Dartford Marshes

I haven't been to Dartford marshes for a couple of years now; quite frankly, that is because it isn't that great a place and when I'm home I usually visit other sites; however, I decided to take a look today to see what was about.

Dartford marsh is not much of a marsh really, just a bunch of fields and rough land, but an open area of land in what is becoming an increasingly developed corridor along the River Thames which can sometimes turn up some interesting species. I drove as far towards the river wall as is possible and parked. I walked just a few metres when a Corn Bunting landed on a fence post and began to call. He was a real monster of a Corn Bunting and not at all shy allowing me to approach to about 3 metres. I watched him for about 10 minutes as he called across an area of ryegrass cultivated for a local model airplane club. The few times I flushed him, he immediately returned to the same place, indicating that this was his selected territory. at no time did I see any female or any other calling males. However, I didn't walk around the whole area so they may have been other birds around, although the sun was out, ideal weather for calling Corn Buntings, and search as I might, I couldn't detect any other Corn Buntings.

Further along a Reed Bunting was singing from a reedy ditch along with some Reed and Sedge Warblers and numerous Skylarks were singing away as was a lone Meadow Pipit.

At the river a number of gulls were loafing around; a few Great Black-backed, about 10 Lesser Black-backed, 3 Herring Gulls and lots of Black-headed Gulls including a few of this year's juveniles, but most interesting were two first year Yellow-legged Gulls - Dartford Marsh is a pretty reliable site for this species. A Common Sandpiper flushed from the river bank and headed towards Essex. Further along 3 more Common Sandpipers were feeding and a family of Linnets were feeding on weed seeds.

I walked along to Littlebrook power station to look for Black Redstarts that used to nest there but found only House Martins, Starlings, Pied Wagtails and Cormorants.

By this time I was getting hot and was late for lunch with my grandparents so I hurried back to the car seeing a Green Woodpecker and a Whitethroat on the way.

Littlebrook Power Station and Queen Elizabeth 2 Bridge, Dartford Marsh

Searching for Corn Buntings

Yesterday evening I went for a stroll to chceck out the Corn Bunting population near my mother's home in Hawley, near Dartford. Most of the oilseed rape had already been harvested, leaving just a few fields of wheat standing. I saw a few Skylarks and Linnets but no buntings; quite unusual.

A few other birds were around: Swift, Swallow, Wood Pigeon and a singing Whitethroat, but it wasn't until the last field that I saw a Corn Bunting, followed by another and another....
I counted 22 all in just about 1 hectare of land. Many were juveniles with just 3 calling males. Strangely these were the only Corn Buntings I saw. I hope that this isn't all that is left otherwise theyare in trouble here. I think more likely that most of the population is already lying low, moulting after completing breeding quite early.

Not much else on the way back, just Magpie, Carrion Crow and Stock Dove, but that is expected - Corn Buntings are the only real speciality of these arable fields.

Corn Buntings

I spent most of today thinking about Corn Buntings, not actually looking at them, just thinking. I'm in the third year of my degree in Wildlife and Countryside Conservation, and my dissertation is concerned with the breeding habitat selection of Corn Buntings. I did all the fieldwork in East Yorkshire/North Lincolnshire from May to August 2006 and I'm finally getting a chance to write up my findings.

I surveyed in the region of 100 square kilometres near RSPB Blacktoft Sands and found 168 singing male Corn Buntings. I plotted their territories and recorded the crops that each was using, whilst mapping the land use of the entire area. Fortunately, the weather was really warm and sunny for most of the study period, so the task was very pleasant indeed.

The initial results show quite a preference for Winter Barley in the period from 15th May to 15th June, but this changed after this period. The Barley was harvested in the first few days of July and the implication is that most of the nests were destroyed by this. On the positive side, birds seemed to be making use of other crops after this, perhaps making another attempt to breed. Winter Wheat and Peas were both popular from mid June to mid July. The next stage is to work out a biodiversity value for each kilometre grid sqaure and to compare that with Corn Bunting territory density, to see if there is an association between crop diversity and Corn Bunting density.

I also recorded Corn Bunting song posts, although this will not be a part of my dissertation as I already have quite enough data with the crop selection records. I recorded what the males were using as song posts, and the results were quite interesting (See graph below).

The labels are a bit too small to read I can see:

The first tall column from the origin is for umbellifers; both Cow Parsley and Hogweed.

The second tall column, which reaches to about 50, is for trees and large bushes.

The last tall column is for overhead wires.

All the other columns are for various arable weeds and crops.

Most birdwatchers that have seen Corn Buntings will have noticed birds using wires and trees to call from, but the massive preference for umbellifers over other arable weeds has been of interest to most people I have spoken to, including Simon Tonkin of the RSPB, who has done lots of work on the species (See his post about some of his success with CBs here).

There will be plenty more about Corn Buntings here when I've done further work with my data, I'll have to get a move on, my dissertation has to be in by mid April; almost a year after doing the work!