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HomeMy WebLinkAbout; Carlsbad Golf Course Burrowing Owl Study; Burrowing Owl Survey Municipal Golf Course; 1999-01-07& ASSOCIATES, INC. Engineering, Planning, Environmental Sciences and Management Services Corporate Office: 605 Third Street Encinitas, California 92024 760.942.5147 Fax 760.632.0164 /January 1999 Mr. John Cahill City of Carlsbad Las Palmas Avenue Carlsbad, CA 92009 Subject: Dear Mr. Cahill: 2093-01 Carlsbad Golf Course Burrowing Owl Survey Due to the incidental observation of a burrowing owl {Athene cunicularia) on the proposed Carlsbad Golf Course site, a focused survey for the species was determined to be necessary. The survey for the burrowing owl took place during the winter residency period of the owl and was completed on 4 January 1999. The purpose of the survey was to determine the number and pattern of distribution of the burrowing owl. This letter summarizes the incidental and protocol survey results and observations. Th'e'b'urirowin^ GM^l is a .GaH Same Species of'SpedM^^ It was alsB oil f heAudtiboh'So^^ County'(EveMt; 1979)'.'-•'Tfiis'owl' species'is'^^^ of'deserts'arid'open grasslandis. It typically perches oh fence''posts'or 'stands ori a inouhd'at'the entrance to its nesting burrow! The burrowing owl nests in abandoned rodent (typically ground squirrel) burrows by enlarging the opening; The presence of the burrowing owl was recorded near Palomar Airport a number of years ago and has not been documented' within the area- in recent years. The survey for the burrowing owl on the Carlsbad Golf Course property followed the "Burrovcin'g Owl Survey Protocol and Mitigation Guidelines" prepared by the California Burrowing Owl Consortium (1997). The survey generally followed the winter survey guidelines which include the following methodology: survey includes four site visits On separate dates; visits to be made 2 hours before to 1 hour after sunset or 1 hour before to 2 hours after sunrise; survey coriducted between December 1 and January 31; map owl sightings, occupied burrows, burrows with sign, foraging areas; initial visits include examining the burrows for bvvl sign; subsequent visits are conducted from numeirous fixed poihfs'to.^provide visual cov'ef%e of the'-site^witfi^^iT^^^ pbferi'tialiy occupied burrows'-avoid'sijih^ dutiia'g'rhidda^J' d'iie t'o'tKe^a'cK-W'owhdbs^ the'fiirstThfefe'sui^ey Mr. John Cahill, City of Carlsbad Re: Carlsbad Golf Course Burrowing Owl Survey Survey Results A burrowing owl was observed on 18 and 24 November, 1998 by Harold A. Wier. The observations were made in the afternoon. The owl was observed on the ground at a burrow entrance in the embankment of the Hidden Valley Road and within the drainage that is adjacent to and east of Hidden Valley Road, approximately 650 feet north of Palomar Airport Road. The winter survey, according to protocol, was initiated after December 1. The first visit was made on 21 December, 1998 by Brock A. Ortega. No owls were observed. According to the protocol, potential burrows were examined to search for owl sign. Two burrows were identified onsite that contain owl sign: owl excrement is located at the mouth of the burrows, owl pellets are scattered in front of the burrows, prey remains are located near the burrows, and the burrows appear to have been enlarged from the previous use as a ground squirrel burrow. The second, third and fourth visits were made on 24, 28, 31 December 1998 and 4 January 1999 by Anita M. Hayworth, Ph.D. Due to the size of the property and the short amount of time allowed by the survey protocol for the early morning and late afternoon visits, two visits were required to cover the entire project area. The midday visit conducted on 4 January was completed during the one visit due to the greater amount of time available. The second visit was made in the morning of 24 December from 0630 to 0900 with calm, cool conditions and in the morning of 28 December from 0625 to 0855, also with calm, cool conditions. The third visit was made in the evening of 28 and 31 December from 1500 to 1730 with calm, moderate conditions. The fourth visit was made during midday on 4 January 1999 from 1100 to 1355 with calm, sunny and warm conditions. No owls were observed onsite during any of the protocol visits. The burrovvs were observable from vantage points on the property and the excrement was observed with binoculars. The two burrows are located on the slopes within the Hidden Valley drainage and are approximately 600 and 1200 feet north of Palomar Airport Road. The locations of the burrows have been mapped on a 1" = 300' aerial photograph of the site. Although the burrowing owl was not observed onsite during the protocol winter survey, it was observed in November and owl burrows were identified from signs of occupation which included excrement, owl pellets, and prey remains. According to the burrowing owl survey protocol, occupancy of suitable burrowing owl habitat can be verified at a site by an observation of at least one burrowing owl or owl signs at or near a burrow entrance. The protocol states that a site should be assumed occupied if at least one burrowing owl has been observed occupying a burrow within the last three years due to their high site fidelity. The current winter survey was conducted to determine the number and pattern of distribution of owls onsite. Based on the observation of one burrowing l& ASSOCIATES, INC. 2093-01 January,?, 1999 Mr. John Cahill, City of Carlsbad Re: Carlsbad Golf Course Burrowing Owl Survey owl on two occasions in November and the identification of two burrows within the same drainage, approximately 600 feet apart, it is concluded that one owl or one pair of owls is present onsite. The proposed site design may impact one of the burrowing owl burrows. It is recommended that the impact to the burrow be mitigated by passive relocation which is defined as encouraging the owl to move from an occupied burrow to an alternate natural or artificial burrow at least 50 meters from the impacted area. Within the Hidden Valley Road drainage, numerous ground squirrel burrows are present for potential occupation of a burrowing owl. Owls should be excluded from the impacted burrow for approximately one week prior to grading. The burrow should then be excavated using hand tools and refilled to prevent re-occupatioii. Please feel free to call me at (760) 942-5147 if you have any questions regarding the contents of this letter. Very truly yours, DUDEK & ASSOCIATES, INC. Anita M. Hayworth, Ph.D. Biologist V cc: Howie Wier, DUDEK Brock Ortega, DUDEK & ASSOCIATES, INC. 2093-01 January 7,1999