Biodiversity Newsletter April 2012

Transcription

1 Biodiversity Newsletter April 2012 Stratford Park woodland (photo Mike McCrea) Hi All, There are no two butterflies more symbolic of spring than the Orange tip and Brimstone (above). Both of these lovely butterflies are on the wing this month. The Orange tip can be seen along the stream on sunny days where its food plant Cuckoo flower grows. The Brimstone is a species which hibernates through the winter as an adult butterfly, emerging during the first warm days of spring. Many of you sent positive comments about the addition of photographs in last month s newsletter. As we approach the busiest months for biodiversity in the park, I hope to add photos of some of the more interesting wildlife as it is recorded. The addition of photographs initially came with some teething problems regarding the size of files being ed, and some of the usual recipients were unable to open the document. However, Kevin Ward (Museum in the Park), provided me with helpful advice with compressing images and files, so all future newsletters should be transmitted and received without any problems. It is always good to see the park staff working with nature to help wildlife, and this was never better illustrated than seeing our pair of swans building their nest with the material we placed in

2 February. We have been accommodating a Hartpury college student (Stuart Cooper) for 2 days each week, who is studying for a degree in conservation management. Stuart has recently constructed a second owl box and several smaller boxes to add to the park s collection of nest boxes, and will also be assisting me with recording and collating data on the butterflies and moths. Most of the bird boxes are now active with nesting birds, so a walk through the park this month will yield much to see. Our woodland management work has now concluded until the autumn, and will resume then with proposals to develop the pond in the beech plantation. Enjoy the park and its wildlife this month. Mike News from the Supervisor s Trap Wildlife pond (update) It is now almost 2 years since we excavated and created our new dipping pond, so how has it developed since then? Well, slowly is the answer. With a constant flow of fresh oxygenating water, the pond has remained quite clear. Circulation from the inlet pipe prevents stagnation but is also of a diameter that does not wash away valuable nutrients during times of heavy rainfall. As a result of this, water is fed through the pond and into the lake at a steady rate. An overflow which is fed into the adjacent stream stops the pond from overflowing during flash floods. When we created this new pond, I based the hydrology and engineering on my past experience in the swimming pool industry. Having spent many years dealing with ground water, springs and high water tables the new dipping pond posed an interesting challenge, and diverting the natural spring water into the pond on route to the lake proved a feat of testing engineering for me, and

3 the staff assisting. Constructing the chamber and weir that regulates the flow from pond to lake, was in itself a challenge, with inlet and outlet pipes having to be installed with the aid of a laser level. In retrospect this was the easy part. Maintaining a healthy ecosystem within the pond has been more challenging. A multitude of aquatic wildlife has been introduced into the pond from frog spawn, sticklebacks and other small fish to water beetles, snails and other invertebrate life. The perimeters have been planted with marginal plants which have been difficult to establish due to the disturbance and foraging of Mallards. Dog walkers who allow their dogs to enter the pond inadvertently stir up the mud and sediments causing root damage to aquatic plants. The pond has also seen its fair share of vandalism, and although it is always mentioned with reluctance, it is nevertheless a fact of life. To counter-act structural damage, we bedded the top course of stone around the pond with mortar, and this appears to have stopped damage. A closer look into the water will reveal hundreds of small fish and other organisms, so we know that some form of establishment is taking place. The pond is also popular with families and children. Although the pond is still going through transition, the disturbance by ducks, swans and dogs is restricting that establishment. Perhaps the answer is to protect the developing wildlife by way of covering with mesh or other protection until all organisms have developed to a stage where natural predation and disturbance has less impact on the ponds natural balance. The answer for now is to monitor the pond taking into consideration the foregoing concerns, and introduce some protection measures later in the year. Regardless of this, during the coming months, the dipping pond will provide interest for all those visiting the park, and with the advance of the surrounding vegetation, provide an important niche for the park s biodiversity. A pond dipping event in Stratford Park April 2011 (photo Mike McCrea)

