Table XIX. Incidence and actual or potential breeding status of 

 adult birds on study plot at Barrow, Alaska, 1970. 



18 June 29 June 



Species 



U F U 



9 July 19 July 



F U F M Attempts Success 



Snow bunting 

 Plectropbenax nivalis 



Lapland longspur 

 Calcarius lappoaicus 



Red phalarope 

 Pbalaropus (ulicarius 



Pectoral sandpiper 

 Calidris melanotos 



Semipalmated sandpiper 

 CaJidris puslilla 



Baird's sandpiper 

 Calidris baitdii 



Dunlin 

 Calidris alpina 



Golden plover 

 Pluvialis dominica 



Long-billed dowitcher 

 Limnodromus scolopaceus 



2 2 



16 11 9 6 



(10) 2 2 



6 6 4 



2 2 2 



2 2 



7 7 



2 2 



1 1 



-2211 



12 6 5 2 



110 



3 1 







110 



2 2 11 



2 2 11 







Totals: 31 



4* 



20 



*Estimates: not all nests found. 

 M - Male 

 F - Female 



the absence of brown lemmings there was no attempted breeding by predatory birds in the Barrow 

 area in 1970. Snowy owls were rarely seen, and jaegers occurred only as wandering individuals or 

 small groups. Breeding activities of nesting birds were followed by a single observer at 2-day 

 intervals, between 10 June and 28 July 1970, supplemented by synchronized intensive censusing 

 by three observers on 18 and 29 June and 9 and 19 July. Nine species of birds made 35 nesting 

 attempts, of which 20 were successful, at least to the point of one or more chicks being reared to a 

 stage of independence from the nest and from resources within the study area. These data are 

 summarized in Table XIX. These figures can be used to make at least a crude estimate of energetic 

 significance of the bird species. Estimates indicate that the Lapland longspur was the single most 

 important avian consumer on the study area, although the shorebirds as a group consumed more 

 energy (sum = 1736 kcal/Ha) than the two passerine species (sum = 883 kcal/Ha). 



Observations suggest that the proximity of a heavily traveled gravel road, an artificial impound- 

 ment of snowmelt water, and an unusually large snowdrift, all served to diversify the habitat over 

 its natural state, making it attractive to more species and to greater numbers of birds, especially 

 during the peak of snowmelt in mid-June. 



49 



