HomeMy WebLinkAboutCUP 01-22; AVIARA COMMUNITY PARK; FOCUSED CALIFORNIA GNATCATCHER SURVEY RESULTS; 2003-01-06Ms. Elaine Blackburn
City of Carlsbad
January 6, 2003
Page2
east of the December 26 CAGN location. This bird was well seen and carefully identified by its
diagnostic plumage details ( e.g., clean white underparts and entirely white outer rectrices) and
vocalizations.
It is the opinion of the P&D biologists conducting this sun1ey that the vegetation surrounding the
project site, including distances out at least 500 to 750 feet from the site, would not likely
support breeding pairs of the CAGN. The vegetation in the vicinity of the December 26 CAGN
identification consists of chaparral habitat dominated by chamise, as well as several coast live
oaks. Although coastal sage scrub (CSS) plant species are occasionally present in the chaparral
surrounding the project site, these are fairly rare and generally consist of black sage. California
sagebrush and bucbvheat, CSS species most preferred by CAGN, is e:\.-tremely scarce to absent
in this general area. Although the structure of the chaparral plant community surrounding the
project site is occasionally not quite as arborescent as other types of chaparral, it is still taller and
much denser than CSS associations typically occupied by the CAGN. Due to the density of the
Yegetation. for example, it was eA"tremely difficult to nearly impossible in many areas to traverse
through the habitaL except in the rare instances where small game trails were present. This
vegetative structure. as well as the species composition, is not typical of habitat occupied by the
CAGN in southern California.
Based on the lack of habitat that would be considered suitable to support resident, breeding pairs
of the California gnatcatcher in the vicinity of the project site (including out at least 500 to
750 feet), it is our opinion that the CAGN recorded on December 26 represents a dispersing or
transient individual. The inability to relocate this bird on other sun1eys would further support
this conclusion.
Finally, there may be a low possibility that a bird could had been drawn in by the tape-recorded
vocalizations from an eA-treme distance. After sunreying the outlying native plant communities
from the higher vantage points on the site, no suitable CAGN habitat of any extent could be seen
within at least a half mile. Small patches of vegetation dominated by CSS species were seen
about 500 to 600 feet to the west (approximately a 1/2 acre in total) and about 750 feet to the
north (1/2 to one acre in total), although these were surrounded by either dense chaparral or
developed areas.
Sincerely,
P&DENVIRONMENTAL
~fl~
Betty Dehoney, CEP
Director of Environmental Services
cc: John Cahill -City of Carlsbad
John Martin -USFWS
P A'ZJ9,Park,CAGN-Surve~-Ltr.doc (175508)