Our Liviii!' Resources — Birds 



59 



growth woodland, show significant population 

 dechnes. Uphind sandpipers (tail-grass habitats, 

 including croplands) show a significant 

 increase. The remaining sandpiper species 

 breed principally north of the contiguous 48 

 states. Six of these — ruddy tumstone (Arena ria 

 interpres). red knot (Calkiris caiiiinis). sander- 

 ling (C. aiha). white-rumped sandpiper {C. fii.s- 

 cic(illis). Baird's sandpiper (C hainlii). and 

 buff-breasted sandpiper ( Tryngites 



subnificollis) — are principally high-latitude 

 breeders: two (red knot and sanderling) of the 

 three species for which trend analysis data are 

 available are in decline (Table). The remaining 

 species can be grouped as taiga or middle Arctic 

 breeders; seven of these have not been evaluat- 

 ed for population trend change; five species — 

 whimbrel (Niimenius phaeopiis). semipalmated 

 sandpiper (Calidhs pusilla). least sandpiper (C. 

 miiuililla). short-billed dowitcher 



(Limnodromus griseiis), and common snipe 

 (Gcilliiuigo gallinago) — were in significant 

 decline (Table), and four species — greater and 

 lesser yellowlegs {Tringa melaiwleuca and T. 

 flavipes). spotted sandpiper (Aclitis macidaria). 

 and dunlin (C. alpina) — showed no significant 

 change (Table). No species showed significant- 

 ly increased population trends. 



Phalaropes 



Only one (Wilson's phalarope: Pludaiopus 

 tricolor) of the three species of North American 

 phalaropes has been evaluated for population 

 change, and it showed significant declines 

 (Table). 



Summary and 

 Recommendations 



Population trend evaluation has been con- 

 ducted for 27 of 41 shorebird species common 

 in the United States east of the 105th meridian. 

 Of the 27 species for which trend data are avail- 

 able, 12 show no change, 1 increased, and 14 

 decreased (Table). There were no clear correla- 

 tions with habitat. 



It is important that shorebird populations are 

 monitored nationally, yet most species are hard 

 to monitor because they inhabit regions that are 

 difficult to access for much of the year. 

 Migration seasons appear to be the most practi- 

 cal time for monitoring most species. 

 Unfortunately, sampling for population moni- 

 toring during nonbreeding seasons presents a 

 group of unresolved analytical challenges. 

 Additional work on existing data can help iden- 

 tify how or whether broad, voluntary, or profes- 

 sional networks can collect data that will better 

 meet requirements for monitoring population 

 change. 



References 



Clark. K.E.. L.J. Niles. and J. Burger. I'W.^. Aliundance and 

 distribution of migrant short-hirds in Delaware Bay. 

 Condor 95:69-70.S.'" 



Forbush. EH. 1912. Game birds, wild-lbwl. and shore 

 birds. Massaehusetts Stale Board of Agnculture, Boston. 

 622 pp. 



Graul. W.D., and L.E. Webster. 1976. Breeding status of the 

 mountain plover. Condor 78:26.'i-267. 



Haig. S.. and J.H. Plissner 199.^. Distribution and abun- 

 danee of piping plovers: results and implieations of the 

 1991 international census. Condor 9,S:145-I56, 



Hamngton. B.A.. F.J. Leeuwenberg, S. Lara Resende, R. 

 McNeil, B.T. Thomas. J.S. Grear. and E.F. Martinez. 

 1991. Migration and mass change of white-rumped sand- 

 pipers in North and South America. Wilson Bull. 

 103:621-636. 



Table. Species, major habitats, 

 and population change in North 

 American breeding shorebirds in 

 the United States east of the 105th 

 meridian.* 



' In the "reference and status" column and the "significance" column, "a" through "g" refer to a reference in footnote ".The 

 reference footnotes also give the years the survey was conducted If "*" follows the letter in the "reference and status" col- 

 umn, the population is increasing. If "-" follows the letter, the population is declining. In the "significance" column, "ns" means 

 population increase or decrease is not significanl. "P" is a measure of the confidence that the decline or increase is actually 

 significant A lower Pvalue means there is more confidence that the trend is real. A population trend change at the P< 0.10 

 level IS considered sfafistically significant, 

 "a- Howe et al. (1989) for 1972-83 



b — B.G Peteriohn, NBS, unpublished analysis. National Biological Service, Breeding Bird Survey 1982-91. 



c — Haig and Plissner 1993 



d — Mornson et al.. in press 1974-91. 



e — Clark etal. 1993 for 1986-92 



f — Sauer and Bortner 1991. 



g — U. S. Fish and Wildlife Service, Office of Endangered Species, unpublished data. 



