Back from the Bijagós archipelago

We have just arrived from a new expedition to Guinea-Bissau. This time logistics were far easier to arrange, both because we start to know some tips about “how to move and where to go in the Bijagós”, but also because we didn’t aim to catch waders. This was somehow a relief, but worms and clams proved to be sometimes also hard to collect!

The expedition team

Our first work area was located in the northeast of the main island of Bubaque, a place called Praia das Escadinhas. We previously knew that place, since we have worked a few days there last year, what we didn’t know was that the mud was incredible soft in some areas!!! We spend the first days filming foraging waders, collecting droppings and carrying out a systematic invertebrate sampling in this area. Bird densities are rather low, which obliges finding and pursuing the birds across extensive muddy areas under temperatures over 30º C. At this time we were regretting not working during the night…

Escadinhas Beach

Invertebrate sampling at Escadinhas

We did a similar job at Bruce, the longest beach of Bubaque at the south end of the island, and at Bijante, on the opposite side of Escadinhas. Here, at least some of the intertidal areas are mostly composed of sandy sediments and, accordingly, both the invertebrate fauna and part of the wader community is different from Escadinhas. At the mudflats of Bijante we found the first area where small bivalves were apparently abundant. Of course, Red knots had discovered it first!

 

 

Flock of foraging Red knots at Bijante

Apart from us and the waders, there were others digging in the mud. Bijagós’ women and children collect blood cockles (Anadara senilis) and razor shells (Tagelus adansoni) to eat.

Shellfishers

The Bijagós hold huge numbers of different tern species, including wintering birds from Europe and resident birds that breed in small sandy islets around the archipelago. We spend a couple of days at Orango, the most offshore island of the archipelago, and had the opportunity to visit a Caspian Tern (Sterna caspia) colony, in the scope of a collaboration with other Portuguese researchers.  Terns are quite asynchronous: there were couples still incubating their eggs and others with flying juveniles.

Pelicans and terns

Mixed flock of Royal and Caspian Terns

 

As always, when exploring new sites, we bumped into exciting new landscapes, plants and animals. We leave here some photos documenting such an adventure.

 

Black heron (Egretta ardesiaca) using their wings like an umbrella to shade the water and attract fishes.

Crocodiles at Orango

Weird (but beautiful) flower

Dunlin movements: summarizing resighting data

Since 2009 we have been colour ringing Dunlins (Calidris alpina) at the Tagus Estuary, southern Portugal (https://sites.google.com/site/migratagis/Home/colour-ringing). So far we have marked ca. 700 birds with individual colour combinations (from a total of 1500 dunlins caught), some of which were subsequently observed in several sites in Europe and Africa. In January 2013, we had the opportunity to visit the Banc d’Arguin (Mauritania) in the scope of the current research project – Invisible links (https://sites.google.com/site/migratagis/Home/projects-1/invisible-links) – which allowed us to fit birds with colour rings there as well. Only a few birds (46) were marked, but already interesting movements were reported. The map bellow shows lines linking the ringing and sighting sites. Blue and red lines represent dunlins marked at the Tagus Estuary and Banc d’Arguin, respectively. Orange lines represent birds wearing a foreign metal ring that were recaptured at the Tagus Estuary. Take a look!

(open the image in a new tab to view the map with higher resolution)

Spring Fieldwork is Over

Spring fieldwork is over. It ended a couple of weeks ago and now we are preparing the material for stable isotope analysis. After ca. 20 field trips and over 400 waders captured (and a few recaptured with a foreign ring), we gathered hundreds of samples, not only from birds but also of the different components that compose the estuarine food web. It will tell us interesting and important information about the migration strategies of the birds using the Tagus estuary on route to their northern breeding grounds.

Long but cheerful nights and days were passed in the field, with too much mosquito bites also collected. Ask Pedro! Less appealing were the days in the lab (joking! although it is true ; ), but that is part of the process and fundamental to have meaningful data sets.

We hope to have preliminary results in the next weeks. For now, we share a few images of this spring.

Enjoy! 

The core team of Tagus estuay fieldwork

Ringing by day. Dunlins and Ringed Plover.

Ringing by nigth. Black-winged Stilts, Grey Plover, Little Egret and Bar-tailed Godwit.

 

Expedition to the Bijagós Archipelago, Guinea-Bissau

On the 12th of January, Lisbon airport was highly crowded, and the Invisible Links team was there, anxiously waiting to check-in on the flight to Guinea-Bissau.

That was the start of the three week trip to the Bijagós Archipelago, the second most important wintering area for waders in the eastern Atlantic. As it happened in previous expeditions to Banc d'Arguin (Mauritania) and Sidi-Moussa (Morocco) the main goal was to collect biological samples representative from the Bijagós’ trophic  web, so, not only from waders, but also their prey, the prey of their prey, and so on! (take a look here and here). Some of the team members, using their feet, even “collected” and transported to Portugal a couple of Djigan, the native name of what scientists call Tunga penetrans. The females of this species burrow into exposed skin of mammals and feed there while the eggs develop!

The first week was mainly dedicated to explore the area: where birds roost, possible catching sites, places to collect invertebrates, etc. In addition, some members of the team also participated in the World Waterbird Count, along with technicians from Instituto para a Biodiversidade e Áreas Protegidas da Guiné Bissau and Gabinete de Planificação Costeira da Guiné Bissau as well as other experienced ornithologists from Europe. 

