90 ALASKA FISHERIES AND FUR INDUSTRIES IN 1915. 
section of the beaches. A young bull is much more likely to start a new rookery than 
he is to repair to the vicinity of one or two old bulls to swell some scattered harem 
section. 
The percentages of gains are shown in the following table: 
PERCENTAGES OF GAIN oF BuLis Over 1914. 
Harem bulls. Idle bulls. Total, 
Rookery. 
1914 1915 | Gain. 1914 1915 | Gain. 1914 1915 | Gain. 
ST. PAUL IST.AND. 
IocTiO Wal Sea Sebbasaccadeagens:~ 58 67 | 15.52 5 24 | 380.00 63 91 44,44 
Bt Karrin ee eee ie Jae eyes 39 46 | 17.95 1 18 |1,700.00 40 64 60. 00 
Gornbatehteeaess-se eee es 112 152} 35.7 9 35 | 288. 89 121 187 54, 54 
AT GIPUeNS. 22-62 ese csoseen as 15 25 | 66.67 0 tl RE Sense 15 31} 106.67 
Reel cee a hae acs eee 193 294 | 52.33 26 59 | 126.92 219 353 61.19 
Sivmpleh gets soos ose eee 91 96 5. 49 10 23 | 180.00 101 119 17. 82 
Tas On eee ee eee eee 8 15 | 87.50 2 4 | 100.00 10 19 90. 00 
Rost oie ee cee ess pete 161 237 | 47.20 38 46 | 21.05 199 283 42.21 
LADAGDIE SSE Meenas eae 114 173 | 51.75 24 $2 | 283.33 138 265 92. 03 
Little Zapadni......-.----.--- 90 106 | 17.78 10 26 | 160.00 100 132 32. 00 
Zapadni Reefs.) ....-. 2.2. - 3 t |)'133533 1 6 | 500. 00 4 13 | 225.00 
Polovina....--. BSE SB OS AS 58 70 | 20.69 3 31 | 933.33 61 101 65. 57 
Polovina Clits 22 33 | 50.00 6 11 83.33 28 44 57.14 
LittleRolovinas. --222- 2a 18 21 16. 67 0 iliseesosKe 18 30 66. 67 
MOT OV Eee sst te aaamc ctor nas 43 51 18. 60 4 21 | 425.00 47 72 53.19 
Viostoehmi es soes-eee-ee 291 396 | 36.08 20 135 | 575. 00 311 531 70. 74 
Motalnsseaey 5. s-eees ae 1,316 1,789 | 35.94 159 546 | 243.39 1,475 | 2,335 58. 30 
ST. GEORGE ISI AND. 
Nort bhas! < 22s ao 5s. as eee 94 141 | 50.00 4 53 |1,225.00 98 194 97.96 
StarayayAntelscone sees serr cee 63 89 | 41.27 4 31 | 675. 00 7 120 79.10 
deyorXe have pa aee Sar ya seo sere 14 23 | 64.28 0 TO} |Gaaeeee 14 33 135. 71 
Sou Ghee eee anes eet aj 3 | 200. 00 0 (pl bebeesse 1 3 | 200.00 
Ditters one ween eae ee 1 0 |5100. 00 0 Ue rn dies 1 0 | 2100.00 
East)Restas: 2525355 2 2tea isc 14 30 | 114. 28 3 18 | 500.00 17 48 | 182.55 
asti@hiis: 2 a6 Seep aaa) ese 57 76 | 33.33 2 15 | 650. 00 59 91 54. 24 
Rotaleete ei ereeene 244 362 | 48.36 13 127 | 876.92 257 489 90. 27 
Stal tslande.c- o22- 2-22 1,316 | 1,789 | 35.94 159 546 | 243.29 | 1,475 | 2,335 58. 30 
St. George Island.....----.-- 244 362 | 48.36 13 127 | 876.92 257 489 90. 27 
Total, both islands...-| 1,560 | 2,151 | 37.88 172 673 | 291.28} 1,732} 2,824 63. 04 
@ South rookery had one harem in 1914. Bureau of Fisheries document no. 820, p. 172. 
b Loss. 
This table is one of the most interesting compiled from the 1915 figures. It shows 
the enormous percentages of increase of the idle-bull class over the percentage of 
increase of the harem-bull class on the same rookery. The fact that there was an excess 
of idle bulls and still the average harem is large seems to be the best evidence that the 
natural average harem is large. But that the natural average harem has not yet been 
reached is shown by the fact that, whereas harem bulls increased 37.88 per cent, 
breeding cows increased only 11.02 per cent. This discrepancy is partly offset by the 
fact that pelagic sealing was more destructive to the females than to the males. It 
seems that in a state of nature the percentage of increase of harem bulls should be 
only slightly greater than the increase of the breeding cows. The percentage of increase 
of the males over that of the females should, however, increase gradually, as the 
necessity of fighting shortens the life of the males. 
The natural average harem—that is, the minimum average harem—will undoubt- 
edly be almost reached in 1916, when there will be an enormous increase of the idle- 
bull class. Then with accurate counts of breeding bulls and cows it is believed that 
definite data as to increases and average harems may be obtained. 
