Data Zone
Justification of Red List category
This species has a very restricted range, and is suspected to have a very small population size. The most severe potential threat is the introduction of the parasitic fly Philornis downsi and avian pox. The species is therefore listed as Vulnerable.
Population justification
Given the species's extremely small range, its population size is suspected to be small, and is placed here in the range of 250-999 mature individuals.
The subpopulation structure has not been formally investigated, but it is here tentatively assumed that the species forms two separate subpopulations on Wolf and on Darwin.
Trend justification
The population is currently assessed as stable in the absence of any evidence for a decline.
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 drinks 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, perhaps the most severe of which is that from invasive species (Wiedenfeld and Jiménez-Uzcátegui 2008). The bot-fly Philornis downsi was first discovered in the Galápagos in 1997 and has been demonstrated to reduce fledgling success in landbirds, but has not yet invaded Darwin and Wolf (Fessl et al. 2006; Dudaniec et al. 2007; del Hoyo et al. 2020). The potential for the introduction of a suitable vector for avian pox is however high, and P. downsi, although preferring more humid islands, would appear to be a potential risk to the species.
Conservation Actions Underway
At present, visiting Darwin and Wolf is strictly controlled and great effort is made to minimise the possibility of the introduction of potentially harmful species.
Conservation Actions Proposed
Quantify the population size. Monitor population trends. Monitor the possible spread of bot-flies and avian pox on range islands. Continue to restrict access to range islands.
Text account compilers
Hermes, C., Martin, R.
Contributors
Butchart, S., Ekstrom, J. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Vampire Ground-finch Geospiza septentrionalis. Downloaded from
https://datazone.birdlife.org/species/factsheet/vampire-ground-finch-geospiza-septentrionalis on 21/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 21/12/2024.