Justification of Red List Category
This species has a very restricted range, and is suspected to have a very small population size that could be sufficiently threatened by the introduction of invasive predators or disease to drive the species to Critically Endangered within a short time. Therefore, it is listed as Vulnerable.
Given the species's extremely small range, its population size is likely to be small, and is placed here in the range of 250-999 mature individuals.
The population is classed as stable in the absence of any evidence for a decline or substantial threat.
Geospiza septentrionalis is found on the two tiny islands of Darwin and Wolf in the extreme north west of the Galápagos Islands, Ecuador.
Vampire Ground-finch G. septentrionalis is so named due to sanguinivory. The species opens wounds at the base of the feathers of nesting booby species (Sula spp.) and drinking the blood that ensues. It is posited that this adaptation represents a response to resource scarcity in the late dry season on these arid islands (Schluter and Grant 1984).
The avifauna of the Galapagos Islands face a litany of threats (Wiedenfeld and Jiménez-Uzcátegui 2008), perhaps the most severe of which is that from invasive species. The bot-fly Philornis downsi was first discovered in the Galapagos in 1997 and has been demonstrated to reduce fledgling success (Fessl et al. 2006) but at widely varying rates each year, which may be related to rainfall (Dudaniec et al. 2007). The potential for the introduction of a suitable vector for avian pox is high, and P. downsi, although preferring more humid islands would appear to be a potential risk to the species.
Conservation Actions UnderwayAt present, visiting these islets is strictly controlled and great effort is made to minimise the possibility of the introduction of potentially harmful species.
Conservation Actions ProposedContinue to restrict access to these islands, and monitor populations. Montior the possible spread of bot-flies and avian pox on these islands.
Text account compilers
Butchart, S., Ekstrom, J., Martin, R & Westrip, J.
BirdLife International (2017) Species factsheet: Geospiza septentrionalis. Downloaded from http://www.birdlife.org on 17/12/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 17/12/2017.