FUR-SEAL CENSUS, PRIBILOF ISLANDS, 1918. E25 
SURPLUS BULLS. 
No count of bachelors on the hauling grounds was made at the 
height of the season because of the interference this would have 
caused in the killings then taking place. In its stead the surplus 
bulls were counted about the back of the rookeries. This class 
includes those males found here and likewise those which are on the 
hauling grounds and elsewhere; obviously, the last must be estimated. 
No counts of them are possible. A count about the rookeries, 
however, is valuable because in a way it shows a breeding reserve 
which is unquestionably known to be in existence. For this purpose 
they might be added to the idle bulls but would tend to give an 
erroneous impression, because the count only represents a very small 
fraction of the number in actual existence. it those counted were 
added to the number of idle bulls they would make 2,444 +3,951, or 
6,395 nonbreeding males found about the rookeries at the time of the 
1918 height of season harem count. This makes the percentage of 
idle and surplus bulls to harem bulls 119.66. From this it is apparent 
why the average harem was at or very near a minimum. 
Surrtus Butts CounteED In 1918. 







Rookery. Seine Rookery. sas 
ST. PAUL ISLAND. ST. GEORGE ISLAND. 
LS G7 phe Sc acer ep a 5 fe GOUNOntN ct aes aes aaoee bee cecebek cs cosas 91 
PRcaMine 2420 a8 cele. bbe ae sea OGi||Petaraya Arto coco cescncsids ces one cise oe 56 
GUN RLCH 22. k. wot cere t na don cous shat cece 1GOSHRZADACMIL Son dese choke seen caaeee ees 29 
(3) i ce A See ALS Me ee RY Dp SOOM ASOUL ess ssa a ae Gotineee ere eins oe eee 4 
SL ADD Tie on Bae Siee Oy, See SR Rs ay een a ZOOM eR BSh WOR Locsccg.gacicchpecsseces cesmeence 37 
EEGINLOL Samet a wee ee Ramee ade one tae ocean 267 
Butholtmparr ss fete f sae tse coset he 93 Total 217 
ERO RAIA Se pie pee oh viata niee ere 500 
Laivile Zapadniz —. 2 st Pee es eee 54 Total, both islands. ..............- 3,951 
LEC TaN: eng 3 pea —eg are emareatl Heiipeanetae sie ay  Ne 194 
PTHS POIOVINAT tel c e nL sates tec mecee ne 
MEOH Gyl reeset en teen ccc cen accne ne 157 
IV GStOChnit4 ache e sereh ee eae ao 1, 260 
Total cen, ate oie te 3, 734 


GAINS OF BULLS. 
The great significant fact standing out in the census work of 1918 
is the percentage of gain of harem bulls. This was 10.18 for the 
entire herd, a figure differing but slightly from the increase of the 
cows. Since there was an overabundance of idle and surplus bulls, 
it seems to show conclusively that the average harem in these two 
years was at its minimum. ‘The average increase of harem bulls the 
five preceding years was 36.68 per cent. The increase or decrease of 
idle bulls means but little at this time. The difficulties of deter- 
mining the actual number in this class as distinct from surplus bulls 
are almost insurmountable. Those animals at the rear of the rooke 
which might properly be called idle bulls either merge into the haul- 
ing grounds on one side occupied solely by surplus bulls and bach- 
elors, or on the other side into the group properly known as idle bulls. 
It would not be right to: call all bulls on the hauling grounds “idle 
bulls.” Neither could the figure obtained from counting surplus 
bulls on the back of a rookery be considered to represent all the 
animals in this group, The great difficulty lies in the fact that in a 
large number of cases there is no line of demarcation between a 
rookery and a hauling ground. The rearward extension of the breed- 
ing seals is bordered by a sharp line, but the other classes are not. 
160695 °—20——25 
