Olive Drive Subdivision Project -- Biological Resources Report by BayAreaNewsGroup


									11 March 2013

Frank M. Abejo
Senior Planner
City of Concord, Planning Division
1950 Parkside Drive
Concord, CA 94519

Subject: Olive Drive Subdivision Project – Biological Resources Report Peer Review (HTH

Dear Mr. Abejo:

Per your request, H. T. Harvey & Associates has conducted a peer review of the biological
resources report prepared by the biologist for the applicant of the proposed Olive Drive
Subdivision Project (Project) in the City of Concord, California. It is our understanding that the
proposed Project consists of the development of six residential lots on a 1.37-acre parcel at the
southeast corner of Olive Drive and Gyger Court in Concord, California. The applicant hired
Moore Biological Consultants (Moore) to prepare a biological resources assessment for the
Project; the City has asked that we review Moore’s report and conduct an independent biological
review of the Project. This letter documents the findings of our peer review, describing our
methods, our general assessment of the accuracy of Moore’s report, an assessment of any
evidence that barn owls (Tyto alba) are nesting or have recently nested in a windmill on the site,
and our recommendations.


Prior to conducting a site visit, I reviewed the 8 February 2013 biological assessment report
prepared by Moore. I reviewed the California Natural Diversity Database (CNDDB) for records
of special-status species in the vicinity of the property, and aerial photographs to determine
general habitat conditions on and in the vicinity of the site. I also reviewed a list of wildlife that
had been reported to the City as occurring on the Project site by a neighbor. I was already
familiar with the biological resources in this region of Concord, having served as H. T. Harvey &
Associates’ principal-in-charge for the preparation of the biological resources chapter for the
Concord Community Reuse Project Environmental Impact Report in 2009, and for ongoing
permitting and endangered species consultation support for that Project.

On 5 March 2013, I visited the site. From 11:00 a.m. to 12:30 p.m., I thoroughly inspected the
entire site to assess its existing biological resources, potential for occurrence of special-status
plant and animal species, and regulated habitats such as wetlands. I inspected the existing
residence (now unoccupied) and all out-buildings for evidence of nesting birds and roosting bats,
using a ladder to access any platforms above eye level that could potentially have served as
nesting sites. I climbed the windmill to inspect the platform below the top of the windmill for
evidence of use by barn owls. At the request of the City and applicant, I also conducted a

     983 University Avenue, Building D Los Gatos, CA 95032 Ph: 408.458.3200 F: 408.458.3210
Olive Drive Subdivision Bio Resources Report
11 March 2013
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thorough inspection for evidence of active bird nests (i.e., nests with eggs or young) in shrubs
and trees, the main house, and outbuildings.

General Findings and Assessment of Moore Report

In my opinion, the biological resources report prepared by Moore was accurate and sufficiently
thorough to adequately characterize the existing biological resources on the site and the potential
impacts to these resources. The descriptions of existing vegetation on the Project site in Moore’s
report were accurate. I concur that there is no evidence of wetlands or other sensitive or
regulated habitats on the Project site, as I observed no hydrophytic (i.e., wetland-associated)
plants, evidence of wetland hydrology or any sources of such hydrology, or other evidence of the
presence of wetlands. I do not expect special-status plants to occur on the Project site due to its
dominance by non-native ornamental and ruderal vegetation and long history of disturbance.

Special-status animals that occur in the Concord area are not expected to occur on the site due to
the absence of suitable habitat, the suburban/residential context of the site (which would impede
dispersal to the site), and the absence of source populations in nearby areas. For example, the
California red-legged frog (Rana draytonii) and California tiger salamander (Ambystoma
californiense), which are known to occur on the Concord Community Reuse Project site to the
north, are not expected to occur on the Project site. It is possible that the white-tailed kite
(Elanus caeruleus, a state fully protected species) could occasionally occur on the site (perching
in trees on the site, and possibly foraging on occasion). However, such occurrence would be
infrequent at best, and there were no nests (active or old) on or near the site suggesting that
white-tailed kites have nested on the site. I noted that the neighbor’s bird list included
observations of two special-status species, the loggerhead shrike (Lanius ludovicianus, a
California species of special concern) and white-tailed kite. While it is possible that these
species had been observed on the site, they would be very infrequent visitors due to the absence
of sufficiently extensive open grassy or ruderal habitat to support these species. The neighbors’
bird list also includes two species (black catbird [Melanoptila glabrirostris] and five-striped
sparrow [Amphispiza quinquestriata]) that have never been recorded in California
(http://www.californiabirds.org/ca_list.asp) and one species group (“rosy finch”) that has never
been recorded in the San Francisco Bay area.

Thorough inspection of the home and all outbuildings on the site revealed no evidence of
roosting bats, and the trees on the site did not support large cavities or crevices that could serve
as roosting sites for bat colonies.

Moore’s report discussed reasons why the burrowing owl (Athene cunicularia, a California
species of special concern) is unlikely to occur on the site but suggested the possibility that the
species could occur if California ground squirrels (Otospermophilus beecheyi), which typically
excavate the burrows that are used by burrowing owls in the Bay Area, were to occupy the site.
However, like Moore, I observed no ground squirrel burrows or other refugia for burrowing owls
on the Project site. Burrowing owls are unlikely to occur, even as occasional visitors, on a site
possessing so little open grassy habitat in such close proximity to so many trees and buildings.
As a result, I would consider the burrowing owl to be absent from the site, though as a

                                                             H. T. HARVEY & ASSOCIATES
Olive Drive Subdivision Bio Resources Report
11 March 2013
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precautionary measure, the burrowing owl pre-construction surveys proposed by Moore could be
performed to ensure against any possibility of impacts to the species.

