Macquarie Island Elephant Seal Populations 1985 Onwards

This dataset contains the results from studies of the Elephant Seal (Mirounga leonina) at Macquarie Island. Results from branding surveys and photographs from 1985 onwards are reported. Numbers, life stage, sex, moult stage and migration patterns have been reported. Currently some 2000 pups a year are branded and the dataset includes birth dates, weights at birth and weaning and at 6, 12 and 18 months.This work was completed as part of ASAC (AAS) project 2265 (ASAC_2265).Objectives:1. To prepare research papers, from the extensive southern elephant seal dataset, that deal with key demographic parameters of the population such as size, age specific survivorship, fecundity, recruitment into the breeding population, age specific growth rates, and intrinsic rate of change of the population. In addition, later papers will investigate interannual variability in these parameters, how these relate to changing environmental conditions, and the effects of this on long term population fluctuations.2. To analyse and compare stable isotope ratios in the facial vibrissae of the seals and the hard parts of their prey to determine the geographical positions of the major foraging grounds of the seals. The isotope values will also allow the food webs, that support the seals, to be better defined.3. To measure the growth rates of elephant seal vibrissae so that changing isotope values, related to the prey and foraging areas, can be referred to particular foraging periods. Elephant seals characteristically have two separate periods of foraging: one in summer and one in winter. The positions of these episodes on a vibrissa can be identified once the growth rates of vibrissae are known.Taken from the progress report for the 2009-2010 season:Progress against objectives:1. One paper published from the elephant seal dataset. Two papers also published during 2009/10 using data collected opportunistically during the life of this project.2. PhD student Andrea Walters continues to analyse the results of the whisker analyses. She has presented some of her results at the AMSA 2009 marine connectivity conference in Adelaide.An honours student has been engaged (start date March 2010) to analyse the squid component of the seals' diet.3. John van den Hoff spent the early summer at Macquarie Island finalising the collection of the demographic data. 2154 tag/brand resights were recorded. Collection of the data has continued on the island by Chris Oosthuizen, Ben Arthur and Iain Field since John returned to Australia. When those field workers return data collection will cease.

本数据集收录了麦夸里岛南象海豹（Elephant Seal, Mirounga leonina）的相关研究结果。本数据集涵盖1985年起开展的标记调查与影像拍摄所得的数据，记录内容包括种群数量、生命阶段、性别、换毛阶段以及迁徙模式。目前每年约有2000头幼崽被标记，数据集同时收录幼崽的出生日期、出生体重、断奶体重，以及6、12和18月龄时的体重数据。本研究系ASAC（AAS）项目2265（ASAC_2265）的组成部分。
研究目标如下：
1. 基于本南象海豹大型数据集撰写学术论文，聚焦种群核心人口统计学参数，包括种群规模、年龄特异性存活率、繁殖力、繁殖种群补充率、年龄特异性生长率以及种群固有变化率。后续还将发表系列论文，探究上述参数的年际变异性、其与环境条件变化的关联，以及该变异性对种群长期波动的影响。
2. 分析并比对海豹面部触须及其猎物硬组织中的稳定同位素比值，以确定海豹主要觅食场的地理位置。同时，同位素数据将有助于更精准地刻画支撑海豹生存的食物网结构。
3. 测定南象海豹触须的生长速率，以便将与猎物及觅食区域相关的同位素值变化对应到具体的觅食时段。南象海豹存在两个独立的觅食周期：夏季觅食期与冬季觅食期。明确触须生长速率后，即可确定每个觅食时段在触须上对应的位置。
以下内容节选自2009-2010财季进度报告：
目标完成进度：
1. 基于本南象海豹数据集的学术论文已发表1篇；2009/10财季还利用本项目期间偶然采集的数据发表了2篇论文。
2. 博士生Andrea Walters仍在开展触须分析相关结果的研究工作，其部分研究成果已在阿德莱德举办的2009年AMSA海洋连通性会议上展示。2010年3月起，一名荣誉学士学生参与本项目，负责分析海豹饮食中的鱿鱼组分。
3. John van den Hoff于初夏在麦夸里岛完成了人口统计学数据的收集工作，期间共记录到2154次标记/标识重识别记录。自John返回澳大利亚后，Chris Oosthuizen、Ben Arthur与Iain Field仍在岛上持续开展数据收集工作，待上述野外工作人员返程后，数据收集工作将终止。