Wrentits

Ryan Winkleman
 

All,

There has been an inordinately high number of recent Wrentit reports in eBird lately in north coastal Orange County. Many of these have been from birders visiting from out of town, but some have been local "known" birders. I have been following up on these over the last several days and as expected so far they have generally amounted to user input error, misidentifications, or just sightings with inadequate documentation to accept. 

There has never been a valid, properly-documented report of Wrentit from Orange County's northern coast. Wrentits are obligated to coastal sage scrub and chaparral and are sedentary; they do not wander around much. The dispersal distance from hatching grounds when birds leave the nest and are establishing their own territories averages less than 400 meters (0.25 mile). Once a territory is established, Wrentits essentially stay in the same territory year-round for life, only occasionally leaving when foraging as post-fledge family groups or during occasional winter movements. Even still, during these "long-distance" episodes movements are still restricted to only around 450 meters from established territories. As noted in Orange County's breeding bird atlas (available at the Audubon House at San Joaquin Wildlife Sanctuary), under normal conditions even a standard roadway can present a formidable obstacle to dispersal movements. This absence coincides with a similar absence along the southern Los Angeles County coast.

Thus it is highly unlikely that Wrentits would occur along OC's northwest coast and into Huntington Beach where urban sprawl and habitat fragmentation has effectively eliminated any chances for birds to move up and down intact suitable coastal sage scrub habitat. Any eBird reports of Wrentits anywhere north of Upper Newport Bay should include solid documentation of photographs and/or audio recordings in order to be accepted. This also includes quite a few 2017 and 2018 (and now 2019) eBird reports of Wrentits in Fairview Park, Talbert Nature Preserve, and Canyon Park, all of which are in an isolated area about 2.5 to 3 miles away from intact/contiguous coastal sage scrub and none of which include any documentation. If you are one of these people who reported Wrentits in these areas in the last year or two, please consider including documentation if you have any. 

Remember: the best way to avoid getting an email asking for more details is to know the county's status and distribution and always include proper documentation when you find a species--and this includes local resident species--that is unexpected for the time and/or place. 
--
Ryan Winkleman
Rancho Santa Margarita

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