Saturday 27 October 2012

Fieldwork frustrations

Bad rain this week has meant that we have been without internet for a while, hence the late post... This week’s task has been to try and catch some of the returning birds from last year. Along with presenting a good opportunity to test my Whinchat ageing and sexing skills and see how individuals have changed since last year, the main reason is to make sure that I will be able to catch returning birds with geolocators next field season. Fitting the geolocators is one thing, but to download the data I will need to have them back. So yesterday I chose two of the returned birds and made the decision that I would do whatever I needed to do to catch them. This is much easier said than done! The experience of being caught once using bait, playback and traps is enough to make them wary and rather un-responsive of playback, and so the traps don't work. Yesterday I tried a long line of nets by each of the birds but was well and truely outsmarted. I think I was trying too much at one time with two birds. This morning I tried just one of them and added more nets to the set up to make a big giant C shape. The theory is that at some point there will be enough net to cross the whole territory and catch the bird, even if it sees the net. I spent the morning running around waving my arms and looking like an idiot at the same time, but it was worth it as I managed to catch one bird from last year. Irritatingly this was not the originaly bird I was after! So I have mixed feelings about our sucess. The original target has taken to flying over the top of the net, so I think the only way to catch this bird will be to set a further line of high nets in front or behind the first line. It's a lot of work for one bird and not entirely urgent right now, so next time I will swap to the other bird I tried yesterday and give this one a rest. I may need more people with me to run around waving their arms to persuade it to fly in the right direction. It sounds a little mad but now the birds know what I am up to I need all the help I can get!

Gotcha! One of last year's birds, Blue-Blue-Red, now fitted with a brand new red ring to replace the bleached one


Some exciting news is that earlier in the week I saw a colour-ringed Whitethroat at my site ‘John’s Farm’ whist catching whinchats. This is brilliant. It means that the Whitethroats have also come back to last year’s wintering grounds. I am working in quite a small area of a large site that is quite good for Whitethroat, so it is very promising that this bird was very close to the territory it held last year. The Whitethroats present quite a problem when trying to determine territoriality and residency over the winter period. They are very ‘skulky’ birds that move quickly and quietly in dense bush and it is very hard to read any colour ring combinations if you spot one. Sometimes I feel like I have put colour rings on mice, and mice with wings for that matter. I have tried quite a few methods of re-righting colour-ringed birds effectively, but even with playback and a spotting scope you can never be sure they are there, and if they are that you will see them. I have had to lower my ambitions and work with determining site fidelity and residency over the winter rather than territory size like I am doing for Whinchats. I am doing this by placing mist nets with playback throughout the site to catch and colour-ring whitethroats and then repeating this several times over the winter. Next week I will begin netting for a week throughout my two sites, and I will then repeat this after Christmas. I will colour-ring all the Whitethroats I catch. Any resident birds are likely to be re-caught the second time, along with any birds that I colour-ringed last year that have returned. I am really excited about netting the first time as I think there is likely to be more birds from last year. This site also has some great species that we don’t often catch at APLORI, such as Emin’s Shrike and Yellow-fronted Canary, so maybe I will have some added treats. This morning we worked hard setting up nets ready to start catching on Monday.

We are still having some rain and were treated to a heavy downpour yesterday morning right as we got out of the car. The night before there was a big storm with dramatic lightning and extremely loud thunder that had me quivering under my mosquito net int he early hours. There have been bad floods throughout Nigeria and it does seem like a lot of rain for this time of the year. I hope things cal down soon, although I am not looking forward to when it is as dry as a bone and I come back from the field covered with a layer dust.

This weekend I climbed the big rocky hill in front of the house to get a view of the Reserve. Last time I did this was in late March after the bush fires and there has been quite a transformation with the rains. It’s a brilliant place to watch the sun going down with a whiskey (if you have any) and a good book. Just don’t forget the head torch or the climb down gets interesting. This time a family of Rock-loving Cisticolas came to investigate me, much to my amusement. Their call is exactly like a squeaky dog toy and is quite hilarious when you are surrounded by about 10 of them.

Amurum Forest Reserve from the top of the hill

Keep posted for news next week on how many Whitethroats have made it back this year and into my nets.

