Diversity of Nocturnal Breeding Birds

About this map

In Los Angeles, nocturnal breeding birds are composed primarily of owls, including the Great Horned Owl, Barn Owl, and California Spotted Owl. With their large eyes and binocular vision, owls are well adapted to low-light conditions. They are also able to hear in 3D due to their slightly offset ears and ability to rotate their head and hear at different angles.

The most common nocturnal bird in Los Angeles is the unmistakable Great Horned Owl, followed by the Barn Owl which has a near global distribution. Most of the remaining owl species (Western Screech Owl, Northern Pygmy Owl, California Spotted Owl, Northern Saw-whet Owl) are solitary and occur in mountainous areas with forest.

Nocturnal bird surveys or “owling” is challenging. However, scientists are now using sound loggers to survey nocturnal birds and improve our understanding of their distribution in Los Angeles.

Data source:
Los Angeles County Breeding Bird Survey © LA Audubon 2016

About this map:
The data in this map has been adapted from the Breeding Bird Atlas, a Los Angeles Audubon Society publication created by Larry W. Allen and Kimball L. Garrett, with maps compiled by Mark C. Wimer. The Breeding Bird Atlas includes data for over 200 breeding bird species in Los Angeles County, based on fieldwork conducted from 1995 to 1999. Over 300 volunteer observers contributed 10,000+ hours to gather more than 28,000 records.

The Breeding Bird Atlas is an excellent model of systematic biodiversity research and surveys. The book contains summaries of breeding bird distributions, habitat requirements, and important conservation indicators (abundance, population trends), as well as maps of confirmed and suspected breeding locations. The Biodiversity Atlas presents summaries of the data at a 10- by 10-kilometer spatial resolution.