The Last of the Butterflies

-

 This week was supposed to be the last week of the year when I did my share of walking the butterfly transect at the nearby Waitby Greenriggs reserve owned by the Cumbria Wildlife Trust. There are set parameters for the transect and the weather has been too cold, too wet, and too windy to meet these conditions so that is me finished for the year. There are 4341 different transects that are walked every week in the summer by volunteers across Britain. Butterfly monitoring has been a "thing" in Britain since the early 19th Century and what we have is one of the longest running datasets in the World. The reserve at Waitby Greenriggs has been monitored since the early 1970s.

Because butterflies have a relatively short generation time, are easy to spot, and are sensitive to changes in the environment , they are perfect species to use as indicator species to monitor environmental trends (such as climate change for example). The results from our work at Waitby Greenriggs from this year are shown in graphical form here.

The reserve is not particularly special as far as butterflies are concerned. but one can detect some trends. This year, as is usual the biggest spike in numbers comes when the Ringlet butterflies hatch.( Last year bucked the trend when we had an explosion in the Peacock butterfly population). We didn't get the usual spike in painted lady butterflies this year - as they migrate from the continent that might have to do with wind directions or climatic conditions in North Africa and Spain. As I have recorded in the blog I spotted one Scotch Argus butterfly this year and they haven't been seen here since the 1990's. Anybody interested in the National trends can register with UK Butterfly Monitoring and dig down into the publicly available data.
The day after I posted this a newspaper article in the Guardian showed results of a survey showing that butterfly numbers this year are at a record low. Peacock butterfly down by 63% on last year.
Guardian

Diary
In between the rain showers yesterday I saw one speckled wood butterfly in the garden. Interestingly not a single speckled wood was counted on the reserve this year which is only 500m away from us. It has rained and rained over the last 24 hrs. I saw a couple more dilatory swallows in torrential rain this morning as they made their way South. Last night's camera trap revealed the usual rabbit count and one bedraggled looking fox.


Comments

Post a Comment

Popular posts from this blog

The Dunnock

-
Image
 When I was a boy my first bird book described "hedge sparrows" but at some time in the last 50 years this name has all but disappeared and these birds are now called dunnocks (as they are not closely related to House and Tree Sparrows) Its easy to miss a dunnock! They are little brown birds and they tend to feed on the ground and keep to the cover of vegetation if they can. The males are territorial and the birds pair up in the spring. The pair are not strictly monogamous and the female will mate with another male if she gets the chance. DNA testing reveals that a brood often has more than one father. The male dunnocks are alert to this possibility and can sometimes be seen pecking at the cloacal opening of the female in an attempt to get her to expel the sperm of the competitor. The sexes look alike and these birds are common and widespread in Britain. The males get involved in feeding young according to their breeding success so it is common to find two males and one femal...
Read more

White Clawed Crayfish

-
Image
 I went for a walk yesterday that took me along the Scandal Beck (a tributary of the River Eden). On the banks of the river was a stone that had obviously been used as a picnic table by an otter and the remains of his meal were strewn about. A recognisable part of the leftovers is shown below. It's clear that this claw comes from a white clawed crayfish. These animals are not common in the UK as they need the water to be rich in calcium. This requirement is fulfilled in the Eden valley by the limestone substrate. I think that the River Eden is as far North as theses animals get. I know that there are crayfish in this part of the system because for a number of years I have volunteered with the Eden Rivers Trust to survey them. It was not uncommon to find a couple of hundred animals in a 300m stretch of river. The following images give an indication of scale. In recent years the population of the native white clawed crayfish has been threatened by the arrival of the invasive signal (...
Read more

Otters

-
 Well another Covid lockdown! As I am confined to the local area I have been having a closer look at the local wildlife. I treated myself to a trail cam and started to see what I could find. After a couple of experimental sessions to get to know the kit I set the camera along a fence line by an old railway track. On the first night I was astonished to get footage of an otter carrying a rabbit! The site is at least 500m from a watercourse which is a drainage ditch that eventually flows into a tiny tributary of the River Eden I hadn't realised that otters eat anything other than fish but apparently they do. I wonder why the otter was carrying the rabbit rather than eating it where it was found. Perhaps it was feeding young? Apparently ottters have young throughout the year. I have only seen an otter near the house once before and that was a late night encounter in the car headlights.
Read more