Greater Prairie-chicken (Tympanuchus cupido): revise global status?

Greater Prairie-chicken (Tympanuchus cupido) originally was thought to occur in natural prairies from central Alberta (Canada), south through central U.S.A. and into Texas. Now, however, it is no longer found in Canada, and only remains in scattered patches, predominantly in mid-western U.S.A. (see de Juana and Kirwan 2018). Loss of its habitat is thought to have played a key role in declines in this species, including the extinction of subspecies T. c. cupido, and continued habitat fragmentation may lead to reduced genetic variance within subpopulations (Westemeier et al. 1998). The species still also suffers from hunting pressure, and the introduced Ring-necked Pheasant (Phasianus colchicus) may be acting as a competitor to this species (see Johnson et al. 2011, de Juana and Kirwan 2018). As a result, the species was considered to be undergoing a rapid decline, and the species is currently listed as Vulnerable under criteria A2bcde+3bcde+4bcde (see BirdLife International 2018).

Following the publication of Partners in Flight (PiF) Landbird Conservation Plan (Rosenberg et al. 2016) and The State of North America’s Birds 2016 (North American Bird Conservation Initiative 2016) we have reviewed the new information held in these publications, particularly regarding population trends. This has allowed us to reassess the species outlined in these publications against IUCN Red List Categories and Criteria. As the PiF data are long-term trends (1970-2014), where possible we have also used data from the North American Breeding Bird Survey (Sauer et al. 2017) to assess more recent trends over the period relevant to the Red List. Having completed this review, Greater Prairie-chicken appears to warrant a change in Red List status. Therefore, we present here our reassessment against all criteria for the species.

 

Criterion A – Rosenberg et al. (2016) do not give a clear population trend. Looking at data collected for the North American Breeding Bird Survey, between 2005 and 2015 the species has undergone a recent non-significant annual increase of 9.13% (0.80% decrease to 18.88% increase) (Sauer et al. 2017). This would equate to a 322.7% increase over three generations (16.5 years) (12.4% decrease to 1,635% increase).

Sauer et al. (2017) also holds historical year by year records, and so we could extrapolate population trends for any three generation period. Three generations ago (pre-2018) is approximately 2001. Therefore, we can extrapolate the trends between 2001 and 2015 to 2018 in order to estimate the population trend over the past three generations. Between 2001 and 2015 the population has been, in general, increasing with a significant, estimated annual increase of 8.77% (2.66%-16.07%) (Sauer et al. 2017). This would equate to an increase of 300% over three generations (54.2-1,069%). Therefore, the species would not even approach the threshold for Vulnerable under this criterion, and from the data held by Sauer et al. (2017) it likely has not warranted listing as such for some time.

However, these population trends may be as a result of targeted conservation action. If the removal of these actions could mean the species would meet the thresholds for listing as Vulnerable within 5 years then the species could warrant listing as Near Threatened under criteria A3cde+4cde.

 

Criterion B – The species’s range is far too large to warrant listing under this criterion (Extent of Occurrence = 1,990,000km2).

 

Criterion C – Rosenberg et al. (2016) estimate the population size to be 750,000 mature individuals. This is too large to warrant listing under this criterion.

 

Criterion D – The species’s population size and range are too large to warrant listing under this criterion.

 

Criterion E – To the best of our knowledge there has been no quantitative analysis of extinction risk conducted for this species. Therefore, it cannot be assessed against this criterion.

 

Therefore, Greater Prairie-chicken potentially warrants downlisting to Least Concern. However, given that the species’s population trend may be due to ongoing conservation measures, it is instead, very conservatively proposed that the species only be downlisted to Near Threatened. We welcome any comments or further information but please note that this topic is not designed to be a general discussion about the ecology of the species, rather a discussion of the species’ Red List status. Therefore, please make sure your comments are about the proposed listing.

 

References

BirdLife International. 2018. Species factsheet: Tympanuchus cupido. Downloaded from http://www.birdlife.org on 14/03/2018.

de Juana, E.; Kirwan, G. M. 2018. Greater Prairie-chicken (Tympanuchus cupido). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/53335 on 14 March 2018).

Johnson, J. A.; Schroeder, M. A.; Robb, L. A. 2011. Greater Prairie-chicken (Tympanuchus cupido), version 2.0. In: Rodewald, P. G. (ed.). The Birds of North America. Cornell Lab of Ornithology, Ithaca, New York, U.S.A. https://doi.org/10.2173/bna.36.

North American Bird Conservation Initiative. 2016. The State of North America’s Birds 2016. Environment and Climate Change Canada, Ottawa, Ontario.

Rosenberg, K. V., Kennedy, J. A., Dettmers, R., Ford, R. P., Reynolds, D., Alexander, J. D., Beardmore, C. J., Blancher, P. J., Bogart, R. E., Butcher, G. S., Camfield, A. F., Couturier, A., Demarest, D. W., Easton, W. E., Giocomo, J. J., Keller, R. H., Mini, A. E., Panjabi, A. O., Pashley, D. N., Rich, T. D., Ruth, J. M., Stabins, H., Stanton, J. and Will., T. 2016. Partners in Flight Landbird Conservation Plan: 2016 Revision for Canada and Continental United States. Partners in Flight Science Committee.

Sauer, J. R.; Niven, D. K. ; Hines, J. E.; Ziolkowski, Jr, D. J.; Pardieck, K. L.; Fallon, J. E.; Link, W. A. 2017. The North American Breeding Bird Survey, Results and Analysis 1966 – 2015. Version 2.07.2017 USGS Patuxent Wildlife Research Center, Laurel, MD.

Westemeier, R. L.; Brawn, J. D.; Simpson, S. A.; Esker, T. L.; Jansen, R. W.; Walk, J. W.; Kershner, E. L.; Bouzat, J. L.; Paige, K. N. 1998. Tracking the long-term decline and recovery of an isolated population. Science 282(5394): 1695-1698.

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3 Responses to Greater Prairie-chicken (Tympanuchus cupido): revise global status?

  1. James Westrip (BirdLife) says:

    Tim Meehan has kindly provided analyses of Christmas Bird Count data. Taken from long-term trends (1966-2017), these data suggest an annual decline of 0.87% (6.48% annual decline to 3.65% annual increase) in this species. This would equate to a reduction of 13.42% (66.91% reduction to 80.64% increase) over three generations.

  2. James Westrip (BirdLife) says:

    Preliminary proposals

    Based on available information, our proposal for the 2018 Red List would be to pend the decision on this species and keep this discussion open until 2019, while leaving the current Red List category unchanged in the 2018 update.

    Final 2018 Red List categories will be published on the BirdLife and IUCN websites in November, following further checking of information relevant to the assessments by both BirdLife and IUCN.

  3. Peter Dunn says:

    The population in Wisconsin has been declining steadily for the past 15+ years, and the same is true in most other states. So I was surprized to see estimates of increasing population size on the birdlife site, but then I saw the source — Breeding Bird Surveys. These are conducted in June, well after Prairie-chickens have finished displaying. At this time of year they are very hard to see. The BBS is not designed to track cryptic species like prairie-chickens. A more usable population index would be the booming ground counts conducted in most states (when the males are displaying in April).

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