A Sad Day for Unicorns

The last few weeks have delivered grim news indeed about the world’s beloved rhinoceros.

Today the annual update of the International Union for Conservation of Nature (IUCN) Red List was released declaring the western black rhino (Diceros bicornis longipes) extinct. Another rhino subspecies, the northern white rhino (Ceratotherium simum cottoni), is on the brink of extinction.^1,2

Only last month the Javan rhinoceros (Rhinoceros sondaicus) was declaired extinct in Vietnam by WWF and the International Rhino Foundation. If verified, it means yet another extinction of an entire subspecies, this time Rhinoceros sondaicus annamiticus. Only one subspecies of Javan rhino (Rhinoceros sondaicus sondaicus) would then remain on the island of Java itself with a population of approximately 50 individuals. A faecal based genetic study carried out in Vietnam’s Cat Tien National Park during 2009-2010 discovered that only one individual remained. Soon after the study was conducted this last rhino was discovered having been shot in the leg and its horn removed. This is a scene that has been replayed many times.³

Poaching had seen record numbers of rhino being killed in recent years and with the value of horn exceeding that of gold it shows little sign of slowing down. The sad reality is that the rhino is caught in a vicious cycle; rhinos become increasingly rare – the price of horn increases – more poaching – rhinos become increasingly rare – the price of horn increases – more poaching…. Where rhinos remain in the wild they are largely afforded security but even then it isn’t fool proof.

By far the predominant poaching driver is the Asian medicine market and this is where the tragedy really hits home. Many still hold onto the belief that rhino horn medicine is a cure for a variety of ailments including cancer, arthritis, nose bleeds and fever but there is no evidence to substantiate such claims. Research has proven rhino horn is comprised of keratin. This may be a familiar word to some of you as it is the same material our hair and nails are made from. Therein lies the tragedy. Instead of supporting a market that is slowly obliterating an entire genus people could simply sprinkle some fingernails on their salad or mix some hair in with their spaghetti.⁴

References

1. “Another leap towards the barometer of life” – IUCN – http://www.iucnredlist.org/news/another-leap-towards-the-barometer-of-life
2. “Western black rhino declared extinct” by Daniel Boettcher – BBC News -http://www.bbc.co.uk/news/science-environment-15663982
3. “WWF report confirms Javan rhino extinct in Vietnam” – WWF -http://www.wwf.org.uk/what_we_do/press_centre/?uNewsID=5367
4. “Scientists crack rhino horn riddle” – Science Daily – http://www.sciencedaily.com/releases/2006/11/061106144951.htm

Of White-Tailed Sea Eagles and Overactive Imaginations

The Scottish Gamekeepers Association (SGA) has irrevocably proven that they have an overactive imagination.

In a letter to the Scottish Government’s Environment Minister Stuart Stevenson the SGA requested a public inquiry and the formulation of an “exit strategy” in the event of white-tailed sea eagles (Haliaeetus albicilla) having adverse effects on social, economic or leisure activities. The request was put forward in light of a white-tailed sea eagle “attack” on Rev Hunter Farquharson in Abernethy in fear of further “aggression” from the birds with the SGA questioning whether “… these very large creatures differentiate between a small child and more natural quarry?”¹

What the SGA failed to identify was that Rev Hunter Farquharson’s actions towards the bird were confrontational and thus provoked the attack that left him with injuries to his head and shoulder. Rev Hunter Farquharson is said to have tried to scare away the juvenile bird as it attempted to kill Bertie one of his prize winning geese after killing another, Beatrice^{2, 3}. Such actions would warrant defensive action  by any predator to preserve itself and its food source.  Thus for the SGA to suggest that this isolated incident caused by poor judgement and confrontational human behaviour could result in further attacks by white-tailed sea eagles is horrifically outlandish.

It should also be noted that after birds being taken by a white –tailed sea eagle in 2008 the RSPB invested in protective netting for Rev Hunter Farquharson’s flock which had since been removed ³.

The SGA also makes reference to buzzards that have “obviously” undergone desensitisation attacking people. Again, the SGA misses the critical detail in that these incidents are attributed to parental defence of young nearby ^{4, 5} .

