Tuesday, 29 September 2015

A season of Barn Swallows (pt 1 - nest monitoring)

Monitoring nests as part of the BTO's nest record scheme, brings with it the ups and downs of observing their successes and failures. This year has been no exception and the changeable and at times unseasonably cold weather has brought with it trials and tribulations at one of the farms where I monitor the Barn Swallows near Knutsford, Cheshire. The site is very successful for Swallows and from April onwards provides a home to approximately 20 pairs of adults - by the end of the season there will be between 150 to 200 flying around including the fledglings. (Swallows typically attempt to raise 2 broods of 4/5 chicks each.)

Along with the observations of the owner, we have had moments of mild peril (as when one newly fledged youngster failed to return to the nest to roost with its 3 siblings in the afternoon, only to return safely much later), and days of concern, like when the runt of a brood failed to fledge on the same day as its siblings. Having flopped to the floor when s/he attempted to leave and been returned to the nest by the farm's owner Sue, over the next couple of days the young bird could be seen desperately flapping its wings at the edge of the nest building up the strength to fly. This particular story did have a happy ending and the parents continued to tend to their smallest chick and s/he was able to join the others, fledging properly 2 days later. Of course there have been the occasional scenes of devastation, the nests which have been attacked by a predator, sometimes leaving the tiny lifeless bodies of its former occupants scattered over the floor (which happened at another farm I visit). The nests full of eggs which never hatch, perhaps abandoned, perhaps orphaned. And occasionally those where the contents seem to simply disappear between one visit and the next - times when nests where I have counted the eggs and returned expecting to see chicks only to find an intact nest, mysteriously empty. The reasons will never be known for certain but in cases like this the expectation is that very young chicks may have died and been removed from the nest (for example if the parents have failed to find sufficient food - in cold bad weather the insects they need to find are considerably harder to come by), or infrequently, an errant male may pull out the very young chicks of a rival. Sometimes the evidence is clear to see, often it isn’t. 

Another hazard facing the chicks at this farm is ostensibly harmless horsehair. At any one time there are 5/6 horses stabled and when the hair is used by the adults in the nests it can become as lethal as discarded fishing twine. Swallows generally use grasses and then feathers to line their mud-constructed nests - here the feathers come from the resident ducks and chickens, however horsehair is also used. As the chicks grow they can become hopelessly tangled in a tight web from which they cannot escape. For the nests which I can sensibly reach with ladders (the lowest in the barn are about 4.5 metres high), I monitor the nests and ring the chicks and will dispose of the horsehair and even give the nests a ‘haircut’. It can be a tricky and delicate operation to remove the chicks (temporarily) from their nests for ringing, so entangled have they become. Without the extravagance of something like a ‘cherry picker’, the highest nests remain out of reach and I cannot monitor them. It’s an incredibly sad sight to see, too late, a young bird hanging from the side of the nest, lifeless, having been unable to free itself from the horsehair to fledge. (This happened in one of the highest nests this summer.) I've no doubt that untangling chicks for ringing and removing horsehair from the nest lining has prevented more similar occurrences from happening. Others have been more lucky and if spotted dangling and flapping the owner has managed to cut them free.

Newly ringed Swallow chick

And another newly ringed chick, clearly showing wing feathers just starting to emerge from their waxy protective sheath

