Wheatear trapping in Senegal

It’s hot, dry, sunny, sandy and windy outside: a semi-desert, in northern Senegal. It’s dry season and all the areas that are flooded and filled with life during the wet season are now just moon landscapes of crevices in dry mud. I’m in Djoudj national park, close to the boarder to Mauritania, to catch wintering wheatears (Oenanthe oenanthe) and equip them with geolocators to try to gain information about their migratory routes and stop over sites. My main target is ssp. leucorhoa, the subspecies found on Greenland and in eastern Canada, but also birds of the nominate subspecies will get loggers this time.

I’m here with Petter Olsson, a keen birdwatcher and ringer, and so far we’ve caught ten birds (five of each subspecies). There are plenty of birds around, but they are rather scattered and many of them are very cautious and hard to catch. Our best strategy has been to search out good locations in the afternoons and evenings, learning where the different individuals move and forage and then return to these areas early the next morning and put the traps out before the birds become active. In the afternoons it’s still too hot and the birds are not hungry enough to be interested in our mealworms. We brought mist nets along as well, but the habitat is just too open so there’s really nowhere to put the nets. Well, if we can keep up the pace we’ll still manage to get all the loggers out in the two weeks we have left.

I was here three years ago, catching wheatears to collect faecal samples for hormone analyses, partly overlapping in time with a PhD student from Cardiff University, Adam Seward. He was looking at fuelling, also in wheatears, and colour ringed his birds to be able to identify them when they visited his feeders. A few days ago Petter and me went to Grand Lac, a large lake in the middle of the park, where Adam and me caught most of our birds three years ago, and just outside the hide we found one of the colour ringed birds caught in 2010. That gives me more hope and confidence that we have good chances to be able to retain some of the loggers even when they are put on in the wintering grounds. I recall from three years ago that Adam back then also had a bird, ringed in 2009, that returned to the exact same feeder as the year before.

Even during the dry season the park is filled with birds and other animals. Apart from the approximately 150 bird species we’ve seen so far, there are plenty of warthogs and golden jackals around and we’ve also seen some patas monkeys. Walking around at night with headlamps and flashlights we’ve seen several common genets and a wild cat. As far as reptiles go we’ve seen Nile crocodile, Nile monitor lizard and agamas so far. There are supposed to be puff adders just outside the park and three years ago we saw an African rock python by the river, so there are still more species to be found and to keep us occupied during the hours when the wheatears are not willing to take a bait or it’s too dark to search for new good trapping locations.


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