Small Skipper

The Small Skipper, Thymelicus sylvestris

The Small Skipper is a low-flying and often missed small orange-brownish butterfly that many people initially just don’t notice, or assume is a relatively nondescript day-flying moth. And yet there are probably quite a few in the parish, leading their complicated lives in full sight if only we care to keep an eye out for them. Although not actually the smallest of the skippers, The Small and Essex Skipper are the two almost identical species of smaller skippers found in and around Hadlow, to be compared to the significantly chunkier and more patterned Large Skipper which is more commonly found in the parish than either. Patches of long grass might hold individuals of all three species.

The first Small Skippers emerge early in June and the last tattered individuals last until the end of August. Most are seen nectaring on the flowers or jinking in amongst long grass, and the ones seen generally represent only half the population – the males. The females are inconspicuous, and spend much of their time on the ground, only flying occasionally to feed or lay eggs. 

Description

The Small Skipper is a little smaller, brighter and less patterned than the Large Skipper, but holds its wings similarly, “like a half-open book”. This one was photographed in the parish south of the Medway.

Photographed at The Hop Farm, on the 20th of June, 2014.

The forewing of both the Small and Essex Skippers has a narrow but clear brown line on the rear margin. The way to separate the Small Skipper from the Essex Skipper is to examine the underside of the antennae tips – they are orange in the Small Skipper but a clear black in the Essex Skipper. The butterfly below is therefore a Small Skipper!

Most of the time however all you can see with naked eye is the golden flicker of wings through the long grass, or a small triangular golden shape feeding off a knapweed or other flower!

But when you get closer you can see detail such as the two palps in front of the antennae:

Distribution

Good places to look for Small Skippers in the parish are the small rich meadow just off the footpath MT136 across the River Bourne, the wide headland of long grass on Fairlawne land seen from the footpath from Carpenters Lane just beyond Hope Cottage, the long grass by the hedge to the east of the reservoir beyond Malt Cottage, and in the grassland south of the Medway, in fact any patch of long grass not cut too hard back each year.

Here is an apparently very good patch of habitat for Skippers in the parish – a “hay field” allowed to grow long and flower fairly regularly in the west of the parish. Look for Small or Essex Skippers in the hedgerow bases just off the footpath crossing this field.

The Small Skipper is confined to the southern half of the UK, but has naturally expanded its range over the past three decades by about 60 miles, nearly to the Scottish border, possibly as a result of global warming. Experimental introductions into apparently suitable sites north of the natural spread were successful, indicating that the Small Skipper could be spreading faster if it were a more naturally mobile insect. This could indicate that artificial movement of butterflies could help with populations coping with climate change. There is only one known site where the Small Skipper occurs in Ireland, which may indicate that it is a recent artificial introduction there as well.

The grassy “conservation” boundary strips of many fields are generally thought to be quite poor for wildlife. Some research showed that the two metre margin strips of sown grass around fields introduced as part of the Countryside Stewardship Schemes (CSS) conservation efforts in farming policy did seem to hold more adult Small/Essex skippers than corresponding field edges without such conservation margins, benefiting perhaps from the long grass larval food sources, and some flower survival, but the numbers of adults (nectar feeders) held in these strips seemed to decrease over time, as the uncut grass thickened up and flower nectar sources were reduced (the grass was cut several times in the first year, but not thereafter, as specified in the CSS rules).

The Small Skipper has been shown to be much more sedentary than the Essex or Large Skipper and an individual may only move between 20 and 280 m in its lifetime. Populations can be quite high – up to 1,000 per hectare, or one every 10 sq, m. Mean residence time on one site in the NorthEast was just over 5 days, and the probability of any one individual surviving to the next day was 82%

Life cycle

Careful observation of Skippers in long grass may eventually yield the intriguing sight of a female carefully exploring the rolled up sheath part of the leaf of a Yorkshire Fog grass plant by crawling backwards down the sheath, probing gently. Patience will then reveal the reason – she is about to lay 3 – 5 eggs inside the furled sheath! When all is ready she lowers her antennae and squeezes her eggs into the sheath. When the tiny caterpillars hatch, they eat most of their own eggshells, and then spin cocoons in which they will hibernate, still in the group they were laid in. They re-activate in April, separating and feeding off the tender leaves, while tying sections of the leaves into tubes with silk. In May-June they form their chrysalis in a silken tent at the base of the plant, and emerge a fortnight later

I have seen the egg-laying process only once so far, in the tall grass by Dene Park car park.

Oddities

The main foodplant is Yorkshire-fog, a common grass in the British Isles, although other grasses are also used. This grass has slightly looser leaf-sheaths than its relatives, which may make the egg laying process itself easier.

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