Ramsey Island and Grassholm

Ramsey Island and Grassholm

Ramsey Island and Grassholm
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Ramsey Island and Grassholm

  • Island Hopping

    After our planned trip to Skokholm this weekend was cancelled due to the forecast, Lisa and I decided to head down to south Pembs anyway to revisit some old haunts. A night in the Lobster Pot in Marloes was followed by an 8am start for a trip over to Skokholm to pick up some guests. Thanks to Kenny from Dale Sailing for allowing us to jump aboard the Dale Princess and at least say a brief hello to Giselle and Rich. All too soon we were back on the boat and heading across to Skomer.

    Approaching Skokholm from the north


    Giselle, Rich and Will on Skokholm

    We landed on Skomer and went for a quick walk round before a cup of tea with wardens Bee and Eddie at North Haven. It was lovely to see the old cabin we used to live in looking in such good condition!

    The 'cabin' on Skomer - home to Lisa and myself in 2004 and 2005

    GM with Captain Kenny on board the Dale Princess (yes that really is Kenny smiling!)


    Lisa at High Cliff on Skomer with Skokholm in the background

    By 12pm were were on our way back to Haverfordwest, a quick food shop then back 'up north' for the 4pm crossing to Ramsey. Three islands in one day! Not bad going!

    If you want to visit Skomer or Skokholm see details on the WTSWW website here

    Boats to Ramsey will be running daily to the end of October (weather permitting) and it won't be long before seal pups start being born in good numbers and become readily visible from the cliff top paths. Most years we have up to 700 pups born on Ramsey, the largest grey seal pupping site in SW Britain.

    Contact Thousand Islands Expeditions on 01437 721721 for boat booking details for Ramsey.

  • Bats, not birds (for once!)

    In May of this year BSG Ecology deployed a bat detector on Ramsey (along with Skomer and Skokholm) to monitor seasonal variation in bat encounter rates and species diversity on the Pembrokeshire islands

    Each week we download the data and send it across to the BSG team. They will analyse it fully later this year and produce a report on their finding in winter 2014/15. I have to admit to being slightly reticent at first that we would find any bats bar the odd pipistrelle but this soon changed when Matt and Rachel from BSG took a quick peek at some of the early data. I am now quite happy to eat my words as we have logged a minimum of 6 different species of bat on the island with the prospect of more to come!

    Greater horseshoe bat, common and soprano pipistrelle, noctule, brown long-eared and one of the myotis species have all been recorded in varying numbers. The common pipistelles are nightly and the greater horseshoes are recorded most weeks. Noctules have been present sporadically since June with the others producing occasional records

    There might well be more to come when analysed fully and with migration season upon us again it will be very interesting to see what else the island can turn up.

    The data will also be of interest in that there is little baseline information concerning the bat fauna of the Pembrokeshire islands, so it will be good to fill a gap in our current knowledge. Ramsey is well known for it's high invertebrate populations (e.g. beetles and moths) so this is one possible reason that bats are finding the island so attractive. The pipistrelles are probably using the old barn and with bats being seen coming out of one of our sea caves earlier in the season it will be fascinating to see the final results of this work.

    For more general information on bats see the excellent Bat Conservation Trust website

    The BSG kit comprises an Anabat recording device which uses Analook software to produce sonograms of the bats calls. This is a typical greater horseshoe back sonogram with the call peaking at 80kHz


    The noctule bat produces a very different sonogram and calls at a much lower frequency

  • Seabird monitoring: the old and the new

    Just realised it's been 20 days since we last posted a blog! Hopefully this might explain why........

    In the 13 years since I started working with seabirds there has been a huge advancement in the technology that allows us to monitor their lives away from the colonies. Until relatively recently we could study them at their breeding colonies but were largely reliant on ringing recoveries to tell us anything about what they did whilst at sea i.e. for the bulk of their lives!

    The past few weeks on Ramsey and Grassholm has seen a wealth of modern technology used in the name of seabird research and science. But there has also been room for some good old fashioned methods too.....

    Gannets

    Exeter University led by Steve Votier are now in their 9th consecutive year of tracking gannets on the RSPB reserve of Grassholm using a range of bio-logging devices (GPS, geolocators, Time Depth Recorders (TDR's) and bird-bourne cameras). This work has led to a whole host of scientific publications which have opened our eyes to where our birds are feeding, how long they feed for, which areas are used on a regular basis, the difference strategies between males and females, how deep they dive, what they feed on, how reliant they might be on fishing discards and even what it look likes to fly with a gannet!

    Apart from valuable scientific data that enhances our knowledge of species, this work also contributes significantly from a political advocacy viewpoint too. When we campaign for increased protection of our seas (sorely needed and still desperately lacking in Wales) we can draw on this data to show politicians and decision makers hard evidence instead of just saying ‘we think’ and ‘to the best of our knowledge’ etc. Maps and graphs carry far more weight!

