Category: Biology

The Cambridgeshire village of Cottenham lies partly on an ancient (early Cretaceous) lower greensand ridge just 8 metres above sea level and until the draining of the Fens in the 17th century it was essentially the only dry land between the city of Cambridge and the Isle of Ely almost 20 km northeast of the village. Regardless, the nearest stretch of seaside is about 60 km away (as the crow flies) and so you don’t necessarily expect to see seabirds in this village…unless, of course, you head northeast out of the village on Long Drove until you reach the gravel pits.

There you enter a world of wonder visible from the passing places along the drove: Gulls of many kinds, including recently an Iceland Gull, but more commonly Lesser Black-backed, Greater Black-backed, Herring, Black-headed Gull,
Gadwall, Shoveler, Tufted Duck, Teal, Coot, Mallard, Wigeon. It’s like having a waterfowl bird reserve in our back garden. Of course, strolling around such a site would be dangerous and as it’s private property, I did not venture beyond their boundaries, snapping from the safe side of the gate.

It’s been a week of Turdidae, what with the Fieldfares (Turdus pilaris) arriving in our gardens and the Blackbirds (Turdus merula) chasing off Redwings (Turdus iliacus). Then, a quick stop at Wimpole Hall to check in on the Hawfinches (none seen, this time) led to my witnessing and recording a tussle between two Song Thrush (Turdus philomelos), I assume with all this aggression it was a fight rather than courtship.

A friend asked me why we should feed wild birds, especially given the harsh weather conditions, wouldn’t it just be natural to let them fend for themselves, he suggested.

Well, isn’t it kinder to help? But, more to the point, it’s human behaviour (intensive farming practices, pollution, industrialisation) that has meant that so many species face extinction, surely we have an obligation to assist where we can? I spoke to an experienced birdwatcher not too long ago who told me of the flocks of birds that he used to see as a child, species that rarely make an appearance these days. And, yes, while there have been increases in numbers and some species have bounced back from extinction, the figures are not pretty overall.

For a nation of bird/animal lovers, we don’t have a good record. (Perhaps not as bad as nations that trap birds illegally in nets or on limed trees like so many aerial fish nor those places where shooting birds for sport or out of sheer malice (which also includes this country) is regarded as acceptable.

So, I will continue to break the ice on our birdbath, fill the feeders with expensive nijer seeds and sunflower hearts (as opposed to the cheap mixed bags of seed that are mostly filler that the birds discard anyway). I will keep adding suet pellets to other feeders and scatter meal worm on to a tray under a refuge that small ground feeders, but not rats nor corvids can enter.

This week, we have had a small influx of Fieldfares coming in from the cold fields, there is a pair of Pied Wagtails flitting about and seeking shelter under our lean-to, and a Song Thrush turned up recently, not seen one of those in the garden for a while. There are also the dozen or so Goldfinches that enjoy the nijer seeds, one Redpoll, the usual Blackbirds, Robin, Starlings, overwintering Blackcaps, Greenfinches, and Tits – Blue, Great, and Coal – in the garden on and off, as well as the Collared Doves and Wood Pigeons.

What else? Oh, yes, a few Jackdaws, Magpies, and Rooks. And, hopefully, any time soon, seeking out our berry bushes (Firethorn, pyracantha) Waxwings (I can only hope). No Bramblings nor Hawfinches yet, although they’re not far away according to bird reports.

Many bird species have gone extinct in recent decades, you are very unlikely to see a Bluethroat in the UK ever again, but there are many others. Most of the decline is our fault, it’s not a natural decline, it is farming, industry, and transport that have removed the natural world the birds previously inhabited, so, yes, we should feed the birds, even it is no longer “tuppence a bag”.

I’ve taken a few fairly close snaps of Wood Pigeons (Columba palumbus) and noticed that the pupils of their eyes do not seem to be perfectly round. Same with a few other birds, I assumed it was just an aberration, however, I wanted to be sure.

