Data for the estimation of the demographic parameters of New Zealand sea lion (such as survival, breeding success, etc.) are collected by tagging sea lion pups, and then recording subsequent resightings of tagged animals. Sea lion are tagged using plastic numbered flipper tags. In the past brands and micro chips have also been used to identify animals. This database contains data on the tagging and resighting of tagged individuals, from 1980. Data on the effort spent on searching for tagged animals, or on animals found without tags are not recorded here. Other work is also carried out dusring the Auckland Islands field season, such as counting the pups. These other data are not included. An overview of New Zealand sea lion biology, they issues they face, and current management is available in the sea lion species management plan.
The majority of sightings data were collected by a series of research projects at the Auckland Islands. A detailed understanding of the field methods used is crucial to any meaningful analysis. Users of the data should be familiar with the annual field reports, and associated analyses, that can be found on the Conservation Services Programme publications webpages. The tagging and resighting work that was carried out in the 2011–12 season is summarised in a report by Louise Chilvers. Other sightings reported to the Department of Conservation are also included in the data.
The Department of Conservation encourages investigators conducting any analyses relevant to the understanding of commercial fishing impacts on New Zealand sea lions to report draft findings to the CSP Technical Working Group. For publications and details of meetings see the website of DOC CSP. A recent analysis of the demographic parameters os New Zealand sea lion using these data is available in a report by Darryl MacKenzie.
Data were provided in as spreadsheets. They were groomed to complete missing data, and to correct inconsistencies. A key grooming step was the creation of individual sea lion records, associated with a consistent set of tags, brandings and microchips. Other minor errors, such as incorrect dates, incorrect tag colours, and errors in sea lion locations were also corrected. A record was kept of all changes to the data. These changes are visible from individual sightings, by following the details link. A record of all updates is available as a CSV file.
Some additional text comments attached to sightings are not provided here, as they have not had personal information redacted. To access this content, contact the Conservation Services Programme (firstname.lastname@example.org).
Data are made available for reuse by the Department of Conservation, under a creative commons attribution licence, following the recommendations of NZGOAL. This licence allows the data to be used for any other purpose and republished, provided only that attribution is given to the source. At the bottom of each page, a citation is given with a preferred format for referencing the data.
This database was developed by Finlay Thompson and Richard Mansfield of Dragonfly Science. We are grateful for the scientists, most recently Louise Chilvers, who run the tagging and resighting research, and who have collected these data. The development of this database was funded by the Department of Conservation's Conservation Services Programme project POP 2011/01, principally through a levy on the quota holders of SQU 6T fish stocks.