Life of a Chalkstream: Beware the yellow peril

Greetings!

Just when you think you know it all along comes an email which makes you think, how dumb can I be?

Recently, we’ve hosted an invasive plant species survey that is being conducted across the Test and Itchen catchments by the Wessex Rivers Trust. Over the years I reckon we’ve been pretty good eliminating the likes of Himalayan balsam, so it came as a shock to find out a plant we’ve nurtured as a bright splash of June yellow is Monkey flower, an unwelcome invader from far shores.

First there was one ......

Yes, we’ve being strimming around it, giving it space and generally being nice to Mimulus guttatus who’s natural home should be the western states of America and New Zealand. Apparently unknown to us chalkstream types, it is something of a star in botanical circles, the subject of over 1,000 scientific papers being what is referred to as a ‘model organism’ a species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms.

It is certainly pretty clever at being invasive. One seed begats a single plant of this bog herb which in turn spreads an extensive root system that will unnaturally narrow any stream or river whilst crowding out the native marginal plants.

The good news is that Monkey flower is relatively easy to eradicate without chemicals or machinery, pulled out by its roots to be composted into oblivion. So, no guessing our first job on the river next week.

You can check out invasive plants on the excellent Test and Itchen Invasive Non Native Species Project website.

.... and then there were many

Hedgehog roll

My piece last time on roadkill prompted many comments, some ruminating on why we see so much death on our roads. My guess, for what it is worth, is that it is due to the number of cars on the road increasing by nearly 5 million since 2000, a rise of close to 20% to over 32 million. So, with country roads taking a disproportionate bulk of the increase, it is a statistical certainty that more cars will equal more animal and bird deaths.

However, as others mentioned, hedgehogs are seen to be killed in far fewer numbers which is, paradoxically probably not a good thing as the population continues to plummet. Why? Nobody knows for sure. Hard facts are hard to come by, but one estimate has the population at 30m in the 1950’s down to 1.5m today, with a 50% decline since the turn of the millennium. Badgers are blamed. Roads as well – 10% are killed this way annually. Reduction in habitat with an increasingly segmented landscape partitioned by roads, fencing and impenetrable barriers. And, of course, the use of pesticides both in farming and gardens which kills the insects and bugs on which hedgehogs depend.

So, despite all that gloom, on the subject of our spiky friends, you might rather like this night cam clip sent by a reader. The roll we suspect is the hedgehog rearranging his or her quills after forcing itself through the narrow opening.

In search of the Southern damselfly

Some of you may have had reason to curse the Southern damselfly, a rare member of the dragonfly clan, not found in many places these days but it does hang out (allegedly) on the River Itchen at Breach Farm.

Its preferred breeding ground is soggy banks, pock marked by the hooves of cattle. Sound familiar to those of you who have fished the eastern bank on this part of the Itchen? Ordinarily, we would fence it off to keep the cattle out but at the behest of Natural England we leave the cattle to do their worst for the best life chances of the Southern damselfly.

Southern damselfly

June, into early July, is the prime time for these dark vivid blue creatures, that flutter in huge numbers amongst the margins of the riverbank in preparation for egg laying in the boggy water where, like our favourite Mayfly, the larvae spend two years before emerging as damselflies.

The trouble is I can’t tell you what I saw. Yes, my hunt threw up damselflies in profusion but when it comes to differentiating between your Common, Variable, Azure or Southern variant my eyes failed to spot what the online guide calls the “distinctive mercury shaped marking on segment 2 near the top of the abdomen.” Err, so I’m looking for a black marking about 3mm long that resembles the astrological symbol for the planet Mercury. Well, it might be distinctive to some but to me not so much.

Regardless, I did get to take a reasonable photo of what may or may not be a Southern damselfly (the above I've stolen from the internet) and admire close up the wild orchids growing in the margins.

Lady orchid (Orchis purpurea)

River Test - Private water

Just occasionally I have a few days on this private beat of the River Test between Longparish and Whitchurch.

With 1.5 miles of double bank, with a variety of bank and wading fishing, on the main river and carrier, there is plenty to go at. It is available for three Rods on Sunday 24 July. The cost will be £435/Rod. Additional Rods over and above the three might be possible.

There is a very comfortable fishing cabin. Please note this is a dry fly only water. Email for more details ….

That was the month that was June

Well done to Bob Ibell who wins the June snood from the Feedback Draw having fished at Fisherton de la Mere on the River Wylye.

Despite the copious thunderstorms of late we are in a distinct dry spell. For rain nerds like myself here’s a nugget: in the seven months November-May rainfall has been the 5^th lowest since the records began in 1891. The rivers are holding up for the most part, though I’d say they have more of an August than July look.

As regards a Mayfly retrospective the consensus was that 2022 was a good year, fairly typical in timing and profusion. As I write, there are still the typical sporadic hatches on the Avon attachment and I even witnessed a brief evening flurry of a Mayfly rise at Bullington Manor last week, which was rather fun.