On another occasion a crisis happened on a day when I had been working in London. I was finally on the train home when I received a call from Sue asking for any advice I could give regarding two chicks she had found on the floor of the stables. Unsure of which nest they had come from, and having tried to return them to another nest, they had fallen out (or been ousted) again. (This was a week (well, the week) which was exceptionally hot. Sometimes when the weather is especially hot, the chicks (particularly if they are large) seem to be at increased risk of falling out as they stretch out and try to make some breathing space between themselves and their nestmates. The timing, and that it was two birds (from different nests) would indicate that this was most likely what had happened here. I offered my best advice and set about researching Swallow rehab further on the train journey home. Once I got back we loaded up the ladders and my husband and I went over to see what we could do to help. It was too late to take the chicks to a wildlife hospital and Swallows are notoriously difficult to hand rear. It’s not impossible, but their chances of survival in human care are very slim. The owner had been able to give them water but not food and both chicks felt skinny (their sternums were very pronounced). They were both fairly similar in age and size and probably a week or so from being ready to fledge, though they had been sufficiently feathered so as to survive the fall from their respective nests. Their premature attempts at flight may have saved them, but at the same time made it impossible to tell which of the many potential nests they might have come from. All we knew was that being at that age and unringed, they hadn’t come from any of the lower nests that were being monitored. 

Quickly, a plan was hatched. We knew the chicks couldn't have been fed for several hours, and being nighttime there was no chance they would be fed by any adult birds until the morning. What to feed them….? Well it was going to be just one makeshift meal, so the best we could do was beef cat food (I’d read that minced beef could be tried, as well as cat or dog food in the absence of better invertebrate options, hence the choice). Then came the not insignificant issue of how to feed them. Of course chicks are not accustomed to a giant approaching them with tweezers and an unfamiliar blob of food intended for something else. Beaks remained tightly shut. Luckily I knew this would probably happen, so knew to very gently squeeze at the sides of their beaks to help in gently prising them open. It quickly became apparent that food close to the front of their beaks would just sit there, it needed to be gently pushed towards the back of the mouth to trigger the desired swallowing reflex. Having done my best to fill little tummies with the equivalent of several dozen insects, the next step was to try to rehome the chicks. Not knowing which nest they had come from, (and in any case not being able to reach the highest nests which were the most likely), two nests which were already being monitored were chosen which already contained chicks but not too many, and of the closest match in size as possible, and the chicks placed in with what I hoped would become their adoptive siblings. Then followed an anxious wait to see if they would be rejected and/or ejected by the adults. Takeaway dinner by candle and moonlight followed as we anxiously waited to see if they remained in their new nests. The next hour or so passed uneventfully so we finally returned home at about 11pm.  

Sue kept a close watch over these two nests in the days that followed and as far as we can tell, in the absence of any evidence to the contrary, it seemed both of these chicks were accepted and successfully fledged.
The season finished with a total of 106 nestling Swallows being ringed from 25 nests monitored. (106 out of 111 chicks from the nests I can reach - 5 in one nest were too close to fledging to ring when I visited.) Of these 4 ringed chicks from the same nest were found dead on the floor before fledging though the nest was intact, the remainder appear to have fledged successfully. An additional two nests failed at the egg/very small chick stage.

Apart from the last few stragglers, they are now making their way to southern Africa, so I can only wish them well, and look forward to their return next spring.

On the move... Close to fledging, one of the chicks is more keen to wander from the nest than the others, we watched as the most adventurous individual sidled up and down the bar while the others looked on....

Back together again

Monday, 28 September 2015

Blood Moon Supermoon

As many people will be aware, in the very early hours of 28 September (for the UK) we were treated to the incredible sight of a ‘Blood Moon Supermoon’ where a 'Blood Moon' coincided with a ‘Supermoon’ making the event an even more spectacular as well as relatively rare occurrence.

The phenomenon of a ‘Blood Moon’ occurs when the sun, Earth and moon are in alignment, with the moon the opposing side of the Earth from the sun so that the Earth blocks light from the sun from illuminating the moon, resulting in a total lunar eclipse  – the moon is entirely in the Earth’s shadow. The limited light that does reach the moon has passed through the Earth’s atmosphere. Green through to violet light of the colour spectrum is scattered more than red through filtration and refraction as it passes through the Earth's atmosphere leaving more red light than other colours remaining to illuminate the moon’s surface.

A ‘supermoon’ occurs when the moon is at its closest to Earth on its orbit and this also coincides with a full moon – the moon at this time appears larger and brighter than at other times.