The question of whether “… these very large creatures differentiate between a small child and more natural quarry?” hardly deserves a response. The diet of the white tailed sea eagle is predominantly comprised of seabirds, waterfowl and fish and they are known to scavenge carrion ⁶. Few children resemble these food sources. Furthermore, the Scottish Government has pointed out that there are no other known instances of white-tailed sea eagle attacks on people in other countries in which the eagles reside. Interestingly the SGA has not raised similar concerns regarding children and golden eagles that have a 90% dietary overlap with the white-tailed  sea eagle, a wider distribution, a comparative tenfold population size and an impressive maximum wingspan of 7.5ft (only half a foot shy of that of the white tailed sea eagle)^{6, 7, 8}. Perhaps we are one negative news story short of taking that leap.

What is so concerning about this “alarmist nonsense” (words RSPB Scotland used to so eloquently described the ignorance of the SGA) is that nowhere in its theatrical statement did the SGA mention further implementation and research into safeguarding people and social, economic and leisure activities to which they referred should their worst fears become reality. With of all of our knowledge and all of our ingenuity the SGA would prefer a UK wide re-extinction of a magnificent species should it become an inconvenience. This is deplorable and highlights the knowledge deficiency and bias that needs to be overcome if we are to continue to re-engage with our species rich past.

The Scottish Government has made it clear that there are no grounds for a public inquiry.

1. http://www.scottishgamekeepers.co.uk/content/sga-calls-public-inquiry-sea-eagles-impact
2. http://www.telegraph.co.uk/news/newstopics/howaboutthat/8718155/Sea-eagle-attacks-reverend-and-his-flock….of-geese.html
3. http://www.bbc.co.uk/news/uk-scotland-tayside-central-14631018
4. http://news.bbc.co.uk/1/hi/england/cornwall/8158022.stm
5. http://www.bbc.co.uk/news/uk-wales-south-east-wales-14169093
6. WATSON, J., LEITCH, A. F. and BROAD, R. A. (1992), The diet of the Sea Eagle Haliaeetus albicilla and Golden Eagle Aquila chrysaetos in western Scotland. Ibis, 134: 27–31.
7. http://www.rspb.org.uk/wildlife/birdguide/name/g/goldeneagle/index.aspx
8. http://www.snh.org.uk/pdfs/strategy/GEConsult/8-KEYFACTSLEAFLET-B464148.pdf

Personal Log: Stardate 65010.3

My life as a student is officially over. My MSc thesis has been handed in and now I have a council tax bill to remind me that the hard protective shell of the student status egg  has been passed on to some unknown whippersnapper. I’d like to think that this means more time to frolic with a plethora of wonderous organisms and working on acquiring superhuman knowledge of the natural world but I fear this will be somewhat stymied by the never-ending quest for money that capitalist society demands. As my position as an Assistant Ecologist comes to an end I can but hope the two can once again intermingle.

Barn owl chicks (Tyto alba) copyright Emma Thomas

A few weeks ago the single most amazing ringing outing of all the ringing outings I have been on took place. The aim was to ring more chicks at some farms around Doncaster with swallows and barn owls featuring prominently on the agenda. Swallows were coming out of our ears and the barn owl nest yielded no less than 5 beautifully wise looking chicks. The parents had decided to use a massive stack of hay bales to nest in rather than their usual nest box in the barn. Considering the hot weather the move was commendable. I was incredibly impressed by how proud the farmer was to have them nesting on his property every year. At another farm nearby the resident pair had failed to return much to the disappointment of the farmer who was keen to discuss all the reasons why this may have happened and how to encourage another nesting pair to the site.

Adding to the excitement of the day was a collared dove chick who elicited a “what the hell is that?” response from myself. If there’s one thing ringing chicks has taught me it’s that Columbidae chicks are really quite amazing and bizarre looking. The picture of the wood pigeon chick we ringed exemplifies this with its wide beak and chunky legs. I must admit the little guy (or girl) was the highlight of my day.