Emma

Friday 19 October 2012

Onwards and upwards

I have been making good, steady progress with fieldwork all this week. The successful catching at the Bridge site continued over the next few days, and there are now 19 newly ringed birds at this site. If I can, I will visit there again tomorrow morning to mop up a few more birds and clarify whether there has been another re-sighting from last year. I have been catching at the other sub-site known as 'John's Farm' too, and have caught a further 10 birds here. Both of these smaller sites had only 5 ringed birds last year. John's Farm is quite a bit smaller than the others with not as much potential to expand until perhaps when the corn fields are harvested. I have noticed that there are quite a few birds hanging out in the corn, and if last year is anything to go by then these birds will maintain their territories even when the corn is gone. They will be far easier to catch when there are places to put the traps.

I am really pleased that we have managed to expand the Bridge site. Last February I found very few birds in the spot where I have now caught 14 birds, which makes me wonder if Whinchats do shift territories over the winter. If they do then I should find out. Ringing all or most of the birds in a contiguous area not only makes re-sighting more productive, but gives a much clearer picture of what is going on between territories. Knowing who the neighbours are may shed more light on why some birds may have smaller or larger territories than others, for example.

The weather has been pretty bad over the past few days. Wednesday evening felt very looming and stormy when I was re-sighting. The next morning I was transported back to Scotland as we started fieldwork in steady rain that stopped and started all morning. Conditions during catching really make a big difference, and unsurprisingly we had a bad day in the field. No birds! We left with our pride a little dented and wishing we had traded a soaking for sleeping in. Yesterday evening saw very heavy rain that continued throughout the night. It is a blessing in disguise that I scheduled today for catching up with data entry and organising equipment, as I doubt I would have made it to the sites after such a downpour. Plus I left my shoes outside... The ground had just started to dry up so I hope the tracks have not gone back to the treacherous state they were in when I arrived.

A misty and soggy morning at John's Farm

Spirits are still high as the total of newly ringed birds is now 40 this season. This is the same as last year - so far - and I still plan to catch more birds to include in the territory study. I will also fit geolocators to 40 more birds at another site within Plateau. Perhaps by the end of the winter I will have ringed 100 Whinchats. In fact that sounds like a nice round number, so let's make it the target for the season!

More exciting news is that the total number of returned birds so far is now 15, with 11 of these at the main APLORI site. I think I am getting close to finding most of them, but I am sure one or two will crop up during the following months when I focus on re-sighting.

11 of the 15 returning birds are at the main APLORI site.
All in the same territories they held last year.

The most intriguing aspect of all this is the fact that birds are returning to the same territories as last year. This has got me thinking about how these birds ended up here again. Did they arrive before the others? What if a bird was already there? Did the returning bird eject a resident bird from the territory, and if it did, does this suggest that returning birds are the ones that are more dominant? What happened if a bird came back to find its old territory already occupied by a more dominant bird? Did it move on to another area altogether, or have these birds just reshaped their old territories to accommodate another individual? Perhaps next year I will aim to answer these questions and plan to be here to see the birds arrive. We will see. The plot thickens!

Next week I will focus on trying to re-catch returning birds so that I can plan for fitting geolocators later in the season. Re-catching birds that come back with their geolocators is essential, as we need to have the device in hand to access the data. I anticipate a challenging and most likely a very frustrating week ahead! Good news that John's Farm was full of Whitethroats and so I can think about that aspect of the work soon.

Emma

Friday 12 October 2012

An eventful week


The past week has certainly been busy. The CES finished on Tuesday, with a final total of 156 new birds captured of 53 species, plus a further 52 birds that were re-traps. A nice treat for the last day was a Tree Pipit - another Palearctic migrant. The next CES will be at the end of November/early December before I take a break for Christmas. I have some ideas for refining data collection during the CES so there is plenty to work on between now and then.

 
A juvenile Tree Pipit ringed during the CES
 
This week I have been able to visit my Whinchat sites again to look for more colour-ringed birds from last year. The total is now 13 birds, all in the same territories as last year, which is very exciting stuff. 10 of these are from the APLORI site where I ringed 30 birds last year, meaning that at least 33% of the birds have returned. I think that’s brilliant. One of these birds was another individual that vanished after ringing last year and I am happy to see again. Because of the boggy ground I have been parking the car further away from the site, and I re-sighted it a little outside of the study area. I think it was around all of last winter but I missed it on the way in. Usually we manage to catch birds within or very close to their territories, so it looks like this one was trespassing when we caught it last year. Expanding the site with new captures is one of this season’s objectives, and already the APLORI site is growing. This will increase the chances of re-sighting individuals like this one next year, along with adding more new birds to the pool of colour-ringed birds.

