BirdPulse — glossary

Name: BirdPulse live feed
Creator: BirdPulse

Plain-language definitions of the terms used across BirdPulse (GBIF + eBird).

Migration

Migration: The regular seasonal movement of birds between breeding and non-breeding ranges, driven mainly by changing day length, food supply and weather. Spring is northbound; fall is southbound.
Photoperiod: The length of daylight, and the master cue that triggers migration. Because it repeats identically each year, it is a more reliable signal than temperature or food for timing the journey.
Flyway: A broad continental corridor that migration concentrates along — such as the Atlantic, Mississippi, Central and Pacific flyways in the Americas — shaped by coastlines, mountains and stopover sites.
Irruption: An irregular, hard-to-predict mass movement of a species — often northern finches or owls — pushed far south of their usual range when their food, such as a seed crop, fails.

Nocturnal migration: Flying at night, as many songbirds do, to use calmer air, avoid daytime predators and navigate by the stars. Dense nights are visible as a bloom on weather-surveillance radar.
Stopover site: A place where migrating birds rest and refuel between flights. As essential to a successful migration as the breeding and wintering grounds; coastal and oasis stopovers can hold huge numbers.
Fallout: A sudden concentration of grounded migrants, often when bad weather forces a flying flock down or a backlog of held-up birds moves at once. Prized by birders for the spectacle.
Hotspot: A shared public birding location that many observers report from under one name. Pooling their checklists builds a far richer species list and seasonal picture than any single visit.

Checklist: A birder’s record of one outing — the species and counts seen, the place and time, and the effort behind it. The basic unit eBird is built from and the source of each point shown here.
Effort: How much watching produced a checklist — duration, distance and whether the observer aimed to record everything. Effort is what lets counts be compared fairly between outings.
Citizen science: Research powered by volunteers. eBird’s reach comes from hundreds of thousands of birders, balanced by automated filters and regional reviewers who vet unusual reports.
Notable sighting: A report flagged as unexpected for a place or season — a rarity or out-of-range bird — that is reviewed, ideally with photo or audio evidence, before it is accepted into the dataset.