Warden's Blog

With this blog I am currently playing a little bit of catch up with communicating some of the work and other bits that occur on site, and today I am looking back to some (not all) of the work party tasks over the last six or seven weeks.  I am sure we will very soon settle into a rhythm of one a month, or thereabouts.

First up then, looking all the way back to mid-October and the estate volunteers helped to clear the view in front of the Wildlife Watchpoint hide.  It is a job we do each year to provide better views.  This year we had a little extra help from the Softrak machine at the beginning of October, as discussed in a previous blog.  The Softrak cut and collected the bulk of the vegetation but couldn’t access all areas, and this is where the team were dispatched to cut additional reed, where the water was deeper.  They provided improved sight-lines and better views from the hide, and piled some of the vegetation in to neat rows which will allow ducks to loaf and roost close to the hide, again giving those views.  The rest of the vegetation was piled into a decent-sized habitat pile and left to rot.  This will provide habitat for the decomposers and the creatures that feed on them.

A recent view from the Wildlife Watchpoint hide

Another task the team have been making good progress with, is the removal of Sea-buckthorn, largely from the Haverton end of the reserve.  This part of the site is a mosaic of habitats, with scrub, reed fringed pools and nutrient poor grassland.  It is one of the more interesting areas when it comes to flora and  probably invertebrates (though we haven’t done any survey work on those there yet).  Sea buckthorn can be quite an invasive plant, spreading over a large area through stolon-like roots and suckers and forming impenetrable thickets which over time will alter the balance of the mosaic and reduce interest.  It is also a nitrogen-fixing plant and so will be altering the chemical nature of the ground.

For two seasons now, our residential volunteers have been working with groups from Houghall college for a five-week period of winter work, helping to clear sea buckthorn.  I n addition, our weekly estate volunteers have been in the mix and the progress has been impressive.  It is worth noting as well, that we have not been using any herbicide for these tasks.  In the past we would have stump-treated the cut stems with Glyphosate to prevent regrowth.  For the last two seasons we have been using a fantastic tool called a ‘tree-popper.’  This tool grabs hold of the stem, low down, and is used as a lever and when the handle end is pushed down it exerts an upward force on the stem.  The result is the sea-buckthorn is pulled out of the ground along with roots and, because the roots are so shallow, the majority is easily extracted.

Once removed, we have been using a lot of the material to form barriers and reduce unwanted access to certain parts of the site; as our volunteers will attest sea buckthorn can have a very nasty thorn, known to have even got through wellies, and so can acts as a pretty decent people barrier.  

One of the piles of sea-buckthorn removed this year

At our Cowpen Marsh site, near to the sea wall is an old well-head, similar to ones on our main site.  Access to this was maintained after the sea wall was moved in 2018 and we have seen Grayling butterflies on or by the track each year since.  Grayling is a butterfly that favours areas of bare or sparsely vegetated, nutrient poor ground and was recently (2022) classed as endangered on the GB red list by Butterfly Conservation.  It is one of the species we target our conservation work at, and at Cowpen Marsh we have noticed Buddleia and bramble creeping in, both of which will spread if not managed.  So, after neglecting this task for a couple of years we got round to removal of these plants.  If time allows this season we will also cut and rake some areas where there is stronger grass growth to complement this management and benefit this cryptic butterfly.

A Grayling, Hipparchia semele, at Dorman's top car park

A couple of weeks ago we had help from Reserves Ecology as they came to site to carry out an electrofishing visit.  An anode (held at the front) and a cathode (trailed from further back) are put into the water from a boat and an electrical field is created as the team travel about the pool.  The electric field can attract fish and then, when close enough, temporarily incapacitates them, at which point they can be fished out to be identified and weighed.  The fish are then returned, unharmed.  The reason we do this is to learn about fish numbers and whether or not there are enough to support, for example, breeding Bittern.  We have had bittern breed twice now, the first time in 2022 and then again this year, though it appeared only a single chick was successfully fledged this year compared with what looked like at least four in 2022.   We concentrated the electrofishing on the Top and Middle Tank and Haverton Hole and early signs show that we may be a little under what would be expected for a site with breeding Bittern, though we await the full results of the survey.

An eel caught in Top Tank 

Lastly a mention of some of the recent sightings we've had on site.  I was personally very happy when a Richard's Pipit turned up in the last week of October, near to the sheep shed and I managed to get a view, as it is a species I had not seen before.  This scarce pipit is a bit like a Meadow Pipit on steroids, a much larger bird with a distinctly different hoarser call, which again, was great to hear.  About a week before a first winter Barred Warbler had been seen, though just the once, and there were a couple of sightings of Willow Tit, all at the Haverton end of the site.  At the very end of October a Hawfinch was spotted on the path beyond the Phil Stead hide about the time there was a large influx into the country. 

Starlings have undoubtedly been one of the stars over the last few weeks with counts of up to 30,000 birds coming into roost at our Haverton end delighting our guided groups with their fanciful, pre-roost displays along with a cast of extras that has included Marsh Harrier, Sparrowhawk and Barn Owl.  Bittern have also been putting in an appearance or several, with views from Haverton and also Saltholme East, Bearded Tits have put in an appearance or two around the Main Lake and a kingfisher has been delighting visitors with regular sightings from the edge of Allotment Pool, best viewed from near the adjacent cattle grid.