Above photo: the view from the house
The aim is to understand how Palearctic-African migrants use and move around the different vegetation zones found in West Africa, ranging from the semi-desert Sahelian region in Burkina Faso to the lush tropical rainforest in southern Ghana, and whether habitat change may impact them on their wintering grounds.
During the temperate winter of 2009/2010, using point count methodology and mist-netting, we recorded migrants along a degradation gradient at five different stations on a north-south transect. In 2010/2011 we plan to re-visit these sites as well as roving further afield to get a broader picture of migrant habitat use.
Above photo: the view from the house
With Japheth back and our confidence with tracking increasing, we put a net up in a spot where yesterday we saw an unringed wood warbler. And bingo! After a half-hour of playback a bird is caught, and a few minutes later our third radio-tagged wood warbler is released. Brilliant!
On top of this capture success, we manage to see both other birds this morning – bird 1 for the first time!! This was foraging with an un-ringed bird in a bug-filled flowering tree by the river. Not identified it yet, but I think it might be a Berlinia species.
We manage to track and get fixes on bird 3 this evening. Hopeful to actually see it tomorrow!
Aside from tracking today, we have a meeting with the owner of some wholly decent accommodation on the edge of town. Essentially a holiday home/ weekend retreat for himself, he has built some chalets nearby and rents these out to local professionals. He says that sadly there is no free chalet at present, but explains that for our last two weeks we can move into 3 rooms in his own house! Deal done!!
The grounds of our prospective new accomodation
On our way back from fieldwork this evening we were treated to some pretty good views of long-tailed nightjars resting on the track ahead of us. This meant that poor Japheth had to wait a short while in town for us to pick him up. Sorry Japheth!
Above photo: long-tailed nightjarThe nightingale tracking continues anabated. The team now have a full complement of 10 radio-tagged birds, which has become quite a handful to track twice and even three times a day! Bee and Chas have also undertaken some more habitat mapping of the site, and during the course of fieldwork came across this rather confiding African crake:
Above photo: African crake
A second morning seeking out the birds, and we head straight for down into the valley where bird 1 was yesterday. We get a good signal from the word go. We find that the valley is in fact quite grassy and scrubby, demonstrating that we are at the very northern edge of the forest zone, and the southern edge of the savannah. Plenty of farmland at the bottom too, readily irrigated from the river continuing north towards the Volta, from the waterfall we passed yesterday. Wondering whether the bird will be accessible in the dense forest at the head of the valley, we’re pleasantly surprised to find that it appears to be hanging out at the farmland/forest edge. No matter how hard we try, however, we cannot see the bird, but feel we must be within 50m of it. A few decent fixes, and we’re pretty pleased with this so head for bird 2. Little problem finding this one, and we see it in a mixed canopy some 70m away from yesterday’s spot.
Above photo: early morning tracking
Considering our success so far, we decide to up-sticks from the mountain-top and head for the closer accommodation, so we head straight back to camp and start packing. We say our farewells to the caretakers, grab some lunch in Mpraeso, and head for the new guest house.
The afternoon foray into the field is spent in the valley, chasing after bird 1. It appears to have moved within some particularly troublesome shrubby terrain, and we take 2 hours to get 2 fixes, and as a consequence we end up with no time to search for bird 2. We decide that our pm fieldwork in future should start with bird 2, and then get as good fixes as possible on bird 1 from vantage points on the ridge above the valley.
Not a peep from the receiver. A walk up the road and 100m in every direction, and still nothing. Wondering if the bird has moved on already, we decide to switch to bird 2, hoping for some reassurance that at least the equipment is working! Straight away we get a beep in the headphones. Very quickly we home in on the direction of the strongest signal, and make our way towards the bird.
Amazingly after about 45 minutes we not only pin-point the location of bird 2 about 160m from the ringing site, but we actually spot it, replete with colour rings, foraging a few metres above us in a path-side tree. What an amazing feeling! Yesterday we attached the tag wondering if we’d even get a signal from the birds today, and here were are actually watching one of them!! Brilliant.
Next task was to try again for bird 1. Understanding that the range of the tag is about 500m, up to 1km in the best conditions, we resolved to walk 500m in every direction from the ringing site. Should this fail, we’d expand the search to 1km, and then further if necessary. For the first foray off the main East-West track we head south, listening all the while for any signal from bird 1. An occasional switch to bird 2 shows that we can still detect it from up to 650m away, but 500m S of the ringing site, still no bird 1.
