Month: March 2018

Today was not an impressive opening to the butterfly season at Butterfly Conservation Ireland’s  reserve  at Lullybeg, County Kildare but at least butterflies were finally sighted.

The last butterfly sightings  at Lullybeg before today, 24 March 2018, was of  six species: Brimstone, Green-veined White, Red Admiral, Peacock, Small Tortoiseshell and Speckled Wood, all recorded on 30 September, 2017, nearly six months and 174 days ago! The lateness of the season is also clear from the records on this website. Up to the 23 March 2017, 34 butterflies were recorded on the Butterfly Conservation Ireland Records page. Up to 23 March 2018, only three butterflies were recorded.

That underlines how long winter lasts in Ireland, and  in particular how long the winter of 2017-2018 has been.  And if the forecast for next week is correct, winter will make another attack, on us, but not as severe as  earlier in March.

Twelve Celsius with sunshine is usually the temperature that allows flight, but today 11 Celsius was sufficient, with butterflies buoyed by extremely calm conditions and bright sunlight. Lullybeg’s first butterfly of 2018, and  also my first sighting was a Peacock that  glided rather feebly, wings fully expanded, across my path and a stream to perch on a great bleached ball of moor-grass to warm itself.  Soon afterwards, in a clearing, a spectacular male Brimstone, an almost luminous daffodil yellow, cheerfully fluttering around the wood edges, already searching for a mate. His golden gleam promised a end to the misery of winter, and here’s hoping that promise is kept.

Lullybeg’s Marsh Fritillary caterpillars were busy feeding and basking in the sunshine.. Some had reached the fifth instar stage but most were still in the fourth instar, the stage in which they spend the coldest months of the year. They still look small for late March but hopefully better days for feeding are close at hand.

Wherever you live, now is the time to get outside and look for signs of spring. At this time of year, butterflies are usually found very close to cover, in warm, sheltered sunny situations such as the south side of a hedge, along lanes, in woodland clearings, along wood edges and tracks though woodland especially tracks running from east to west.

Don’t forget to send us your sightings. We’d love to see how our butterflies are faring after such a long winter. Email sightings to us at conservation.butterfly@gmail.com. Tell us:

your name, date of sighting, species, life stage and number seen, six figure grid reference and location name. Details of the conditions and temperature are also welcome. We will publish your sighting on our records page, which you can find on this website.

Enjoy spring, and make butterflies part of your spring walk.

All images ©J.Harding.

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The snow and ice are still melting and spring is attempting to make itself felt.  Warmth, when it comes, will awaken our insects, our bees, moths and butterflies. Their first priority is to find food; after all, many of our insects have fasted for six months and need to recover diminished body weight to build reserves for activity, such as flight, mate-seeking and breeding.

One of the great challenges faced by nectar and pollen dependent insects is a simple but critical one of a lack of food. If the grassy hedge-bank in which a bumblebee hibernated is cut severely, the Primroses, Cowslips and Common Dandelions on it will be killed or be so reduced that flowering does not take place as it should. Worse still, some flowery verges, hedge banks and lawns are sprayed to kill ‘weeds’. A bland green desert replaces colour, and the endless Saturday drone of lawn mowers and the snarl of strimmers replace the hum of bees shouldering their way through the leafy vegetation.

Happily, there is action being undertaken and lots we can do ourselves.

The National Biodiversity Data Centre has, since 2015, been involved in the National Pollinator Plan which describes actions that can be undertaken by me and you, by public bodies such as county councils and community groups, such as Tidy Towns to enhance the landscape for our flower feeders. Please click on this link and take on at least one action suggested.:

https://biodiversityireland.us9.list-manage.com/track/click?u=ce2a764d51802fda4e5f78c14&id=750bd1c771&e=7408737bc7

If you are encouraged by rising daylight to pop to the local garden centre to brighten up the garden, look for plants that are good for insects. Not all very attractive flowers are valuable. Some are almost useless. Begonias, many roses, gladioli, daffodils contain little or no pollen or nectar. As far as helping bees and butterflies is concerned, these plants might as well be plastic ornaments.

Here are some suggestions. Herbs such as mint, Wild Marjoram, often called oregano, borage and thyme carry lots of nectar. Lavenders are good too. Primrose, by which I mean the native Primula vulgaris will be welcome, as will the native Irish Cowslip, Primula veris.  Hebes, small to medium-sized evergreen shrubs produce lots of nectar too, and when planted in warmer coastal areas, these plants bloom in winter and sustain insects that wake up on mild days. There is evidence that the hebes grown by gardeners on Howth Head is helping Red Admiral butterflies, which usually leave our shores in autumn for sunny climes further south to remain there throughout the winter.

For mid-summer, there are buddleias which are medium-sized shrubs that like sunny, dry conditions. Bees and butterflies are irresistibly drawn to these shrubs, and you will have weeks of pleasure observing their antics. Verbena bonariensis is a tall, willowy flower that bears purple flowers is a great draw too, and this will provide nectar into September. Ice Plant, a small succulent plant, flowers in September and if in a sunny sheltered spot, be ready for crowds of bees and butterflies.

