Tuesday, 19 November 2013

The widow-maker gets christened!

After a week's reconaissance in Dublin, the Exeter catch team set nets this morning, the first at an inter-tidal location (narrowly missed the opportunity and Arenaria interpres got in the way!) and the second on a golf course in Dublin. The latter resulted in a catch of ca. 20 birds - hopefully the team can send an update which is more accurate with pics!
It's turned cold and, at this stage, not too many Brent are on grass in Dublin.

The subject line refers to our pet name for an extraordinarily large cannon-net which is brand new and was fired successfully today. The first of many successful firings we hope!

This coming weekend there will be some posters and talks on Brent at the 6th Irish Ornithological Meeting at University College Cork.

Thursday, 17 October 2013

Fat light-bellied Brent geese have more offspring - but only if the weather's good

I pinched this neat catchy headline from Xav's twitter feed when he circulated the link to this further neat paper from his thesis.

Entitled "Environmental Conditions during Breeding Modify the Strength of Mass-Dependent Carry-Over Effects in a Migratory Bird" this paper continues on the main theme of Xav's PhD work - looking at carry-over effects in our study population of Light-bellied Brent Geese and Xav's phrasing in the headline of this post just about says it all!

So we have demonstrated that female geese in better spring body condition are more likely to successfully raise young in that breeding season (established in a few other populations too and previous Brent papers led by the Exeter team have shown this). What is new here is an examination of the role of summer breeding conditions (snow melt, temperatures, winds on migration - those sorts of factors that we might expect would have an impact on the birds directly or indirectly) which shows that if the arctic breeding conditions were poor, irrespective of birds body condition, reproductive output would be bad. 

The full article is available here http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0077783 and is well worth the read. Well done to all involved.

Results rolling in from the October census: headlines over 34,000 birds; hardly any young

A few weekends ago various groups of Brent-enthusiasts were out and about counting Brent; trying to get a comprehensive count in that snapshot in what is always a very short and unpredictable time window when we know the majority of the population are concentrated at relatively few manageable sites. I say manageable - it still requires the unenviable job of counting birds from the air in Iceland and the not-to-be-taken-on-lightly job of counting the very large numbers at Strangford.

Provisional results from many sites are still to be compiled but the running totals approximate to:

21,000 (Strangford)
10,000 (W Iceland)
2,000 (L Foyle)
1,000 (Tralee & Castlemaine Hbr, Kerry)

Thanks to the participants and local organisers for covering these key major sites.
A lot of other folk have submitted data from all round the Irish coast and also Wales and Scotland - thanks all.
We'll collate this and circulate the results.

What has also become apparent is that the 2013 breeding season was not a very productive one for Brent in the Canadian breeding grounds. It seems likely that we will be lucky to have more than double figures this year. We suspect that the combination of late snow melt, low temperatures and other climatic factors in the breeding range have led to this - presumably the same is the case for other species on the same flyway (e.g. Turnstone) or those that migrate south within continental North America but have the same breeding range (e.g. Greater Snow Geese). We'll put the feelers out and try to report what info we can accumulate over the coming weeks.

Monday, 23 September 2013

Brent totals now exceed 16,000

I don't have any further details but the subject line says it. Latest count from Strangford suggests about 16,000 there at present... That is all.

Tuesday, 17 September 2013

Irish numbers building to 6-8,000 at Strangford

So the usual autumn build up is well and truly in train at Strangford. Kerry Mackie reports between 6 and 8,000 Brent on the north end of the Lough over the weekend. So despite the pretty nasty weather conditions (some of our first autumn westerly gales) thousands of Brent evidently made the leap from Iceland south.
Graham read 38 rings - some of the first of the season - in these windy conditions and amongst these was a bird observed recently in Highland (Scotland). No juveniles reported as yet.
And in Iceland aside from the smattering of lapland Longspurs, Sabine's Gulls and the odd American wader, Brent have been observed in some of the usual haunts. There some juveniles have been observed so at least some have been observed.

Sunday, 15 September 2013

Autumn influx still slow

At least until a few days ago the numbers of Brent remained relatively low in Strangford with none at Lough Foyle - all suggestive that the vast majority of birds remain in western Iceland. Our friends there suggest small groups are widespread there in the usual haunts but we have no reports as yet from the 'big' sites in Faxafloi and Breidafjordur.
Within each of these large bays, whilst a range of smaller sites are used, the main concentrations are those at Akraos/Straumfjordur (Faxafloi) - the complex west of Borgarnes, and Alftafjordur (just east of Stykkisholmur) in Breidafjordur. The common denominator being that both sites have very large intertidal Zostera beds. Why rush past these when there's so much food available.
In previous autumn's we've seen these flocks of Brent getting disturbed or attacked by White-tailed Eagles and Gyrfalcon. Which in part explains when they come down to Ireland they take no chances when a Grey Heron flies past.

