Sand Martin Ringing On The River Lune

The Sand Martin ringing season is about to get underway. I have prepared an account of our activities at the colonies on the River Lune to  to to provide information to those landowners and farmers  who have kindly given members of the North Lancashire Ringing Group access to their land to undertake our studies. I thought I would share this on the Blog.

We carry out a census each year of the breeding colonies from Skerton Lancaster  to Kirkby Lonsdale by counting occupied nest holes. Over the past five years the population has ranged between 3026 pairs (2011) and 1309 (2014). We have 40 years of counts and historically the population has varied between 370 (1984) and the recent high of 3026 in 2011. It is  thought that these fluctuations are mainly due to drought conditions in their African wintering areas causing high mortality, but river floods during the breeding season and lack of suitable nesting banks have also played their part.

Since 2001 we have caught nearly 27,000 Sand Martins mainly at the Lune colonies. The recovery locality of those reported away from the Lune is shown in the table below. Around 99% of these are birds caught be other bird ringers and released both in Britain and abroad.

Recovery  Localities of Sand Martins Ringed on the River Lune 

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Senegal	1		2									3
Spain			1	3			1	3	4	4
France					4		6	31	9
South Coast							16	112	28
East Anglia				3		5	28	14
Midlands				1		3	15	10	1
Yorkshire						7	13	7	3
Scotland					1	3	6	1

The late summer migration is well shown with  first brood juveniles already in East Anglia and the Midlands in late June and on into July many of these are caught on migration ,roosting in colonies on their way south, until the colonies are vacated in early August then they roost in reed-beds or maize fields  with Swallows.  The recoveries from Scotland are mainly .of juveniles  caught roosting in our colonies on their way south. The speed of departure was well shown this year by-one of the few birds we have ringed as a nestling. It probably left the nest about the 18^th of June but it was caught27 days later in Northern France a distance of 493 km SE, certainly a quick mover.  By . July many birds are along the south coast and into France, a movement that continues throughout July and reaches a peak in August then on to early September with adults and second brood youngsters joining in. August is the peak month for passage through western France and on into  Spain. Smaller numbers occur in France in September with none at all in October by which time they have moved in to Eastern Spain to eventually reach their wintering areas in West  Africa where we have six recoveries from Senegal.

Spring migration is not well documented as  little ringing takes place, also birds are moving through quickly and return to the  colonies where  ringing is not attempted to avoid disturbance at this critical time. Returns from Spain and France suggest a similar route to autumn.

John