This discussion was first published on Dec 1 2010 as part of the 2010-2011 Red List update, but remains open for comment to enable reassessment in 2013.
Red-cockaded Woodpecker Picoides borealis is presently listed as Vulnerable under criteria C1; C2a(i), because its population was estimated to number fewer than 10,000 mature individuals and was previously estimated to be declining at a rate of 20-29% over 16 years (1994-2010: estimate of three generations). In the 1990s, this species’s population was estimated to number 10,000-11,000 individuals (Jackson 1994, Guynn 1997, J. A. Jackson in litt. 1999), suggesting that the number of mature individuals was below 10,000. It has undergone a large and statistically significant decrease over the last 40 years in North America (70.2% decline over 40 years, equating to a 26.1% decline per decade; data from the Breeding Bird Survey and the Christmas Bird Count: Butcher and Niven 2007), and James (1995) calculated a 23% decline in the number of known sites between the early 1980s and 1990. The species’s decline has been driven largely by habitat loss and fragmentation (U.S. Fish and Wildlife Service 2008).
It has recently been confirmed, however, that the species’s population has exceeded 10,000 mature individuals since at least 2000, and is provisionally estimated to have numbered 14,500 mature individuals in 2008 (W. McDearman in litt. 2010). In addition, it is now thought that the population is stable and possibly increasing, and has been at least since 2003 (W. McDearman in litt. 2010). The species’s recovery is the result of successful conservation efforts, including habitat management, nest-site provision and translocation of birds (U.S. Fish and Wildlife Service 2008), whilst improved knowledge has been acquired thanks to intensive studies.
This improvement in our knowledge of the species’s status suggests that it has not met the thresholds for Vulnerable under the C criterion for at least five years and is consequently eligible for downlisting. As the species’s population size still approaches the threshold for Vulnerable under the C criteria, it is proposed that the species be listed as Near Threatened under criterion C2a(i). Although there is evidence that the population is increasing, deciphering the actual trend is compounded by the ongoing discovery of new colonies, thus the species is currently considered to be stable and possibly increasing. In this case the use of the Near Threatened category also expresses concern over the safety of all sub-populations. Most of the sub-populations are small, and require continued growth until they can resist sudden environmental changes (W. McDearman in litt. 2010). It is also acknowledged that although the overall population is stable or increasing, some sub-populations are still in decline and losing their viability (W. McDearman in litt. 2010).
Comments are invited on the proposed downlisting to Near Threatened, and further information on the species would be welcomed.
Butcher, G. S. and Niven, D. K. (2007) Combining Data from the Christmas Bird Count and the Breeding Bird Survey to Determine the Continental Status and Trends of North American Birds. Ivyland, Pensylvania: National Audubon Society.
Guynn, D. (1997) Red-cockaded Woodpeckers. Birdwatcher’s Dig. 20: 60-65.
Jackson, J. A. (1994) Red-cockaded Woodpecker (Picoides borealis). Pp. 1-20 in Poole, A. and Gill, F., eds. The birds of North America, No. 85. Philadelphia, and Washington, DC: The Academy of Natural Sciences, and The American Ornithologists’ Union.
James, F. C. (1995) The status of the Red-cockaded Woodpecker in 1990 and the prospect for recovery. Pp. 439-451 in Kulhary, D.L., Hooper, R.G. and Costa, R., eds. Red-cockaded Woodpecker: recovery, ecology and management. Nacodgdoches, Texas: Center for Applied Studies in Forestry Publication, College of Forestry, Stephen F. Austin State University.
U.S. Fish and Wildlife Service (2008) Red-cockaded Woodpecker Fact Sheet. Available from: http://www.fws.gov/rcwrecovery/files/rcwoodpecker.pdf. Accessed: 20/10/2010
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