4 Stratford Park springs into Bloom at Burton on Trent The Westside leisure centre Burton on Trent was the venue for the 2012 Britain in Bloom spring seminar sponsored by the Landscape Group. An attendance of around 200 was given presentations by the Landscape Group and British Flora. Stratford Park provided the case study presentation within the Landscape Groups address to the audience, and I was asked to fulfil this duty, which initially was a little daunting. However, any opportunity to promote the park and its biodiversity is an opportunity not to be missed, so I travelled to Burton on Trent armed with the appropriate information. The presentation covered 4 key elements relating to what we are doing in the park, Conservation, Development, interpretation education and communication. Attempting to condense 3 years work into minutes is always going to be difficult, but these areas were covered starting with the measures being taken to conserve existing wildlife and habitats within the park, then moving on to how we are working with SDC to develop and manage the woodland and other green areas. This included a brief overview of the Stratford Park Landscape and Management action plan presently in place. Following this, I then moved on to discuss how we are communicating and informing the public of our work, before finishing with a section about how we are educating the public through events held through the museum in the park. The power point presentation showed pictures of park staff carrying out woodland management work, and images of the varied wildlife found in the park. I left the venue hoping that this presentation might be a prelude to a Gold Stroud in Bloom award this year, but I suppose that we will have to wait until September for this. (Stratford Park represented at the Heart of Britain in Bloom Spring seminar Burton on Trent)

5 Some notes on the larval food plants of Scarlet Tiger On the wildflower bank In the January newsletter, I mentioned that over-wintering caterpillars of the Scarlet tiger moth had emerged early and were feeding on new shoots of comfrey on the wildflower bank. I recall also, commenting that a late cold snap can have an adverse affect on wildlife. On inspecting the bank at the end of February following a very cold snap of weather, I noted that frost had killed back the comfrey that the caterpillars were feeding on, and that no caterpillars were in evidence. At that point I was gravely concerned that our colony may be wiped out. How wrong I was, and how pleased I was that nature is so adaptable, when on the morning of 16 th March I again checked the bank to find many larvae in the next stage of moult, feeding vigorously on stinging nettle and teasel. In the previous years of monitoring this colony, the only food plant taken has been comfrey, and no roaming onto other food plants has been noted. It is widely know that the Scarlet Tiger will feed on a wide range of plants within its range, In the case of a colony in Standish Woods the sole food plant is bramble, however, in the case of our colony, it is clear to see that when a food plant becomes unavailable due to the impact of adverse weather, the small larvae will retreat into the leaf litter and re-emerge in suitable conditions to feed on alternative plants. This has now prompted me to monitor the larval feeding habits of the species more closely in future. (Scarlet tiger caterpillar wildflower bank Stratford Park Photo: Mike McCrea) Long-tailed tits nest in works Compound Long-tailed tits have been observed building a nest in the works compound. The nest discovered by Adrian Watts (park staff), was found on 19 th March, and is located in the bramble hedge that divides the compound from the adjacent car park. Long-tailed tit nests are

6 notoriously difficult to find as they are often built deep inside dense hedges and camouflaged with an outer layer of lichens which the birds spend many days building. Only one previous nest has been found in the park, but the park supports a healthy population of Long-tailed tits, which are often supplemented in winter by continental birds. The nest of the Long-tailed tit is one of the most beautifully built and ornate of British bird s nests. It is dome shaped and lined with thousands of feathers and hairs. Past research into these nests has shown that up to 10,000 feathers are used to line the inside, demonstrating a feat of engineering for such a small bird. We have been watching the birds take feathers to the nest, which is carried out by both sexes. At the time of writing, recent nest boxes placed by our works compound are already occupied by Blue tits. Long-tailed tit nest Beech plantation works completed Park staff has completed the first phase of woodland management in the beech plantation adjacent to Salmon springs. The work, part of the 10 year Biodiversity and landscape action plan for Stratford Park has involved thinning the beech plantation to create more light to the under-storey, clearing fallen debris and removing invasive trees and shrubs such as Holly and Yew. Much of the timber felled has been sold, and the funds from this will be re-generated into the park by SDC. The Landscape Group have invested in training, equipment and PPE to facilitate this work, using park staff. Now that the wild bird nesting season is well underway, all activity in the woodland will be halted until the autumn. Also during March the council s own tree maintenance contractors have carried out a site survey to identify any diseased and dangerous trees throughout the park. Sadly this involved the felling of one of our Monkey puzzle trees by the orangery, and a large mature beech on the woodland edge. Both trees had suffered from stress