The next time these events are predicted to coincide again won’t be until the year 2033, so with perfectly clear skies predicted (hooray!!!) I made the effort to set an alarm for a little before 3am to watch this rare event. This was the view from our garden at 03.13am this morning.

Blood moon supermoon, Cheshire, UK 28/9/15 at 03.13 am

Sunday, 20 September 2015

CBeebies - 'Nina and the Neurons' and nest building

A BBC 'CBeebies' programme that will be of interest to young children interested in birds is currently available on iPlayer for another 3 weeks or so - 'Nina and the Neurons' and an episode on how birds build their nests. 'Nina and the Neurons' is a science series aimed at kids aged 4-6, and with the help of some simple experiments, answers questions posed by young children - in this episode the question being "How do birds build nests?".

My children are rather older than the age group this programme is aimed at - I am aware of the series and of this episode in particular because it was a lovely surprise a little while ago to be contacted by the show's production team who asked if they could use a couple of my photos to illustrate two of the bird species whose very different nests they would be displaying; a Long-tailed Tit with its wonderful elastic nest made from mosses and lichens held together by spider silk, and also a Blackbird with their solid nest (typically built by the female) of grasses, leaves and moss lined with neatly plastered mud. The Blackbird and Long-tailed Tit photos had just been taken in our garden. There was also a lovely photo of a Reed Warbler (not one of mine) and an example of its nest - a beautiful construction of intertwined grasses and reed flowers which is woven around the stems of Common Reed (Phragmites australis) in their watery reedbed homes.

A couple of screenshots from the programme below;

And one of the original images, taken in spring;

Male Blackbird

Tuesday, 8 September 2015

Early autumn macro

All too quickly summer is gradually fading into autumn, most of the birds have fallen silent and the nights are noticeably drawing in. I've even seen the first of the Christmas decorations appearing for sale!  Exceptions to the quiet bird rule have been the local Robins, birds in which both sexes sing, and they also do so right through the winter. After an absence through much of August it is a joy to see these charismatic birds back again, singing and scolding in turn.
After a cool and largely cloudy couple of weeks, yesterday was a day of glorious sunshine, and not being in work the obvious thing to do was head out with the camera to make the most of the dwindling days (for this year at least), of being able to enjoy insect macro photography. I headed over to the Quinta arboretum and Wildlife Trust reserve of the same name in the small Cheshire village of Swettenham. My impression has been that this summer has been fairly poor for butterflies generally, however today, late in the butterfly season, my spirits were lifted to see a number of different species. A male Brimstone with his vibrant lemon yellow wings enjoyed lavender, Large, Small and Green-veined whites visited the last flowers of Green Alkanet, as did a surprisingly late Holly Blue. A rather old and faded Red Admiral lazed on nettle leaves, and a beautiful Small Tortoiseshell enjoyed the late flowering hydrangea and Colutea plant. Speckled Wood butterflies flew along rides of dappled sunlight, one which caught my attention was an individual with a large chunk of one forewing missing, though still flew surprisingly well.

Male Brimstone

Small Tortoiseshell

Small White butterfly
Speckled Wood butterfly (nearly half of the furthest forewing is missing)

Hoverflies were plentiful too, mostly they looked to be Eristalis species, but amongst the flowers of a selection of Hebes I watched the distinctive large and beautiful hoverfly that is Volucella pellucens, also known as the Great Pied hoverfly due to their markings and large size (also one of the few hoverflies where I can be confident of the ID without needing to look them up!). 

Volucella pellucens (female)

Clambering through pine needles was an adult Forest bug, a type of large shield bug.
Forest bug (Pentatoma rufipes)

The rich bounty of autumn was everywhere I looked with Rowan berries ripening on the trees, and the deepest purple of blackberries ready to be picked. (Something I love at this time of year is a few berries along the way of my walks, though at the risk of stating the obvious, only take ones which are out of the range of peeing dogs (or humans for that matter!!!!).) Acorns were ripening on oak trees, but as well as the regular acorns were acorns with Knopper galls, caused by the developing larvae of the Andricus quercuscalicis wasp. 

