Friday, 7 May 2021

Out on the Downs

I was going to call this blog "A pair of Bottoms" but I have a feeling some visitors would have been disappointed in that I was referring to a geographical feature of the South Downs. Whilst I can find no accurate geographical definition of the word bottom, I assume that it literally means the bottom of a valley or the valley itself.

However, I digress. Another outing in the pilgrimage vein, keeping tabs on a couple of orchid populations that I have frequented over the years. I know I have done it all before but there is still excitement in finding little jewels that a vast majority of the public will never see and most of them wouldn't know an orchid if it fell on their heads. Both of the populations are tucked away - off the beaten track as it were. The first, Castle Hill reserve just behind Woodingdean is popular with dog walkers but even they decline to take the long walk on the far side of the reserve. I arrived at the car park about 07:20 well before everyone else and set off along the trail to Falmer Bottom. In the next three hours I met just one person - sheer bliss - a whole nature reserve to myself.  Having been before, the Early Spider Orchids were easy to find, even though this year, they are miniscule compared with other years. Lack of rain has left parts of the Downs parched, underfoot the grass is crunchy and dry. On the grassy slopes there are clear signs of what would be called overgrazing, I am sure winter grazing finished on time it is just the lack of rain that has failed to replenish the growth.

I reckon that I had seen a couple of hundred stems and there seemed to be plenty more to come. Though the numbers are down there are encouraging signs that outlier populations are being established away from the main site - time will tell.

Early Spider Orchid, Ophrys sphegodes

Early Spider Orchid, Ophrys sphegodes

Early Spider Orchid, Ophrys sphegodes

Early Spider Orchid, Ophrys sphegodes

Early Spider Orchid, Ophrys sphegodes

On the way back I recorded a couple of Small Coppers, one worn specimen was exhibiting blue spots on the hind wing - probably just sufficient to call it ab. caeruleopunctata 

Small Copper, Lycaena phlaeas ab. caeruleopunctata

Botany is not my strongest subject but I managed to record the well known Kidney Vetch, Anthyllis vulneraria.  Important as the sole larval host plant for the Small Blue Butterfly. However a small purple flower had me poring over the books when I arrived home.

Kidney Vetch, Anthyllis vulneraria

Common Milkwort, Polygala vulgaris

I returned to the car park and noted that I had been exactly three hours on the round trip.

Next venue was Anchor Bottom, access land between Shoreham and Upper Beeding. In a normal year there would be a thousand, probably more Green-winged Orchids on the southern side of this valley. Not this season, orchids few and far between and of diminutive stature. Still I managed to find both purple and pink forms. 

Green-winged Orchid, Anacamptis morio

Green-winged Orchid, Anacamptis morio

Green-winged Orchid, Anacamptis morio

Green-winged Orchid, Anacamptis morio

Green-winged Orchid, Anacamptis morio

Green-winged Orchid, Anacamptis morio

Green-winged Orchid, Anacamptis morio

Green-winged Orchid, Anacamptis morio

Green-winged Orchid, Anacamptis morio

Green-winged Orchid, Anacamptis morio

The rabbit population has increased fairly dramatically and grazing damage was evident, someone used to shoot here and this kept them in check.

On the way back to the car I noticed, on the grassy bank next to the road, a specimen of what I believe is False Oxlip, Primula veris x vulgaris, a hybrid between the Cowslip and the Primrose, large quantities of which were growing on the bank as well.

Tuesday, 27 April 2021

Pilgrimage to Rewell Wood

 This is a bit of a resurrection job as I published this blog several days ago and subsequently spotted an error. I corrected the error pushed the update button and lo and behold the lot disappeared into cyberspace, never to be seen again. Of course no back up so I have to recreate what was after all a small blog.

About this time of year for the past seven years we have made what has become a pilgrimage to Rewell Wood in West Sussex. Primarily to pay homage to that most scarce and beautiful of butterflies - the Pearl-bordered Fritillary, Boloria euphrosyne. I believe the attraction is that this is a butterfly that was "hanging on" when we first started but now, locally, is on the up.

We usually park up in the layby at Fairmile Bottom and take the walk over the hill, of late I am sure the hill is getting steeper. On the way there is great anticipation and discussion, will we find it, who will spot it first? Questions that almost distract you from the sea of blue created by the Bluebells that carpet the woodland floor. This year the season seems a tad late and the blue vista is just emerging.

Arriving at the favoured ride it wasn't long before Martin spotted our first specimen, a male on a mission, not stopping, careering along the ride in search of a mate. Times past there would have been the sight of two elderly butterfliers chasing after each specimen, hell bent on getting the perfect shot. Things are a little more sedate nowadays, we have learned patience and the reward is the satisfaction of gaining some not too shabby record shots. We hung around for a couple of hours and in that time we probably had a dozen butterflies, mostly males, some of which were freshly emerged and preferring to bask in the warm sunshine. Orange Tip, Brimstone, Speckled Wood and Peacock were the supporting cast.

I managed to record a Gooden's Nomad Bee, Nomada goodiana, a wasp mimic that is a kleptoparasite. These are organisms that take over the nest or nest cell of the target host species. The offspring then feed off the food supplies intended for that of the host.

