Monday, 21 July 2014

All at seabirds.

It’s been a busy summer, with seabirds taking up a lot of our time – a welcome change from many recent years. It’s also been busy at the Obs, with a virtually ‘full house’ for much of the last month, so there’s not been a lot of time for keeping the blog up to date – sorry about that!
The Swedish training ship the Atlantica called into Fair Isle for a night and its crew were responsible for a sizeable percentage of the 37 people watching the World Cup final in the Warden's flat!
A generally busy time of year also saw the first Sheep Hill of 2014. Here Ciaran takes a yowe off to be clipped (Ciaran is the slightly taller of the two). Photo by Carol Jefferies.
Amongst the birds, the obvious highlight has been the Swinhoe’s Petrel, which is still present in the Havens (although it is only recorded when we have Storm Petrel ringing sessions taking place, obviously). There’s been Leach’s Petrel also regularly recorded at the trapping sessions, usually arriving simultaneously with the Swinhoe’s and the two are often heard calling together; a nice comparison. In order to try to make the most of the Storm Petrel ringing (we currently stop for the night if the Swinhoe’s Petrel is caught to ensure it isn’t caught more than once a night), we’ll be trying out other sites around the island to see where else we can catch Storm Petrels without the Swinhoe’s coming in. That means for the next week at least we’re very unlikely to be ringing in the Havens (we’ll put a further update out on Storm Petrel ringing on 28th July).
There's a long way to go for the Arctic Skuas, but some have large chicks now, whilst in other nests, the chicks are just hatching.
However it's been mixed news for the Bonxies, where record numbers nesting are not going to produce a massive amount of chicks judging by the evidence so far. Cannibalism in the colony has been noted, usually a sure sign that there isn't enough food to go round. Of the two ringed chicks I have found eaten, both were near their nests, suggesting that the parents were away for extended periods foraging when the youngsters were attacked (or that older chicks are killing their younger siblings in times of food shortage).
The other good bird that has been lingering is the Marsh Warbler in the Obs garden, whilst the oversummering Chiffchaffs (at least a couple of them) and Robin have been joined by the occasional unusually-timed migrant, with Blackcaps on 30th June-1st July and 7th July, Willow Warbler (1st July), Lesser Whitethroat (2nd July), Song Thrush, sporadic Mealy Redpoll sightings (of up to two birds) and a Whitethroat (which is ringed and very likely one that has summered quietly somewhere unseen on the island - an apparently injured bird seen in mid-June suggests it could have been lurking in the heather keeping out of sight). Also summering was the male White Wagtail, which was still present at Easter Lother Water. A few Collared Doves were expected birds of mid-summer, as were the autumn’s first three Grey Herons (heading south on 11th) and a Quail flushed from Mire of Vatnagaard on 3rd July continued the good spring for the species. Less usual were the House Martin (11th), Sand Martin (17th) and especially the Great Spotted Woodpecker which flew south over the Obs on 12th and was seen near the base of Malcolm’s Head on 15th – the first July record for Fair Isle! Also not expected at this time of year (although not as rare as the woodpecker) was an Iceland Gull on Meoness on 11th and again on 16th-17th.
A good selection of plants and flowers can be enjoyed at this time of year, including Sundews (although this one was close to a particularly aggressive Bonxie, so was only enjoyed briefly.
Another addition to the year list came in the form of Ruff on 12th July, the highlight from the typical build up of waders that occurs at this time of year, whilst offshore there were Manx Shearwaters daily from 2nd-5th (14 birds recorded in total) and four more during 15th-18th, a reasonable showing for Fair Isle, where seawatching is not really a major feature of the birding year. Staring out to sea can have its advantages though, with a distant group of five Killer Whales (including a couple of mighty bulls) off North Light on 14th, although the two on 1st July were much closer as they came right into South Haven and then Mavers Geo. Unusually, this couple were seen at half past midnight and were first seen by people by on the nets at a Storm Petrel ringing session (on a night that was light enough to be able to read petrel rings by the net at 1am, despite there being no moon!).
The atmospheric setting looking west from North Light, as photographed here by Ciaran Hatsell (and featured in the opening credits of the BBC series Shetland).
We’ve got a period of easterly winds coming from central Europe on the way now, which would be ideal conditions at almost any time of year except mid-July, but there are still birds moving out there, so maybe there’s still a chance it could deliver us a surprise yet…

Wednesday, 9 July 2014

Swinhoe's Petrel Update

A Swinhoe’s Petrel was retrapped in the early hours of 9th July during a petrelling session in the Havens. It was the second bird to have been caught here last year (i.e. the male which was retrapped on several occasions between early August and early September, the other bird was also a male, but was trapped only once, in July), so we’ll now be following the procedures agreed with the BTO and outlined here.
It was the sixth petrel-ringing session of the season and the first one that we’d played the full mix tape (the previous nights having all been quite light, so we decided to stick to just Storm Petrel calls to increase our chances of catching anything). It was the first really dark night and, after a total of 107 Storm Petrels ringed during the first five sessions, we ringed 47 last night; showing what a good night it was. There was also a Leach’s Petrel regularly singing around the nets (although skilfully avoiding them).
The phones have been pretty non-stop since 7am this morning with people wanting to know more about the bird (so not much chance for us to catch up on sleep!), so this seems a good a time as any to answer some of the questions we’ve been getting:

·      We shall not be playing Swinhoe’s calls during routine petrelling sessions from now on.

