Last week I received new rings and dug out my ringing equipment and nets here at the farm in Denmark. The last feathers I felt in my fingers were neo-tropical birds in the lowland jungles of Peru. It was both exciting and refreshing to reacquaint myself with some locals, despite the fact that the spring weather left my fingers more than a little cold and stiff – that didn’t happen in Peru!
One of the first birds I caught was a male greenfinch (Carduelis chloris). I haven’t had much experience with greenfinches, having ringed a total of 4 to date, and I didn’t realise they could present some interesting challenges, especially in spring. Adult birds undergo a complete post-breeding moult in the late summer / early autumn, while first year birds have a partial post-juvenile moult slightly later than the adults, which can be limited or quite extensive, sometimes including primaries as I found out from David Norman’s detailed blog and Stephen Menzie’s blog. However in southern greenfinch populations the post-juvenile moult can also be complete (Harris, 1992).
I decided to review my photos to better understand how to accurately age Greenfinches in spring, for when I (hopefully) come across them again. Firstly the plumage was in superb condition with bright contrasting colours and sharp clean edges on the feathers, with little or no sign of wear. The primaries and secondaries appeared dark, with a pale yellow edge. The tertials were broad, square and grey with dark centers (adult like). I was unable to find a moult limit within the greater coverts, or any contrast in wear between the adjacent carpal covert or alula (adult like) .
The primary coverts were round in shape and had dark centres, with a yellowish green fringe, becoming greyish towards the tip of the feather (adult like). The tail feathers were broad, rounded and also in good condition (adult like). Having a closer look at the wing I spotted a feather which was a little different to the others. The innermost secondary (identified above with red arrow) contrasted with both the tertials and other secondaries as it was more brownish in colour, showing a reasonable amount of wear.
Combining all the information “presented” in the feathers, along with photos and information from various sources, it appears that this bird is an adult (3rd calendar year or older, EURING 6). However it has retained one secondary from the previous years plumage. According to Jenni & Winkler (1994) arrested moult, where a bird retains unmoulted feathers can “accidentally” happen in almost all species. It is more common among birds with that have limited time to moult i.e. long distance migrants, northern populations and late breeders.
As mentioned previously, research has shown that in southern populations (Harris 1992 in south Portugal) first year greenfinches (among other finches) can undergo a complete post-juvenile moult, thus making it difficult to differentiate age groups from late autumn onwards. However as this greenfinch was caught in Denmark, I think there is a very small possibility that it is a juvenile with a very extensive post-juvenile moult, retaining one single secondary. Furthermore I would expect a retained juvenile feather to have far more extensive wear, as the feather quality of juvenile feathers is much poorer than that of adults.
With southern greenfinches in mind I dug out some photos I took while ringing in Aiguamolls National Park in northern Spain in the spring of 2014. It is possible that the female greenfinch below is either an adult (EURING 6) having undergone a complete post-breeding moult, with no retained feathers, or a second year (EURING 5) with a similar complete moult, with no retained juvenile feathers. I’m somewhat glad I’m on the northern edges of the breeding range!
Now all I have to do is catch a few second years to put it all into practice!
First-year Greenfinches with moulted primaries – David Norman Blog
Finchy Fun – Stephen Menzie Blog
Harris, P. (1992) Ageing finches in southern Portugal, Ringing & Migration, 13:3, 175-176
Jenni, L. & Winkler, R. (1994): Moult and Ageing of European Passerines. Academic Press, London, UK
Yesterday while soaking up the afternoon sun at the back of the house an exciting natural drama unfolded before my eyes. It began when I spotted a hooded crow (Corvus cornix) behaving a little odd. It appeared to be hovering over the adjacent field which is filled with knee high rapeseed plants. As I sipped my tea, I became a little confused as crows don’t generally hover, a behaviour I associate with birds of prey like kestrels (Falco tinnunculus) and common buzzards (Buteo buteo).
I kept watching closely and suddenly the crow dived into the field and disappeared out of view. When it reappeared in the air, something was dangling in it’s grip. Straight away I knew it wasn’t a small mammal, like a mouse or a vole, it has seized, it was far too big! And it was making a strange noise, something I can only describe as a cross between a squeal and a grunt.
