Initial deadline for comments: 31 January 2012 [note that this has been moved back by about two months].
Watkins’s Antpitta Grallaria watkinsi is a Tumbesian endemic, restricted mainly to western and south-western Ecuador, with some occurring in north-western Peru, where it inhabits semi-deciduous forest (Stotz et al. 1996), forest edge (I. Isherwood and J. Willis verbally 1998) and regenerating secondary scrub (Ridgely and Tudor 1994). Although it also occurs in areas of dry deciduous forest, it tends to keep to the greener, denser vegetation in narrow ravines (Parker et al. 1995). It is currently listed as Least Concern on the basis that it was not thought to approach the thresholds for Vulnerable under any of the IUCN criteria.
Although this species has a small range, it was not believed to approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence [EOO] of less than 20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appeared to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (at least a 30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (fewer than 10,000 mature individuals with a continuing decline estimated to be at least 10% over ten years or three generations, or with a specified population structure).
Remapping of the species’s range with reference to a map of suitable habitat produced through BIOCLIM modelling (Freile et al. 2010) has resulted in a new EOO estimate of 16,600 km2, suggesting that the species meets the range size threshold for Vulnerable under criterion B1. However, the species is known from more than 10 locations and its habitat is not considered severely fragmented (over 50% in patches too small to support viable populations). Of the 18 antpitta species studied by Freile et al. (2010), G. watkinsi had experienced the greatest extent of habitat loss in Ecuador, at 63%. Despite its ability to survive in secondary habitats, the critical degree of habitat degradation that has occurred throughout its range in recent decades has reportedly resulted in the complete devastation of all vegetation cover in large areas (Freile et al. 2010). The species can inhabit dense regenerating scrub and secondary forest, indicating a moderate to high tolerance of habitat degradation and disturbance; however, it is absent from areas described as completely modified or forest patches frequented by livestock. In western Ecuador, remnant forests are generally small and the level of habitat protection is regarded as limited (Freile et al. 2010).
With this information in mind, on-going declines are thought to be taking place in the EOO, Area of Occupancy, and area, extent and quality of habitat. This suggests that the species qualifies as Near Threatened on the basis that it has an EOO of less than 20,000 km2, but is known from more than 10 locations and its habitat is not severely fragmented.
Freile et al. (2010) also predict a population decline of 10-30% over the next three generations, estimated by BirdLife to be 11 years, based on the likely rate of habitat loss (c.290-870 km2 over 10.5 years), thus the species may qualify as Near Threatened under criterion A3c (typically a 20-29% decline over three generations). Comments are invited on the proposal to uplist this species to Near Threatened, and further information is requested.
Freile, J. F., Parra, J. L. and Graham, C. H. (2010) Distribution and conservation of Grallaria and Grallaricula antpittas (Grallariidae) in Ecuador. Bird Conserv. Int. 20: 410-431.
Parker, T. A., Schulenberg, T. S., Kessler, M. and Wust, W. H. (1995) Natural history and conservation of the endemic avifauna in north-west Peru. Bird Conserv. Int. 5: 201-231.
Ridgely, R. S. and Tudor, G. (1994) The birds of South America. Austin, Texas: University of Texas Press.
Stotz, D. F., Fitzpatrick, J. W., Parker, T. A. and Moskovits, D. K. (1996) Neotropical birds: ecology and conservation. Chicago: University of Chicago Press.