Beside the long walks across the forest, the recognition of the place included to travel on very comfortable (or not!) bikes from one end to another of Bubaque island (an unforgettable 30 km ride, they say). 

For part of the time the team was reinforced with two Guinea-native ornithologists - Hamilton Monteiro and Mohamed Henriques – whom, by sharing their expertise on birds and making the contacts with local populations, proved to be crucial for the success of the expedition! The gang moved a lot between and within islands to accomplish all the pre-established goals. Those travels were not always easy to arrange, but they managed to perform numerous nights of catching and ringing in several different places. Regardless all the difficulties the team was able to collect over 200 samples (almost half from birds!), which are now getting ready for analysis.

 During some of the bird catching sessions the team also captured (undesired) mammals, in some nights as many as birds! Fortunately, they did not catch other big mammals also present in the tidal flats during the day (see the picture below).

 

Apart from the work the team still had time for birdwatching, and managed to observe a large number of new and colorful species (once that was the first time in Guinea-Bissau for the most). Plus, they made new friends, as Helena, a kind young little girl that talks a lot! She is the granddaughter of Dora, the owner of the hotel (Casa Dora) where the team stayed for a bunch of nights. It is a very nice hotel! Part of the team departed a few days before the end of the expedition, which was a pity because they did not get the taste of Bissau night life at the X-bar!

 text: Camilo Carneiro

photos: Teresa Catry & Camilo Carneiro

New expedition to Banc d'Arguin Nov/Dec 2013

As it happened last winter, I joined a NIOZ expedition to the Parc Nacional du Banc d’Arguin (PNBA). This time, the five hours between flights at Mohamed V airport (Casablanca) went much smoother as I met a Portuguese birdwatcher, allowing a very nice and long chat. He left Lisbon in the same flight, but he was heading Gambia for a bird week!

The Dutch team arrived just before the flight to Nouakchott. Pierrick Bocher, a Professor at the Université de La Rochelle also joined the team.

After a short night at the Hotellerie Rachad, a good breakfast, the shopping and bureaucratic work, we left Nouakchott towards Iwik. The first afternoon and next morning were dedicated to make the field station inhabitable: clean everything, wash kitchenware, store food, et cetera. Then the work started. My mission was to reinforce the tasks carried by the Invisible Links team last winter (see http://www.migratagis.blogspot.pt/2013/03/expeditions-to-banc-darguin-mauritania.html), i.e., collect more samples!

Although I had my own work, getting bird samples (mainly toenails) was dependent on the effort made by the NIOZ team to capture birds. Of course I helped to raise that effort and altogether we managed to achieve very good catches! Within  all captured birds, we had quite a number of recaptures, including birds ringed in Europe (along the East-Atlantic Flyway) and some recaptures of colour ringed birds, allowing replacement of old worn rings.

Sampling invertebrates at Baie d'Aouatif

 Apart from work, and rather unexpectedly, I managed to add a new species to my bird list: the Black-crowned Sparrow Lark Eremopterix nigriceps. This species was never spotted by the NIOZ team in the peninsula in previous years, but this winter several birds were present! I also managed to have a glimpse of what I think it could be a Cape hare Lepus capensis!

It was “mooie”, and I think it is fair enough to claim that the mission was accomplished!

Camilo Carneiro

Sunset at Poste d'Iwik

NEW RESEARCH FELLOWSHIP 
(November 2013)

In the scope of the project "Invisible Links: unveiling origins of migratory waders using biogeochemical markers" a new call is open for a Master Research Fellowship.

Job description

Main research and tasks: i) participation in ringing sessions and bird sampling; ii) participation in the sampling of estuarine biota, namely water, sediment, plants, invertebrates, etc; iii) participation in bird census; iv) participation in data compilation and data analysis; v) participation in laboratory work, namely invertebrate identification and sample preparation for stable isotope analysis; vi) participation in bird captive experiments in Monsanto. Fieldwork will be carried mainly at the Tagus estuary (Lisboa), but there may be a need for participation in work in western Africa (Guinea-Bissau or Mauritania).

Host institution: Museu Nacional de História Natural e da Ciênica and Faculdade de Ciências da Universidade de Lisboa

Fellowship duration: 3 + 4 months, starting on the 1st of December 2013. Candidates should send a (max. 2 page) motivation letter and a CV (max. 4 pages, with grades) to teresa.catry(at)gmail.com until the 15th of November.

More informations available at http://www.fc.ul.pt/concursos?id=692.

Dunlins' resightings from Banc d'Arguin, Mauritania

Last January, we extended our dunlin colour-ringing program to Banc d'Arguin, Mauritania, one of the most important wintering areas for this species. Dunlins were colour ringed with a combination of 3 standard colour rings plus one blue flag (instead of the green flag used at the Tagus estuary, Portugal). Despite the low number of birds marked during this first expedition, we have already 2 resightings! 

One of the birds, WO-BfR, was captured by Hugh Hinsley in Cuinabunag-Benbecula (Western Isles, Scotland) in early May. The other one, GW-BfR, was spotted by Geoffrey Hunt in Ballylongford, Kerry (Ireland) by the end of July.

 

 

 

Camilo and Pedro colour-ringing a dunlin at Banc d'Arguin, Mauritania

Foraging dunlins at the mudflats of Banc d'Arguin, Mauritania