Last night I met and worked with the font of all knowledge. Corncrake knowledge that is. And of other bird species knowledge too. But we only need to think about corncrakes right now. Professor Rhys Green. The most scientisty scientist that I’ve met so far.
I took him to locations on the Nene Washes reserve where I knew there to be male corncrakes calling from each night.
Equipped with a lure tape (corncrake recording), mist net (a special bird catching net), and dozens of apparatuses that Rhys designs and makes specifically for the job, we managed to catch five male corncrakes.
The aim is to set up the net in-between the crake and the crake recording. The crake hears what he presumes to be another male calling close by within his territory and comes forth to challenge him.
Some take a while to lure. Some are in the net within seconds. Some take their time and creep forward cautiously (under the net). One was sneaky and appeared within a few feet of the tape lure before he responded vocally. And one was extremely angry and continued to call whilst in the net and whilst Rhys untangled him from said net.
All the boys we caught were yearlings and had a silver ring on their legs. The unique reference number on each ring will tell us who each bird is – age, sex, where he’s been (if he’s been caught and recorded previously), where he was released, which zoo bred him, and who his parents were! They were all very probably released here, as part of the reintroduction programme, on RSPB Nene Washes. Since then, they’ve migrated to western Africa, then again mid winter to the Congo, and then back to Cambridgeshire recently. Amazing!
We didn’t last night, but if we caught one with no ring, this would indicate that he was wild born. Catching one of these guys would be an extra bonus because that would signify that the captive bred released females are also doing what they should.
The males are calling for females, who arrive a tad later than the males, saying “here I am, come make baby corncrakes with me!”. Their calling also advertises to other males “this is my territory, go find your own”.
Due to the nature, behaviour and lifestyle of the birds, we can only survey for male corncrakes and make a guestimate of the population from those numbers. That’s what I do on any pleasant weathered night. I locate the calling males, using my ears, and record their exact location using GPS and compass triangulation methods (or just walk to within a metre or two of the bird and take his exact GPS reading. Oh if only they were all that obliging!
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