DOI: 10.5281/zenodo.6905505
title: Bird counts at Buanyuantula, Makalondi, Niger (1991-1993)

description: Bird counts along transects carried out by Pierre Souvairan (1921-1998) from June 1991 to September 1993 at Buanyuantula (spelled Boignontoula in OpenStreetMap), Makalondi, Niger, near the Kulbu pools. Patrick Giraudoux helped Pierre Souvairan to design the protocol during his stays in Dijon, France. Patrick Giraudoux (in December 1991) and Dominique Michelat (in July-August 1995) visited Pierre Souvairan once on the spot at Buanyuantula, then digitized and secured the data. Two transect strips were walked, corresponding to grids of 100 x 100 m mesh. Each transect was walked along a line crossing the grid, observing birds at maximum 50 m on each side of the transect line. - The NS strip corresponds to a 2.5 km x 200 m strip. The grid consists in two contiguous sub-strips (one north, one south of 100 x 100 m mesh each) stretching E - W between Buanyuantula and the Kulbu pools depression. Three 2.5 km transects lines were walked: one "N" in the middle of the northern strip, one "M", median, at the common border of the two strips, one "S" in the middle of the southern strip. - Transects B, for "bas-fond" (wetland), has two discrete segments 01B-10B and 16B-25B, and was walked at the higher water limit of the Kulbu pools area. Transect dates Transect Beginning End Fortnight number N June 1991, fortnight #1 May 1992, fortnight #2 24 S June 1991, fortnight #1 May 1992, fortnight #2 24 M September 1992, fortnight #1 August 1993, fortnight #2 24 01B-10B October 1992, fortnight #1 September 1993, fortnight #2 24 16B-25B September 1992, fortnight #1 August 1993, fortnight #2 24 <strong>Caveat:</strong> the <strong>approximate</strong> place of those transects has been georeferenced in July 2022 by Patrick Giraudoux and Dominique Michelat based on Google Earth and Bing satellite backgrounds imported in QuantumGIS 3.24.2-Tisler, and on a hand-made document (Itinéraire lettre 18101992.jpeg) Pierre Souvairan prepared and sent in October 1992. On the satellite background, Pierre Souvairan's compound (cabin and field), some tracks (e.g. Makalondi trail), the Buanyuantula village were still clearly visible as well as the general geomorphological features of the area. However, irrevocable differences still remain between georeferenced files and Pierre Souvairan's paper maps. We have prioritized the consistency with undoubtful features such as well identified tracks, acknowledging that after more than 30 years when the hand made maps have been drawn, vegetation features, wetland border, etc. might have sensibly changed. Pierre Souvairan was an excellent ornithologist, but had one bad eye (half blind). Assuming a constant bias due to this, comparability between observations is fine in term of relative abundance. This issue must however be considered, should comparisons with other observers be done. <strong>FILE DESCRIPTION:</strong> <strong>Main files</strong> Files carres_date.txt , especes.txt , observations.txt are tables of a relational database. They can be linked using the index field 'carre' between carres_date.txt and observations.txt, and the index field 'espece' between observations.txt and especes.txt. carres_date.txt carre, grid square ID : digits 1-2, the grid square ID; digit 3, transect ID (N, north; S, south; M, Median; B, <em>Bas-fond</em>); digit 4-5, the fortnight number from the first survey fortnight to the last one (1 - 24). Examples: 01N01 is square 01 of transect N, first fortnight; 01N10 is square 01 of transect N, tenth fortnight. annee, year (91-93 for 1991-1993) duree, crossing duration (in hour fraction: e.g. 5 mn = 5/60 = 0.08). The speed at which each grid square was crossed (depending on vegetation density, number of observations, etc.) mois, month (1-12) date, the date of the crossing (computed for convenience from the year, month and fortnight: day 10 was given arbitrarily for the first fortnight, and day 20 for the second fortnight of the month). especes.txt espece, ID number nom, Latin name code, 4 digits abbreviation observations.txt carre, carre ID (for joining see the field ‘carre’ field in the file carres_date.txt) espece, species ID number (for joining see the field ‘espece’ in the file especes.txt) nombre, number of individuals observed <strong>Supplementary files</strong> Carte Makalondi.jpeg the scan of a map Pierre Souvairan drew with the location of the places mentioned in his correspondence. Geometries_Grid_NS_B_transectLines.zip the grid and transect geometries (ESRI and kml). Itinéraire lettre 18101992.jpeg the scan of a map Pierre Souvairan drew and sent to Patrick Giraudoux (letter received in October 1992). Georeferenced locations are available in Name_coordinates.kml. Name_coordinates.kml the georeferenced locations of places mentioned in the field map Carte Makalondi.jpeg. PhotosNumbered.pdf photos taken on the spot in December 1991 by Patrick Giraudoux. The place where each photo was taken and the direction is in red in the transect map ScanTransectPhotos.jpg. ScanTransectPhotos.jpg 20 x 140.4 cm field map of the NS strip with vegetation data, drawn by Pierre Souvairan likely in 1991. Transects_Grids_Map.jpg Map of the area, with the exact location of pools, Buanyuantula village, Pierre Souvairan's cabin, and the general location of the grids and transects. Note that the latter two have been <strong>approximately</strong> located based on Pierre Souvairan's field maps (see caveat above). Background Bing satellite accessed 31/07/2022.