Transect

Reports

2020

A year with a record breaking early spring followed by a wet windy summer made for a mixed year

Overview

The season was rather dominated by the pandemic and we were unable to record for the first 6 weeks of the 26 week recording season but a majority of recorders managed to restart in May or June and then put in their normal number of walks. We apprecaite the charities suffered and staff were furloughed and unable to undertake their duties. We hope they will be back in 2020 as the last lockdown comes to an end but prepations are behind and may make it difficult to repair some of the losses in 2021 .

The Weather

After a very wet warm autumn in 2019 with floods which returned in late February to be promptly followed by lockdown 3rd week of March! At which point the sky cleared to weeks of glorious sunshine and record breaking temperatures. Few can remember such an early and protracted spell of fine weather through April and then into a heat wave in May. As a consequence of emerging very early was we were not there to see them and some were already in decline or had finished before our first recording day in mid May, as the lockdown rules were eased, and transect walking was allowed once again. By this time the heatwave had really set in, the ground dried and cracked and dryer grasslands suffered badly with plants stunted and withering lower leaves. The spring early summer species were emerging nearly 10-14 day early with 23 species in the UK recording their earliest ever emergence: an exceptional year. Hopes were high that unlike 1976 the heat waves of 2019 would not be followed by a disastrous decrease in numbers of 1977. It has not repeated; and most species came through although there were more losses than gains. .The weather broke in the first days of June and went in reverse with a cool June and a conveyor belt of Atlantic storms which pock-marked the rest of summer. The summer in many ways was a disappointment after 2018 and 2019 but there were good spells between the storms. Finding good days with sunn and temperature were often hard even in high summer. The end of the season was average

The Results

A Summary of all sites was prepared in spreadsheet form. For each site the percentage change from the 5 year average is shown for each species. The number of negatives and positives are then totalled and the the first conclusion was many more species were negative (14 ) that positive (9) with 3 uncertain.

As ever there is a good deal of variation you might expect for a biological organism but still we can draw a few trends and use them when interpretting each transect later.

The golden skippers were both down alot which could be weather related as they prefer longer grasses which had their growth stunted in spring 2020 particularly on dryer limestone sites of the tabuler hills like Pexton Bank . In contrast after the winter flooding on some sites in winter you can pick out some increases on wet sites.

Large and Small Whites were up a little maybe with the good spring and a second generation but there was considerable variation between sites. In contrast more moisture loving Green-viened White was somewhat down particularly on the dryer limestone sites. Due to the necessity to estimate during lockdown 1 we cannot be certain about Orange tip or Green Hairstreaks.

Small Copper shows no pattern and although strong differences as does Brown Argus and Common blue a slight decrease but witha good deal of variation. Holy Blue was down if a little uncertain due to teh smal sample size.

The Vanesids were interesting with the migrant Painted lady nearly absent and Red Admiral well down along with Comma. Peacock also showed a slight decrease but the highlight of the year was all sites had many more Small Tortoiseshells which had a boom year on many sites.

Dark Green Fritillary had a good year while Silver-washed on one of its main sites Bishop Wood was average, but sample size makes thes conclusions uncertain

Possibliy for the same reasons the drought probably played a part in the Skippers and Green-veined White being down Speckled Wood suffered bad losses in 13 out17 sites and Wall Brown suffered equally badly

The Browns in general were a mixed bag with the courser grass loving species not fairing so well with Ringlet down in 11 of 18 sites and Gatekeeper down in 6 out of 8.

In contrast Meadow Brown emerged well with increases in 11 out of 18 while the fine grass loving Small Heath had a very good year only down on the thin limestone soil at Hawnby.

Transect reports 2020