Tuesday 2 August 2022

Danish Nightjar details

I have just received the original ringing details of the Danish-ringed Nightjar that I controlled in North Wales. It was ringed as a juvenile on 21st August 2021 at Glæde, ThistedViborg, Denmark.

Given the age at ringing and the date of ringing there is still some uncertainty about the provenance of this individual. In many species of bird juveniles often make exploratory movements away from their natal area before heading south on migration. This bird could have been a bird reared in Denmark that has subsequently nested in Wales or perhaps more likely it could also have been a British-bred bird that dispersed north (or even got blown north whilst on migration) before correcting itself and heading south to its winter quarters.

Normally we would be left not knowing which scenario was correct but in this instance we may have an ace in the hole that could give us more clarity. Over that past few seasons, as assistance to George Day (a PhD student at York University working on European Nightjar breeding systems) I have DNA sampled a large proportion of the birds breeding and reared on the wind farm monitoring site at Clocaenog. I also managed to collect a shed feather from the Danish-ringed bird. It may therefore be possible to compare the DNA profiles and see how likely it is that the bird was from the local Welsh population or whether it was sufficiently different to imply a more distant origin.



Male Nightjar on day roost

Saturday 2 July 2022

A nocturnal surprise!

When I was a newly qualified 'C' ringer living in Shropshire in 1980  I dreamed of catching a Nightjar. One night, at a local forestry plantation near Pontesbury I even, unexpectedly, had one flying around the nets we had set for general warbler netting. Despite placing a white birdbag in the bottom shelf of every net and even tying moths into the mesh we didn't catch it and it was clearly just passing through as it was never seen again. It was however a very notable sighting for Shropshire at the time. Fast forward 42 years and part of my work is now on Nightjar surveying for wind farm developments. Despite having personally ringed a total of 619 Nightjars (nearly all in Wales) and also retrapped at least 265 individuals I still get a massive buzz every time I catch one. That adrenalin rush was however amplified to an unbelievable level the other night when I extracted a ringed Nightjar from the net and realised immediately that the ring wasn't a BTO ring!

After an agonising search of the car for my glasses I read the word DENMARK! WHAT!!! A Danish-ringed Nightjar (or should that be Natravnen?) clearly breeding in a forestry plantation in North Wales! What on earth is going on there? I now have an equally agonising wait to hear where and when this bird was ringed. Was it ringed on autumn passage so possibly a lost UK bred bird? Was it ringed as a chick? Or was it possibly even ringed by Danish ringers on an expedition to Africa? At least things are a bit quicker these days, when I used to ring Starlings as a student in Aberystwyth we sometimes had to wait five years or more to get the original ringing details back from behind the Iron Curtain! I will of course share the results of this amazing capture as soon as I get them. This is only the fourth foreign-ringed Nightjar ever recovered in Great Britain and the first recorded movement between Denmark and GB. Who says we don't have anything left to discover through traditional ringing methods?