130 
Table 3 
Nesting densities and success compared between similar avifaunal components at Prudhoe 
Bay and Barrow. 
PRUDHOE BAY 
Density 
Species (nests km?) 
C. alpina 4.6 
C. pusilla 39.8 
C. bairdii = 
C. melanotos 5.7 
T. subruficollis 4.3 
P. fulicarius 29.7 
L. lobatus 5.0 
C. lapponicus hed 
P. nivalis Be 
Overall 96.7 
' Calidris species data based on Norton (1973). 
2Phalarope data from 1971 at Barrow only—preliminary. 
3_ongspur information from T. W. Custer (pers. comm.). 
BARROW 
Success Density Success 
(nests km) 
0.5 13.9 0.72 
0.68 9.8 0.73 
se 24.8 0.39 
0.67 13.6 0.69! 
0.50 SS = 
0.57 (26.4 0.50] 2 
0.67 = = 
0.60 [30.0 0.63] 3 
= [15.0 0.80] 4 
0.62 (133.5 0.65] 
4 Snow bunting data from 1971 IBP census plot only—incomplete. 
Row E represents the interface between terres- 
trial and aquatic systems that was partially 
underwater until about 20 June 1971, and until 
1 July 1972. By those dates, most nesting birds 
were in late stages of commitment to territories 
on the western and central rows of Plot B. As 
soon as the sizeable lake east of Plot B was 
partially drained, heavy use of the formerly 
submerged land began. Shorebirds with broods 
of young could be found abundantly in Row E 
and eastward thereafter. In summary, tundra 
birds appear to move seasonally through a series 
of habitats that are successively later to emerge 
from either snow or water. 
Recaptures of semipalmated sandpipers 
banded in 1971 have confirmed findings by 
U. N. Safriel (1971, pers. comm.) on the mating 
system of this species. Fig. 4 shows the recap- 
ture histories of the 14 pus///a that returned in 
1972. All 14 returning birds nested successfully 
in 1971, although three of them only did so by 
renesting following predation of their first 1971 
nest. In three cases, both banded members of 
pairs returned, and the 1972 nests of these six 
birds were all less than 100m from the 1971 
nest. Only one known case of remating occurred 
between the two seasons. No young of 1971 
returned as breeding adults in 1972. The semi- 
palmated sandpipers at Prudhoe Bay therefore 
are similar to those breeding at Barrow— 
monogamous, site-tenacious, and mate-faithful. 
They are especially faithful to mates and terri- 
tory following reproductive success in the previ- 
ous season. Young birds do not breed until at 
least their second year. 
No Lapland longspurs (Ca/carius lapponicus) 
or snow buntings (P/ectrophenax nivalis) banded 
in 1971 returned to Prudhoe Bay plots in 1972, 
but this may be explained by the small sample 
size. Banding of male red phalaropes and female 
pectoral sandpipers (Ca/idris me/anotos) in 1971 
and an absence of returning birds in 1972 
indicates that these species at Prudhoe, as at 
Barrow, display no site-tenacity. 
Discussion 
Tundra resource use by terrestrial birds at 
Prudhoe Bay is essentially similar in pattern to 
that of Barrow birds despite difference in species 
composition, density, and reproductive success. 
Information from this study places Prudhoe Bay 
on a continuum of sorts, relating to terrestrial 