The crow began to fly with it’s catch across the open fields above the house (where the horses and sheep are grazing), and right behind it in hot pursuit was an adult hare (Lepus europaeus)! Suddenly what I was seeing made sense! The crow had spotted a young hare (leveret) hiding in the rapeseed field, swooped down and snatched it and one of the parents was, of course, not happy!
The baby hare was a fighter and was struggling in the crows grip. As I watched in amazement it managed to wiggle free, and landed on the ground in the open field. However by this time, the adult hare had vanished. I took this as my cue to intervene. I jumped into my wellies and ran to rescue the tiny hare. Yesterday I stood firmly on the side of adorable baby mammals, as opposed to hungry foraging birds, that must be said.
The tiny leveret sat motionless on the grass, breathing rapidly, stressed from it’s ordeal. It was now a very easy target for the hungry crow, that was still hanging around, hoping for some lunch. I carefully picked it up and placed it in a box. As it recovered, I realised it was not as defenceless as I had first imagined. It began to “attack” everything and nothing by launching itself across the box and making a strange barking noise. Tiny but fierce! (We took this rare opportunity to take a few photos and two short videos before releasing it – see videos here and here.)
Not exactly sure what to do, we decided to return it to the place it had been taken from, as there maybe a sibling in the area that the parents would return to. From my later investigations, I learned that hares don’t use dens or burrows like rabbits. To avoid attracting predators (like foxes) the young are left alone most of the day in “forms” (depressions in a sheltered location) close to where they were born. The mother returns once a day at sunset to feed her young. We released the leveret into the knee high rapeseed plants. Fingers crossed it found a good hiding place, and was reunited with it’s mother again at sunset.
From the doorstep of the house we witnessed this amazing drama, first hand. Not on a television screen, in a zoo or even a nature reserve. Just outside the back door (granted we do live on a farm). Yesterdays “nature in action” drama reminded me of how much we can experience and connect with nature if we simply spend more time outside. Here’s my message: turn off the screens and get outside – you never know what you will see!
There is a lot to be said for waymarked or signposted trails – leave your map and compass at home and enjoy a wander, which we have signposted for you. Perfect for an Easter Sunday springtime ramble with Hanne and Max. I was excited to visit this somewhat longer 15km circular route I found on Holsterbo Kommune’s website which winds around Subbergård lake, not far from our farmyard home.
The path, which for the most, part doesn’t stray too far from the lake shore wanders through different habitats, from open heathland and grassland to both deciduous and coniferous forest and there is even a small taste of agricultural land. The weather was, as to be expected in spring, changeable, and we were rewarded with sunshine, rolling clouds and a fresh breeze as we walked.
There were plenty of signs of spring to be seen. The fluffy soft buds of the willow trees were bursting out, and I learned that these are known as “gæslinger” in Danish, which translates to baby geese – how adorable!
I was happy to find a small blanket (more like a rug) of early woodland flowers (Wood Anenome) and at one corner of the lake we spotted a small group of Greater Crested Grebes. To my surprise they were already beginning their exceptionally romantic courtship displays, which includes synchronised swimming, dancing, head shaking and giving each other gifts (mostly wet grass or weeds!). This is a must for everyone to see, and will melt the hearts of even the most cynical!
Anyone who has joined me on an outdoor excursion, is familiar with my slight obsession for poo and poo like objects produced by mammals and birds. The lake side walk offered me many chances to get up close and personal with various forms of excrement – how exciting! I spotted what appeared to be signs of fox, otter and possibly a bird of prey pellet (undigested bones and fur are coughed up by owls, falcons etc.). My favourite was a fox dropping filled with the blue / purple shells of many many beetles (see below). Remember to wash your hands before eating, if you do, like me, decide to play with droppings!
In the ruins of a monastery we also spotted signs of life. Stuck on to the white walls inside the strange shaped building, I counted the remains of over 20 barn swallow (landsvale) nests. It was all very quiet in the old building, but in no time at all the adult birds will reach Denmark, after flying a LONG way from Africa, and will start renovating their nests and starting families. It will get a little crowded in their I imagine! Keep your eyes peeled for returning swallows!
When the sun broke through the clouds we were greeted with many tiny voices singing from the trees. The air was filled with the songs of skylark, robin, wren, coal tit, chaffinch and chiffchaff to name just a few. We were lucky to make it back to the car, with heavy legs and sore toes before the clouds brought rain. I’m looking forward to visiting again and spotting more signs of spring and maybe even summer!