Wednesday, 4 September 2013

Here we go again

With intermittent reports of groups of Brent in Iceland and from various other locations including the Antrim coast (60 last week) and the Isle of Skye it was only a matter of time before numbers started to build up at Strangford. 800 were there at the weekend and the first rings read. 
Eyes peeled!

Tuesday, 2 July 2013

The Importance of Spring Staging: Why do female geese get fat faster?

The numbers on the y axis are body condition scores (our scale goes from 1-7). The start period was mean API measures for all individuals resighted between 01/05/2013 and 03/05/2013. The end  period was mean API measures for all individuals resighted between 26/05/2013 and 28/05/2013.

We talked quite a lot about measuring body condition towards the end of the time we were in Iceland. One thing that is particularly apparent towards the end of the spring is the big difference in API within each pair. As this graph shows this is because females are leaving in Iceland in much better condition than males. We've known this is the case for a while, but its nice to be able to show it with my data! Little results like this help to show that while you may have gone crazy whilst collecting all the data, you were doing a reasonable job still......

Clearly, females have to make more of an investment in reproduction once the birds arrive in the Arctic so have to leave their spring staging areas with more fat reserves. There is not much for a goose to eat when they first arrive in the far north, so all the energy reserves they can accumulate in Iceland are of vital importance!

Perhaps of more interest is trying to work out why the males do not end up equally fat...... It seems likely that there might be a cost to being fatter than you need to be, particularly if you take into account just how far the birds have to travel to reach their breeding areas. However, it is also very noticeable during our time in Iceland that there are differences between members of a pair in their levels of aggression and vigilance. It could well be that males are unable to accumulate the same energy reserves as they are spend more time engaging in these social behaviours to enable the female of the pair to forage more efficiently. This seems to be backed up by the fact that the Whitefronts that colleagues study just up the coast are very similar in this regard.

It is also very apparent that the birds left Iceland in much better condition this year than last spring - hopefully that bodes well for a successful breeding season!

Friday, 28 June 2013

Spring 2013 social network

Map of social interactions for Alftanes and nearby areas in May 2013

After a good few weeks of painstaking data entry and shuffling excel spreadsheets around, I'm finally in a position to see what some of our data from this spring looks like! Its amazing to think how much work goes into producing a social network like this!

Its good to see that its is broadly similar to last years social networks, although the shift in home range of LIRY and LHRY (a pair of geese I know well from Dublin too) half way through the spring from Hafnarfjordur to the President's Fields on the main peninsula has resulted in the network being more cohesive overall.

[LIRY and LHRY are the two red nodes sitting halfway between the main "red" social cluster and the "blue" social cluster]

Monday, 27 May 2013

The end of spring....

In the last few days Greylag goslings, Eiderlings (not sure what else you'd call a baby Eider?) and the family of Whooper Swans pictured below have all made an appearance on Alftanes - very much a sign that May is coming to an end and the Brent will be on their way soon.

The geese are all now looking very fat - and everyone up here seems to be in agreement that they are ready to go. This is borne out by the fact that the vast majority were just sat around, loafing this morning (hence why I'm back at base writing this). It seems likely that a change in the weather is all that required. The last few days have largely been fairly miserable with drizzle, squally showers and often strong winds making doing fieldwork a real pleasure. I'm hoping this will happen before I leave on Wednesday morning as it would be really cool to see!

Wednesday, 22 May 2013

The final countdown....

And so we're in it - the final week to 10 days of stockpiling and processing food, strengthening and testing muscles (not to talk of internal physiological changes which we know little about). But enough about the Brent research team, the geese themselves will be going through this.
We know that female body weight will continue to increase over the coming week, right up to departure; male index profiles (an index of body 'condition') on the other hand, plateaus off this week. Such information based on repeated scoring (visual) of 'belly profiles' of marked individuals throughout the spring staging period, an index calibrated against biometrics of birds at times of capture. It is always amusing to observe the 'fat-bottomed girls' getting progressively fatter as the month progresses. Photos of v fat geese will be posted in due course.

Tuesday, 21 May 2013

Not a brent goose....

Eiders are everywhere around Reykjavik! In some places they even join the mallards coming from bread....
Their breeding season is already well under way unlike the brent geese which aren't even half way through their migration. This female was sitting on a nest containing a couple of eggs on Seltjarnarnes Golf Course. Eiders are "farmed" in many places in Iceland to in order to protect nests and collect eiderdown to use in duvets and other soft things!