7 due to recent dry summers. The Monkey puzzle will be planed and used for wood turning and perhaps tables and other furniture for the park. (Woodland management work being carried out by Landscape Group staff Photos Mike McCrea) Warm weather produces Hummingbird Hawk Moth On what was probably the warmest March day in many years, a Hummingbird hawk moth was seen by the Bowling Green on 26 th, a very early date for this species. The moth is an immigrant species usually arriving from Northern Africa and southern Europe during periods of high pressure in late summer. This moth undoubtedly arrived on thermals of warm air, during a month that has seen very high temperatures in the UK. Hummingbird hawk moths have been sighted in the park in previous years, and particularly during the heat wave of The majority of records are in September and October, but a March sighting is very unusual. (Hummingbird hawk moth Macroglossum stellatarum)

8 Observations from Adrian Watts (Park Staff) Adrian has confirmed a very busy month with the following observations and records Blackcap 20 th March, Mistle Thrush 21 st March, Treecreepers building nest by the orangery behind bark in a Wellingtonia 22 nd March, Bullfinch (female) by the bowling green 25 th March, and again in the walled garden on 14 th March. First Chiffchaff heard in the woodland on 28 th March, Little owl observed fighting with Jackdaws in the walnut tree on 16 th March and 2 Lesser Black-backed gulls by the play area 27 th March. 2 Herring Gulls have been present on the lake during March and a pair of Kingfishers has been fishing regularly on the lake during March. Adrian s Coot nesting platform is being used by the pair of Coots on the lake and Mute Swans have laid 1 egg on the island. Wildlife to see now, in Stratford Park BIRDS: April has so much to offer in Stratford Park for the bird enthusiast. The Park and woodland is alive with nesting birds, Blue tit, Great tit, Nuthatch, Treecreeper, Goldcrest, Chaffinch, Blackbird, Song Thrush, Jackdaw, Magpie, Rook, Carrion Crow, Mallard, Mute Swan, Coot, Great-spotted woodpecker, Robin, Wren, Dunnock and Wood Pigeon. The best place to see the birds in numbers is by the orangery and throughout the woodland, especially along the stream. Visit the park early in the morning to see and hear the park s Nuthatches. MAMMALS: Red Fox 2 new earths have been found in the far woodland by Salmon Springs and beneath an oak above the play area. Fresh bedding has been discovered at these earths indicating that cubs will be born soon. Sadly, in Callowell fields, a female fox has been observed suffering from a severe case of mange. Park staff has consulted the RSPCA and is providing food for this fox whilst a long term solution is sought for controlling the problem. INSECTS: Scarlet tiger moth - The colony on the wildflower bank is doing very well and all larvae are healthy. The first Brimstone butterflies have been on the wing, and Small tortoiseshells are starting to emerge and lay on stinging nettle. Some early Green-veined whites have been seen along the stream. The hoverfly, Bombylius major is showing by the bowling green. This stunning hoverfly imitates a bumblebee. Among the moths recorded at the park s moth trap this month are Hebrew Character, Small Quaker, Oak Beauty, Diurnea fagella and Anticlea derivata (The Streamer) a new species for the park. To Look out for: Watch for Kingfishers on the lake. Grey Wagtail is present on the lake. Look for Goldcrest in the large Cedars. Most of the bird boxes are active. The camera box is sited on the red brick walled garden wall by the museum. See live footage of the nesting birds in the museum.

9 Contact: Mike McCrea Tel: Links: A beautiful sunset over Stratford Park (Photo Sharon Tucker)