Wood pigeon chick (Columba palumbus) copyright Emma Thomas

Kestrel chicks (Falco tinnunculus) copyright Emma Thomas

The “I will kill you” award of the day belonged to the kestrel chicks. They were nestled in a hole in a tree which meant putting them in a satchel keeping them calm and safe while they were brought to the ground. Getting them out of the bag was another matter altogether. Upon opening the bag we were met with 4 pairs of talons. It transpires that kestrel chicks will lie on their backs and greet you with their not so little daggers of pain at any available opportunity. They were successful little warriors drawing blood from everyone that handled them. They’ll no doubt do well.

Liquid Gold

The U.K. has been revelling in the recent weather with the absence of rain that plagues the nation in the cooler months being a hot topic for many. I will readily admit that I’ve enjoyed the opportunity to get out into the great outdoors more frequently but while there it was obvious that wildlife, crops and water bodies are feeling the strain.

Today the Secretary of State for Environment, Food and Rural Affairs Caroline Spelman is meeting with Natural England, the Environment Agency, the National Farmers’ Union, Water UK, and British Waterways (to name but a few) at a high level summit in order to “prepared for prolonged dry conditions”. The aim as communicated by Spelman is “to lessen harm to crops, wildlife or rivers, and to minimise the effect on households”; a quote that should highlight to the public that long rain free periods are not always sunshine and lollypops (bad pun intended).

Though this summit concluded that we are not yet experiencing drought conditions the statistics are quite impressive. We only received 61% of our average rainfall in the last 3 months and a meagre 24% of April’s average rainfall. This inevitably has consequences; fires, hosepipe bans, increased food prices due to failed crops, dehydrated hedgehogs and limited nesting material in the form of mud for swallows and martins.

I’m continually surprised that both public and non-public sectors squander vast amounts of the precious commodity that is H₂O every year. It’s great that both government and large bodies are keeping an eye on the situation but I’m a big believer in people power and there is much a single individual can do to curb water usage.

Here are some top tips on how to change your water use habits and benefit both people and planet.

1.       Get your hands on a water butt – an excellent source of FREE water for your garden. It’s worth the investment and it’s common for water companies to give reduced prices. More information about water butts at:

http://www.direct.gov.uk/en/Environmentandgreenerliving/Greenerhomeandgarden/Greenergarden/DG_064410

 2.       Water your plants early in the morning (using water from your water butt of course) – if you have to water your plants do it before it gets too hot. More water will enter the rhizosphere (root zone) instead of evaporating, decreasing water wastage.

 3.       Leave your lawn to grow longer – longer grass protects against scorching which means watering your lawn can be a thing of the past or at the very least a rare event. Besides, super manicured lawns are over rated and provide little habitat for beautiful bugs and the associated fauna that feeds on them.

More water saving garden tips at: http://www.direct.gov.uk/en/Environmentandgreenerliving/Greenerhomeandgarden/Greenergarden/DG_064410

4.       Turn the tap off when brushing your teeth – even better is to put a little bit of water in a tumbler and use that for all your brushing requirements. You’ll soon realise how little water you actually need. Saves up to 6 litres of water… PER MINUTE!!!

 5.       Take a shower instead of a bath – I often put the plug in the bath to see how much water I use when showering. If anything it makes me shower faster to meet the challenge of using as little water as possible. Great for those of us that have a habit of running late in the mornings.

 6.       Get a cistern displacement device – many water companies supply these free of charge but you can also get them online. Saves approx. 1 litre each flush.

 7.       Fix that dripping tap – not only are they annoying but you can waste up to a whopping 5,500 litres of water a year.

 8.       Fill up dishwashers and washing machines – and if you have the option choose water and/or energy saving modes.

 9.       Don’t pre-rinse your dishes – I have never understood why people do.

 10.   Be an active car washer – There’s no need to wash your car every week and when you do avoid car wash places as they use loads of water. Instead be more active about the whole event and opt for the bucket and sponge technique.

Personal Log; Stardate 64813.3

I started this blog with the intention of blogging  regularly, as I’m sure everyone does, but alas I have faltered.