A short walk west along the main track we arrive at the village, and ask for a path northwards. We are pointed in the direction of the river, but are told we need a guide. A quick explanation that the Queen Mother has given us permission, and we’re waved on. About 150m after leaving the village, and bingo, I start to get the faintest signal from bird 1. Continuing on past the river, where it disappears underground and emerges at a sacred waterfall, we’re crossing a grassy, rocky plateau – quite unsuitable for wood warblers it would seem. The valley below is wooded however, and this appears to be where the signal is coming from. We find a path down towards the valley, through some farmland, and then further down to scrub on the edge of the forest. At this point the path runs out, so we take a waypoint and a compass bearing towards the strongest signal. We back-track and seek out other vantage points to take bearings, but back on the plateau we find that we’re heading further away from the signal as it gets weaker, and there seems no other way down to the valley. We decide to head back to the village, and from the road we can “circle” round to the other side of the valley, and maybe get bearings from the opposite ridge.
The road runs south-north along the west side of the valley, and the slopes down are farmed and passable via many paths. We find one which takes us to a vantage point overlooking the valley, but still some 500m from where we were on the other side. A good signal from here, and we finally get a good picture from 2 more bearings. Happy with these “fixes”, and with the sun now high in the sky, we head back to our camp on the mountain.
En route through Abetifi we discover a fantastic little canteen in the grounds of the University, amazing value and service, probably cheaper in fact than catering for ourselves! We resolve to take our lunches here, and self-cater for breakfast and our evenings from now on.
After a long morning, we decide that we must move to Pepease tomorrow. This commute is just too long! It will be much more practical for tracking the birds twice daily.
Whilst out tracking the nightingales, Bee and Chas continue to engage with the locals, and the wildlife pin-badges are going down well.
Above photo: Bee with some local kids on their way to help on the farm
Instantly we get a response. First one bird, then another, calling, but not seen, from over the net area. Then a couple of minutes later another two arrive in that first main tree from yesterday. These two drop down towards the net, and the pewing continues. Just a few minutes later, two reappear in the tree, then a third, fourth and fifth are spotted. None are now calling and all are foraging and moving steadily further away from the source of the song. None is calling, however. Not even those that were very vocal at the start. We need to check the net.
Craning a neck around the corner into the net ride, we spot our first trapped wood warbler, and there next to it is a second! Bowled over by this success, we hurriedly extract the birds from the net and return to the car to prep for ringing and tagging.
Above photo: ringing the wood warbler
Above photo: measuring the tarsus
Above photo: checking age and for any moult
The start of the transect route suggests not. Today’s mission is not to carry out a complete point count survey, but to determine, including with the aid of playback, whether or not any wood warblers are here at all. Remembering the locations (including the same trees) of the wood warblers from last year, we cover as much ground as possible, using short bursts of song and call from the mp3 player. From 0600 until 0930 we see and hear nothing wood warbler like and are more than a little disappointed, until at last at 0945 we hear a faint “pew” from behind. Turning back, we locate our first study-site wood warbler, in a broad-leaved tree next to the roadside and a cassava field. It moved off a short hop to a different tree, so to get a closer look we find a newly cut path through some scrub on the edge of the field. Quite ironically, the path leads to a felled tree, creating a small clearing in the scrub. With nothing to lose, and considering December is looming and tagging time running out, we decide to attempt to catch this first bird at this first opportunity. The perfect though somewhat regrettable ready-made net ride serves a purpose, comfortably accommodating a 9 metre long net.
Before going back to camp, we stop in Pepease to see if there are any guest houses at all. We are directed towards one, which looks ok, so depending on our success/ failure rates over the next day or so, we at least have some lodgings closer to the study area that we can move to.
Meanwhile, Bee and Chas are continuing in their efforts to catch further nightingales for tagging. As a result they managed to get hold of this fine individual!
Above photo: sulphur-breasted bush-shrike
Chris Orsman writes: Last night we finally plucked up the courage to split the team in two. In the last few days I’ve managed to convince myself that I’ve heard wood warblers calling on a couple of occasions, so we need to go and check our site in the Mampongtin Hills. And with 7 nightingales tagged, Bee and Chas have plenty to be getting on with, even if they don’t catch more! Leaving them in Oppong’s capable catering hands, Japheth and I head for Mpraeso with driver Emmanuel promising to cook when required...
