The tides were right this morning; neap, covering an hour or so after dawn. Went to have a peek at the Black-tailed Godwits at Rainham Docks East. RDE is the old remnants of a cement factory quayside.
I have posted on Godwits at this particular site before (in relation to fog) but will now expand a little on how/when they congregate at RDE the most.
The site is within the Riverside Country Park, with a freshwater feed into Rainham Creek making RDE a popular loafing site with duck and, sometimes, with certain wader species, especially Black-wits (green). Footpaths (yellow) pass close to the two main roost areas, and while birds can put up with 'non-threatening people' passing by, they will take flight at those who take too close an interest in them (including birders).
Disturbance levels increase when the park is busy, as there are no restrictions on walking out along the two arms of RDE (orange).
So, the best chances of seeing waders using RDE as a roost are early morning tides. The Country Park car park here is open all hours, but many of the early visitors are dog walkers who prefer a stroll around the grassy field just south, or along the seawall westwards and back through the field. If a park visitor heads north, and takes the arms, or is simply noisy enough to be perceived a threat, the birds will be off.
Yup, today, the covering tide was right. Another reason for choosing neaps, the RDE roost sites go under on a spring tide. Sure enough, many of the 600+ Godwits feeding in Rainham Creek made the most of RDE. They followed the tide right in, gathered, roosted, snoozed. Northside, by the wreck. Southside, along the arm. For all of a half-hour.
So, what disturbed them today? One of those noisy dogwalkers? Nope. A keen amateur 'togger? Nah. Drone pilot? Not this time. Clueless birder with no fieldskills? Not me guv'nor. (Not today, anyway.)
A Sparrowhawk. There I was, all ready to hang the innocent citizens of Medway. A blooming big ol' female sprawk. Hunting in stealth mode behind the southern arm- duck flopped low into the water, waders flighted high, circling, unwilling to reassemble, then off to Motney Hill saltings, a much 'safer' roost on most tides.
RDE can be a roost. When high tide has happened an hour or so before dawn, you can go find birds there that have clearly sat the dark hours out safely there. But RDE, as well as being out of favour on certain tides, also changes use- from being a roost to a sub-roost; a gathering point, a pre-assembly before moving off to the choicest site for the high tide.
The question for me today was this- why not simply head off to that safest first choice roost straight away, rather than bother with a broken nap at a sub-roost? The Sparrowhawk gave me an idea. Here on the Medway, with a fair number of roosts and sub-roosts available, if you spent all of the roost time on the best roost site, every single tide, predators would have an easier time of it. Make them work for their lunch. (And more reading up for me in due course.)
I've always had the dream of a couple of signs at the start of the arms of RDE, asking people to consider not disturbing birds if present over the tide. I always wake up and realise those signs would end up in the mud after a day or so. Besides, the birds have do have those other sites they end up at.
But does having a choice of sites help to increase the appeal of the Medway to staging Black-tails? Would losing some, all sites along this southern shore place too much pressure on the birds? This had been another morning with more questions than answers.
The more we see, the more there is to see.
(For anyone interested in 'proper' studies of Black-tails, you can do no better than visit 'Wadertales'. Go. Visit. Learn. Much more than you ever will here.)