I do rather enjoy sinking my teeth into conventionally educational topics but this takes time to do even half decently so I have decided to mix it up a bit. I have much going on at the moment what with completing my MSc thesis, starting my own jewellery business and recently (literally two days ago) being offered an assistant ecologist role on a reptile and great crested newt contract with a local consultancy thus time is scarce. On the plus side there have to be a few naturey blog posts hidden in the chaos and this is the mixation element that I previously refered to. In between informational blogging I’ll be doing these personal logs (yes, I’m a Star Trek fan) that will most definitely take less time to construct and help keep my blogging from going completely stale.

On that note I give you a tale of bird ringing but first let me introduce you to lobotomized happy stick, otherwise known as my ringing trainer’s push stick for the mist nests.

Today’s bird ringing adventure was launched in hope of ringing individuals of the family Hirundinidae (swallows and martins). The weather promised cooler conditions and drizzle, perfect for driving tasty aerial insect treats down near the ground to entice swallows and martins into strategically placed nets. We didn’t catch a single one of these stunning birds. The weather wasn’t miserable enough. To quote Doctor Claw: “Next time Gadget. Next time”.

Counting our loses we high-tailed it to another ringing site to ring some Lapwing, Linnet and Chaffinch chicks in hope that they had become old enough to sport BTO bling. I’ve always found chicks terribly cute but admittedly the prospect of ringing Linnet and Chaffinch chicks in all of their utterly helpless, see-through-skin- glory was nerve-wracking. Once I got past the fact they also felt like warm rubber comedy chickens I was cucumber-esque. The Lapwing chicks had yet to emerge from their eggy strongholds.

Indeed the whole day was scarce on the avian front but it was highly enjoyable.

My total ringing count for today was as follows:

Whitethroat – 2

Long-tailed tit – 1

Blackcap – 1

House sparrow – 1

Great tit – 2

Linnet (chicks) – 4

Chaffinch (chicks) – 2

My partner also ringed a fantastic juvenile male Sparrowhawk.

Creating Real Estate for our Avain Friends

It’s not only humans that are struggling to find property in the economic downturn. Our avian friends are struggling too. Our love of over manicured gardens and woodlands together with making those long awaited home “improvements”, such as fitting new eves, leave little room for birds to establish nesting sites and can destroy ones that are habitually visited year after year.

Given that the sum area of our beloved gardens exceeds that of our nature reserves there is huge potential to create wildlife havens literally right on our very doorstep. It’s a tantalising prospect.

A great many of our U.K. birds have seen dramatic population declines for a variety of reasons, namely changes in land management practices and agricultural intensification which have reduced food availability, nesting and roosting sites. Long term change needs to be established if bird populations are to make a wholesale comeback but for birds that are happy to take up residence in nest boxes more immediate help is to hand. Us. Accompanied by a constant and suitable supply of food and water, nest boxes can aid the breeding success of some local bird populations.

Next boxes are widely available to purchase but it’s not all that difficult to make one especially when there are so many instructions about how to do so online.

When buying a nest box there are a few key things to bear in mind:

1. Building material – Nest boxes need to be made from wood (ensure the wood is certifies FSC to ensure a sustainable future for forests). Plastic and metal can result in overheating and condensation build up.
2. Thickness of walls – Walls should be no less than 15mm to provide good insulation and prevent warping.
3. Water drainage
4. Access for cleaning
5. Perches – they are not needed and can facilitate access for predators if present².

Whether you buy or make a nestbox of your own you need to have realistic aspirations about the residents you want to attract. There is no use putting up an extra large nestbox on the wall of a house situated in a very urban location and be disappointed when a pair of barn owl fails to move in. You need to consider what habitat you have to offer then choose according to the requirements of the species you want to attract. A good point to start is by identifying the species of birds you come across in the area you want to put up your nestbox. To help you match your chosen bird species with its requirements below is a table comprising of nestbox size and habitat requirements for the most common species that use nestboxes.

I need to stress at this point that the data in the following table represents generalisations. Some species are notoriously finicky with their requirements so it’s recommended to do some species specific research to be sure you are creating the right home for your potential avian neighbours.

