78 



Birds — Uur Living Resoiinvs 



Table 1. Numbers of wintering 

 piping plovers and sites where 

 birds occurred in IWl. 



Location 



Birds 



Sites 



U.S. Atlantic 



North Carolina 

 South Carolina 

 Georgia 

 Florida 

 Total 



20 



51 

 37 



70 

 178 



9 

 30 



less than 1 '7f occuiTed on the Great Lakes. Sites 

 with the highest concentrations of breeding 

 birds also were found in the northern Great 

 Plains (also known in Canada as the Great 

 Prairie): however, each local population consist- 

 ed of only a small (less than 8**) proportion of 

 the total breeding population. Local populations 

 were even smaller on the Atlantic coast. 



Migration Areas 



Atlantic coast piping plovers are commonly 

 seen on east coast beaches during spring and fall 

 migration. Migration routes of inland birds are 

 poorly understood, however. Only a few occur- 

 rences of piping plovers have been reported at 

 seemingly appropriate inland migration sites 

 such as Kirvvin National Wildlife Refuge in 

 Kansas. Cheyenne Bottoms Wildlife 

 Management Area in Kansas, and Great Salt 

 Plains National Wildlife Refuge in Oklahoma. It 

 appears that inland birds may fly nonstop to gulf 

 coast sites. 



Trends 



Because simultaneous, species-wide census- 

 es were not conducted in the past, assessing pop- 

 ulation trends is difficult. Examination of long- 

 term census data at specific sites is useful in 

 some cases. Most midcontinent sites that have 

 been monitored for 10 years or more have expe- 

 rienced a decline (Table 3). The cumulative 

 effects of problems in the prairies have been 

 modeled, and results indicate that piping plovers 

 in the Great Plains are now declining by 7% 

 annually (Ryan et al. 1993). a devastating trend 

 for the species. Atlantic coast numbers remain 

 stable; however, there has been unprecedented 

 effort to protect piping plovers along the U.S. 

 Atlantic coast. Results from previous censuses 



(Table 3) should be considered rough population 

 estimates; as is true with many bird species, we 

 have little information regarding the intensity of 

 census efforts in those population estimates. 



Threats 



In the northern Great Plains, water-level reg- 

 ulation policies on the major rivers (e.g.. Platte, 

 Missouri) serve as a direct source of chick mor- 

 tality and an indirect source of habitat loss 

 through vegetation encroachment and flooding 

 (Schvvalbac'h 1988; Sidle et al. 1992). We know 

 that because 2()9f of northern Great Plains 

 (Great Prairie) birds use river sites, loss of pro- 

 ductivity on rivers such as the Missouri can 



