Ringlet

The Ringlet, Aphantopus hyperantus

Ringlet butterflies are not particularly easy to locate in Hadlow, but these slightly tricky to spot butterflies are a great pleasure when you do see them! The most likely areas for me to find them in previous years have been along the rides and the two triangles in Dene Park in July, and others may know of other good “hotspots” in the parish? In 2019, I found them in new areas of the parish, and in much greater numbers than I have previously seen them. Have I just not noticed these in the past, or has been a significant increase in the Ringlet population and distribution in the parish this year?

Description

This delicate beauty is a bit difficult to pick out from the much commoner Meadow Brown initially, but is generally just a bit darker. The darkest individual Ringlets are fresh males which might seem almost black, contrasting clearly with the narrow white wing edges when you get a good view. Females in general are very similar but are a bit lighter and browner than the males. The dark wings and reputedly neater flight pattern of Ringlets may be enough to separate them from Meadow Browns with a bit of experience I am told. But both genders also seem to become a little lighter over time, and it is often necessary to get good close views, hopefully seeing the “ringlets” on the underside of the wings, to be absolutely sure that you are actually looking at a Ringlet, and not a Meadow Brown.

Sometimes the best way to spot them can be their behaviour. Dark brown butterflies jinking neatly a few inches over clumps of grass in a slow determined manner might well be the males, looking for females. I haven’t seen Meadow Browns doing this in quite the same way. Ringlets will also often rest on shrubs, brambles or other vegetation wood edges about a metre up, perhaps with other butterflies such as the Meadow Brown and Gatekeepers. Ringlets may also be seen competing for access to flowers, such as bramble, thistle and others, feeding off the nectar available.

This male, in pretty good condition, was resting on the grass of the second triangle on the standard circuit path around Dene Park. This is a photo of the top, darker, surface of the wings, spoilt by a grass leaf, but it will have to do until a better one come along.

This is the same male, showing the under, browner, surface of the wings.

Although quite early in the flight season, this one, found on its own on the southern edge of Monkdown Wood, Bredhurst, seems to have had a sizeable chunk taken off one of its fore-wings, presumably by a large-ish bird.

Distribution

One of the really nice things about Ringlets is the challenge to find and accurately identify them! In Hadlow there is apparently at least one colony within Dene Park, in the small triangles of grass and herbs on the near and far side of the wood from the car park, and along the rides. I have found them there occasionally, in ones and twos in 2011, 2012 (photo below), 2013 and rather more in 2017, and 2019 for example. I also think there might be some in the privately owned damp grass field to the north of Dene Park, which might be visible from the public access to the edge of the wood, and some in the drive west from the wood towards Shipbourne Road, both of which are just outside the parish. In 2019 I also found good numbers of Ringlets in the hedge/shaw next to MT133 running south from Clearhedges Wood towards Stallions Green, and also in the hedges alongside MT133 along the access trail, and then MT136 alongside the Bourne, past Bourneside Farm and towards Victoria Road. Is this a population boom, or have I just missed them there before?

The butterfly is stronger in the south but can now be found throughout most of Britain up to the highland line, with some patches of absence, such as the northwest of England, where it may still not have re-established after the heavy pollution of the later Victorian period. It is widespread throughout Ireland.

Research in Eastern England indicates the importance to a dispersed colony or meta-population of keeping the rides between the glades open to allow interchange of genetic material. The rides in Dene Park are perhaps a little too shady to greatly encourage this butterfly to explore sufficiently far away from the sunny spots where it is generally found. That’s a personal opinion of course.

However, I am sure that I have missed others, and any mix of grass and nearby woodland, scrub and even hedges on heavier moister soils might hold another colony.

The supposed best time of year, when most butterflies are flying nationally, is said to be about the third week of July, but anytime from the beginning of July seems good in Hadlow.

This photo (above) is light enough to be a female or a very worn male.

In the wider UK Ringlets may be found across most parts of the country, except some swathes of NW England and all of the Highlands of Scotland, again particularly in damper grass sheltered from drying out by woods, hedges and ditches. This species of butterfly can also be found across the middle latitudes of Europe and into Asia, with a number of different subspecies.

As a moisture and shade-loving species the Ringlet has increased significantly in distribution and abundance as woods have become denser, shadier and therefore moister over the past five decades. A reduction of some air pollution factors might also have helped. In Victorian times soot in cities is thought to have led to an overall reduction at that time, and local extinctions in and around cities. It is also a possibility that decreases in soot may also run more or less in parallel with increases in nitrogen deposition, which favour the coarse grasses on which Ringlet caterpillars depend.

However apart from habitat changes, climate change is thought likely to have a tendency to reduce Ringlet numbers, as summers become on average drier and the chance of summer drought increases. IN 1976 there was a very hot dry extended summer and numbers crashed temporarly, reecovering well after a couplre of wetter summers. In 1995 the very dry summer reduced numbers of Ringlets temporarily the following year, but the species recovered again over the next few moister years, returning to its gradual upward trend. Could it be that the numbers of Ringlets might be even higher if climate change was not occurring?

Life cycle

The adult butterflies can be found flying from the end of June until the beginning of August, the males perhaps searching doggedly for the females in their characteristic manner. The average life expectancy of an individual male butterfly is in the region of 10 days.

The females invite the males initially, mate once, and then reject further male advances. In this species there are no nuptial gifts donated by the male during mating, and therefore there is no nutritional benefit to the female of mating more than once. Once mated the females squirt out or drop the somewhat triangular initially whitish eggs onto or near grass, possibly in response to chemicals released by fungi infecting the grass, and the caterpillars hunt out suitable infected plants of a particular species of grass to feed on. On any one site it seems that just one species of grass is used. Grasses preferred are supposed to be lush tussocks of ungrazed Cock’s-foot and False Brome. These can be found along the rides in Dene Park.

The light brownish caterpillars live for about 10 months, hibernating between September and March while still small, after the second of four moults, until after starting feeding again, they form a little chrysalis in about May deep in their grass tussocks from which the adults then emerge. Just before pupation, searching tussocks of grass with a torch for the greyish caterpillars as they feed off the leaves at night may produce some results.

It may be that the adults retain some of the toxins that they absorbed from the fungi in the grass which the caterpillars ate.

Oddities

The pattern of spots may be quite varied – it would be very interesting to hear of any odd patterns you might find!

This rather worn individual is showing good visibility of the eyes on its upperwings, but some possible damage to its thorax:

This individual though is only showing relatively small dots on its upperwings:

The exact pattern of spots on the underwing also varies. In several of the individuals above, when you look at the rear underwing spots 2 and 4 are noticeably larger and more obvious than spots 1, 3 and 5, and this is the pattern you see below. However in one of the individuals above, the spots are far more even in size and brightness. What this means genetically I have no idea, but there has been a lot of genetic research into spot pattern in other butterfly species, particularly the Meadow Brown.

Predators and parasites

Lots of birds might have a go at these, despite the assumed content of toxins. Trombidiid mites may infest the butterflies from time to time, infestations lasting for 2-3 days on average. These external mites appear to have little impact on the butterfly’s abilities to fly and survive.