The Device ID Field Is the Chain of Custody
Every tracking device in a seabird telemetry study has a serial number — a Device ID that links the raw data streaming off the logger to a specific individual bird at a specific nest, caught at a specific location by a specific researcher at a recorded timestamp. When a study reports that yellow-eyed penguin (hoiho) foraging ranges contracted by 30% during an El Niño year, the finding is only as credible as the deployment records that match device to bird to site.
If the Device ID field is blank, misspelled, or inconsistently formatted across records, you lose that traceability. The data becomes a dataset without provenance. Funding bodies have asked for less after finding that.
The Deployments (PAT1) template is built around that chain of custody.
What Gets Logged When the Device Goes On
The template's deployment section — everything without the "(R)" suffix — records the event of attaching a tracking device to a bird.
DateTime timestamps the moment of capture and device attachment. Site is a hardcoded choice field covering the specific monitored locations: Breakwater Bay, Tommy Island, Goat Island, Groper Island, Pigeon House East, Sealers Bay, Alphonse, Penguin Bay. These are real sites within a real New Zealand penguin monitoring program. Hardcoding them as a choice field prevents the site name drift that destroys cross-season comparability — no one writes "Breakwater" in one record and "BB" in another.
Tagger is a named individual from the research team — Thomas Mattern, Richard Seed, Michelle Bird, Thor Elley, Ursula Ellenberg. The tagger field matters when device attachment technique varies between operators. If one tagger consistently applies harnesses at a slightly different tension and this correlates with higher device loss rates or behavioral changes in the birds, the tagger field is how you detect that pattern.
Bird ID and Nest ID are relational entries — links to the Bird ID (PAT1) and Nest ID databases that are part of the same monitoring system. The deployment record doesn't contain the bird's banding information or physical description; it points to the record that does. This keeps the deployment log lean and the data model normalized.
Weight is logged in grams at the time of deployment. The device represents a mass addition to the bird, and tracking biology guidelines require that loggers not exceed a defined percentage of body mass — typically 3% to 5% depending on the species and attachment method. Having the pre-deployment weight in the record makes compliance checking straightforward.
Device start-time captures when the logger itself began recording — which may differ from the capture time depending on how far in advance devices are activated before attachment.
Recovery as a Mirror Record
The (R) fields — DateTime (R), Location (R), Weight (R), Image (R), Recovered by, Notes (R) — capture the exact same data categories for the retrieval event. This isn't redundancy; it's the comparison set.
Weight (R) against Weight is how you calculate mass change during the deployment period. For birds fitted with GPS loggers during foraging trips, a weight reduction between deployment and recovery reflects the energetic cost of foraging — a metric with direct conservation relevance in studies examining food availability. For birds fitted with longer-term archival loggers, the weight trajectory over multiple recaptures tracks body condition across the breeding season.
Recovered by is its own named-individual choice field because the person who recovers the device may not be the person who deployed it. In a field study where multiple team members are rotating across sites on different days, the recovery person is the one responsible for device condition checks and data download protocol. If a device comes back with corrupted data, knowing who recovered it — and from which site at what time — is the first step in diagnosing what happened.
The Location (R) field captures the GPS coordinates of the recovery event, which may not be at the nest. A bird fitted with a GPS logger at Sealers Bay nest 14 and recovered at Breakwater Bay tells you something about movement patterns during the deployment period before you've even downloaded the logger data.