Tuesday 2 May 2017

May Day in Hertfordshire 1st May 2017

The first day of May and I awoke with no pain in my troublesome knee, a Blackbird was easing  out his laconic contralto song in the flowering cherry tree by the bedroom window and early morning sunshine illuminated the walls of the room. It was a good day to be out and I had something definite in mind.

At this time of the year it is not unusual for small parties of Dotterels, called trips, to be recorded at traditional sites in various parts of England, often in the south, resting and awaiting  a propitious time to move on and up into the mountains of Scotland, Scandinavia and northern Russia to commence breeding.

They have arrived from their semi desert wintering grounds in the Mediterranean and North Africa which can encompass anywhere from Morocco in the west as far to the east as Iran, and wherever they land on our shores they usually remain for a good number of days before moving on further north. Often their favoured transitory habitat is agricultural land such as a large, often stony, flat and fallow field at the highest point of the local topography where they can find an abundance of invertebrates and their plumage blends in with the brown earth.

This is one of those few species where the breeding roles are reversed and as a consequence the females are brighter in plumage than the males. The male mates with the female, the female lays from two to four eggs and then leaves the male to incubate the eggs and raise the young on his own whilst the female will mate with other males and lay further eggs.

Today, May Day, I went to Therfield in Hertfordshire where four Dotterel have been present for a few days, residing in a typically large, fallow field surrounded  by other huge fields. It was serendipity that I went to Therfield which is near Royston, as James the First of England went every year to Royston to shoot dotterels and it was nice to think that despite everything the dotterels, albeit now in much reduced numbers and the passage of four hundred years, still use the area as a staging post on their northward migration. The name dotterel dates from around 1440 when it was used as an insult to someone considered simple or stupid and the connection to the bird is that dotterels are almost always confiding and unsuspecting when encountered.

I walked down Mill Lane in Therfield, enclosed on both sides by huge expensive properties and then passing a farmyard took a wide bridleway before branching off onto a grass footpath heading east, passing through hawthorn hedges before opening out to run alongside the fallow field in question. The whole area imparted a sterile, uninspiring feel as far as finding any birds was concerned, being located at the highest point in a rolling countryside vista of similar huge fields where all you could see was a monoculture stretching for miles in all directions. Nonetheless its comparative isolation was not unpleasant.

The Dotterel field
I could see four birders standing at the far corner of the field and looking back into it. Good, as this almost surely meant the Dotterels were still here and my journey was not a wasted one. I walked the seven hundred metres to the corner of the field and stationed myself in front of an isolated straggly hawthorn so as not to be silhouetted on the horizon.

The Dotterels were immediately obvious, running and then stopping in that halting, typical plover action to stoop and pick prey from the ground. They were close to me and gave ample opportunities to take photos.Typically they showed little concern about my presence or that of the other birders but just carried on feeding. Two were very brightly plumaged whilst the other two appeared to be almost in non breeding plumage. The duller two showed more caution towards us but the brightly coloured pair of birds came ever closer.

Duller plumaged Dotterel- male or possibly non breeder?

Brighter plumaged Dotterel-female?
I was not complaining and followed them from the side of the field as they moved down and across the ground, always remaining in contact with each other as a loose group of four.

The two bright individuals were really beautifully marked and I suspect were females. The most distinctive features were the huge white supercilia which meet in a point on the back of the black crown and also the white semi circular breast band separating the grey brown upper breast from the rich chestnut lower breast and flanks and the black belly.The upperparts appeared scaly due to buff fringes to the brown wing feathers 

The other two individuals appeared drab in comparison, their plumage loosely mirroring the patterning of the supposed females and showing the distinctive supercilia, albeit buff rather than pure white, but the overall appearance was far more subdued and with little contrast in colouration apart from on the breast and belly and even here it was more diluted and less distinct. I did in fact wonder if these two  were still to moult into brighter plumage as their plumage appeared to be partly non breeding plumage and there was a further contrast between the two, in that one showed more colouring on its underparts than the other. Dotterels often arrive in this country still in active moult and can rapidly acquire breeding plumage over just a few days. This also may explain why they remain for some time at lower elevations so as to arrive at their breeding areas in full breeding plumage. The two individuals subdued plumage made them much harder to pick out on the ground than the supposed females, although none of them were easy to see with the naked eye until they moved. Possibly the duller two birds were non breeders, as sometimes they do not breed until their third year and these two were just undertaking the migration with no intention of breeding, although this seems unlikely. Maybe they were males that have a duller plumage than the females and still had a little way to go until they acquired their breeding plumage. Frankly I just do not know, having relatively little experience of Dotterels in their various plumages

                                  This was the brighter of the two dull coloured birds. Possibly still moulting
                                                                                            into breeding plumage?

The above images show possibly male Dotterels still to acquire full breeding
plumage or maybe even non breeders
The only other sign of birdlife was a singing Corn Bunting sitting at the top of one of the few small hawthorns left standing and jingling out his simple song in an area that was obviously popular with the villagers, some of whom passed me on the track,  greeting me as they walked their dogs.

After about half an hour the other birders departed and I was left to myself to stand on the track opposite the Dotterels and enjoy their presence and close proximity. It always brings me a sense of privilege to share some time with these birds as it is only in the briefest of circumstances, such as this, that I get an opportunity to see them. Sadly, although globally not threatened they are declining in Scotland where they breed on mountain plateaux such as The Cairngorms. A survey conducted in 2015 showed that between 1987 and 2011 the population of breeding male Dotterels in Scotland fell from 980 to 423, a decline of 57%. Not at all good.

As I watched the sky progressively became a darker grey as a large cloud moved closer on the easterly wind and a light rain shower peppered me which brought proceedings to a natural conclusion.

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