Review and rejuvenate

The work diary is filled with Annual Reviews at the moment; a yearly assessment of how each nature reserve is performing against its habitat and species targets.  Two of the top 12 wetland reserves in the UK for waterbirds were recently visited for a review: Berney Marshes/Breydon Water and the Ouse Washes.

Rejuvenation of key areas of habitat by a careful bit of ‘disturbance’ turned out to be a dominant theme for both sites.  Nature reserves can become rather ‘tired’ over a number of years as habitats become rather stable under routine management operations and the actions of natural succession.  Early succession wetland habitats in particular can become overgrown as invasive swamp species begin to dominate what were previously bare muddy areas with annual plants.  In many habitats, a degree of disturbance can knock back the succession and open up opportunities for a greater variety of species to flourish again.  This disturbance through management is seeking to mimic natural events such as flood and drought.  

Berney Marshes recorded a peak of over 91,000 waterbirds last winter and over 200 pairs of waders bred in the spring.  Increasing areas of rough grassland are being retained around the reserve; last year it also had up to 5 Rough-legged Buzzards and 16 Short-eared Owls.  However, the ditches and floods within the wet grasslands are the key feature of the reserve and increasing amounts of Sea Club-rush can become a problem in these areas as the grazing animals avoid eating it.  Staff at Berney have been drying out, cutting and rotovating areas of club-rush with great success, allowing re-colonisation of the resultant muddy ground on re-flooding by annual plants that provide abundant food for wildfowl. The newly flooded pools were covered with hundreds of Lapwing, Wigeon and Teal.  New projects currently being planned on the reserve will deliver significantly more scrape and lagoon habitat alongside Breydon Water for the benefit of terns, Avocets and passage waders.

The Ouse Washes has been suffering for a number of years from increasingly frequent summer flooding, resulting in a sharp decline in breeding waders as nests are washed out.  As a result, conservation work in recent years has been directed at creating habitat outside of the washes.  This year, the so called ‘Pilot Project’ the initial trial of creating wet grassland habitat for breeding waders on ex-farmland adjacent to the washes, held an amazing 174 pairs of waders on 76 ha.  The dry summer this year also allowed some increase in the waders on the main washes. The ‘crake-ometer’ accurately reflected the dry summer conditions: Corncrakes increased to 3 or 4 while the wet-loving Spotted Crakes were absent.  The fenland Cranes are increasingly finding the washes to their liking with up to 21 present at the moment.  Scrapes and floods grow over quickly on the Washes so the dry conditions have allowed a considerable amount of restorative habitat work to be undertaken.  New scrapes have been created and chisel ploughing has opened up compacted soils to the delight of feeding Snipe.  This work will significantly benefit waders and waterfowl in the coming breeding season – if the rains stay away.

Photos: above Wigeon and Club-rush rotovation at Berney. Below: wildfowl and new scrapes at the Ouse Washes.

Guest blog - Bruncher Badger

Hi to all you dopey conservationists (no offence ha ha).  My name is Bruncher Badger and I’ve been asked to write a guest blog for Grumpy.  Now you conservationists have been very kind to me, so I thought I would give something back in return.  The way you stood up for me against that despicable Owen Paterson has been a source of great joy for us badgers.  And that Brian May is great also.  I’ve always liked him since I had a sett under the floorboards of the Hammersmith Odeon back in 1972.  Him and his mates had a good little support band.  Not as good as the great Mott the Hoople though!

Anyway, back to the point.  I gather that there were a few gasps of surprise after that footage of me eating my breakfast on Springwatch.  Guess how I got my name – I ‘brunch’ on your baby birds  ha ha brilliant.  Hey, to us, wader chicks are nature’s little biscuits and we love’em.  They are a nice crunchy change to the usual boring old worms.  Even that very nice, clever Mr Packham (didn’t he do well on Malta!) noticed the calorific value of that snack!  Mind you I couldn’t eat more than 30 chicks in a sitting ha ha.  Anyway the point is; what do you expect?   You create excellent concentrations of ground-nesting birds on your nature reserves and then you expect me and my mate Freemeal Foxie to keep away.  Well I’ll tell you; we’ll walk miles to get at these super cafes.  You set up nature reserves around the place and provide food for us.  Lovely.  Don’t you even seem to think about what’s happening when bird numbers begin to decline.  Normally we have to search around for what we can find, but you dumb conservationists concentrate it in one place for us, year after year.  We nip in and out when you’re not looking and polish them off.  We’re not even members  ha ha ha! There’s even one Wildlife Trust site where they kindly guard the Avocets so those nasty men don’t pinch the eggs and then we can come along to munch up those tasty chicks for our breakfast.  We call them Shredded Tweet or Tweetabix  Ha ha  geddit!  And funnier still, you think we can’t swim! Ha ha. Did you see me in my speedo’s at Minsmere?  You lot need to be thinking a lot cleverer about how you manage sites.  Why don't you move birds around by rotational management, turning sites 'on and off' and making it more difficult for us to find all that lovely food?

