drying at different times to maximise the potential for waders.  Visitors will also see Something’s happening at all times.

Eventually we got out into the field, no doubt they saw the Lines on my face.  I said ‘Show me the way’.  The first scrape held a Black-necked Grebe and nine Little Gulls.  A couple of Temminck’s Stints grovelled around an island on the next scrape, while the third had Greenshank, Black-tailed Godwit and a number of broods of Avocet swishing for food in the shallow water. Baby, I love your way.  The adjacent wet grassland scrapes held 100+ Dunlin and Ringed Plover, Curlew Sandpiper and Garganey.  A bright future would seem set to Shine on Frampton.  Do you feel like we do?