·      The Swinhoe’s Petrel calls we’ve been using have come from the excellent Petrels Night and Day book.

·       Owing to the vagaries of the Shetland weather we simply cannot advertise the days we’ll be Storm Petrel ringing in advance; we may be able to give an indication in the morning that we’ll be considering a session that night, in which case we’ll be happy to let people know what we’re thinking (but sessions can be cancelled right up until the last minute if there are changes in the weather or other unexpected circumstances).

·       We will not be ringing Storm Petrels either tonight or Thursday due to the forecasted weather conditions. No decision has been made on days beyond that.

·       There are no plans to fit any sort of tracking device to the bird. The advice we’ve received is that there are no tags small enough to remotely offload the data and that it is still very early days in the field of long-term attachments of tags to storm-petrels, so attempting to fit a tag to discover the winter movements of the bird would not be advisable. There wouldn’t be a huge amount of value to be gained from finding out its daily movements, given that it’s an out of range vagrant and isn’t breeding in the area.

The reason for the change in practice from our usual Storm Petrel ringing sessions is due to the unusual behaviour of this particular Swinhoe’s Petrel. The vast majority of petrels we catch are roaming birds that do not stay with us (we know from retraps etc that they are birds that are below the expected breeding age, whilst ringed birds from our breeding colonies are not caught in the nets in the Havens). This Swinhoe’s Petrel developed the habit last year of returning to the nets during every session and repeatedly in the same night on some occasions, unlike any of the other 3000 or so petrels we’ve caught in my previous three years on Fair Isle. We have no objection to people seeing the bird if we catch it (as I hope the folk who visited last year will agree) but feel it’s best for this bird if it is not repeatedly attracted to the nets.
Another factor to bear in mind this year is that is currently one of the best years for breeding seabirds in recent times. Last year’s almost total failure of several species meant we had more time to spend on Storm Petrel ringing, whereas that time is likely to be reduced this year due to the increased monitoring work, a very happy situation to be in!
It’s purely speculative at the moment, but one theory for this Swinhoe’s Petrels behaviour is that, whilst Storm and Leach’s Petrels roam between colonies as non-breeding birds (after spending their first summer further south than the UK) before eventually settling upon somewhere to breed at about four years old, this bird may be an adult that has been unable to locate another Swinhoe’s Petrel in the North Atlantic, hence its unusual behaviour. This perhaps lends a little support to the theory that UK Swinhoe’s Petrels are lost vagrants rather than part of a North Atlantic breeding population (one of the Tynemouth individuals returned for five years, suggesting it would have been at least six years old when last retrapped, by which time it probably should have been at a breeding colony).
Just to be clear, this is the first time that the Swinhoe’s Petrel has been seen (or heard) this year and we will be reporting any further sightings through the usual channels. If it does keep coming to the nets regularly despite Swinhoe’s Petrel calls not being played, we’ll review the procedures again.
I hope that this helps answer any questions people have got, if you do have any others though, please email me at (which is easier than me trying to keep abreast of all the goings on of social media).

Many thanks

Thursday, 3 July 2014

A New Hope: Fair Isle's seabirds so far.

As most people will know, there have been a series of very poor years for Fair Isle’s breeding seabirds, reflecting the situation over a lot of the Northern Isles. On Fair Isle several species have declined quite dramatically (although none have been lost as breeding species) and productivity has often been poor (with some species producing no young at all in some years), with a lack of food the primary cause.
There are still a few crucial weeks to go in the breeding season yet, but there are some early signs of optimism for the seabirds this year. This is very much a ‘from the notebook’ update, and some of these figures are likely to change as we put things together properly later in the season, but here’s a quick species by species update of how things are going:

Fulmar - one of the later breeding birds, it’s too early to say much on how they’re doing, although the population plots seemed fairly similar to last year.
Storm Petrel – no information on the breeding status, but the Storm Petrel ringing season has started well, with over 50 in total trapped in two nights in the Havens. A Leach’s Petrel was also caught, which, intriguingly, had been ringed on Fair Isle in August 2013.

