Heermann records reflect California’s dry interior, where sandy flats, open scrub, grassland, and desert basins form a patchwork rather than one continuous habitat. The Central Valley, Mojave Desert, and eastern rain-shadow valleys differ greatly in soil and vegetation.
Agriculture, roads, and expanding towns have broken up many lowland sites, especially in the San Joaquin Valley. Reports don’t measure abundance, and the scarcity of nighttime surveys can leave suitable-looking ground with few or no mapped observations.
The California record set combines 134 research-grade community observations with 2,643 museum and survey records. Monthly patterns can also reflect weather and observer activity, so they shouldn’t be treated as a direct count of animals.
Full species profile