I have been catching and colour-ring new birds this week. There are now 11 new birds at the APLORI site. This morning I went out to the ‘Bridge Site’, about 2km away, where I caught 5 birds last year. This morning went better than expected and we caught 7 new birds, almost 8. A great spirit-raising morning, unfortunately tied with the ‘most birds in a day’ record of 7 in a morning (although to be fair this time it was just me and Arin my field assistant instead of 3 of us). Credit goes to Arin for 5 of today’s birds. We often joke about who gets the most birds in a morning and we seem to have started a little competition between us for this season. So far it’s me in the lead with 10 and Arin close behind with 8. Sometimes a little extra incentive is needed to keep going on long mornings when the sun gets hot and lunch and a cold drink is far more appetising than willing Whinchats into the traps.

 
A beautiful African morning out in the field
 
I am really pleased how trapping is going, especially after this morning. As I have already let on, it has been a bit tricky with so little bare ground and the whinchats constantly squabbling with each other. There are still turf wars going on and playing calls gets everybody quite furious. I think the boundaries between territories are still being deliberated. Yesterday at the APLORI site I was catching on the edge of 3 territories and the morning was a chorus of ticking whinchats. I got two of the birds within 30 minutes, but the other one was far less gullible and took a great deal of coaxing to get into the traps. The first 2 birds were males, which are often easier to catch as they respond more aggressively to playback (and of course we all know that females are known for being the more intelligent of the sexes!). After 2 frustrating hours I had 8 traps right under the bush that the whinchat was perching on. Finally, after 20 minutes of it staring at the traps (during which I could clearly see the personal battle it was having with itself as to what to do about the situation), it went for the bait and was caught. Luckily for me in the end it just couldn’t overcome millions of years of evolution telling it to eat the wiggly bug.

 
A male Whinchat with his black wing coverts and bright white flashes.

Soon the Whitethroats will be here in large enough numbers and I will switch focus to netting. I hope some of my birds from last year will come back to their territories like the Whinchats have. Tomorrow I will return to the Bridge site to hopefully add to the number of ringed birds there. It will be a busy morning, mainly as the road to the site is impassable after a point (which I found out from personal experience last year...) meaning that we take the kit into the bush and set up there. I have to been even more on top of how long traps are left for now that the weather is hotter and we have to move further to find new birds. Sunday morning is reserved for sleep and breakfast in bed :)

Emma

Saturday 6 October 2012

Ringing delights

We have now run the CES for four days, two at each site. Captures are a lot lower than I expected, but I prefer it this way when there is a steady stream of birds coming in. It's just right - having time to appreciate each bird individually is always a sign of a happy ringing session. Birds are still busy breeding so things will be different by the next CES at the end of November. If last year is anything to go by it will be quite busy.

Ringing at APLORI is brilliant because of the diversity of species we have here. I am lucky to run two sites in different habitats, and not surprisingly the species caught differ between them. At the guest house site we catch more of the smaller finches, thrushes and birds which prefer more wooded vegetation. In the grassland site it is Cisticolas, Bishops and surprisingly more Sunbirds than one would expect. Today's highlight: a stunning male Yellow-mantled Widowbird in his glorious breeding plumage. Normally these are drab brown birds very similar to female Northern Red Bishops, but at this time of year it's all about looking your best.

Now that is what I call breeding plumage!

The migrants are still arriving, and today saw the first Willow Warbler of the season. These tiny birds fly all the way from Europe to South Africa with less then 10 grams to their name. Also around and in the nets are Pied Flycatchers, more Garden Warblers and Wrynecks. I was lucky to spot a Wryneck out birding yesterday. In the field they are a somewhat unusual bird, but in the hand they are just plain bizarre. You will see from the video below why they are called Wrynecks. It's enough to make you feel dizzy!


 


It is a little unfair that I get all the fun, so for those at home, here is just a handful of the stunning birds we have been lucky to see during the CES so far. Enjoy!



