This discussion was first published as part of the 2017 Red List update. At the time a decision regarding the status of several was pended, but to enable potential reassessment of these species as part of the 2018 Red List update this post remains open and the date of posting has been updated.
Lesser Prairie-chicken, Tympanuchus pallidicinctus, is currently listed as Vulnerable under criteria A2bcd+3bcd+4bcd on the basis of long-term and rapid population declines (BirdLife International 2017). It is endemic to U.S.A., occurring in the states of Kansas, Colorado, Oklahoma, Texas and New Mexico; and historically possibly into Nebraska as well (e.g. Wolfe et al. 2007). Recent population estimates from 2015 place the population in the range of 22,000-44,000 individuals, most occurring in Kansas (McDonald et al. 2015). A re-evaluation of population trends by Garton et al. (2016 [per C. Hagen in litt. 2016]) suggests that over the preceding 48 years there had been a measurable decline in population, but this may not be to the same degree as previously thought. Over that 48 year period it was found that the abundance may have declined on average by 49% at an average rate of annual decline of 1.7% per year (Garton et al. 2016 [per C. Hagen in litt. 2016]). Such declines are as a result of habitat conversion (Wolfe et al. 2007) and historically due to market hunting (Wolfe et al. 2007); although recreational hunting for Lesser Prairie-chicken is now closed in most of the states where it occurs, and is no longer considered to be a significant threat to the species (Van Pelt et al. 2014). However, since 1995, most populations of Lesser Prairie-chicken have stabilised or increased as a result of a variety of conservation measures being enacted (C. Hagen in litt. 2016).
To meet the threshold for Vulnerable under criteria A2+3+4 would require this species to be have undergone and continue to undergo declines in the range of 30-49% over 3 generations or 10 years, whichever is the longer (IUCN 2012). The generation length for this species is currently listed as 5.5 years, and hence the time period used should be approximately 16.5 years – a time period over which most of the populations have been stable or increasing. Conservatively assuming that the annual figures shown above have been continuous over the 48 year period would roughly equate to a decline of 20-25% over 3 generations. Therefore, even taking this conservative assumption the rate of decline would not be sufficient for listing as Vulnerable anymore and the species would warrant downlisting. However, the removal of conservation measures would likely mean that the species would decline once again and would likely again warrant listing as Vulnerable. Therefore, it is proposed that this species be listed as Near Threatened under criteria A2bcd+3bc+4bc on the basis that it has undergone historic declines that have meant the species qualified as Vulnerable, and these are now only prevented from continuing as a result of continued conservation efforts.
We welcome any further information and comments on this proposed downlisting.
BirdLife International (2017) Species factsheet: Tympanuchus pallidicinctus. Downloaded from http://www.birdlife.org on 06/01/2017.
Garton, E. O., C. A. Hagen, G. M. Beauprez, S. C. Kyle, J. C. Pitman, D. D. Schoeling, and W. E. Van Pelt. 2016. Population dynamics of the Lesser Prairie-Chicken. Studies in Avian Biology: 48: 49-76.
IUCN. (2012). IUCN Red List Categories and Criteria: Version 3.1. Second edition. IUCN, Gland, Switzerland and Cambridge, UK.
McDonald, L., K. Adachi, T. Rintz, and G. Gardner. 2015. Range-Wide Population Size of the Lesser Prairie-Chicken: 2012, 2013, 2014, and 2015. Technical Report prepared for the Western Association of Fish and Wildlife Agencies. Western EcoSystems Technology, Inc. (WEST), 200 South 2nd Street, Laramie, Wyoming, 82070.
Wolfe, D. H.; Patten, M. A.; Shochat, E.; Pruett, C. L.; Sherrod, S. K. 2007. Causes and patterns of mortality in lesser prairie-chickens Tympanuchus pallidicinctus and implications for management. Wildlife Biology 13: 95-104.
Van Pelt, W. E., S. Kyle, J. Pitman, D. Klute, G. Beauprez, D. Schoeling, A. Janus, and J. B. Haufler. 2013. The Lesser Prairie-Chicken Range-Wide Conservation Plan. Western Association of Fish and Wildlife Agencies, Cheyenne, Wyoming, USA.