156 



E. H. DUNN 



Table 5. Age of thermoregulatory control in various species of northern seabirds. 



Species 



Age when moderate 



temperature control 



is attained (days) 



Source 



Common eider 

 Herring gull 



Leach's storm-petrel 



Mew gull 



Lesser black-backed gull 



Greater black-backed gull 



Pigeon guillemot 



Common tern 



Roseate tern (Sterna dougallii) 



Common murre 



Razorbill (Alca torda) 



Black guillemot 



Tufted puffin 



Northern phalarope 



Cassin'sauklet 



Horned puffin (Fratercula corniculata) 



Common puffin 



Black-legged kittiwake 

 Double-crested cormorant 

 Shag 



0.1-0.3 8 V. V. Rolnik, in Belopol'skii (1961) 



1.5-2 V. V. Rolnik, in Belopol'skii (1961) 



2-3 E. H. Dunn (19766) 



[2] Ricklefs (1974) 



2-3 V. V. Rolnik, in Belopol'skii (1961) 



2-3 E. K. Barth (in Earner and Serventy 



1959) 

 2-3 E. K. Barth (in Earner and Serventy 



1959) 



2-4 Drent(1965) 



3 LeCroy and Collins (1972) 



3 LeCroy and Collins (1972) 



3 V. V. Rolnik and Yu. M. Kaftonowski 



(in Sealy 19736) 

 3 V. V. Rolnik and Yu. M. Kaftonowski 



(in Sealy 19736) 



3-4 V. V. Rolnik, in Belopol 'skii ( 1 96 1 ) 



3-5 b Cody (1973) 



4-5 c Hilden and Vuolanto (1972) 



5-6 Manuwal(1974a) 



2-6 Sealy (1973a) 



6-7 V. V. Rolnik and Yu. M. Kaftonowski 



(in Sealy 19736) 



6-7 V. V. Rolnik, in Belopol'skii (1961) 



14 Dunn(1976a) 



12-15 V. V. Rolnik, in Belopol'skii (1961) 



a Common eider, 2 to 7 h. 



b No data given. 



c lndirect evidence that young are brooded this long. 



food preferences while raising nestlings (Belo- 

 pol'skii 1961). For example, female mew gulls 

 in the Barents Sea forage in the tidal zone, 

 eating more small invertebrates than at other 

 times of the year, while males continue to for- 

 age at sea and consume larger quantities of 

 fish (Fig. 13). 



Commuting distances vary tremendously 

 among species (Fig. 14), but the number of feed- 

 ing trips to the nest per day does not corre- 

 late with foraging distance (Cody 1973; Sealy 

 1973a, 19736). There is not, therefore, a 

 simple relationship between time and energy 

 expenditures of the adults and foraging dis- 

 tances. Nocturnality, on the other hand, cor- 

 relates with reduced feeding rates (usually one 

 visit to the nest each night). Seabirds feeding 

 far from the colony tend to show adaptations 

 for bringing larger amounts of food per visit, 



such as carrying more than one fish at a time, 

 as in tufted puffins, Lunda cirrhata, and rhi- 

 noceros auklets, Cerorhinca monocerata, vs. 

 guillemots and murres (Richardson 1961; 

 Cody 1973; Sealy 1973a, 19736); developing a 

 sublingual storage pouch, as in Cassin's auk- 

 lets (Speich and Manuwal 1974); or concentra- 

 tion of food into stomach oil, as in petrels and 

 albatrosses (Ashmole 1971). Commuting 

 costs are largely eliminated when the young 

 leave the nest, but only in the alcids does nest 

 leaving occur long before attainment of full 

 growth. Early nest leaving may allow adults 

 and young to disperse to better feeding areas 

 than are exploitable from the colony site 

 (Sealy 19736) and probably involves a major 

 change in optimal food size and type as well 

 (Lind 1965). 

 Patterning of adult time budgets may differ 



