Habitat/Wildlife
Birds of Coyote Hills: Gnatcatcher Facts
By Kathleen Shanfield
Mar 15, 2005, 22:32

What Exactly is a Gnatcatcher?

Kathleen Shanfield

            “The most important thing for birds is the habitat”.  This was the resounding message of the third Education Series hosted by Friends of Coyote Hills in February at the Fullerton Main Library. Becky Stewart, M.Sc., Biologist-Educator for Bird Programs at the Starr Ranch (a bird preserve in South Orange County owned by Audubon), treated all to the sights and sounds of our local birds here in Coyote Hills. The topic was Birds of Coyote Hills, with emphasis on the shrinking populations of threatened and endangered species due to dwindling habitats.  The presentation reinforced the importance of valuing and saving our open spaces here in Fullerton for all to enjoy now and for the future.

            The coastal sage scrub habitat in Coyote Hills is home to many birds, many that we see regularly and others that require the skill of a seasoned birdwatcher and a pair of binoculars.  However we can hear these winged neighbors easier than we can see them!  With pictures and audio, Becky put the faces to the songs we like to hear when we go outside.  The Song Sparrow, Towhees, Cactus Wren, Bewick’s Wren, Loggerhead Shrike, Red Tailed Hawk, White Tailed Kite, Northern Harrier, Coopers Hawk, California Quail, and the Great Horned and Burrowing Owl, are all commonly seen and heard in Coyote Hills.  Many of these are “Sensitive Species”, which means that they are declining in numbers in this area.

            Listed on the Federal Threatened/Endangered list is the Gnatcatcher, which relies solely on the coastal sage scrub habitat that is found in Coyote Hills and throughout Southern California. This habitat is being destroyed quickly however, as Southern California land is developed.  This little bird is important in that, as their name implies, they eat gnats-those nasty little flying black bugs that are annoying to us humans.     Becky informed us that there are approximately 500 pairs of gnatcatchers in Orange County, and 46 pairs in Coyote Hills.  Their numbers are decreasing rapidly due to the loss of their natural habitat.  Why is it so vulnerable?

            Coastal sage scrub is the only habitat in which they build their nests, and they are quite picky about their homes.  They prefer low sage scrub with buckwheat, which is the type that is in Coyote Hills, making it a prime nesting spot.  A single female averages 2.5 young/year.  They usually have 4 eggs, but only 29% make it.  They are very susceptible to disturbance.  If anything disturbs the nest they will abandon it.  They are non-migratory and they usually only fly about 2 yards.  They can go further when predators are in the area, however typically they do not fly far.  When they do fly, they only fly over coastal sage scrub. They have natural corridors that they travel, but they do not typically fly over streets or grassy areas.  The juveniles will disperse no more than a mile from their nest home. 

            Most importantly, the approximately 46 pairs of gnatcatchers in Coyote Hills require the entire 500 acres they currently reside in for survival.  In winter, when insects are scarce, the gnatcatchers need dry arroyo and grasslands near their nests in order to find enough food. Coyotes, a keystone animal that also lives in this area, keep the habitat in check because they eat the predators, such as rodents and other mid-sized animals that eat the birds’ eggs and destroy the nests.   This sensitive balance is crucial to maintain for biodiversity and survival of all the species in this area.  All of these facts lead us to realize that if this habitat is disturbed or removed, the gnatcatcher and other bird species that do not easily migrate or disperse will not survive.

            The 760 unit housing development that is proposed by Pacific Coast Homes in W. Coyote Hills is mandated by the U.S. Fish and Wildlife regulations to protect the existing nests of the Gnatcatchers.  So far, we have not been assured by an Environmental Impact Report (EIR) how this will occur.  Given the disturbances caused by moving land with bulldozers, the noise, and increased activity that would be generated, it does not seem likely that any gnatcatchers or other species of birds or animals could survive.  It will be interesting to see how the developers plan to deal with this issue in the next EIR due out in Spring of 2005. 

            The Friends of Coyote Hills sponsors many educational events and opportunities regarding the wildlife and recreational value of this last 510 acres of open space in North Orange County. Their goal is to preserve this entire parcel of land for a park and nature preserve for all to enjoy.  Guided hikes are led by bird enthusiasts and naturalists every second Saturday of the month.  The next hike will be on April 9^th.  Meet at the recreational riding ring at Laguna Lake Park at 8:00am.  With the rains we will see the Coyote Hills in full bloom!  For more information visit our website at www.coyotehills.org.  For more information on the gnatcatcher and other birds of Orange County, visit the Audubon’s Sea and Sage website at www.exo.com/~kenyon/, and www.starr-ranch.org.