When the effort to tag all the pups born into the McMurdo population was initiated in 1973, an effort to walk through the pupping colonies and record all the individuals present along with their tag numbers was also begun. These “census” efforts were generally repeated at least seven times each pupping season and the census tallies became the central part of the growing database. Initially, data from these census undertakings were recorded in a standard field notebook and, of course, were subject to the errors that can exist in field notebooks. In the early days of the project, upon returning each day to the field camp, data would entered into a summary log book. These summary log books along with the field notebooks were returned to the university after each season, which began an interesting period of comparisons of notebooks, interpretations of penmanship, and other discussions before a final version of the year’s efforts was prepared for analyses in the university’s central computer system.
In the mid 1980s, small handheld computers became available. This started a process of developing a data entry system that could be used to record tag numbers and other data as researchers moved through the pupping colonies. Ward Testa was instrumental in this development and wrote the first data entry program which contained routines that checked each entry as it was entered to make sure the new data were consistent with what was already in the database. This data checking routine proved extremely valuable in limiting the number of mistakes entered into the database. The field computers were very successful, and each evening data were downloaded into the master laptop computer and backup copies were recorded.
In the late 1990s Michael Cameron contributed significant upgrades to what Ward Testa had developed, and we purchased new field computers as they came on the market. This was essential as the data base was continual increasing in size and the data checking programs needed additional computer storage space and increased speed.
These methods remain the major procedures for maintaining the database’s integrity while work continues at Montana State University. More recently the data entry program has again been rewritten by the MSU program in order to take advantage of upgrades in handheld computers and bring the data entry software up to date.
In 2013, the project began using new Trimble Ranger 3 handheld field computers with GPS capability. Having built-in GPS capability is a substantial upgrade that will allow researchers to more quickly input location information on seals during tagging and census surveys.
Currently Jay Rotella and Bob Garrott at Montana State University continue to support graduate student research on the Weddell seal project. Four PhD students--Gillian Hadley, Kelly Proffitt, Glenn Stauffer, and Thierry Chambert--and one Masters student--Jennifer Mannas--have completed their degrees at MSU based on Weddell seal research work. In addition, the program has given numerous graduate students, such as Jesse DeVoe, and undergraduates experience in the field in Antarctica.
All of these research initiatives depend on maintaining the integrity of the mark-recapture database by tagging all the pups born into the McMurdo Sound population, and replacing lost tags when an adult seal is observed with only one tag. As a result, the Weddell seal project database now consists of perhaps the most complete record on marked individuals that have been seen repeatedly over their lifetimes.
The database now contains records of the sightings of all pups born in the study area since 1973 and has been used in a series of analyses that take advantage of recent developments in mark-recapture methods to produce recent publications exploring a variety of hypotheses about population structure, stability and regulation; demographic variation and buffering; and life-history evolution. These analyses employ recently developed techniques for exploring how individual animal characteristics (e.g., birth year, age and breeding state) and environmental conditions relate to variation in vital rate values and population status.
Since its beginning, this project has prolifically published papers on the research findings of the project. Recent published papers by the Montana group include a detailed look at factors influencing how the various population statistics, such as reproductive and survival rates, are influenced by annual environmental changes, and how the yearly cohort into which a seal is born influences its long-term population contributions.