Hungry caterpillars expand their menu... but so does someone else!

Brimstone butteries were first recorded breeding in Wirral at New Ferry Butterfly Park in 2014. Then the larva were feeding on alder buckthorn shrubs planted in 2004 by the 4th Bebington Scouts, St John’s New Ferry.

Alder buckthorn shrubs prefer damp acidic organic soils. Since the park is on a well-drained railway site such suitable areas for alder buckthorn to flourish are limited. The brimstone caterpillars have expanded their menu to feed on another host plant, purging buckthorn. These purging buckthorn shrubs were planted in March 2014 and weeded this April by Liverpool John Moores University Conservation Society. The freshly exposed purging buckthorn may have been more attractive for egg laying, as the competing vegetation was removed and the shrubs were exposed to the full sun, which helps speed up the caterpillar’s development. 

28 May. Brimstone caterpillar feeding on purging buckthorn

Purging buckthorn is rare a shrub in Cheshire as it prefers calcareous soils. Here at the park purging buckthorn was established on the outflows of a water softening plant, used to provide lime free to water prevent the stream engines furring up. Paul Loughnane, the Park’s secretary, said “We are delighted to see the brimstone using purging buckthorn at the park. It will enhance the breeding success of the brimstone butterfly tremendously and the butterfly experience for our visitors. Brimstone butterflies have been restricted locally by the absence of larval food plants. Once the plants are established in a sunny and sheltered aspect, the brimstones have an opportunity to colonise these areas. I know of only one other record of them breeding on purging buckthorn in Cheshire and that was in a garden in Alderley Edge in 2010. The male brimstone is a large yellow butterfly, a strong flyer and can be easily recognised at a distance.  These butterflies will be on the wing in July.”

Brimstone butterfly feeding on Red Campion. Photo: Paul Loughnane

Interest in the caterpillars is not only restricted to human visitors, the Bronze shield bug (Troilus luridus), sometimes known as the Stealth shield bug, has expanded its menu at the park to brimstone caterpillars.  It creeps up upon the unsuspecting caterpillar and, using it mouth parts which are shaped like a syringe, stabs the caterpillar and sucks out its innards. One of the distinguishing features of this shield bug is the orange band on the penultimate segment of each antenna, which can be clearly seen in the photograph. This is the first record of a Bronze shield bug in Wirral. Thanks to John McGaw, Wirral Wildlife Invertebrate Recorder, for identifying this shield bug. John, who has never seen this shield bug species before, commented “A really interesting find, but for the sake of the butterfly population in the park let's hope there are not too many of them around!”

12 June. Caterpillar attacked by shield bug.

Great News from Delamere

Delamere’s first ‘dragon’ of the year has been spotted in the forest… well the white-faced darter dragonfly.

White-faced darter. Photo: Kevin Reynolds

As one of the UK’s rarest dragonflies, this beautiful species has been extinct in our county for over a decade. However, an ambitious project over the last several years has meant that the adult dragonfly has been spotted again this year. The work has involved countless Cheshire Wildlife Trust volunteer and reserve staff hours, reinstating and improving habitat in Delamere Forest, in partnership with the Forestry Commission, as well as a series of white-faced darter translocations.

Doolittle Pool, Delamere. Photo: Richard Gabb

Chris Meredith, Delamere Conservation Officer at Cheshire Wildlife Trust explained the importance of this. “Sightings this month are really significant as it is the first year where we have not introduced new larvae to the pool. This means the adults you can see flying around the pools, are either from larvae that were at an earlier stage and have therefore survived for a longer period, or are in fact the result of adults breeding successfully at our site. A huge thank you to all of our supporters, volunteers and funders who have contributed to the success of the project.”

Dragonflies have been on the earth for over 300 million years and during that time have remained largely unchanged. Although the dragonflies you see are usually flying through the air, they will have all started life in the water. After an egg has been laid, the larva hatches and spends between 3 months and 5 years feeding and growing underwater. Once the larva has reached its full size, it will climb out of the water where it breaks out of its outer skin, revealing its adult body with wings. The adult dragonfly is several times bigger than the larva and has to spend a few hours letting its body and wings stretch out after developing in such a small space. Once dry the dragonfly can take its first flight.

Adult emerging. Photo: Chris Meredithsmall

The white-faced darter reintroduction project is a partnership between Cheshire Wildlife Trust, the Forestry Commission, Natural England, the British Dragonfly Society and Cheshire West and Chester Council, with funding support from the Heritage Lottery Fund and the Linley Shaw Foundation.

Early Summer at Cleaver Heath

Birds

The breeding season has now reached its climax. To date, late May, we have conducted 7 Common Bird Census (CBC) surveys and will probably finish with 2 more.  The idea of the CBC is to build up a picture of the main territories of birds which are present during the breeding season. This is done species by species. While I am walking round the reserve over a standard route, I am marking on a large scale map what I am seeing and hearing. Below is what my scruffy map looks like.  The codes tell us what the identified bird is, where it is and what it is doing. This takes about one and a half hours and I try to do it before the roar of commuter traffic builds up, the garden and building machinery springs into action and the early morning dog walkers arrive. There is one map for each visit. And now for the exciting bit. Some rainy day(s) at the end of the season, I will create a new map for each species (maybe 15 of those?!) showing the history of where and when birds of that species have been active over the breeding period. This information can then can inform us when we come to our habitat management strategy.

The order of arrival of the warblers has been Chiffchaff, Blackcap, Willow Warbler then, after a gap, Whitethroat.