Scarlet-chested Sunbird
Little Bee-eater

Rock Firefinch
Yellow-crowned Gonolek

African Blue-flycatcher
 
Variable Sunbird
 
Red-cheeked Cordon-Bleu
 
Lavendar Waxbill


Viellot's Barbet
Don't get your fingers near this one!
 

Yellow-fronted Tinkerbird

 
Snowy-crowned Robin-chat
 
The new APLORI Masters students trying out thier new binoculars

There are two more days to go next week and then it's back on with fieldwork. I am excited to get back to the Whinchats. I wonder if more have arrived? I still haven't managed to out-wit the ringed bird, but I haven't played all my cards yet. This bird is valuable for the study and I am determined to make sure it has colour rings by the end of the week.

Emma


Wednesday 3 October 2012

The first day of CES


Today was the first day of the Constant Effort Ringing (CES), in which we set up a large number of nets at two sites within the reserve. Each site is run for 3 days, alternating between the two. The nets are opened at first light (5.45am here) and we usually ring until 10:30. The CES is run 5 times throughout the year and gives us valuable information about the breeding, moult, survival and residency of Amurum’s birds. Check out the research section of the APLORI website for some of the results from long-term ringing at APLORI.

Ringing is a big passion of mine and I really enjoy the CES. It is a great opportunity to see many of the species here ‘in the hand’ and there are always nice surprises. Today we started at the site around the guest house where I stay (so conveniently close to the coffee pot), and tomorrow we will ring down at a site further into the reserve. I was a little apprehensive as it has been a while since we ran a CES and so we were likely to catch lots of birds, but in fact captures were steady. This is just how I like to ring – busy but with plenty of time to appreciate the birds. Tomorrow’s site is more akin to grassland savannah, and I anticipate plenty of Cisticolas (a group of very similar-looking species that are always a challenge to identify) and of course Northern bishops. Bishops are a treat at this time of the year, with the males now kitted out in stunning red breeding plumage. They are a rich scarlet and deep black with a wonderful texture, not dissimilar to your finest fleece, and their red napes stand proud behind their heads. It is hard to remember them as they were in the non-breeding season with the males matching the drab females. 

 A superb specimen of a male Northern Red Bishop in breeding plumage

Bird Of The Day for me was a Red-winged warbler. I remember seeing this bird for the first time the day I arrived at APLORI in 2011 and it is still as stunning now, with its brick-red wings, slate-grey head and cream belly. It is really beautiful. Other highlights were 5 Snowy-crowned Robin Chats, Blue-cheeked Cordon Bleus, Bronze Manikins, a Black-crowned Tchagra, an African Yellow White-eye and a male Northern Red Bishop. Evolution did a superb job when designing the colour scheme of each and every bird I know, and you really can admire them this close up. If I dressed in the bright red and cyan blue of the Cordon-bleus, or mixed green and red like the Scarlet-chested Sunbirds, you wouldn’t be seen dead with me! Although I have to admit that the Yellow-fronted Tinkerbird is stuck in the 80s.

A picture-perfect Red-winged Warbler

We also caught some migrant Garden Warblers. These are long-distant migrants from Europe, like the Whinchats and Whitethroats, and pass through earlier than other species. Garden Warblers are known for being ‘non-descript’ and birders use the fact that they have no distinguishing features to distinguish them... it sounds odd but it works. They are very gentle looking birds and another favourite of mine. They can also be a bit of a challenge to age, but the more you see the more obvious it gets. For this species, it is a matter of looking at how worn the feathers are. Adults moult once a year after arriving on the wintering grounds (quite unusual for European species), and so the adult birds we were catching had used their feathers to fly to Europe, breed, and then all the way back. Understandably they were looking a little worn around the edges to say the least. Juvenile birds, however, grew their feathers in the nest earlier in the summer and were looking a little more dapper. Ringers generally use moult and plumage to age birds because juvenile and adult birds change different feathers at different times of the year. Knowing the age structure of the population gives us vital clues to the ‘health’ of the habitat, survival rates between adults and juveniles, and of course breeding success. In conservation, this is vital information. Fewer juveniles to adults, for example, may mean reduced breeding or high juvenile mortality. I am known amongst my ringing friends as being a bit of a geek when it comes to moult, but in my defence it is incredibly fascinating. You really have to look at the finer details, and I love a challenge. 