In conclusion, I concur that no wetlands or other sensitive or regulated habitats, and no special-
status plants, occur on the Project site. If any special-status animals occur on the site, they would
be limited to occasional visits by birds such as the white-tailed kite. Thus, loss and modification
of habitat on the site will not result in substantial effects on any special-status species, and the
Project would affect only regionally common, widespread habitat types and associated species.
Because these biological resources are regionally common, and the Project site supports such a
small proportion of regional occurrences of these resources (due to its small size and highly
modified habitat), it is my opinion that impacts to these habitats and species would be less than
significant under the California Environmental Quality Act (CEQA).

Barn Owls and Other Nesting Birds

It is our understanding that neighbors had reported that barn owls had used a wooden platform
approximately halfway up the windmill for years. As a result, I climbed the windmill to inspect
the platform (Photos 1 and 2). The platform supported the remains of numerous owl pellets
(indigestible prey remains regurgitated by owls) and droppings (Photo 2). Organic material on
this platform was approximately 6 inches deep, and much of this may have resulted from barn
owl pellets and droppings, suggesting years or even decades of use of this platform by barn owls.
Moore’s report described this platform as being partially enclosed by vertical boards during a 30
January 2013 site visit and included a photograph of the enclosed platform. Such enclosure
would have provided suitable cover for barn owls, and given the depth of pellets, as well as old
bones and hair from pellets, on the platform, it is my opinion that barn owls likely nested on this
platform for years.

Moore’s report recommended that the platform be inspected for nesting activity prior to removal
of the vertical boards. Because there was some question (again, by neighbors) regarding whether
owls were actively nesting when the vertical boards were recently removed, I looked for
evidence that an active nest had been present recently. Several fresh pellets on the platform, and
one on the ground below, suggested owl use of the platform within the previous weeks or
months; a pellet on the ground below the windmill had likely been deposited since the heavy
rains in December since it was still well consolidated (heavy rains would have disintegrated the
pellet into unconsolidated hair and bones). Because barn owls frequently roost year-round in
their nest sites due to the concealment provided by such sites, these fresh pellets could have been
regurgitated by roosting owls (i.e., the presence of fresh pellets did not indicate that the owls had
begun nesting yet this year). I observed no eggshells or remains of young barn owls. If any eggs
or young had been present, they could have been depredated or scavenged prior to my visit.
Therefore, I can neither refute nor confirm that an active nest was present when the boards were
removed; I can only say that barn owls have used the platform for some purpose (e.g., for
roosting) relatively recently and that no evidence of a recently active nest (such as eggs,
eggshells, or remains of young) were present during my visit. In the absence of the protective
cover (from the elements and avian predators) provided by the vertical boards, the windmill
platform no longer provides a suitable nesting site in its current condition.

                                                              H. T. HARVEY & ASSOCIATES
Olive Drive Subdivision Bio Resources Report
11 March 2013
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Photo 1. Windmill with round wooden platform.

Photo 2. View of the platform on the windmill, showing pellets and numerous bones of
barn owl prey from decomposed pellets.

                                                   H. T. HARVEY & ASSOCIATES
Olive Drive Subdivision Bio Resources Report
11 March 2013
Page 5 of 7

My thorough inspection of the site revealed no active nests of other birds on or immediately
adjacent to the site. Several incomplete (likely old, rather than recently begun) nests suitably
sized for California towhees (Melozone crissalis) and western scrub-jays (Aphelocoma
californica) were observed, but they did not contain any eggs or young. As a result, weed
abatement and pruning activities that the applicant was proposing to perform on 5 March would
not have impacted any nesting birds.

Although no special-status birds are expected to nest on the Project site, all native birds that
occur there are protected by the Migratory Bird Treaty Act and California Fish and Game Code.
As discussed above, it is my opinion that Project impacts to these birds would be less than
significant under CEQA, but physical destruction of a nest containing eggs or young would
violate both of these laws, and disturbance that results in the abandonment of eggs or young by
adults would be considered a violation of the California Fish and Game Code by the California
Department of Fish and Wildlife. Because nesting activity by the common birds that may nest
on the site is likely to increase through the spring, with some birds possibly continuing to nest
through August, we recommend that the applicant have a pre-activity survey conducted by a
qualified biologist just prior to any further demolition or construction that occurs during the
breeding season (roughly, 1 February to 31 August). If any active nests are detected, we would
recommend that appropriate buffers (typically 50-100 feet for non-raptors and 300 feet for
raptors, or as otherwise determined by a qualified biologist) remain free of any new Project-
related disturbance until young have fledged from the nest.

In addition, I would recommend that the applicant close the doors and board up any openings in
the existing home and outbuildings (after double-checking that no birds are inside) to prevent
birds from initiating nests in these structures prior to their demolition.

Please feel free to contact me at (408) 722-0931 or srottenborn@harveyecology.com with any
questions you may have regarding our assessment. Thank you very much for contacting H. T.
Harvey & Associates regarding this Project.


Stephen C. Rottenborn, Ph.D.
Principal – Wildlife Ecologist

                                                           H. T. HARVEY & ASSOCIATES

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