7fi 



E. LÖNNBERG, CONTEIBUTIONS TO THE FAUNA OF SOUTH GEOEGTA. 



of a common vole. Outside t lie entrance lies the earth that has been scratched out. 

 From the entrance the burrovv is conducted more or less crookedly into the interiör 

 of the tnssock-hill which consists of a peaty soil. The length of the burrow varies 

 from l / t to 1 m., depending upon the size of the tussock-hill. The nest lies 20 to 30 

 cm. below the surface.» The diagrammatic sketch reproduced here, is made by Sör- 

 ling on South Georgia, and shows approximately the arrangement of a burrow and 

 nest of Prion banksi in a tussock-hill. »Prion is never seen at day time near the 

 nest», Sörling continues in his notes ; »it never visits its nest by day-light, for then 

 it remains in the burrow, or has left it for the open sea already before day-break. 

 In the middle of November it had new laid eggs, at the end of March fullgrown 

 youngs. Only one egg was found in each nest. The development from egg to full- 

 grown young bird took thus four months. When Prion has eggs, as well male as 



female sit in the nest at the same 

 time. But as soon as the downy 

 youngs are hatched, only one pa- 

 rent-bird, or just as of ten none, is 

 found in the nest during the day. 

 The worst enemy of Prion is the 

 Great Skua. I have several times 

 observed, how the Great Skua tried 

 to dig out the nests of Prion.» 



It is evident that it is fear for 

 this terrible foe which compells 

 Prion to stay out on the open sea, 

 or remain in the burrow during the 

 day. »As soon as they show them- 

 selves in the fjords the Great Skua 

 instantly swoops down on them and 

 hunts them. ' When I for instance dug up some burrows to get eggs or youngs of 

 Prion», Sörling says, »and the old bircls were disturbed and forced to fly away 

 Catharacta sat in wait for them, and as soon as they appeared, they were pursued, 

 attacked and swallowed, as it appeared, in one gulp at once.» »As soon as one be- 

 gins digging, » Sörling says, »Catharacta comes expecting to get something, and the 

 poor Prion is, as a rule, always overtaken, and tries in vain to escape its enemy by 

 flying hither and thither. When overtaken, they disappeared so cptickly that they 

 seemed to be swallowed without any previous killing act. 



Pagenstecher (1) refers the specimens of Prion found on South Georgia by 

 the German Expedition 1882 — 83 to »Prion turtur». 1 A specimen procured in Cum- 

 berland Bay in April 1902 by the Swedish Expedition I have myself (9) referred to 

 the same specics (if it is a species), and maintain this opinion, since I have been 

 able to compare this specimen with those of P. banksi, recorded above. The bill of 



Fig/ 7. Diagrammatic sketch of the burrow of Prion banksi. 



1 Prion turtur (Bainks) 1820 regarded as synonymous with /'. desolatus (Gmelin) 1788. 