Knopper gall (and an out of focus Spangle gall)

A pleasure to watch was this solitary bee, about the size of a honey bee and with a pollen 'brush' on her abdomen, I think this is a type of leaf cutter bee (I'm always interested to hear if anyone can confirm or correct my ID attempts). Visiting each flower entailed some contortions and back arching as the photo below hopefully shows, to reach the nectar within. 
Solitary bee, perhaps a leaf-cutter?

Other solitary bees I noticed were considerably smaller, the one here on Hebe flowers being barely one centimetre in length, which I think is Lasioglossum leucozonium.   

Lasioglossum leucozonium?

Saturday, 5 September 2015

Noisy visitors...

This summer a wonderful surprise has been to have had at least 2 hedgehogs visiting the garden. I had wondered if this might be the case from the occasional dropping left in the garden but not being confident in poo ID (!) we hadn’t been certain until one night when I went out into the garden at nearly midnight to bring in some washing that had been long forgotten. Noticing a small dark patch on the lawn I went to have a closer look and was delighted to realise that this was in fact a hedgehog going about his or her business in the garden. I did some research on the internet for what foods were suitable to put out for them (knowing that milk and bread should not be given as they find milk hard to digest and it can actually make them quite ill), and that whilst they can be given dog or [non-fish based] cat food, I was also keen to not attract every cat in the neighbourhood as we try to keep the garden as bird-friendly as possible. As well as food specifically designed for hedgehogs, they can also be given foods you might buy for garden birds such as sunflower hearts, kibbled peanuts and mealworms. I experimented with combinations of these and so far our experience has been that the mealworms seem to be their favourites by far, disappearing first (I watched one night as an individual crunched through all of these first, ignoring the other treats!), then the sunflower hearts and dry hedgehog food.  

We also bought a Hogitat which has been placed tucked out of the way under some garden shrubs and part filled with hay (shelters can be easily made of course with lots of ideas and designs on various internet sites). Having placed it close to where I’d first seen a hedgehog, I was pleased in the following nights to hear the noises coming from the direction of it, and also watching a hedgehog scuttle off towards it. Hopefully it will be of some use to them to rest and/or shelter.

The below is an audio recording was taken at about 10.30 at night - I went into the back garden and could hear a racket coming from the shrub borders, at first I wondered if a neighbour's dog was on the loose! I couldn’t see the hedgehog(s) responsible so had assumed that there was only one present, though a couple of nights later did we see two hedgehogs, so I’m not sure if the sounds are just of one snuffling around in search of food, or if there were two present and maybe some hedgehog flirting is going on! They are known to be noisy animals, though this is the first time I've heard this! 

Below is my first attempt to photograph this entirely nocturnal animal. I was rather loathe to use the flash and risk frightening them away, so the below grainy photo was taken using the available light from the house and a high ISO – hopefully I will have more opportunities to photograph them, maybe even with better results, but regardless, with their critical decline in the UK – numbers are estimated to have fallen to less than 1 million currently from an estimated 30 million in the 1950s, we're just delighted to have had them visiting our garden this year.

I also signed up to Hedgehog street – the site has lots of useful information and resources for encouraging hedgehogs and making garden habitats as welcoming and safe to them as possible. Simple adjustments such as making gaps in garden borders so that hedgehogs can move between gardens and ensuring garden ponds have a shallow edge to avoid the risk of them drowning in them can make a real difference to these loveable mammals. Other dangers posed to hedgehogs, such as use of slug pellets, garden equipment such as mowers and strimmers and bonfires could be largely eradicated with a little more care and attention and some minor changes on behalf of their human neighbours. 

I also recently received a link to a petition which is asking DEFRA to increase the legal protections for hedgehogs.