A ring from middle estuary- #DB97059

Although I restrict myself to the southern shore I trained as a ringer under my good friend Bill Jones out on Oakham Island, which is frustratingly mid-estuary, just north of the main channel. I hope no-one objects to my publishing an occasional map from some of his ringing recoveries over the years here on this blog for interest.

Greenshank Ring no. DB97059
Ringed: 21st August 2001
Found: 4th July 2004, Taka-Aapa, Sodankyla, Lappi, Finland.
Leg recovered from Peregrine nest.
Found 1,048 days after ringing, 2,312 kilometres from Oakham.

Reading very much like DB97190, 059 was more than twice the distance of that Norwegian recovery, being found more than a hundred kilometres within the Arctic circle.

The Greenshank is a monotypic species, meaning no sub-species have evolved. However, discreet populations can be recognised by the timing and direction of their movements as well as their natal ranges and birds passing through here in the south-east of England are believed to mainly be from this Fenno-Scandinavian population (the Russian population move through eastern Europe south to Africa, and the small Scottish population are thought to winter between Ireland, western Britain and south-western Europe/ northwest Africa).

Once again a Peregrine was the villain of the piece. There will be some bias to the number of recoveries found at raptor nests, due to the volume of research work carried out at such sites.

Are losses like this routine on the breeding grounds? In their excellent monograph, Greenshanks, the Nethersole-Thompsons noted 21 Scottish nests out of 112 failed before hatching due to the following predators-
- Hooded Crow (9)
- Fox (4)
- Common Gull (2)
plus
- Red Deer (trampled, 1)
- self-inflicted by fighting female Greenshank (1)
- human interference (4)

As well as these nest failures, during the study Peregrines and Sparrowhawks also took a minimum of five adults, Foxes another four- and this was known to be an underestimation. "In all these years, however, the Greenshank groups have contained a number of surplus birds and pairs, some of which replaced the killed birds."

Reason, if reason were needed, to take all hints of possible population declines seriously- there is an evolutionary need for a surplus population. Reading BirdLife International's latest summary:
 "There is evidence to suggest that the European population (200,000-510,000 pairs, occupying 50-74% of the global breeding range) has declined by up to 30% over ten years (three generations)..." The reasons for this are not known, and could even reflect a shift within the breeding population; there is always more to be learnt.