Stormy skies!

The weather has been all over the place in the last couple of days with a good mix of strong winds, hail, drizzle and sunshine.... All this means geese are often to be found sitting down (about their only way of hiding from the elements) which makes reading colour rings quite difficult!!

Stormy skies over the president's house

Wednesday, 15 May 2013

More from Alftanes...

Sunrise at some time around 4.30am this morning!
All these early starts mean we're going well with resighting lots of geese - I think its getting close to 3000 resightings of several hundred different brent geese. The idea behind doing this is to provide a really detailed picture of what sites individual geese are using and which other geese they are associating with when they do this
Us at work later this morning - you can just about see the geese on the far side of the field

We're also busy doing behavioural watches to learn more about what causes differences in how vigilant and aggressive different geese are. Particularly during the spring when there is more at stake brent goose battles can be pretty intense. This can include charging from one side of a flock to another to target another bird, body slams or even lunging in two-footed in a way Roy Keane would be proud of!

Off to explore Snaefellsnes tomorrow about threee hours drive north of Reykjavik - looking forward to a brief change of scenery!

Saturday, 11 May 2013

Iceland 2013!

A lot has happened since the last time this was updated!

I had a very busy time out in Dublin in February and March, the highlight of which was the full team coming together at the start of March and managing to catch and ring 130 new birds in north Dublin. These birds all have either blue-blue or red-red combinations so if you see any geese with these ring combinations you can know they've been ringed in Dublin in the last couple of winters.

Also see this great blog post from the Trinity College EvoEcol blog that sums up this week quite nicely.

Now its time for spring brent chasing in Iceland. I've been up here for nearly 10 days now, joined by colleagues from the University of Exeter and the full Irish contingent are arriving in a few days time. Just like last year its been long, long days and some crazy weather but its a great place to be. Its been great to see a number of birds we ringed this year in Dublin have made the same journey too and have joined all the now familiar ringed birds out in the fields of Alftanes.

More to come soon hopefully....

Friday, 18 January 2013

All things brent goose!

Last week a good few members of the group made a trip down to Arcachon (see the map if you don’t know where that is) to the 15th meeting of the goose specialist group. The good showing being encouraged by the fact that the meeting was primarily for those researching brent, and in part I imagine due to the promise of lots of tasty food and drink! The three days of talks included presentations about all of the world’s brent populations, including researchers coming from Russia, Canada, the USA and even Mexico! This meant there was lots to be learnt and lots of people equally keen on their Branta to meet.
The East Canadian High Arctic population was very well represented. Kerry Mackie was first up talking about the importance of Strangford Lough as a staging site for this species, including some excellent historical detective work to follow the population size back through the twentieth century. Matt spoke about social networks, and most people seemed to understand, which is an improvement on normal. Graham caused the largest stir of the whole conference showing everyone just how friendly the brent geese can be in Dublin. He had the unfortunate task of trying to keep people awake in a post-3 course lunch session so this was quite an achievement! He went on to show data on ringing and resighting in the full ten year study. Last but not least Gudmundur talked about the importance if Iceland as a staging site in this flyway, before linking this into what we know about brent goose breeding ecology from the Arctic expeditions completed. The slide with a stuffed brent goose posing next to a particularly delicious looking slab of steak probably has to down as a highlight!
Meanwhile, posters made by Rich and Xav (thanks guys!) attracted plenty of attention and it was good to see a poster of Phillipe’s, which contained lots of information about Regneville – the ECHA brent’s main wintering site in France.
The conference was great, with the amount of awesome food available every lunch and dinner a remarkable feat! Being able to spend the second last day exploring the Bassin D’Arcachon both on foot (at Le Teich Nature Reserve) and by boat was also pretty cool. Inevitably geese were seen, both Greylags and Brent (although the organisers were fairly horrified as the 60,000 brent present in December had been reduced to only a few thousand!!) were scattered widely. However, for me at least, the real highlights were some of the species seen. Cracking views of a grey phalarope, numerous great white egrets and spoonbills, a first winter night heron, big flocks of avocets, aerial tussles between a peregrine and marsh harrier and some close-up views of black-necked grebes and great northern divers from the boat all spring to mind.
All in all a great trip! Hopefully I'm  going to get better at this whole blogging thing again now - although work might have something to say in that. Breaking laptops on fieldwork then being outrageously busy in the build up to Christmas left little time but does mean now I have lots of new things to share!