So far, we know about at least 4 Chiffchaff and 3 Willow Warbler territories in what is, after all, quite a small reserve (7.4  acres).  I have seen Linnets on more than one survey including a pair diving promisingly in and out of the gorse. Of course, the frustrating thing is seing other interesting birds and bird behaviour around the reserve but NOT during the official survey time window. These ones don’t count - still great to watch though!

Whitethroat

Maintenance

While the breeding season reaches its conclusion we have restricted reserve maintenance to essential path work.  

View from Cleaver Heath

The view over the Dee is so enticing that many visitors think they may get an even better view by walking ‘off-piste’  into the heather, quite often while following an inquisitive dog. We have scratched our heads over how to deal with this. There is a similar problem when the main path gets muddy and those anxious to complete their dog walk without getting their shoes dirty take to the grass and heather thus creating a network of new unwanted paths. We don’t want to introduce barrier rails, barbed-wire fences, no-entry signs or whatever. So, here are some stop gaps measures we are currently taking.

We have transplanted a couple of bramble plants which should quickly grow and discourage use of the nascent paths while the heather recovers behind them. Dogs tend to avoid bramble. Also, while we await approval to continue the successful stoning of the wetter parts of the main path, we have tried to indicate the correct route with some birch limbs across extra routes awaiting recovery.

Newly planted brambles

Birch across the incorrect path

Natural Futures Project

Some good news for the Reserve is that our bid to The Natural Futures Small Grant Scheme has been successful.  The scheme is administered by the Cheshire Wildlife Trust as part of its major Natural Futures programme funded by the Heritage Lottery. The £1000 grant made to Wirral Wildlife helps provide us with some kit to improve Cleaver Heath for both its human and avian users. Constant re-cutting of the invasive birch and non-native plants/bushes/trees can soak up a lot of volunteer effort but only to modest long-term effect. We now have some Tree Poppers which allow us to remove saplings complete with their root systems with minimal disturbance to the surrounding precious Lowland Heath plants. 

Tree Poppers

We also now have the wherewithal to store securely, and apply safely, herbicides. We can use these to stop regrowth of stumps and, via local spraying, deal with invasive plants which have crept into the Reserve over its boundaries.

Chemsafe

Cleaver Heath has a modest amount of woodland fringe which, together with the managed scrub areas, provides cover and nesting opportunities for birds, both resident and visiting. As yet, we have provided no nesting boxes.

 The new grant has allowed us to acquire some new low-maintenance ‘Woodcrete’ boxes. Our volunteers will help us install these next winter ready for the next nesting season. The plan is to see what difference this makes to the woodland bird population which of course is being monitored annually via the Common Bird Census.

Bird box

The Natural Futures programme had already provided funding for me to get the necessary chemicals certification for working with the herbicides. One main motivation for this was to have quicker, on-site, access to stump treatment following the painstaking cutting activities of our volunteers.  In following seasons, they can move on to new areas without having to re-visit last year’s work.

Signs of growth

We have been encouraging a small, but spreading, Bilberry stand in one of the managed scrub areas. It looked particularly attractive a few weeks ago as it came into bloom.

Bilberry

Also growing apace is the natural hedge which we planted in February 2014.

Hedge planting February 2014

In May 2017 it now looks as shown below.

Hedge May 2017

Note the Oxeye Daisies thriving in the ex-carpark area along with a veritable jungle of potential nectar-source plants. I foresee a new maintenance task coming as the hedge starts to entangle passing pedestrians on Oldfield Road.

Our summer plans, once the nesting season is over will include bracken spraying; cutting back the path edges which are starting to grow vigorously; completion of a survey of all plant life in the reserve. Most of the latter was carried out last year by our team of botanical experts – another area where I am on a steep learning curve. A small region of dense scrub at the North West end of the reserve remains to be checked out. The birds are currently, and quite rightly, showing indignation at any intruders who might wish to trample though their territories.

The bracken is already starting to encroach on the heather as shown here.

Bracken

There are other areas where it has over the years totally dominated the other Lowland Heath plants. It has been previously sprayed in recent years but will need re-spraying to complete the suppression process if heathland regeneration is to be successful there.

Alan Irving

Warden Cleaver Heath

Heswall Dales

Here is some breaking news about our ‘sister’ Local Nature Reserve – Heswall Dales.

Historically, Heswall Dales and what is now known as Cleaver Heath were part of a single SSSI-designated area of Lowland Heath which was also home to Cleaver Hospital. Following the redevelopment of the Hospital site itself and rescue, by Cheshire Wildlife Trust, of the Northern part of the site, the two parts have become a little separated by some intervening private residential ownership.  Nevertheless, Wirral Borough Council who own and manage the 70 acre Southern Dales site and Cheshire Wildlife Trust who own the Northern (Cleaver Heath) site face similar problems in maintaining their valuable Lowland Heath status.

 A group of Dales conservation Volunteers have now started up a Friends of Heswall Dales support group (launched at Heswall Hall on May 31) to provide focus for support activities on what is locally known as ‘The Dales’. The contact address is friendsheswalldales@gmail.com

The idea is to ensure that the needs, hopes and expectations of all user groups can be met and in such a way that the conservation status of The Dales is properly protected. Like Cleaver Heath, Heswall Dales is a local nature reserve whose conservation status places a statuary obligation on its owners. It is not a park or other public space where users may have different recreational priorities. We wish the Friends of Heswall Dales every success in raising the profile of The Dales and helping local users to make good and appropriate use of this perhaps under-appreciated Wirral treasure.

Heather on the Dales