BirdCast Data

Data Sources

Weather Surveillance Radar

Radar is an excellent tool for determining where birds are flying, how many birds are aloft, and in what direction and speed they are moving. BirdCast takes advantage of the WSR-88D (also known as NEXRAD) network of radars surveilling the airspace above the contiguous U.S. These data are collected continuously, and they are stored in a free, publicly available dataset. Because these radars are excellent at detecting biology in the atmosphere, this dataset represents one of the largest archive of biological information available to us. This technology, however, is not effective for identifying species; but in conjunction with visual and acoustic data, it offers unique insight on movements of birds at the continental and regional scales.

eBird – direct visual observations

A real-time, online checklist program, eBird has revolutionized the ways that the birding community reports and accesses information about birds (as reported here ). Launched in 2002 by the Cornell Lab of Ornithology and National Audubon Society, eBird provides rich data sources for basic information on bird abundance and distribution at a variety of spatial and temporal scales. eBird’s goal is to maximize the utility and accessibility of the vast numbers of bird observations made each year by recreational and professional bird watchers. It is amassing the largest and fastest growing biodiversity data resources in existence, with over two billion observations recorded. Importantly, the eBird data offer direct observations and confirmation from humans regarding the presence and absence of a species at a particular location and time. Such observations include information about the identity, number, location, behaviors, and environment, invaluable knowledge with which to enhance information produced by radar sensors.

Acoustic monitoring – flight calls of nocturnally migrating birds

Many nocturnally migrating birds vocalize while in flight, typically simple vocalizations uttered particularly during nocturnal migration. These are often referenced as “flight calls” or “nocturnal flight calls:” often species specific sounds that differ from other calls and songs heard during daylight hours. At present, monitoring of flight calls is the only reliable method for identifying the species composition of nocturnal migration while it is occurring. Such monitoring was now a cornerstone for a sister project, BirdVox, which used machine learning techniques to providing automated, near-real time information on species-specific migration patterns for comparison with radar and eBird data. More recent advances in automatic detection and classification are available, including the Nighthawk software and even dashboard data showcasing species composition and relative abundance from a network of acoustic monitoring stations.

Thermal imaging and tracking technologies

Among other technological evolutions with applications to remote sensing and indirect observations of individuals and groups of nocturnally migrating birds, thermal imaging and various on-bird sensors (“tags” that can be affixed to a bird that allow is to be tracked in real time or when a bird with a tag passes a receiver to collect data) have provided an increasing array of insights into the timing, duration, distance, and altitude of migration; in the future, these sources of data, in addition to those listed above, will represent important ground-truth and complements to drive our understanding of nocturnal migration closer to completion!