Today I was joined by Chima, one of last year’s Masters students who is helping out with the CES. Chima started ringing less than a year ago, and it is a pleasure to see him as the enthusiastic and competent ringer he is now. Ringing is a difficult skill to master. Not only must you be capable of collecting data safely and accurately, you must also have a good understanding of the moult and life-histories of the birds you catch. Most of all, it requires patience and you have to know your limits. Although I have ringed thousands of birds, I always learn something each time I ring, and I still have lots to learn. Today the 5 robin chats provided a great exercise in ageing as we caught birds belonging to each age class. This species has a distinctive plumage as a juvenile, and whilst adults change all of their feathers when they moult, juveniles keep some of their distinct feathers. The result is what is referred to as a ‘moult limit’, and we use this to tell how old the bird is. You can see this in the photo below of a bird that was born earlier this year, as it has both adult (blue-edged) and juvenile (brown tipped) feathers.

 An example of a 'moult limit' - the first 5 feathers from the right are juvenile, the rest are adult

Tomorrow should be an exciting day with plenty of challenges so an early night is in order. I may put playback for whinchats at some of the nets as we sometimes catch this species here.

Emma

Friday 28 September 2012

Back into the swing


I am pleased to announce that there are now 4 new whinchats with colour rings. I haven't caught the ringed bird (yet), but there is plenty of time still. It is a relief after yesterday. It’s usually the case that the first day of fieldwork doesn’t go to plan and yesterday was no exception. After a long morning I just couldn’t catch any of the birds and came back frustrated. Let's hope that yesterday was just ‘one of those days’ after the good day today.

 One of today's 4 new whinchats, still in beautiful plumage even after flying over the Sahara. One of the birds, hatched this year, was in such terrible condition I wondered how it made the journey. I hope it gains condition before making the return flight.

Things do seem different from last year and I think it is because it is still early and the ground is wet and the vegetation thick. It is tricky to find a good place to put traps. Yesterday we set them at the edge of a corn field where 3 birds were chasing each other, plus two more sets by other birds in the area. For the whole morning the birds did not really respond to the playback. Everybody seems very intolerant of their each other (and of me) and all around there are whinchats chasing each other and ‘ticking’ - their way of showing their irritation at trespassers.

The fieldsite after the rains. There is little bare ground and the vegetation is 
green and lush - a far cry from when I left it in April.

This morning we decided to take a different approach and set mist nets in the tall maize. These very fine nets are almost impossible to see amongst tall vegetation, providing you work before sun and breeze give them away. To my surprise they worked well and 3 of today’s bird were caught in the nets. I will take advantage of the maize before it is harvested in late October. The more birds I can catch with nets the better, as it might well be a case of ‘once bitten, twice shy’ with the spring traps. Normally, ornithologists use mist nets to catch small birds like whinchats, and I will indeed use them for whitethroats later in the season. Sometimes, however, it is not possible to use nets because the habitat is too open, or perhaps something else works better, like spring traps. Both methods are good for different situations, and most importantly they are safe for the birds. The word ‘trap’ does sound a little harsh, but these are brilliantly designed and work a treat without stressing the bird.

On the left is a set trap showing the trigger, which when pulled springs the netting shut (as demonstrated by the cotton bag on the right). The playback is put nearby.

For whinchats, spring traps are perfect as they take advantage of the bird’s natural behaviour. Whinchats typically perch on the top of small bushes, flying down every so often to pick prey from the ground. They are also territorial and so will respond to the song and calls of whinchats. Birds use song and calls to attract mates, broadcast territories, announce the presence of a predator and to let each other know where they are. Consequently, birds will often come to investigate the songs and calls of birds of their species. Whinchats are no exception and treat the sound of another whinchat as the presence of an intruder. Using ‘playback’ simply means playing songs and calls to get a bird’s attention. With this in mind, it is relatively straightforward to catch a whinchat. You will need:

whinchats
4 or 5 spring traps
live bait (the wigglier the better)
playback
a small isolated bush
equal parts patience and perseverance
a sprinkling of good luck