Anyway, as I said, I’m here to return a favour.  Those dopey ecologists of yours, the ones that you don’t listen to, they know a trick or two to slow us down.  They have a design for an electrified anti-predator fence that keeps us out.  You ask those guys down at Otmoor, we 've never managed to get through their fence. See my photo below.  But even then, when you are given the design, you think you know better and modify it.  You put the offset wire in the wrong place or space the live wires wrongly.  We think it’s hilarious as we skip over the fence.  My mate Freemeal Foxie knows all the tricks for getting over.  

Anyway, you need a combination fence (stock fencing plus live wires) of at least 1.5m, buried into the ground at least 25 cm.  The livestock fencing should be 1.25m high with a 6-8cm wire mesh.  There should be 2 live wires above the fence; at 1.15m and 1.45m, with an earth wire between them at 1.3 m. The fence needs a live wire 65cm up from the ground on the outside and offset by 15 cm.  This stops us jumping up.  Power with battery or mains and take extra care around gates or ditches.   And don't bother with those strand electric fences, they are no good – we just bundle straight through!  This is all a bit simplified but I'm sure you can find more detail.

So there you are, the answer to your problem.  Anyway must go and get a few more Tweetabix while I can.  Those Minsmere guys have already started on a brand new fence.   Then it’s back to worms for us.  I’m fed up with all them bones anyway.

Grazing - what a drag for Snipe

When is the best time to put grazing animals onto marshy grasslands with breeding Snipe?  We know that trampling rates of nests are high: on average 2.5% of nests are lost per day per cow per hectare.  So at a grazing density of 1 cow per hectare during incubation nearly half of all nests are likely to be lost to trampling.  Snipe can breed from April through to August if conditions remain suitable and later nests are more likely to be successful (early nests are more prone to predation), so the timing of the start of grazing is critical to Snipe productivity.

Recording drumming Snipe will tell you that they are likely to be breeding.  Last week we looked at some fields at the Ouse Washes where there were good numbers of ‘drummers’ in early April but had declined to just a couple on the most recent survey.  So is it now safe to put cattle onto the fields?

To see what was going on we met up with Rhys Green, who knows more about Snipe than most, to try out the rope dragging technique.  A 15mm rope was dragged slowly across the field over the top of the vegetation. ‘Watchers’ looked carefully for any Snipe that flew up as the rope progressed and then carefully checked that spot for nests or chicks.  Birds flying in advance of the rope were more likely to be feeding; those rising almost under the rope more likely to have a nest or chicks.

We found 3 nests and 10 broods. Chicks were measured, aged, ringed and returned before we quickly moved on. Eggs can be weighed and measured to determine hatching date.  Although only the female incubates, both male and female look after the chicks and supply food to them in the early days.  The male takes the first two to hatch, the female the latter two.  The chicks reared by the female apparently grow slower as she is in poorer condition than the male after incubation and provides less food to the chicks.  We noticed that Snipe with young often seemed to rise heavily from the ground with the tail feathers splayed downwards. A similar thing has been noted in Woodcock and may account for the belief that they can carry their young in flight.

So when to graze Snipe grasslands?  We know that trampling rates can be high during incubation, that birds can have nests or chicks long after drumming has ceased, and that eggs can be laid into July or even later.  If you value your Snipe, then start grazing late, at low intensity and only build numbers up from August. 

Photos: above - Snipe chicks and rope dragging.  Below - a typical squelchy area with tussocky, long and short vegetation that Snipe with chicks choose to feed in.

Pop-up wetlands

The idea of ‘Pop –up’ or ’walking wetlands’ has been used in North America for a number of years. They are temporary wetlands where land, usually agricultural, is shallowly flooded to attract waterbirds. This has achieved benefits for both conservation and agriculture. They have been used by conservationists to provide feeding habitat for passage waders or wildfowl. The large concentrations of Snow Geese or cranes that can occur on these sites are well known.

Why do we not seem to employ similar techniques in the UK? Okay these are not natural habitats but where feeding opportunities for birds are lacking, such temporary wetlands are likely to attract large numbers of birds.  We could adapt these ideas on nature reserves. Where a reserve lacks suitable shallow floods in the autumn but has available water, why not pump water up into a temporary scrape? Can we not flood cropped areas to provide autumn habitat for waterbirds?

Dungeness is already employing a variation of
this technique with some success. The
‘hay fields’ at Denge Marsh flood naturally with high water
levels but when they are low, water can
be pumped into the fields from the
adjacent ditches.  I took a trip down to ‘Dunge’ last week to look at these fields.  They have already attracted a flock of 10 Black-winged Stilts this year and a Long-billed Dowitcher was briefly present on the day of my visit. Sadly whilst I was enjoying the delights of 2 booming Bitterns, several Hobbies, Whimbrel, Common and Arctic Terns, the Dowitcher flew away.  Arriving at the hay fields, we discussed how management could be improved (to tempt Dowitchers to stay longer). This year, the fields will be drained by June in preparation for cutting the
 vegetation in early July and
 then several areas will be rotovated.  Water will be pumped 
back on in late July and the area 
maintained wet into next spring.  This
 should provide not only good early autumn feeding for
 passage waders and other waterbirds but also allow early colonisation by chironomids to enable a sufficiently large biomass of larvae by next spring for breeding waders.

Photos above: the hay fields at Dungeness, with Black-winged Stilt.