I prefer the native Irish flowers. The flowers of wild willow shrubs are a big favourite for bees, moths and butterflies. I already mentioned Cowslips and Primroses, but the Common Dandelion trumps these. I cannot think of any butterfly that rejects this plant and when the seeds are ready, Goldfinches will be fed. Common Hawthorn blossom in May is a lovely sight and also a great nectar source. Wild roses, like Dog-rose, Rosa canina, is good too. Honeysuckle is terrific for bees and moths, and its fragrance on a June night is an essential summer scent. Two final winners; Common Knapweed, Centurea nigra and Devil’s-bit Scabious Succisa pratensis will between them, feed our bees, butterflies and moths from June to October.

A couple of further tips. Do not mow your lawn too tight and cut it every six weeks from April to October to allow Red Clover, Common Bird’s-foot-trefoil to fatten our insects. These flowers bring crimson and gold to your lawn too, cheering the place up! And to go all the way, sow a wildflower meadow consisting of these flowers, along with Common Knapweed and Devil’s-bit Scabious and leave uncut from May to September, depending on the warmth of the season-delay mowing/strimming longer in cool years. Cut on a high setting. Remove cuttings to keep the soil suitable to grow your wildflowers the following year.

Never use sprays.

Relax, and enjoy sharing your garden with nature. By taking the steps described here and in the video, you will be enhancing the survival chances of our flowering plants, insects and broader biodiversity as well as increasing the value of your home and garden for your own well-being. People’s well-being is improved by contact with high levels of biodiversity. Make your garden a haven for you, your loved ones, and the creatures who would share it with us, if we gave them what they need.

Enjoy spring!

All photos ©J.Harding.

 

 

 

An earlier post looked at the effect of extreme climatic events on butterflies but this topic is timely given the current heavy snow.

A study published in 2017, Sensitivity of UK butterflies to local climatic extremes: which life stages are most at risk? examined the impact of ECEs on the resident UK butterfly species (n = 41) over a 37-year period. The study investigated the sensitivity of butterflies to four extremes (drought, extreme precipitation, extreme heat and extreme cold), identified at the site level, across each species’ life stages. Variations in the vulnerability of butterflies at the site level were also compared based on three life-history traits (voltinism, (how many broods a species will produce in a year), habitat requirement and range.

This is the first study to examine the effects of ECEs at the site level across all life stages of a butterfly, identifying sensitive life stages and unravelling the role life-history traits play in species sensitivity to ECEs.

Butterfly population changes were found to be primarily driven by temperature extremes. Extreme heat was detrimental during overwintering periods and beneficial during adult periods and extreme cold had opposite impacts on both of these life stages. Previously undocumented detrimental effects were identified for extreme precipitation during the pupal life stage for univoltine species. Generalists (widely distributed butterflies that use a range of habitats, such as the Small White) were found to have significantly more negative associations with ECEs than specialists (local species confined to  specific habitats, such as the Small Blue).

With future projections of warmer, wetter winters and more severe weather events, UK (and probably Irish) butterflies could come under severe pressure given the findings of this study.

What does this mean for our butterflies given the cold winter and heavy snow?

Extreme cold in winter has a beneficial effect on butterflies but cold weather during adult flight period in spring and summer is very negative. Extreme heat in winter, expressed as very mild weather in Ireland when we are likely to see Small Tortoiseshells on the wing during January, is very negative. Certainly, the butterfly will be on the wing at a time when its adult food and larval food is unavailable. Paul Waring in his excellent Field Guide to the Moths of Great Britain states that the large decline in the Garden Tiger moth population may be due to mild, wet Januarys followed by colder weather in February. The Garden Tiger overwinters as a larva which may become active during mild January conditions when food-plant quality may be poor. Feeding requires heat for digestion, and sudden onset of cold weather may affect the animal’s digestive processes and damage the food-plant leaving it vulnerable to starvation. The report also considered that extreme warmth in winter made larvae more susceptible to disease and fungal infections, but the report believes that causing the species, whether over-wintering as an adult or larva to become active before the food is available is a more likely cause of decline.

It is interesting that habitat specialists are at less risk (but are still negatively affected) from extreme climatic events. Factors that may contribute to this reduced impact may be protection given to them by their habitats, the fact that all but one (the Wood White) of our habitat specialists are single-brooded. Indeed, the report found that drought had a much more negative impact on multi-brooded species than on single-brooded species. Yet this does not apply to all life-stages; drought during the egg-stage was noted as a driver of population increase. Furthermore, the response to drought across the species studied was not as uniform as the response to the other extremes. However, there is no doubt that ECEs affect specialists; extreme cold in May and flooding arising from unseasonably heavy rain has eliminated Marsh Fritillary colonies.

Interestingly, the report, when considering why ECEs have a greater effect on generalists than specialists makes the hypothesis that generalist species are more vulnerable as they are filling their climatic niche, and hence, many populations within the species range may be situated on the climatic range edge and be more vulnerable to increased climate inconsistency outside of their comfort zone. In contrast, specialist species are confined to particular host plants which may not common across the specialist species’ climatic niche; hence, those specialist species are not filling their climatic niche and are effectively in or close to their core range and are not subjected to ECEs that are outside their ability to adapt and cope. It is also possible that specialist species are being protected by their habitats where they have been able to survive.

Finally, the report, while careful not to be too definitive, concludes with some important findings. Butterflies (especially single-brooded species) could benefit from warmer, drier summers associated with climate change but milder, wetter winters would damage populations. A key finding is to make sure that habitats do not become fragmented, especially for specialists, and that habitat management should look to protect species from extreme warmth in winter-not a problem for us in 2018!