Maternal strategy of the Cape fur seal (Artocephalus pusillus pusillus) : female attendance, milk transference, and pup energetics /
The Cape fur seal is a common pinniped species along the southern African coastline, with population estimates exceeding 2 million individuals. Little is known about this species, particularly information concerning reproductive energetics. With radio telemetry, my colleagues and I monitored atten...
| Main Author: | |
|---|---|
| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
2002.
|
| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=764785951&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The Cape fur seal is a common pinniped species along the southern African coastline, with population estimates exceeding 2 million individuals. Little is known about this species, particularly information concerning reproductive energetics. With radio telemetry, my colleagues and I monitored attendance patterns from 1996-1999. This data enabled us to establish a baseline for attendance, quantify the degree of inter-annual variation, and examine variations between observed and historic attendance patterns. Reproductive effort was further quantified with measures of nursing female body condition and milk composition. Milk ingestion and field metabolic rates of nursing pups established a baseline for the energetics of one-month-old pups. Milk ingestion and field metabolic rates were examined to determine if nursing females provide more resources to either sex. Attendance patterns of 29 nursing females averaged 1.86 ± 0.765 days on shore and 5.23 ± 2.87 days at sea. Mean cycle time was 7.09 ± 4.326 days, of which 29.6 % was spent on shore and 70.4 % at sea. Mean time on the rookery did not change during the first four months postpartum. A significant increase in length of time at sea was observed. Body composition remained constant from 1998 to 1999 at 11.05 ± 2.308 % lipid and 19.15 ± 2.601 % protein. Milk from 18 individuals was composed of 58.07 ± 6.785 % water, 2.02 ± 0.579 % ash, 10.76 ± 1.231 % protein, and 23.16 ± 8.240 % lipid. Milk energy content averaged 11.02 ± 3.101 kJ ml⁻¹. Thirteen pups consumed milk at a rate of 136.58 ± 29.111 ml kg⁻¹ d⁻¹. Mean energy intake was 1,505.1 ± 320.799 kJ kg⁻¹ d⁻¹, with 37.16 ± 8.042 % going to body maintenance and 62.84 ± 8.041 % to growth. Fat and protein tissue was deposited at a rate of 16.10 ± 34.930 g d⁻¹ and 21.40 ± 59.200 g d⁻¹, respectively. Pup mass gain averaged 4.14 ± 131.420 g d⁻¹. Our results did not support differential investment in the sexes. Male and female pups differed significantly in body mass and field metabolic rate, but no evidence was found that nursing females invested more in either sex. |
|---|---|
| Item Description: | Vita. "Major Subject: Wildlife and Fisheries Sciences". |
| Physical Description: | x, 102 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 91-101). |