Gannet – a total island count of 3591 Apparently Occupied Nests (AON) is over 300 down on last year and may just be a sign of the population levelling off in recent years. Productivity may turn out to be poorer than usual (although it’s still very early – the last chicks may not fledge until October) and a worrying sign has been several adults seen dead or dying, apparently coated in some form of pollutant.
Gannets on Yellow Head, there are a few chicks visible on this picture.
Shag – although the population is still at a much lower level since the 1980s and 1990s, there has been a slight increase in the population plot (to 24 pairs from 21 last year). Productivity seems fairly healthy across the island, with several large young now present in nests. 
This Shag has caught a Butterfish, but it is presumably the availability of Sandeels and Gadoids that is helping the productive season we're having so far.
Arctic Skua – a rare glimmer of hope for one of Fair Isle’s most beleaguered seabirds, as the number of Apparently Occupied Territories (AOT) has increased from last year’s low of 19 to around 26 this year. Of these though, several pairs have not laid eggs, whilst many pairs have a clutch of just one, indicating that the adults may be in poor condition. There is some hope of chicks appearing imminently, but it’s still a long way to go before it can be considered even a half-decent season for the Skooties.
An Arctic Skua performing a distraction display.
A sign that the birds may not be in the best of health included this clutch of two, one of which was a runt egg.
Bonxie (Great Skua) - a record year, with upwards of 350 AOTs already noted (the final total is likely to be nearer 400). There are plenty of chicks now roaming the moors, whilst the adults have been notably more aggressive this year, suggesting that they’re in good health and perhaps even that they’ve a certain confidence that this is going to be a good season for them.
A pair of Bonxies on Hoini protect their chick (the first to be ringed this year on Fair Isle).
Kittiwake – a surprise resurgence (albeit a tiny one), as several years of declines have been reversed and the number of AONs has increased by almost 200 to 963 (although that’s still just a fraction of the 19,000 or so pairs that used to nest on Fair Isle). Productivity has shown a wee bit of promise as several nests have chicks – although the really crucial time is now coming up to see whether they can break a run of three consecutive years with no chicks fledging from the island at all.
Kittiwake chicks just visible under an adult in Dog Geo. The number of AONs and Trace nests recorded this year more or less matches the number of loafing birds recorded last year. These little hints that many seabirds may not be breeding, but are still present, gives a little hope that we could see recoveries in even the most badly hit of populations if conditions improve.
Other Gulls – Common Gulls appear to have fared badly in the small colony on Buness, with most nests having apparently been predated. They have managed to raise a chick to a reasonable size on Goorn though, and there is at least one nest down the island. The three large breeding species appear to be having a reasonable season with 55-60 pairs of Herring, 4+ pairs of Lesser Black-backed and 5+ pairs of Great Black-backed Gull all recorded so far.
Herring Gull chicks on Goorn.
Arctic Tern - 98 AON have been noted (up from 29 last year, but numbers in the last decade have fluctuated between 0 and 818 breeding pairs). Predation has been an issue though and, although some chicks have now hatched, it’s too early to say whether this season will produce any positives.
Although the predated eggs showed signs of having been taken by avian predators, a dead adult showed clear signs of cat predation (including bitten off feathers); for already hard hit seabird populations, this really doesn't help.
Common Tern – a pair that have hatched three chicks on Shalstane are a pleasant surprise as the period 2006-2013 produced only one nesting attempt.
Common Tern chick having been ringed.
Guillemot – more (relative) good news, as the numbers in the population plots have gone up to 1354 individuals (an increase of over 400), which represents the highest count since 2010. There are also encouraging signs that there will be chicks fledging this year, with several now not far off. A 21-hour feed watch saw good numbers of gadoids and sandeels being brought in by the adults (tracking work has shown that the adults have only travelled as far as North Ronaldsay or nearer to collect food, rather than heading down to Fraserburgh as they have been in recent years, a similar situation to Razorbills).

Razorbill – a small increase in the number on the population plot was welcome, but far more so has been the high success rate of the pairs that have bred. Several young have already fledged and it could turn out to be one of the most productive years in the last decade for this species.
Several Razorbill chicks have been ringed and are ready to fledge.
Tystie (Black Guillemot) – the population plot showed an increase to 196 breeding plumaged individuals, the highest count since the population crashed after 1997 and a hopeful sign that they are recovering on Fair Isle.

Puffin – it’s too early to say much about how they’re getting on, although the last visit to Greenholm seemed to show that around a quarter of the nests have failed, suggesting a similar productivity to last year if the remaining chicks go on to fledge. Many have been seen coming in with decent sized fish (compared to the last few years at least), and we’ll have more details on that shortly, with Puffin food watches due shortly.

No doubt there’ll be a few more twists and turns before the end of the breeding season (a day of heavy rain forecast for tomorrow may be the first potential hazard), but things are looking much more positive than they were by this time last year. Whatever you do to wish for luck, do it for our seabirds now please.

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