Eurasian Siskin – April

©Nick Sidle – Full Screen Image

Eurasian Siskin driving off a larger European Greenfinch which had pushed it aside on an approach perch to a feeding site. Siskins don’t like queue jumpers. Yesterday was significantly colder than the normal for late April with snow lying on the ground overnight. As a result smaller birds in particular were desperate for food, that does not excuse abandoning all manners though. There is of course always pressure for resources between small birds and competition is often fierce but some recognition of who got there first can still apply. On a purely anecdotal basis from my own time spent watching them there does actually appear to be some difference in this between species. Greenfinches seem particularly ready to push any other bird aside and, although far from guaranteed, Siskins do seem to be the most ready to wait a turn especially with other Siskins. They also genuinely seem the most put out if they are queue jumped and react most strongly to it, even if the usurper is much bigger than they are. Perhaps there is a study waiting to be done; ‘Manners in foraging birds, a differentiation of etiquette between species’.


Glen Convinth,
Highland Scotland

Gallery – Scotland’s Birds

Gallery – Glen Convinth

Eurasian Siskin – Carduelis spinus

European Greenfinch – Carduelis carduelis

A Rare Visitor


Full Screen Image – Hawfinch, Glen Convinth, Highland Scotland ©Nick Sidle

The Hawfinch is the largest of the finches found in Scotland and the rest of Britain. Size though does not mean that it is seen very often, a combination of being rare, unfortunately in significant decline and having a rather shy temperament which has even been described as ‘self-effacing’, all mean that glimpses of them are few and far between and I was very lucky to see this one in an area of Highland Scotland where they are almost never recorded, the last sighting was in 2010 and that was tens of miles South on the other side of Loch Ness. There are local small breeding populations known much further South in Scotland at Scone Palace near Perth.

This individual is almost certainly a migrant on the move and there have been several sightings of these last week in Scotland, including on the islands, but none on the mainland in this region till now. The Gaelic name for the Hawfinch is the Gobach which translates as ‘Beaky’ which, although not exactly romantic or poetic, is highly appropriate not just because the Hawfinch beak is as large as it is but also because studies have shown it can exert huge pressures in excess of 95 lbs (48 kg) in order to crack things like cherry stones which it feeds on. In Yorkshire, the bird is actually known as the Cherry Finch because of its fondness for the fruit but further South in Europe it is also known for its selection of Olives, the stones of which require over 160 lbs pressure to break them as fast as the Hawfinch is on record as doing with apparent ease. Yes, the muscles for the beak are very well developed. Put simply, the Hawfinch can deliver a crushing pressure with its beak well over 1000 times its own weight. If human beings could do that, we would be looking at forces measured in tens of tons. The noise of the stones breaking can sometimes be the way of finding Hawfinches when they are feeding but it was not the case for my encounter. Cherries are a bit thin on the ground here and olives – don’t even ask. I was just lucky enough to see a bird that was not one of the usual I see and then, after a moment’s doubt, realise what I had found.

Thanks to Susan Haysom at Scottish Natural Heritage and the British Trust for Ornithology (BTO) for their information on the status of the Hawfinch and recorded sightings.

If anyone else is fortunate enough to spot a Hawfinch in North Scotland the BTO would be very interested to have the records and these can be reported through their website

British Trust for Ornithology


Gallery – Scotland’s Birds

Gallery – Glen Convinth


Hawfinch – Coccothraustes coccothraustes

Valentine’s Day is coming. If music be the food of love and you are a mouse do you need to go to school?


Full Screen Image – Wood Mouse, Glen Convinth, Highland Scotland ©Nick Sidle

The achievements and abilities of mice have been greatly underestimated by people throughout the ages. Yet another entry on that list is that most people are completely unaware that mice are accomplished singers, although since they choose to perform using a frequency way above the sounds detectable to human hearing, perhaps this is not our fault, perhaps the mice wanted to keep it private. One reason could be that, in the best Mediterranean romantic tradition, one major use of song by mice is to win the heart of another mouse they have fallen for. Whether this includes performances under balconies or a mouse equivalent of balconies is not, as far as I know, yet recorded.

