Migration routes and staging areas of Abdim's Storks Ciconia abdimii identified by satellite telemetry

This paper presents the results of a satellite tracking study of seven adult Abdim's Storks Ciconia abdimii that were followed from the nesting areas in southern Niger across the equator to the non-breeding range and back. Post-breeding migration started between early November and early December when all birds migrated directly to an area south of Lake Victoria in Tanzania, where they arrived between late November and early January. One bird moved to Zimbabwe for 2.5 months before returning to Tanzania; this bird returned to the same place in Zimbabwe the following year. The other tagged storks remained in northern Tanzania, suggesting that this region (at least in 2003–2004) is more important as a wintering area for the species than previously thought. While in Tanzania and Zimbabwe, most storks were almost completely stationary. Prenuptial migration started during mid-February, when one stork moved to the Central African Republic (CAR). The other storks moved to northern Uganda in mid-March and four continued into southern Sudan in mid-April, following the progression of the Intertropical Convergence Zone (ITCZ). Final migration towards Niger started between early April and early May, when the storks returned to the nests of the previous year in mid-May, almost simultaneously with the first major rainfall. Storks from the same village differed widely in migration strategy. Post-breeding maximum migration speed was between 216km/day and 307km/day, while migration was generally faster on the last leg of the return trip to the nest, with a maximum of 456km/day.Ostrich 2006, 77(3&4): 210–21

Abdim\'s Stork Ciconia abdimii in Niger: population size, breeding ecology and home range

Abdim's Stork is a common breeding bird in most human settlements across the Sahel. However, very few studies have surveyed the population and described its breeding and feeding ecology during the breeding season. We identified the breeding range in Niger, surveyed nests in 23 villages/towns and, based on the number of villages and towns in the breeding area, estimate the total breeding population for Niger at 18 157 pairs (95% CL ± 9 160). Breeding success was 2.6 fledglings per successful pair (95% CL ± 0.28, range 1–4, n = 36), suggesting a total post-fledging population of c. 83 500 birds (95% CL ± 51 267), excluding any non-breeding (sub)adults. The home range of six satellite-tagged breeders in 2003 was 10–120 km2 (median 36 km2); birds adjacent to a major river rarely used that wet habitat. Home ranges were consistently larger, though not significantly so, in the post-fledging period than in the nestling season. The tagged adults stayed in their nesting areas until 16–59 d after the young fledged. After leaving the nesting area, most of the tagged birds moved to one or more staging areas within 300 km of the nest site and stayed there for an additional 8–33 d before the onset of migration. The following season (2004), four out of five tagged storks returned to the previous years' nest (one lost its nest), and started incubation 10–25 d after arrival. Onset of incubation (mean 29 May) varied from 4 May to 4 July (earliest in the east along the River Niger) but with large local variation, with the earliest breeders starting shortly after the first rain in each area. Ostrich 2008, 79(2): 177–18