Click for full sized table

For all species entrance holes need to be situated at least 125mm from the floor of the nestbox to prevent chicks from falling out and predators gaining easy access. The inside wall below the hole or panel opening should also be rough or have a series of shallow notches to enable fledglings to leave the nest. Each species has a preference for entrance hole size with the following diameters being advised^{2, 3}:

• 25mm – blue tit, coal tit and marsh tit
• 28mm – great tit, tree sparrows and pied flycatchers
• 32mm – house sparrows and nuthatches
• 45mm – starlings

The same species differentiation applies for open fronted boxes whereby it is the height of the front panel that is important ³:

• 60mm – spotted flycatchers
• 100mm – robins and pied wagtails
• 140mm – wrens

Commence Construction!

Now you’ve decided who you’d like as a neighbour and know what nestbox they need you’re ready to get down to business and build. The BTO, RSPB, Wildlife Trusts and bird groups have some good blueprints readily available online so the design phase is taken care of for you.

Building Material.

Wood is by far the material of choice with the thickness of the wood being no less than 15mm to prevent warping and provide insulation for inhabitants. Under NO circumstances should metal or plastic be used; these materials afford little insulation in cold weather, overheat easily and allow the build up of condensation within the nextbox. If you choose to build with new wood make sure it is from a sustainable source and look out for FSC certification. This reduces the chances of destroying pristine habitat elsewhere. Hardwoods are more durable than softwoods and therefore last longer. Avoid chromated copper arsenate (CCA) pressure-treated timber at all costs. If you can remember a little chemistry you’ll know from the name this isn’t nice stuff and the leachates may harm birds^{1, 2, 3}.

To assemble the nestbox use galvanised nails or screws which don’t rust and not glue².

As nestboxes need to be cleaned each year the lid cannot be nailed down. Instead attach the lid with plastic or brass hinges (because they don’t rust) and run a piece of rubber along the join (old bicycle inner tube is great for this). Fasten the lid down with a non-rusting catch^{1, 2}.

Finishing Touches

Now you’ve constructed your nestbox there’s only a couple more things to do.

Nestboxes need to have some water drainage. Drilling a couple of holes into the bottom of the nestbox will allow any excess water to leave. This can be lifesaving if a considerable amount of rainwater happens to get in. Covering the top of the box with roofing felt can further waterproof your box¹.

If you’re concerned about predation by woodpeckers or squirrels you can prevent the entrance hole from being enlarged by adding a metal plate. These are readily available in a variety of sizes.

Leaving the nestbox to weather naturally is the best option as it will blend in with the immediate surroundings better, offering some camouflage protection from predators. For softwoods treatment with water-based preservatives is an option but these need to be safe for animals. Sadolin and Cuprinol can be used but NOT creosote. DO NOT apply any preservative to the inside of the box or around the entrance hole even if it is deemed safe for animals. Ensure the nestbox is completely dry and well aired before putting it out for the birds^{1, 3}.

Location, Location, Location

Species are not only fussy about nestbox size and habitat they also have different preferences for height, aspect, vegetation cover and the number of neighbours they will tolerate.

Do not place nestboxes in close proximity to a feeding station; the disturbance created by other birds may prevent its use.

Height

Wherever you place your box the essential take home message is that it needs to be safe from domestic cats and inquisitive humans.

Nestboxes for tits, sparrows and starlings should be fixed at a height between 2m and 4m up a tree or on a wall. House sparrows and starlings will happily nest under eves but need to be away from nesting sites of house martins.

Nestboxes for robins and wrens should be placed below 2m, for spotted fly-catchers 2-4m high and for woodpeckers 3-5m high on the trunk of a tree⁴.

Aspect

Nest boxes should be placed facing between north and east unless there is shelter from buildings during the day. This helps to prevent strong sunlight and wind and precipitation from hitting the nestbox. Additionally, nestboxes should be tilted slightly forward to allow rain to run off the lid and away from the entrance hole^{1, 4}.

Flight Path

Always ensure a clear flight-path to the entrance of your nestbox¹.

Neighbours

Again, the number of neighbours tolerated is species specific. House martins, tree sparrows, house sparrows and starlings are happy to nest close to one another but blue tits are not. They are fiercely territorial and have an average nesting density of 2 or 3 pairs per hectare¹.

And Finally…

You’re ready to put your nestbox up! Huzzah!

However you put your nestbox up make sure you can access it for yearly maintenance. With this in mind it’s better to be able to remove the nestbox.

