N T ORTH AMERICAN" GULLS AND THEIR ALLIES. 
63 
During Buturlin's stay at the mouth of the Kolyma River he paid 
particular attention to Ross's gull and obtained definite information 
in regard to the extent of its breeding range. It is known to breed 
northwest to Russkoe Ustje, in the delta of the Indigirka River, 
latitude 71° N., longitude 149° E.; southwest to Abyi, near the 
Indigirka River, about 300 miles inland from the Arctic coast, latitude 
67° 30' N., longitude 145° E.; northeast to the northeastern part 
of the Kolyma delta near the Arctic coast, latitude 69° 30' N7, 
longitude 161° E. ; and southeast to Sredne-Kolymsk, on the Kolyma 
River, about 200 miles from its mouth, latitude 67° 30' N., longi- 
tude 155° E. The breeding range extends, therefore, through 3^ 
degrees of latitude and 16 degrees of longitude, covering an area a 
little less than 300 miles square. The species has not been found 
breeding on any of the Arctic islands either east or west of the Kolyma 
T y ~~~ , "''^S\ \_-— - 
\ ^-^-^^vV 
t \ o ^ 
^< 
\° ^^\ 
~~%r' 
y\<^ 
Ti 
>r'*\ jT 
/ r^\P 
1 °\ 
/ /P>l 
'M 
\r*** 
7^ 
y\ ' ^°°^ 
/ \ /*' 
■Qf>$£ 
J\A 
) V 
O OCCURRENCE 
/ W /"'-J 
7\r£rT 
^ 
S\\,. 
Fig. 30.— Ross's gull (Rhodostcthia rosea). 
delta, but all these islands are rocky, while Ross's gull is exclusively 
a marsh breeder. 
An interesting habit of this gull is its early desertion of its breeding 
grounds. Only 20 days after the first egg hatched, both old and 
young left the interior of the delta, and four days later the last one 
disappeared from the coast at the mouth of the river. 
If the 60,000 square miles near the mouth of the Kolyma River 
really comprise the only nesting place of this gull, then many non- 
breeding individuals must spend the summer far from the breeding 
grounds. The type specimen was taken in the height of the breeding 
season, June 23, 1823, at Alagnak, Melville Peninsula, near Igloolik 
(Ross). A second was seen there four days later, but the birds 
were certainly not breeding anywhere in this region, for these are 
the only individuals recorded in the vast stretch of 2,000 miles 
between Greenland and Point Barrow. Birds presumably non- 
breeders were noted by naturalists of the Jeannette just west of 
Wrangell Island, June 22-30, 1880; one at Pitlekaj, July 1, 1879 
