APPENDICER.
PUBLIC RECORD OFFICE
Reference :-
6
TPELLCO 885
Humpbacks:---
Total number captured and examined at Leith Harbour
$7=100
M
Malea Females
20= 35%
37= 85%
13- 22:8%
Of these there were captured between 15th November
and 15th December
And between 18th December and 16th January Number captured between 15th November and 15th
December
Number captured between 16th December and 16th
Males Females
January
Males
Females
Average length of all (57) specimens
Average length of all (20) males
Of these 7, or 35%, were less than 37 feet long and are regarded as sexually immature; lengths from
The remaining 18, or 65%, were sexually mature,
and had an average length of
Smallest male regarded as sexually mature Largest male
Average length of all (87) females
Of these 12, or 32.5%, were sexually immature;
lengths
Average length of 25, or 67.5%, mature females Smallest mature (pregnant) female Largest female
If the length of largest male Then that of smallest sexually
mature male
==
100
=
76.8
44 77.2%
13=100
6= 40·1%
7= 53.9%
44-100
14- 31·8%
30- 41.88
68.2%
feet
99.46 feet
95 to 36.7 feet
44-18 feet
38
feet 49-5 feet
49.18 feet
27-6 to 4 feet
46.86 feet
42 feet
52
feet
100
=
80.8
If length of largest female Then that of smallest sexually
mature female
If the length of largest female Then that of the largest male
The genitals were examined in 22 females
Foetuses were found in
Foetuses must have been present in
Evidence of recent impregnation in
22-100
100
95.3
12
13- 59%
1
2= 2=
-9.1%
9.1%
5= 227%
32=100
Unimpregnated 7, of which were mature and nursing Virgin and immature
The organs of lactation were examined in 32 females
Including 10 immature virgins, no milk was present in Doubtful whether present or absent in
Some milk present in
Nursing females
25= 78.9%
1= 8.18% 8= 9.99%
60
Bfue Whalen :=
APPENDICES.
Total number captured and examined at Leith Harbour
Malce Females
Of these there were captured between 15th November
and 15th December
And between 18th December and 18th January ..... Number captured between 15th November and 15th
December
Males
Females
Number captured between 18th December and 16th
January
Males
Females
Average length of all (50) specimens
Average length of all (24) males
Of these 5, or 209%, being less than 70 ft. long, are
regarded as sexually immature; lengths from
The remaining 19, or 79-1% have an average length of Smallest male regarded as sexually mature
Largest male
Average length of all (26) females
50= POD 24= 48% 26 = 52%
7= 14% 43= 86%
7-100
2= 28.8%
5= 71.4%
49=100
22- 51.2%
21= 48.8%
787 feet. 76.9
"
60 to 67-5
80-22 74 91
""
"
80.35
H
"
88:37 82.5
"}
95
"}
If length of largest female
= 100
Then that of smallest sexually
mature female
87
95.8
15=100
5
8= 53.8%
3
1=
6.67%
Of these 10, or 38-5%, were sexually immature; lengths 63 to 73-5 Average length of mature females (16 or 61.5%)
Smallest matare female (pregnant)
Largest female
If length of largest male =
100
Then that of smallest sexually
Mature male
سے
81.3
100 If length of largest female Then that of largest male The genitals were examined in 15 females
Fatases were found in
Foetuses must have been present in
Evidence of recent impregnation in
Pregnancy was doubtful in
Virgins sexually immature
2= 13·3%
4- 28·7%
23 PUBLIC RECORD OFFICE, LONDON
ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC- COPYRIGHT PHOTOGRAPH—NOT TO
The organs of lactation were examined in 23 females
No milk was presefit in
Milk doubtfully present
15 100
23-100
22= 95·8%
1=
4.35%
Note. Of these 23 females, 14 were sexually mature: the teats were retracted In all the immature whales, while in mine of the mature ones, from 85-5 feet upwards, they were more or less protruding: the latter condition probably indicated that a calf had been suckled and weaned.
Five foetuses were examined: the smallest was 1 ft. 8 in. on 12th December, the largest 10 ft. B în, on 9th January. Such varying dimensions indicate a long sexual
seltson.
The female blue whale of South Georgia would appear to breed first when she hale attained a length of between 80 and 84 feet. In No. 43 (84 ft.) the evidence pointed to a recent first impregnation. In this whale one of the ovaries had six corpora lutea (indicating a polyœstrous sexual season), one of which was large, swollen, and provided with a distinct scar: the uterine cornu connected with this overy was congested for about two feet of its length and from the size of the uterus Major Barrett-Hamilton thought that the impregnation, denoted by the enlarged corpus luteum, was recent and a first one.
The rate of propagation is probably the same as in the finners, viz., the female gives birth to a calf in alternate years, the calf being weaned before renewed impregnation.
Note. Of the three cases in which
some
9.99%
82 100
milk was present, two were Of the three certainly, and one was probably, in an early stage of pregnancy. nursing females, one (No. 48) had been quite recently impregnated and had either just weaned or was about to wean her calf; one (No. 126) was apparently not impregnated; the third whale (No. 211) was not examined for pregnancy
Eleven foetuses were examined between 25th November and 15th January; the smallest was 6 inches long (25th November and 20th December), the largest 2 feet 1 inch long (30th December and 15th January).
It is evident from the uniform small size of the foetuses, as well as from the rather high percentage of females with milk, that the period mid-November to mid- January is not far removed from the commencement of the sexual season of the humpbacks at South Georgia. I have tried to calculate the pairing dates for the foetuses found; I assumed that Collett's estimate of eleven months' gestation for