When placing nestboxes on trees different authorities and landowners have different preferences. Some don’t mind nails but others would prefer wire covered by some rubber tubing to protect trees¹.

New nestboxes should be put up in February or March in time for the new breeding season.

Maintenance

Annual cleaning needs to be carried out each year, ideally in the months of October or November. Any old nesting material should be removed and the inside of the box doused on boiling water to kill any parasites waiting for next years inhabitants. Never use flea-powders or insecticides as these are not healthy for our avian friends.

If unhatched eggs are found in the nestbox they are only permitted to be removed from October to January and they MUST be destroyed. Removing eggs outside of the afore-mentioned period or keeping them is illegal under the terms of the Wildlife and Countryside Act (1981).

When you’ve finished cleaning your nest box don’t forget to pop it back into its original place. Nestboxes can protect birds from harsh weather conditions and can be used as roosting sites too¹.

---

References

1. http://www.lincstrust.org.uk/factsheets/nestbox.php

2. http://www.bto.org/nnbw/make.htm

3. http://www.rspb.org.uk/advice/helpingbirds/nestboxes/smallbirds/making.aspx

4. http://www.rspb.org.uk/advice/helpingbirds/nestboxes/smallbirds/siting.aspx

British Butterflies: Swallowtail (Papilio machaon britannicus)

Taxonomic classification

Kingdom           Animalia

Phylum             Arthropoda

Class                Insecta

Order                Lepidoptera

Family               Papilionidae

Genus               Papilio

Species             machaon

Subspecies:      britannicus

Introduction

Of the twelve European representatives of the family Papilionidae, Papilio machaon subsp. britannicus (Seitz, 1907; The British Swallowtail) is the only U.K. endemic^1,2.

Papilio machaon britannicus © Julian Dowding

P. machaon subsp. britannicus is not only the largest butterfly to be found in the U.K. but it is also among the rarest with the population having plummeted in recent history due to habitat destruction. Presently, P. machaon subsp. britannicus is exclusively found on the Norfolk Broads where suitable habitat and healthy populations of its larval host plant Peucedanum palustre (Milk-parsley) remain^2,3.

Papilio machaon subsp. gorganus (Fruhstorfer, 1922; the Swallowtail found throughout the rest of Europe) has also been recorded in the U.K. but as this subspecies is not resident, all subsequent information will relate to P. machaon subsp. britannicus^1,2.

Distribution

Historically, P. machaon extended throughout the fens of East Anglia to many other parts of England including the mashes along the Thames, the Somerset Levels and up to Yorkshire⁴. The last population outside of the Norfolk Broads inhabited Wicken Fen in Cambridgeshire where it first became extinct c. 1952⁵. Subsequent reintroductions to the site from 1955 to 1969 were ultimately unsuccessful; drying of the fen and further drought in 1976 compromised the P. palustre population, the sole larval food plant of P. machaon⁵. Failing to recover the Wicken Fen population once again became extinct at the site. Presently P. machaon is found only in the Norfolk Broads inhabiting a mere 1% of its former range where populations are considered to be fragmented⁴

Distribution map available at http://www.ukbutterflies.co.uk/distribution.php?species=machaon.

Habitat

P. machaon inhabits open mixed fen systems containing healthy populations of P. palustre dominated by Carex spp. (sedges) or Phragmites spp. (reeds) ^2,6.

Annual cycle

In years that yield one generation imagines (adults) fly from May to July. Flight coincides with the laying of ova (eggs) from which larvae (caterpillars) emerge after a duration of approximately one week. Larval development takes one month at the end of which larvae achieve their final instar and pupate. Individuals overwinter as pupae to emerge as imagines (adults) the following May to July⁷.

In years where conditions are favourable enough to produce a second generation, individuals emerge from their pupae in August following a three week metamorphosis⁸. The imagines proceed to mate and lay ova with their offspring then overwintering as pupae to emerge in May to July of the following year^7.8.

Life Cycle

Papilio machaon britannicus ovum © Pete Eeles

Ovum

P. machaon is among the many species of butterfly to lay ova singularly on the leaves of their larval host plant. This is a strategy that aims to increase the probability of survivorship for offspring produced by any given female through maximising food resources per larva and decreasing the likelihood that all offspring succumb to predation by parasitoids, birds, insectivorous mammals and even other larvae⁹.

