Spring seems to have arrived several times this year – the temperatures rose, then dropped, rose, then dropped and so on, with bouts of hail, rain and snow and just a bit of sunshine. This has had obvious implications for our visitors both human and wildlife.
Avian migrants
I have been keeping tabs on the arrival dates of our spring visitors from the south - these notes are being written at the end of April.
In order of arrival, I have observed singing Chiffchaff from March 25, Willow Warblers from April 8, pairs of Swallows at Oldfield Farm also from April 8 and singing Blackcaps from April 15. House Martins appeared locally on April 26. I have not seen or heard Whitethroats yet at Cleaver although they are already around elsewhere on Wirral. These photos are of ‘Oldfield’ Swallows and House Martins. The poor weather is presumably responsible for the roughly 10-14 days delay of most warbler arrivals compared with 2017. However, the Swallows bucked the trend by arriving a week early this year! I began this year’s Common Bird Census at Cleaver on April 5. I described the technique in last year’s Early Summer Newsletter. Basically I make 10 visits (roughly every week) noting on a large scale map where I see or hear the birds. The idea is to get a picture, for each species, of where the territories are. I reported the outcome from last year in the Late Summer Newsletter.
This year, the numbers so far seem to be quite a bit down. One new feature this year has been the observation of a few Collared Doves. These are quite common on Wirral but are a first for Cleaver Heath. Note how dainty they are compared with a Woodpigeon. There is no white on them, just a half collar of black. They have a wheezy flight sound rather than the clumsy clapping of the Woodpigeon. Their song is Coo-Coo-Coo rather than Coo- Coooo- Coo- CooCoo.
We will be holding our annual Dawn Chorus Walk on Cleaver Heath and Heswall Dales on Sunday May 6. This is an opportunity for us all to brush up our bird song and call ID skills and also marvel at one of nature’s spectacular sound spectacles.
Butterflies
If the crazy spring weather confused the birds, it was even more confusing for the butterflies. Nectar- bearing plans have been well behind schedule while the low temperatures and high rainfall have had also inhibited flight for the early butterflies including those over-wintering as butterflies (e.g. Peacock) or as pupae (e.g. Green-veined White and Orange Tip). We started our Butterfly transect survey on April 5 and the total sightings in the first 3 weeks were 0, 1 and 2 respectively! The three species seen were the three mentioned above. Last year, the corresponding 3 weeks resulted in sightings of 2, 9 and 6 respectively. We are currently struggling to find days in each week when the weather is butterfly-friendly. Today, the last day of April, it is 6 degrees and wind force 4. I don’t feel I should have to wear a woolly hat and gloves while I do a butterfly survey.
Plants
This month we completed the botanical survey of the reserve started in 2016. This meant gaining access to the NW corner of the reserve before the bracken started to grow tall again. There was little new there to add to our existing tally of around 140 species of plants, shrubs, trees and mosses. We keep records of species in each habitat area of the reserve as a way on monitoring its health and suitability for supporting wildlife.
The first bracken shoots are now pushing through. It does look like the annual Asulox spraying is having an effect.
These photos show the same area in July last year before spraying (left) and as it looks now at the end of April (right). If there are new shoots there, I have not yet found any. The green and red shoots you can see are rosebay willowherb and bramble.
As far as the heathland birch control is concerned, it is also a bit early to assess properly the effectiveness of our stump treatment over the autumn/winter. However, I can just about convince myself that there is a difference in the extent of regrowth in those areas where we treated and in those where we didn’t get it done.
This photo shows quite vigorous birch regrowth at the edge of the upper heathland where the stumps were deemed too small to cut and treat as compared with the surrounding area where we did treat. There are a few multi-stem stumps in the foreground which seem to have succumbed. The real test will be in the autumn when our work groups go over each heathland panel systematically. Will we have less work to do this year? I hope so.
The dominant colour (and smell) on the reserve is currently provided by the European Gorse which is also providing nesting cover for the birds. The various shrubs and tree species add their own shades of green as they come into leaf. The ex-car park area is starting to look really colourful with whites, yellows and blues all around. The forget-me-nots are quite spectacular. What we really want now is some more warmth to bring out all the butterflies and other insects to take advantage of them.
Alan Irving
Volunteer Reserve Warden for CWT
Cleaver Heath
April 2018
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