    One of the key aspects of this work is its longevity. Long term monitoring is key to establishing patterns and building up a more complete and compelling picture. It is vital that we keep this kind of work going but, sadly, in the current economic climate the squeeze on research funding is being felt all too keenly.

    Researchers from Exeter University attaching a GPS device to a gannet on Grassholm

    GPS tracks (S Votier)

    Tracks of multiple gannets from Grassholm (each colour is a different bird) showing foraging area (colony shown by the star) - copyright S Votier

    Manx shearwaters

    This year I took over the Manx shearwater tracking work from Holly Kirk (Oxford Uni) who has now finished gathering data for her PhD on shearwater migration strategies. It seemed a shame for 4 years of data gathering to come to an end so having assisted Holly during that time I took up the batten and volunteered for the sleepless nights alone in a shearwater colony! (there are worse places to be!)

    For this we use geolocators, tiny (2g) light logging devices that record sunrise and sunset which coupled with an internal clock can work out latitude and longitude wherever the bird is on the planet (using the same principals that mariners have used at sea for hundreds of years). Understandably these devices are not as accurate as the larger GPS units but their tiny size means they can be attached to a plastic ring on a birds leg and left on for a whole year.

    We know that our shearwaters winter off the coast of South America but this technology has allowed us observe the migration route they take, how often they stop off to rest (the device also tells us if it is salt water or not so you know when the bird is sitting on the sea), where they feed on route, how long they take to get from Ramsey to just off the Rio del Plata in Argentina (14 days in some cases!) and even when birds start incubating and how long each shift is (i.e the device records when a  bird is in 24 hour darkness in the breeding season when underground on an egg)

    So we now know a lot more about our Manx shearwaters (of which the UK is responsible for 90% of the world’s population with nearly 50% of those in Pembrokeshire) than we ever did and can say with confidence what these birds are doing when they are the other side of the world.

    It will also be interesting to compare Ramsey’s shearwaters with those of nearby Skomer. Brown rats were eradicated from Ramsey in 1999. Up until then only a small population survived on Ramsey (850 pairs in 1998) due to eggs and chicks being easy prey for the rats. Today we have just under 4,000 pairs on Ramsey. Clearly this population expansion must have involved a lot of young, inexperienced breeders, many of which will be immigrants from Skomer and Skokholm  (don’t tell the Daily Mail!). We can now compare success and strategies of these relatively young birds with the established breeding population on Skomer which numbers a staggering 300,000 pairs.

    GLS device on Manx (T Guilford)

    Geolocator (GLS) device mounted on a leg ring on a Manx shearwater - these devices remain on for a whole year and track their migration routes to the southern hemisphere (a good advert for cable ties!)

    Storm Petrels

    Due to its tiny size this is one of the least well understand of British seabirds. Only now is the technology becoming small enough to think about deploying on these birds. They have never bred on Ramsey during the time rats were present although around 150 pairs breed on the Bishops and Clerks, the small islets 2 miles NW of Ramsey and forming part of the reserve. In 2008 we discovered them breeding on Ramsey for the first time and now have around 10 pairs that we know of but there could be more.

    Last week Matt Wood from Gloucester University visited with a very fancy piece of kit, a thermal imaging camera. This is the type of kit used in disaster zones to look for buried survivors etc and works on heat radiation.

    We spent a pleasant night (regular sleep patterns are not a feature of life on Ramsey in mid summer!) walking the island looking for potential new sites. We didn’t cover the whole island but did find one potential new location where the camera picked up 2 birds flying around a rock fall area. Next week I plan to make my way down there at low tide and have a closer look around using a tape player (well MP3 these days!) and some good old fashioned sniffing of cracks! Not as odd as it sounds! Stormies have a very distinctive musky smell that are good way of locating them. I would take our sheepdog Dewi if it wasn’t so steep – he can sniff out a shearwater at a hundred paces!

    From the extremely modern to the good old fashioned – the other way we can monitor for storm petrels is by setting a mist net and ringing. Before heading to Grassholm this week we did just that with Steve Votier, setting the net at a site on east coast. We only caught two birds in an hour but it shows they are at least commuting through Ramsey Sound and there is certainly suitable habitat on this side of the island so we will check out suitable sites along here too.

    European storm petrel after being ringed on Ramsey Island. From ringing recoveries we know these tiny seabirds winter off South Africa, well some do at least! Little else is know about their migration.....yet

    I hope that has given a brief summary of the kind of research that is taking place on our RSPB reserves in Pembrokeshire and hopefully it might explain why we sometime look so bleary eyed when meeting the visitor boat! If you are visiting the island and want to know more about any of this work please feel free to come up and ask. You can also follow us on twitter at @rspbramsey or follow @SVotier, @HollyKirk and @wood_mj for further information on seabird research.

    Ramsey Island is open to the public daily (weather permitting) from 1st April to 31st October. Thousand Islands Expeditions are the only boat operator licensed to land passengers on the island. For details on this and their trips around Grassholm contact them on 014737 721721 or email info@thousandislands.co.uk