The key is to use the playback to get your bird to come near the traps. If the traps are placed where the bird will see the baited triggers, they will fly down to feed, spring the trap and you will catch your whinchat. A small bush on its own is best - that way the bird is close to the ground (and your traps) and not perched far away. I use maggots for bait as they definitely tick the wiggle box and are marvellously resilient, even under the African sun (you get used to them after a while, getting hold of them is the unpleasant bit!). Getting all of this right is often trial and error and you have to move to a different bush (or 5). Some birds are just not bothered to too suspicious to catch. Some are so territorial that they will perch immediately above the playback and become so transfixed that they ignore the bait. The worst culprits will perch on every single bush apart from the one with the traps underneath. I'm sure these birds are deliberately trying to wind me up! Getting it to work is rewarding, and I am always excited to check the traps. Whinchats are brilliant little birds to ring as they are a bit of a challenge to age and sex (but almost always possible) and have an air of robustness and resilience about them that is reassuring to any ringer. Plus they are really gorgeous.

I am off to take a tentative drive down to my other sub-site. I suspect that the road is undriveable so it may be that I will have to wait to see if my birds have returned. I am excited to see this site. There is a river running along one side and I often see great birds there.

Emma

Wednesday 26 September 2012

Old friends


After two more trips into the field (kitted out with a new pair of rubber boots) I have found 4 more colour-ringed whinchats from last year. These birds are again in or very close to the same tiny territories they held last year. It’s like they never left. This brings the total up to 7 so far, and I am confident that more will show up as the weeks progress. It is still early and it is likely that there are more birds that I haven’t found. It is quite easy to miss birds when re-sighting as they only need to be on the wrong side of a bush or foraging on the ground for you to not see them. It is fantastic news to find so many returning birds this early. At the end of the season I will be fitting geolocators to map migration routes, and it is very promising and somewhat of a relief to know that there is a high chance of recovering a good number next year. It is going to be fascinating to find out where they spend the summer and the routes they take.

One if the birds I saw this morning was Red-Yellow-Red, one of the first birds I caught in January. That was the last time I saw it, and despite searching the area throughout the following months I never re-sighted it. To see it back, not only alive and well but about 10 feet from where I caught it last year was reassuring but also mildly irritating. It was like spotting a truant school kid. Where did it go last winter, and if it did leave that territory after it was ringed, why did it come back to the very same spot? Perhaps it had a favourite perch hidden out of sight, or perhaps it was like another of last year’s birds that had a strange tendency to perch high in a tree (which is not what whinchats are meant to do!). I am happy to see it back none the less. 

7 birds have now been found, all returning to the same territories as last year

This morning I also saw a whinchat with just a metal ring but no colour rings. It was in a territory held by a colour-ringed bird last year, but I think it is unlikely that it had lost its colour rings. I use three colours for each bird and all of the returning birds have their full set. This spot is close to one of the CES sites (constant effort ringing), so I suspect that it was ringed there previously. I can’t wait to find out. One thing I have already learnt is that the red rings have bleached over the European summer and are now pink, which is (unfortunately) very close to the orange I also use. I’ll have to re-think my combinations from now on.


One of the returning whinchats from last year with colour rings (white and blue)

Today I was lucky enough to have a wonderful sighting of a cuckoo perched right in the open for quite some time. A great perk of fieldwork is that you get can’t help but see a great deal of other birds and wildlife. After comparing my notes with the bird book back at the car I believe it was a migrant Common cuckoo from Europe. These birds are very similar to the African species; however this bird had a bill that was black all the way to the head and barring on the breast was clean and sharp. It is a stunning bird. As much as I love tropical species, you don’t have to be bright and flashy to be a treat for the eyes.

My field assistant has just returned from a successful mission to get bait for the traps, so I will begin catching tomorrow. Today we found at least 8 un-ringed whinchats so we already have plenty to start with. Interestingly, these new birds were spread throughout the habitat and not just at the edges like the at flooded part of the site. This spot is dry, so perhaps whinchats do indeed need dry ground. Tomorrow I will start here. I usually catch between 3 and 5 whinchats on a good morning and I have lots to do to make sure everything is ready. Today I was pleased to find a driveable track leading right to the site which makes work so much easier. I wonder when that bird from today was first ringed? Hopefully I will find out tomorrow as that metal ring has guaranteed that I will be making a bee-line straight for that bird.

Tomorrow I’ll post more about how exactly one outsmarts a whinchat and what ringing them involves.

Emma