Glossary · birbs — round 1 archive

Terms that appear repeatedly in the daily logs, prose dispatches, and data files — pulled together here so each post doesn’t have to re-explain them.

Brood patch: A bare, vascular patch of skin on the female's belly that she presses against the eggs (and later, chicks) for heat transfer. The reason the female does all the incubation in this species: only she develops one.
Brooding: Sitting on chicks to keep them warm, distinct from incubating (sitting on eggs). The classifier was extended on hatch day to relabel `incubating` → `brooding` for any adult-on-cup clip after the confirmed hatch timestamp.
Chick gape: The bright-pink open-mouth begging response — chicks crane upward with mouths fully open when an adult arrives at the cup. The classifier counts these as a feeding-readiness signal.
chicks_alone: Cup state: chicks visible in the cup, no adult present, and the classifier is confident.
chicks_alone_occluded: Cup state: cup looks empty but the classifier can't rule out chicks tucked or hidden in the cup geometry. A deliberate middle bucket — the classifier's way of admitting uncertainty rather than mis-classifying as `truly_empty`. Important post-fledge: when the chicks have actually left, this bucket over-counts and the data page corrects for it.
Clip: One video file from one camera. Either motion-triggered (typically 5–20 seconds, fired by the camera's own motion detection) or interval (a few seconds, taken on a fixed schedule regardless of motion). Each clip is independently classified.
CLAHE: Contrast Limited Adaptive Histogram Equalization. An image-processing step that enhances local contrast in low-light or IR frames — used to bring out chick counts in piled-cup views.
Courtship feeding: Male House Finches don't incubate, but they bring food to the female while she's on the cup. Visible as a clip with the male arriving at the rim, the female lifting her head to receive, a beak-to-beak transfer, then the male leaving. Counted as its own metric in the daily logs.
Cup: The actual nest. A grass-and-stem bowl roughly four inches across, built on the second shelf of a sunroom bookshelf in late April 2026. By Day 28 the chicks had structurally collapsed it.
Cup state: The seven-bucket classification of what's in the cup at any given clip: `chicks+adult`, `eggs+adult`, `adult_only`, `chicks_alone`, `chicks_alone_occluded`, `eggs_alone`, `truly_empty`.
Daylight share / on-cup share: Fraction of all clips that day where the female was visibly on the cup. Drops sharply post-Day-15 as the chicks self-regulate temperature and mum spends more time off-cup hunting.
Dispatch: A prose post, distinct from a daily log. Written on days that earned narrative attention (hatch, first count, eye-opening, fledge). There are fourteen of them across the cycle.
Eye-opening: The point in chick development when eyes shift from sealed to opening to fully open — typically Day 5–7 post-hatch in House Finches. In this brood, first eye-opening observed on Day 18 (2026-05-12).
Fledge / fledge day: The day chicks leave the cup for the first time. For this brood: Day 28 (May 24, 2026), four chicks in a fourteen-minute morning window, fifth chick later that afternoon.
Fledge window: The species-typical span during which fledge can occur, roughly Days 13–17 post-hatch for House Finch. The classifier's `chick_phase_estimate` enters `fledge_window` partway through it and `fledged_or_post` once fledge has been observed.
Hatchling / Nestling / Fledgling: Three life-stage labels by age post-hatch. Hatchling: newly emerged, pink and helpless. Nestling: feathered enough to thermoregulate, still in the cup. Fledgling: out of the cup, near or beyond the nest.
IR (infrared): Near-infrared illumination, used for overnight camera coverage. Renders the cup in monochrome with smooth bright (eggshell, IR-reflective) and matte dark (pink chick skin) contrast that's actually easier to count than daytime visible-light shots.
Interval clip: A timed capture — a few seconds of video taken on a fixed schedule (typically every 60–120 seconds) regardless of whether motion fired. The reason the dataset is continuous rather than bursty.
Motion clip: A capture triggered by the camera's own motion-detection system. Catches the action but misses the long quiet stretches.
Quiet 30-min window: A 30-minute span with no visible bird activity during daylight. Counted per day as a proxy for parental absence.
Reolink: The wide-angle camera covering the whole bookshelf and the window beyond. Caught the fledge from across the room.
Sunroom interval / sunroom motion: The room-wide existing camera, in interval mode or motion-triggered mode. Wider view than the close-up Tapos.
Tapo / Tapo C110: The two close-up cameras mounted next to the cup. Different angles on the same cup; one was the "primary" classifier feed.
Tier 2 counts: Secondary per-clip flags: `food_in_beak`, `fecal_sac_removed`, `cup_edge_perching`. Captured but not currently surfaced in the data visualizations.
truly_empty: Cup state: cup confirmed empty, no chicks, no eggs, no adult. The classifier is conservative about claiming this — see `chicks_alone_occluded`.