After a trouble-free trip, our camp to start the visit is back on the wonderful Odwenanoma Mountain. We plan to make the most of any time here, as certainly we will need to find a camp or lodgings much closer to the expected study site should we catch any wood warblers and therefore need to track them twice or more daily. On this first night we collect some tea, bread and bananas, get the local canteen to boil water for our flask, and hey presto we have a breakfast ready for the morning.
It wasn’t long before a signal was received, and the bird re-discovered some 250m or so from the capture site. Not all that far, but with these birds rather hugging the ground the signal can be easily lost. Later tracking forays showed that the bird was moving gradually further away again, and eventually appeared to settle about 600m from where it was originally caught.
Meanwhile the race was on to catch more, with just 3 so far and 7 more tags to use. We weren’t short of birds, as every now and again a new voice would appear, and fill in a gap amongst the thicket. An awful lot of effort by the team went into selecting suitable sites to place the nets to maximise our chances, such that our particular target bird would at some point catch itself without recourse to any tape-lures! By necessity this meant we were catching a lot of other birds, including a whole host of other migrants using the same habitat, such as garden warblers, melodious warblers, reed warblers, whinchat, spotted and pied flycatchers. All of these were providing us with invaluable information about timing of arrival, condition and moult, but also give some clues as to the overall value of this region and its habitats for a wide range of migrant passerines.
Above photo: tagged nightingale (you can just see the antenna)
In almost 3 hours, we see two birds, and up at the top Chris sees one. At one point there was a faint wood warbler voice calling from the high canopy, but our two birds merely continued to happily forage high, and oblivious to the recording. A bit demoralising, but not entirely unexpected.
Considering our failure to catch, and even more so the lack of birds on the lowland site, we resolve to head back to the nightingales. The main concern is that I have not put a radio tag on a bird yet – a skill I need to master before I can do it without Chas and Chris, so our best chance, we feel, is to catch more Luscinias, and come back to the wood warblers in a few days when perhaps they will have arrived at our preferred study areas.
A single net was erected near the camp this afternoon, after 2 birds were again seen nearby. Having elicited a “pew” from the playback yesterday, would they be actually attracted to it? With no other option at this stage – the birds are so high and mobile – we start the tape and stand back.In an hour of trying, we did see the two birds again, but only very high up, looking briefly slightly interested but not really responding particularly positively. With no birds as yet on the preferred farmland site (thought to be better for tracking any birds caught) we decide to at least try a more concerted effort on the hillside the next day. At least we know the birds are here, and we may get an idea of some movements and tracking limitations with one or two birds caught.
Above photo: the team craning to spot wood warblers
In the afternoon, a flowering tree right next to our camp was a-buzz with insect life, and drew our attention with various sunbirds and common bulbuls attracted to it. Whilst watching, a wood warbler appeared here too, and also a willow warbler popped up. Perhaps a net even by the camp would be productive, we thought. Later a stroll around the hill-top produced 2 more, and also 2 garden warblers. And for good measure, a breeding pair of violet-throated cuckoo-shrikes put in a most welcome appearance.
On the last two days the first bird in fact disappeared altogether, and we wondered whether it had moved on further south. Surely this couldn’t have happened? When caught it was very light, carrying no fat reserves. In order to move on it would have needed far longer to fatten and strengthen to cover any great distance. Reluctantly we surmised that it could have perished or that the tag could have failed. With time short on the afternoon of the 12th we took Chris and Chas to the wood warbler zone, once again with our fingers crossed.
Bee writes: Despite our hard work we did have fun too. Every day something amusing happened: either it was Chris H telling another one of his stories, or it was the frog in the toilet, or Chris O’s MP3 Player (which should have played nightingale) suddenly blasting an 80’s power ballad over the fields, or the people we met. One morning we came upon a woman farming her plantain plantation. She was very friendly and not shy at all and as soon as she had greeted us she called all of her children to come and have a look. Obviously, she had not told them what was awaiting them. It was so funny to watch their little faces when they spotted us “obruni” standing in the middle of their plantain field. They looked as if they had seen Santa Claus and the Easter Bunny at the same time.
Bee writes: Friday morning and Chris O and I went to get some Ethanol for preserving any faecal samples we might collect from any migrant birds caught, whilst Chas and Chris H were chasing up the lost bag. It had arrived! By 10 am all of us had fulfilled their missions successfully so we were ready to leave Accra.
The trip was somewhat long yet uneventful, so I kept myself amused by photographing funny advertisements and signs.