In contrast to the blue of the Bluebells the Common Dog Violets, Viola riviniana and Bugle, Ajuga reptans provide a striking purple hue to the areas that have been recently coppiced. Both plants are important to the PbF, the violet as a larval host plant and the Bugle as a common source of nectar. I couldn't resist recording the violet as it is the county flower of God's Own County - Lincolnshire.

Taken on a previous visit


Thursday, 22 April 2021

Hail to the Emperor!

 Almost a year since my last blog, notwithstanding the trials and tribulations of Covid I just couldn't find the wherewithal to set pen to paper. Today I made my first proper foray into the field for many a long month. Way back in 2019 I planned that I would have a crack at finding and photographing Clearwing moths. Purchasing a full set of pheromone lures plus an additional lure for the Emperor Moth (Saturnia pavonia)  from Anglian Lepidopterist Supplies and several months researching likely sites I came up with a cunning plan. Then - all stop - lockdowns galore - no field trips - no photos and no blogs.

However, today all that changed as Martin and I visited a "Sussex Common" armed with two lures and a load of hope. I had read accounts of people using the lure and making irritating reports such as "I opened the lure and ten minutes later the moth magically appeared". Fat chance I thought but I was proved wrong, as we strolled along a track, lures clipped to our camera bags, two moths appeared, almost on the dot of the stated time. One disappeared after a short time but the other remained and perched nearby. Martin found it and of course it was in a position that was impossible for photography so the "moth wrangler" did the business and cajoled it  into resting in a more accessible spot. Great elation at achieving our goal, and as we progressed around the Common we were visited by even more and at one stage we had five in view at the same time.

Using the lure proved to be a steep learning curve, we will have to adapt our methods to be more moth and photographer friendly. The moths are only fooled for a relatively short time, driven to distraction by the pheromone it soon becomes apparent to the moth that there isn't actually a receptive female present. There are none of the added cues that a live moth provides such as movements and posture, so the male drifts off and does not return.

A big thankyou to Martin for helping me get back out there, on the way home I compared the day with having a "brain flush" Several hours of concentrated moth hunting and inane chat had removed a huge amount of mental clutter. I am not given to poetry but to quote Fernando Pessoa, as everyone does, "It's been a long time since I have been me."

Perhaps a go at the Large Red-belted Clearwing next, it has a penchant for birch stumps so there are some Sussex Commons and woodlands worth a visit and maybe another go at getting some improved Emperor photographs.

I hadn't totally given up on the natural world as I have run the moth trap in the garden during the lockdown, never a productive site and this year, so far, has been no exception. A Common Plume was hiding on a fence post, almost the same colour as the wood but definitely worth snapping.

Reports of White-tailed Eagles wandering around Sussex coastal sites have caused me to spend far too much time looking toward the heavens. This paid off with a fairly good sighting of a large female Sparrowhawk that frequents the neighbourhood. Sadly no sign of the eagle - yet.

Tuesday, 28 April 2020

Migrating Monarchs

Being self isolated has added to my knowledge of natural history - little did I realise how few species populate the garden and how slowly the populations change, or how many specimens fly in then immediately depart. Photographic opportunities are fleeting.

The  isolation has at least one upside, I can now catch up on processing a large backlog of photographs. Not least my trip to Cape May in New Jersey back in late September, which was primarily to witness the Eastern Flyway, but afforded me the opportunity to witness another key migration, that of the Monarch Butterfly, Danaus plexippus.

There are few true migrating butterflies, the two that immediately come to mind are Painted Ladies and the Monarch. Both occur in spectacular numbers and travel huge distances. In the Monarch's case millions migrate each year, all heading to one location - the forest mountains of central Mexico. A journey entailing distances of over 2000 miles. Of course the attrition rate is high, unable to tolerate prolonged freezes, many perish. However, the cool mountain temperatures in Mexico allow the butterfly to spend the North American winter in hibernation. In early spring rising temperatures break their sleep and they start the northerly migration, As the Milkweeds of Northern Mexico and the southern United states appear, the larval host plant, the females lay their eggs. It is the progeny of this first wave that will repopulate North America. Two or three non migratory generations occur - then, in the Autumn the migration begins again and this is what I was pleased to observe at Cape May.

Researchers at Cape May are monitoring numbers to learn how varying environmental factors are influencing the migration. A standardised census count is made three time a day between September 1st and October 31st. Thousands of Monarch butterflies are tagged each year in Cape May. The tags consist of small pieces of coded adhesive paper place on the wing which does not change the way the butterfly behaves or flies. Monarchs are not slow during the migration, one butterfly tagged in Cape May was monitored in Georgia three days later - a distance of 558 miles.

Come the evening they roost in huge numbers.

Reproductive hormones are turned off for the duration on the migration - these are just good friends.

"My Monarch"

I had the opportunity to have a lengthy chat with one of the researchers and my burning question was about the genetic make up of the population. Occasionally Monarchs turn up in UK, where they come from is anyone's guess, whether arrival from west or east or the abhorrent "confetti" - who knows. However, I had imagined that these butterflies and those sedentary populations on the Atlantic Islands would have significantly different ancestry. The answer - they are all genetically identical - the mind boggles.

Many thanks to the staff at Cape May for the information on the Monarch and their patience with an inquisitive visitor.