Abstract:
The global Blue Swallow Hirundo atrocaerulea was classified as Vulnerable in 2010 on account of its small and rapidly declining
population estimated at less than 1 500 pairs. We undertook this study to gain a better understanding of the current status and
threats facing this migratory species. Three previously unknown areas that might be part of the species’ non-breeding range
were identified in Kenya and northern Tanzania. Within its breeding range we identified three previously unknown areas of
potentially suitable habitat, one in Tanzania and two in Malawi, which require further exploration. Population viability
assessment predicted that the Blue Swallow population will decline by 8% in 10 years. The overall probability of extinction of the
species in the wild is 3%. Minimum viable population size analysis suggests that a goal for the long-term conservation of the Blue
Swallow should be to mitigate current threats that are driving declines such that the population increases to a minimum of 3 600
individuals. This should consist of at least 900 individuals in each of the four clusters identified, along with a minimum of 500
individuals in at least one of the meta-populations per cluster. The four clusters are located in (1) the southeasten Democratic
Republic of the Congo, (2) highlands of southern Tanzania and northern Malawi, (3) eastern highlands of Zimbabwe and (4) South
Africa and Swaziland. The current proportions of the Blue Swallow population in strictly protected and unprotected areas on
their breeding grounds are 53% and 47%, respectively, whereas on their non-breeding grounds the corresponding percentages
are 25% and 75%, respectively. Our reassessment of the Blue Swallow’s risk of extinction indicates that it continues to qualify as
Vulnerable according to the IUCN/SSC criteria C2a(i).