It didn’t take much web searching to discover that other people have noticed this too. Someone asked about it recently on the RSPB website and got a reply from Hein van Grouw, who is apparently Senior Curator, Bird Group at the Natural History Museum:

“Yes, wood pigeons seem to have non-circular pupils. The pupil, however, is circular but due to a spot of dark pigment in the iris the pupil seems to be non-circular. I have no idea what the reason (advantage) is for this. What I do know is that several other (tropical) species, mainly Fruit Doves, have it too.”

I must say though, it doesn’t look like pigmentation in the iris, it looks like a distortion of the edge of the pupil itself, at least in the photos I’ve taken. Oystercatchers have a pigment fleck too and you can tell what sex they are from this, apparently.

Wood Pigeons do seem to have really good eyesight regardless of the shape of their pupils, and perhaps partly because of them, they will veer off their flight path if they spot you walking below their course even through trees and can definitely see you from trees in the garden when you’re inside the house. That said, they will also completely ignore you if you don’t look at them and then take flight when they catch your eye. The eyes have it. (Hat tip to my Ladybird Farmer friend Simon for pointing that out).

Having invited the Waxwings to feast on our firethorn (pyracantha) berries, it turns out that a solitary Fieldfare (Turdus pilaris) has found the supply and a snow sanctuary in our front garden. Looking rather fed-up it has fluffed up its feathers against the cold and is rapidly working its way through the fruit of the firethorn.

Presumably, driven into more sheltered area because of the chills and snow out in the fields, those downy feathers are as fluffed as they can be.

Those nictating membranes (protective eyelids) are down much of the time in between snacks to protect its eyes from the snow flurries and the wind.

Fieldfares are true Thrushes along with Blackbirds, Song Thrush, Mistle Thrush, Redwing, and Ring Ouzel (the ones you’re quite likely to see in the British Isles, there are dozens of other Turdus species around the world. Turdus is Latin for Thrush as is the other half of the Fieldfare’s scientific binomial, pilaris. So its name is basically Thrush thrush. At least its compatriate the Redwing gets “flank” as the second half of its name Turdus iliacus, to indicate the prominent red markings on its flanks when it is perched with wings folded back.

Here’s my video about the Fieldfare.

A couple of people have asked me about the Peregrine photos I blogged a few days ago, specifically, what camera, lens, and settings I used to get the shots.

Well, first off I was standing at street level on the opposite side of the road to the church, it was a dull and overcast day. The female Peregrine was perched on a corner spire of the church tower about 34 metres above street level when I arrived, I used shutter priority to get a few shots of her and then tested aperture priority. When the male arrived and they mated I was in aperture priority mode and had to be quick to tweak settings as events unfolded.

Canon 6D, Sigma 150-600mm zoom. For what I consider the clearest and best shot I got, I had optical stabilisation switched on (to compensate for hand-held camera shake. I’d set aperture to f/11 to get some depth of field, centre-point focus and left the camera to choose the shutter speed (1/500s) and ISO 1600. I had also nudged the EV up at various stages and for this shot it was +3 to compensate for the camera reading the brightness of the sky, which would otherwise under-expose the birds.

The original photo was snapped in portrait orientation 3648 x 5472 pixels, cropped down to an approximately 1500 square for posting on social media, on Sciencebase it’s a watermarked 768 square. A few PaintShop tweaks included, bringing the blacks in, lightening shadows slightly, turning up the vibrancy a touch, and applying a relatively gentle unsharp mask.

Once again, I headed to our neighbouring village of Rampton armed with various lenses, tripod, camera etc, but there was barely a whisper of a murmuration this evening. A few small flocks and one half-decent one but quite a distance from the roost site that featured in my murmuration video on Sunday. There was definitely an Owl around but the Starlings seemed to favour the Cow Lane side of Rampton this evening. So, just a few scene-setting photos from today’s dusk chorus and one of mini-murmuration.

Here’s the video montage I did of the Starling Murmuration on Sunday in which there were probably 5000 birds in total. You can view it on Facebook or Youtube.