Upon being laid on a P. palustre leaf, the spherical ovum is a greenish yellow. The colour of the ovum rapidly changes to green and as time progresses turns purple-black and finally to a light pearly transparency a few hours prior to larval emergence. The ovum is eaten by the larva upon emergence as it is a valuable source of nutrition⁸.

Larva

Papilio machaon britannicus caterpillar © Pete Eeles

The larval stage of P. machaon lasts approximately one month during which time individuals can reach 41mm in length by feeding on the leaves, buds and flowers of P. palustre  ⁸.  Newly emerged larvae are black with a white patch near the middle of their back; a camouflage colouration that resembles bird guano². With each consecutive instar moult larvae develop the characteristic and conspicuous “warning” colouration of a green head with black markings and a green body with transverse black bands and red spots^7,8.  In addition to “warning”colouration, P. machaon larvae possess an osmeterium which develops after the third instar. The osmeterium is a bifurcated orange scent gland hidden within the first thoratic segment that produces a pungent odour when erect^3,7,8. The odour produced coupled with the visual display of the osmeterium itself is considered an effective defence mechanism against birds³.

Pupa

Papilio machaon britannicus pupa (green) © Pete Eeles

Larvae pupate within 10m of their larval host plant and most frequently do so low down on the stems of Phragmites spp. but have been known to pupate on woody plants and other individuals of their larval host plant^2,8. The pupa is secured to the pupation site in an upright position by both a cremaster (anal hooks) attached to a silken pad and a silken girdle^2,8.

Pupae of P. machaon are either greenish-yellow or brown with black markings in order to blend in with the surrounding environment^2,8. Pupae are able to survive submersion in water for long periods, an adaptation to an environment where later levels may fluctuate greatly over the year⁷.

Imago

As an imago, P. machaon is quite striking. The upper wing pattern is more vibrant than the underside consisting of a mingling of yellow and black creating a stunning visual effect. The characteristic red spot capped with blue can be found on the hind wings¹⁰. P. machaon subsp. gorganus is extremely similar in appearance but can be distinguished by its lighter colouration and larger size². Sexual dimorphism not well characterised in wing pattern but can be distinguished by abdominal characteristics i.e., larger abdomen in females³.

P. machaon imagines are dependent on nectar as a source of nutrition feeding on food plants such as Hyacinthoides non-scriptus (Bluebell), Succisa pratensis (Devil’s-bit Scabious), Lychnis flos-cuculi (Ragged Robin), Trifolium patense (Red Clover), Dipsacus fullonum (Teasel) and Cirsium spp. and Carduus spp. (Thistles). Typically wings continue to beat during feeding².

Conservation status

P. machaon is listed as a species of conservation concern in the U.K. Biodiversity Action Plan and in Schedule 5 of the Wildlife and Countryside Act, 1981.

---

References

1. http://www.searchnbn.net/
2. http://www.ukbutterflies.co.uk/species.php?species=machaon
3. Tolman, T and Lewington, R (2008) Collins Butterfly Guide. HarperCollins Publishers, Hong Kong.
4. Asher, J., Warren, F., Fox, R. Harding, P., Jeffcoate, G. & Jeffcoate, S. (2001) The Millennium Atlas of Butterflies in Britain and Ireland. Oxford University Press, Oxford.
5. Dempster and Hall (1980) An attempt at re-establishing the swallowtail butterfly at Wicken Fen. Ecological Entomology, 5, 327-334
6. http://www.butterfly-conservation.org/Butterfly/32/Butterfly.html?ButterflyId=4
7. A Field guide to Caterpillars of butterflies and moths in Britain and Europe
8. The Caterpillars of the British butterflies including the eggs chrysalids and food-plants
9. Ecology of Butterflies in Europe, eds. J. Settele, T. Shreeve, M. Konvicka and H. Van Dyck (2009) Cambridge University Press, Cambridge. pp. 29-42.
10. Still, J. (1996) Collins Wild Guide Butterflies and Moths of Britain and Europe. HarperCollins Publishers, London.