168 U. S. BUREAU OF FISHERIES 
tive statement of the numerical strength of the various elements of 
the fur-seal herd in the years 1928 to 1939, inclusive: 
General comparison of computations of ihe seal herd on the Pribilof Islands, 1928 





to 1939 
1 
Classes | 1928 1929 | 1930 | 1931 | 1932 | 1933 
ae. | aol) tn A ae ee 
Hinrent balls.<. (=e ee 6, 050 7, 187 8,312; 9,233 10,088; 10,213 
Breeding cows. =< _.c-._ = SS 284.725 | 307,491 | 332,084 358,642 | 387,320 418, 209 
Surplus bulls. = 3 =a Beleoeaeeee 5, 285 5, 207 3,963 | 3,201 | 2,893 | 4,700 
idie bulls: = ee eee 1, 449 1,633 | 1,899 1,888 | 2,349/ 2,341 
year-old tales = 22 <a ee 12.857 10,399 5,612| 6,553; 8,154; 9,335 
5-year old isles 55 an aoe ee 13, 001 7,016 8,191 | 10,193 | 11,669; 10, 216 
_leeroid insies = ee = 7, 79 9,102 | = 11,327 | 12, 966 | 11, 351 | 5, 441 
3 yesrcold sisles= sae er 11.133, 13,639 14,871.) 13,198 | 17,849 18, 216 
2 yeni old tinles- Ses ie a eae Sree | 49,087 | 64,354) 69,674 | 74,828 | 81, 101 87, 
Yearling males Sats ie aa | 65,861 | 85,381 | 92,232} 99,612 | 107,592 | 116, 195 
S-yexr_old Caws oan Lee aE | 57,061 | 67,210) 72,605| 78,410 | 84,682) 91,454 
Yearline copa mnatech Sooner er se | 72,481 | 85,417 | 92,247 99,626 | 107,593 | 116, 197 
Pape! Pee a | 284,725 | 307,491 | 332,084 | 358, 642 | 387, 320 | 418, 209 
A ee ee ee Reet 871,513 | 971,527 |1, 045, 101 |1, 127, 082 |1, 219, 961 1,318, 568 
Classes 1934 | 1935 | 1936 | 1937 1938 | 1939 
Haren bolls =e oe Ea | 10,770; 11,547| 12321] 13,100] 13,160: 10,980 
Breeding cows 20s." fees Se 451.751 | 487,883 | 526,848 | 568,982 | 614,499 | 663, 634 
Sarptns buliss= = a ee 6, 494 6,1 7.994} 9,140] 7,277 | 7, 828 
idle falls! = 226 = ese 22921 2535 2,733 | 3, 031 2, 125 | 2, 973 
é-year-old males_ 8,173 11,117 11,421 | 15,188 | 17, 269 14, 561 
5-year-old males. | 13,897| 142976] 18:985| 21,586 18,201 | 21,839 
4-year-old males = | 15,862 | 21,096 | 23,991 | 33,815 | 24,275 | 26, 486 
yen old-mnles 5 2 =. ek 24.770 | 28,165| 40,170| 45,891 | 32,278 | 37,107 
S-year-old males i. «1 = ee a | 94990} 102,555 110,505 | 118,889 | 107,003| 116,124 
Weabiinpninles <2 eo ee 125,490 | 135,525 | 146,365 | 158,051 | 142,232| 153,621 
year ews! = ae ee | 98,768 | 106,666 | 115,197 124,410 | 123,150 132, 999 
Wearlne cows ==. ey 125,490 | 135,526 | 146,365 | 158, 054 156,470 | 168, 988 
Paps te oe 2 ee | 451,751 | 487,883 | 526,848 | 568,982 | 614, 499 663, 634 
Ota 3 a8 1, 430, 418 |1, 550,913 |1, 689, 743 |1, 839, 119 i, 872, 38 | 2, 020, 774 
Foxes 
A noteworthy activity, incidental to and alternating advantageously 
with the more important sealing operations on the Pribilof Islands, is 
the care and management of blue foxes which roam at large on the 
Islands and supply approximately 1,000 pelts annually for market. 
In the summer the animals subsist chiefly on birds, birds’ eggs, and 
the abundant marine life along the beaches, but in winter, when their 
natural food is scarce, they are fed prepared rations of cereals and 
seal meal and oil. 
Trapping of the foxes is begun when the pelts reach their prime, 
about the first of December, and is discontinued at the beginning of 
the mating season, usually near the end of January, or earlier if neces- 
sary for breeding requirements. Box traps are used, and a number of 
the animals captured are marked and released for the breeding reserve. 
Aboui 1 percent of each season’s catch consists of white foxes, a color 
phase of the species found at the Islands. 
Five live white foxes from St. George Island and one from St. Paul 
Island, which had been taken at the request of the Alaska Game Com- 
mission for cross breeding with blue foxes on the Experimental Fur 
Farm at Petersburg, were shipped from the Islands on the Penguin 