Once you have caught up with the choral skills of mice, there is then an immediate question, are they born with a repertoire of songs that they can use or do they have to learn them from other mice? How much they have to rehearse before another mouse wants to listen to them is a different issue on which, like the balconies, I am again not aware if there is any research. The same is true for the issue of if for mice, like people, there are some of us whose abilities in musical performance are such that the best way to show we care about someone else is to stay silent and fall back on the alternatives like red roses, chocolates and candle lit dinners. If there are mice who would be best advised to skip the singing, then I hope that in their society they have different ways to show they care as well.

To return to the main question of whether mice are born with their songs or have to go to school, the answer, like so much in the natural world, is not that simple or, to put it more simply, looks like a bit of both. Two studies have identified both paths as being active for mice who aspire to be the next sensation on the mouse music scene. One set of researchers at Northeastern Ohio Universities found evidence of substantial learning taking place:

Development of Social Vocalizations in Mice

whilst another based in Japan showed an innate ability in mice to know the songs since they found that sibling mice raised by different foster parents had the same repertoire of songs as their own biological parents and each other:

Cross Fostering Experiments Suggest That Mice Songs Are Innate

So, to make it in the music business as a mouse you need just the same as we do. You need instinct, innate ability and talent, a lot of hard work, possibly some help and even then probably still just a bit of luck. So I wish all mice and people with romance on their mind and a hint of love in the air all the luck they need on February 14th and let’s hope that everyone, and every mouse who wants to, finds the happiness and futures they seek together for however long it can last.


Gallery – Glen Convinth

Gallery – Scotland’s Mammals


Wood Mouse – Apodemus sylvaticus


Hair, Ice, Fungus – Which?


Full Screen Image – Hair Ice, Battan Forest, Glen Convinth, Highland Scotland ©Nick Sidle

The answer is actually all three. This rare phenomenon is called hair ice and is made up of tiny filaments of ice crystals formed on and exuding from dead wood when the conditions are right, it is the infrequent occurrence of the perfect conditions that means it is so rarely seen. It arises from the pores in the wood structure where the bark has been lost. What is required is a very cold temperature below freezing, for the dead wood to be saturated with water and very wet and for the right humidity in the surrounding air which must be high. After that, this particular type of frost can form as hairs about 0.01mm in diameter so it is no surprise that if you touch it, it melts. Now comes the fungal bit. For hair ice to form, what is also required is the presence of a fungus, Exidiopsis effusa, in the wood – an association reported by a team of scientists from Switzerland and Germany and reported in the journal Biogeosciences.

Evidence for biological shaping of hair ice

Hair ice was first recognised and studied in 1918 by Alfred Wegener, perhaps better known for his work on the slightly larger in scale question of tectonic plates. He suggested an association with fungus but it is only the recent work that has finally revealed what that is. In the absence of the fungus, ice forms on the surface of the wood as an encrusting layer, only if the fungus is present then the hairs form and, subject to the temperature staying below freezing, grow. The researchers hypothesis is that the hair ice structures are stabilised by a recrystallization inhibitor that comes from the Exidiopsis effusa. The team showed the presence of complex organic compounds, lignin and tannin, in the ice and identify these as the substances preventing the formation of larger ice crystals on the surface of the wood. Lignin and tannin are metabolic products of fungal activity and Exidiopsis effusa appears to have been the organism to provide all the right conditions.


Full Screen Image – Hair Ice ©Nick Sidle

For someone thinking as a scientist, this sort of discovery makes a beautiful natural phenomenon, even more a wonder of the forests. If for you complex organic compounds get in the way of appreciating a fleeting, unusual and exquisite event in the wild, then there is still the alternative name of ‘Snow Fairy’.


Gallery – Glen Convinth


Fungus – Exidiopsis effusa

Wishing you a very merry and fade free Christmas


Full Screen Image – European Robin, Glen Convinth, Highland Scotland ©Nick Sidle

The question where do birds’ feathers get their colours is not an entirely simple one but we are now one step closer to understanding some of the mechanisms involved. A study based in Sheffield and published in the journal ‘Scientific Reports’ shows that for some birds, including the Robin, their colours are not the results of pigments that could fade but are the product of the actual structure of the feathers. We are though looking at very small structures, they needed the European Synchrotron Radiation Facility in Grenoble to do the research and that just happens to be one of the most powerful microscopes ever built, a very large step up from your basic table top model.

