As many of you will know, Ramsey is an important site for (red-billed) chough (Pyrrhocorax pyrrhocorax). We have between 7-9 pairs breeding most years which represents between 1-2% of the UK population. There are approximately 55-65 pairs in Pembrokeshire, around 250 in Wales and 400-450 in the UK as a whole
Chough chiefly feed on soil invertebrates (e.g beetle and crane fly larvae) and the island provides ideal feeding condition thanks to the large open areas of short grassland from our managed grazing regime using sheep and ponies (not forgetting the contribution the red deer make!)
Late summer flocks can reach 50-60 birds with a mixture of breeders, non breeders and the young from that year. Come spring there is fierce competition for the limited amount of breeding space available – chough nest in sea caves on Ramsey and defend territories of around 1km in size.
However in winter things are more sedate. Some birds leave us altogether but most of the established breeders remain and guard their hard won territories. The arrival of marauding ‘teenage’ flocks of non-breeders adds some spice and we can see anything from 5-20 birds on winter days.
A few days ago I was very pleased to come across our oldest breeding bird and his partner. They were both colour ringed as nestlings on Ramsey so we know their history. The male bird (left leg=white ring, right leg = orange over red – although the orange ring has been lost over the years) will be 15 years old in 2015! A ripe old age for a chough and especially to still be breeding. At the moment he looks like he will be at it again in 2015 as he is regularly feeding near to his nest site with his partner and seeing off any other chough, ravens, crows and even peregrines that come too close.
Ramsey's 'old timer' chough - the white ring is clearly visible on the left leg (he is doing a sort of leg cross over in this photo making it look like his right leg!) while the faded red leg is visible on the right leg if you look closely (the orange ring has been lost at some point)
He has raised an impressive 40 young in his lifetime. He bred for the first time at 3 years old (which is about normal) and at first occupied a different site where he bred for 3 consecutive years. In 2006 he moved to the site he occupies now, originally with a different female.
He has been with his current partner (who is also ringed) since 2011 after the death of his previous female in the harsh winter of 2010-11. They had actually started nest building in the March of 2011 when she died so we didn’t expect him to team up with a new partner so quickly. However there is no room for sentiment in the chough world it would seem and within 2 weeks he had secured a new female!
An interesting twist was that the new partner ‘jumped ship’ from another site that spring where she had already begun nest building with a partner with whom she was successful the previous year (‘divorces’ can often follow failed breeding attempts). The jilted chough did not fare as well as our ringed male and was left without a partner for the rest of that season cutting a lonely figure as he sat on the cliff top above his site!
Chough have a complex social structure and roost together from around mid summer to the start of the breeding season (non breeders all year round in some cases) and probably use these occasions, to pass on information e.g. birds may leave the roost to go to prime feeding spots and are followed by other choughs. Most choughs find new partners this way at the equivalent of ‘youth clubs’ and ‘speed dating’ when lots of first year birds (and 'divorcees') gather together. So it is possible that she ‘discovered’ that the ‘best’ (most successful) chough on Ramsey was on the shelf again and took her opportunity. He was already 11 years old at this stage but the reward obviously outweighed the risk to her.
She was born in here in 2006 and has the colour combination of right leg=white with purple stripes (although this ring has fallen off) and left leg = white over yellow
The female with the white over yellow ring on her left leg and a metal BTO ring showing on her right leg
The pair feeding together on Ramsey's west coat (male on the left) - they have raised 14 young in 4 years
Fledging success is only half the story though. The important things is how many of those birds make it through their first couple of winters and enter the breeding population. The constant stream of new birds taking up vacant territories on Ramsey when they become available suggest that our birds do ok in that respect but we are not complacent. This is why we offer year round grazing on Ramsey and have recently opened up an old arable plot to provide additional winter foraging in the form of spilt grain in future years
So if you visit this year keep an eye out for ringed birds – one of them might just be this fellow – how much longer will be go on for?!.......