2 research outputs found
Do diurnal migrants follow the Guadiana River when crossing dry sectors of SW Iberia?
Little is known on the importance of water courses as migratory
corridors. Here, we present the results of an investigation on the movements of diurnal
migrants associated with the Guadiana River when crossing dry and inhospitable
regions of southern Iberia. Direct observations were carried out along the river and at
control sites away from it, in late August-November 2006. The number of birds seen
was extremely small (<< 1 individual per hour for most species) and most records
probably involved individuals in local movements, as indicated from similar rates of
birds moving up and downriver. The only exceptions were hirundines which, within
our study area, were strongly associated with the Guadiana both when foraging and
when engaged in medium to long-distance daily movements. House Martins Delichon
urbicum were particularly numerous, and 98.7% of the birds seen in directed movement
(n = 4122) were flying above the river. However, passing hirundines (mostly Barn
Swallow Hirundo rustica and Sand Martins Riparia riparia) were scarce and did not show
the same degree of association with the Guadiana. Our results suggest that there is
no significant migratory corridor along the lower Guadiana during summer-autumn,
but hirundines strongly associate with this river when foraging and when commuting
between foraging grounds and roosts