Spatially modulated structural colour in bird feathers

A significant part of the work was based on looking at the Eurasian Jay, known for its varied plumage including a brilliant blue, and found that variations in the feathers at a nano structural level determined the reflection of light and so the colours that we see.


Full Screen Image – Eurasian Jay ©Nick Sidle

Science is using technologies like the European Synchrotron Radiation Facility to look at a number of questions that have evaded a complete answer till now, including the issue of how Geckos can manage to run up vertical surfaces and across ceilings and then how these biological marvels can be adapted to use in human engineering. The whole field is has been called biomimetics and could, in the future, lead to some incredible breakthroughs and not just fade free colours. Till more is known though, please don’t try this at home or anywhere else for that matter. Geckos can do it, people can’t, now and at least for the foreseeable future.


Full Screen Image – Yellow-bellied House Gecko, Thanjavur, South India ©Nick Sidle (Later to become the inspiration for the ‘Hotel Room Lizard’ in the second book of ‘The Heartstone Odyssey’ trilogy)


Gallery – Scotland’s Birds

Gallery – Tamil Nadu, South India


European Robin – Erithacus rubecula

Eurasian Jay – Garrulus glandarius

Yellow-bellied House Gecko – Hemidactylus flaviviridis

Romance lives!


Full Screen Image – Great Tit, Glen Convinth, Highland Scotland ©Nick Sidle

Great Tits are birds that form strong pair bonds that may last for far more than just one breeding season. Starting from this, a team from Oxford University set out to look at competing priorities in the birds’ behaviour, specifically if a male has to choose between staying with his mate or getting to a food source, which comes first? Their results have been published in the journal Current Biology

Experimental Evidence that Social Relationships Determine Individual Foraging Behaviour

and show that it is the relationship that comes first or, as it is put more eloquently on the Oxford University web site, that “birds choose love over food”

Oxford University – Wild birds choose love over food

So the age of romance is not entirely gone and, however valid an explanation of which strategy offers the best survival and evolutionary advantages may be, ultimately all that is saying is that love is worth it.


Scotland’s Birds gallery

Glen Convinth

Great Tit – Parus major

Goldfinch Survey


Full Screen Image – European Goldfinch, Glen Convinth, Highland Scotland ©Nick Sidle

Following existing results showing a 70% increase in reports of Goldfinches in UK gardens in recent years, the British Trust for Ornithology is conducting a survey into the feeding preferences of the birds to try and understand what might be driving the phenomenon and possible impacts on their behaviour of bird feeders and the provision of seed. The survey runs from November 2015 to February 2016 and anyone can help by taking part and any results would be welcome, all it needs is two minutes of observation in your own garden and the ability to recognise a Goldfinch, which is not too difficult since they are one of the most colourful and distinctive of British birds and there are plenty of photographs on the internet and in books to help you get it right. Full instructions on what to do and how to send in results can be found on the BTO website:

British Trust for Ornithology Goldfinch Survey

The instructions for the survey include that it is not necessary to be putting seed out for Goldfinches to take part, observations on what else they are eating are just as valuable. I suspect the Goldfinches would like to point out that this can be read in two ways. The first is that it is not a mandatory requirement to put out seed for them to join in with the survey, but the other way of looking at it is that you are not being told to avoid feeding them to be in on the initiative. The choice is entirely up to you and they might just like to suggest that the second interpretation has a lot to be said for it and that niger seed is rather special.


Scotalnd’s Birds gallery

Glen Convinth

European Goldfinch – Carduelis carduelis

Scotland, where the Elephants Really are Pink

Deilephila elpenor

Full Screen Image – Elephant Hawk Moth, Glen Convinth, Highland Scotland ©Nick Sidle

The Elephant Hawk Moth is a very large moth but the name actually comes from the caterpillar which looks very like an elephant’s trunk. The adults are also very pink so this resident elephant named species here really is that colour. Enormous mammals with trunks have not been in Scotland since the Mammoths became extinct after the Ice Age, but visiting ones with a travelling circus are credited with one of the reports about the Loch Ness Monster, when they were allowed into the Loch to cool off and enjoy a bath after a long journey down the North side to near Fort Augustus.

National Geographic News – Loch Ness Monster Was an Elephant?

As to Nessie? I’ve never seen him/her/them so I’m keeping an open mind but if I ever do, I promise to post the news here.


Scotland’s Insects and Arachnids gallery

Glen Convinth

Elephant Hawk Moth – Deilephila elpenor

I’m not a snake and I’ve not had too much to drink


Full Screen Image – Slow Worm, Glen Convinth, Highland Scotland ©Nick Sidle

After my post on the discovery that the underside of at least one species of snake has a lubricating film on the scales in which I said Scotland has only one species of snake regarded as resident, the European Adder, I was asked ‘what about the Slow Worm?’ True, it does look more like a snake than anything else and it most certainly is resident in Scotland, including in the Highlands in the North, but it is not actually a snake at all, or a worm for that matter. The Slow Worm is actually a lizard without any legs, legless as it is usually described, but in no way connected to alcohol.

Boloria euphrosyne

Full Screen Image – Slow Worm, Polmaily, Glen Urquhart, Highland Scotland ©Nick Sidle

They are smaller than snakes and have what is called as a semifossorial lifestyle, which is a complicated way of saying they spend a lot of time not strictly burrowing into the earth like a mole which is fossorial, but going a bit in that direction by hiding under things, hence semifossorial. The key features that confirm they are not snakes (and are lizards) include:

Having eyelids and blinking

Boloria euphrosyne

Full Screen Image – Slow Worm, Polmaily, Glen Urquhart, Highland Scotland ©Nick Sidle

Having visible ears

Shedding their skin one area at a time, not all in one go

Being able to break off their tail to escape a predator

They are also no threat to anyone, like almost all lizards they do not have a venomous bite (a few do such as the Gila Monster but the only ones I know are from South America, not even Europe, and most certainly do not include the Common Lizard found in Scotland). It should also be remembered that the majority of snakes are not poisonous, but to be fair the Adder is and should be treated with respect and caution.

Slow worms can be very long lived with estimates of up to thirty years in the wild and records of 54 years in captivity. One very important threat to them is the domestic cat which kills them almost indiscriminately, whether this is because the cat also makes the mistake of thinking they are a small snake and a threat that should be dealt with or whether they are too tempting prey to resist is an open question.

In Scotland and the rest of the UK, Slow Worms are decreasing in number and are a protected species under the Wildlife and Countryside Act meaning it is illegal to take, harm or disturb them.


Scotland’s Reptiles and Amphibians Gallery

Glen Convinth

Slow Worm – Anguis fragilis

Stop Thief!


Full Screen Image – Bohemian Cuckoo Bumblebee, Glen Convinth, Highland Scotland ©Nick Sidle

There is a crime wave sweeping the countryside and a new report from the University of Stirling aims to bring it to our attention. The team at Stirling led by Dr Mario Vallejo-Marin, an evolutionary biologist, indict some bees for taking pollen from flowers without acting as effective pollinators in return, which as far as the plant is concerned, is rather the point of the arrangement. It’s a bit like having a meal at a restaurant and leaving without paying – theft. Just like restaurants, plants try and put security measures in place to make sure this doesn’t happen, for example by having structures designed to only allow a bee to reach the pollen after they have provided a cross pollination service in the flower. Bees however have tried to get back to getting a free lunch by finding ways to open up the protective structures, such as by producing the right frequency of buzzing sound, and the study shows that this can mean in some flowers that 80% of visiting bees collected pollen but failed to brush up against the female parts of the flower and so were of very little use to the plant in return.

University of Stirling – Threat posed by pollen thief bees

The system does still work overall, and without bees plants and people would be in a lot of trouble, but this study throws a new light on how it is a much more complex interaction and not always fair in the outcome.


Scotland’s Insects and Arachnids Gallery

Glen Convinth

Bohemian Cuckoo Bumblebee – Bombus bohemicus