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Wildlife experts argue against the plan to destroy the Corte Madera Inn pond habitat
John P. Kelly, PhD, and Scott Jennings, two of the foremost experts on Black-crowned Night Herons in California, have submitted the following comment to the Town of Corte Madera, arguing against their pending approval of a plan to destroy the pond and the roosting habitat at the Corte Madera Inn. To date, the Town planners have continued to assist and align themselves with the developer, who has refused for over two years to even consider any reasonable alternatives to their plans.
Adam Wolff, Director of Planning
Town of Corte Madera Company
300 Tamalpais Drive Corte Madera, CA 94925
RE: Recirculated Draft EIR for the Corte Madera Inn Rebuild Project
Dear Mr. Wolff,
ACR [Audubon Canyon Ranch] owns and manages a system of wildlife sanctuaries in Marin and Sonoma counties. Since the early 1970's, we have conducted scientific research to help ensure the long-term protection of San Francisco Bay area wetlands. We have published numerous scientific articles on the ecology and conservation of herons and egrets (www.egret.org/scientific_contributions ), including an annotated atlas of heron and egret nesting colonies in the San Francisco Bay area (Kelly et al. 2006; www.egret.org/atlas ).
As noted in the RDEIR, the proposed development of the Best Western Corte Madera Inn would eliminate the Black-crowned Night-Heron roost site and the associated pond habitat. ACR is concerned that the proposed development would reduce the regional availability of suitable habitat needed to sustain the number of Black-crowned Night-Herons that occupy central San Francisco Bay. The night-herons are a resident, colonially nesting species that depends on the protection of remnant wetlands and roost sites near the Bay shoreline such as the area considered in this proposal. We offer the following responses to the RDEIR.
- Wetland habitat in the San Francisco Bay Area is regionally and globally important for several species of wading birds, including Black-crowned Night-Herons (Mikuska et al. 1998, Kelly et al. 2007).
- Ensuring the presence of top wetland predators such as Black-crowned Night-Herons is likely to be important in sustaining healthy wetlands (Vander Zanden et al. 2006), and numerous scientific investigators have demonstrated that Black-crowned Night-Herons qualify as indicators of healthy wetlands (e.g., Hothem et al. 2010).
- The number of Black-crowned Night-Herons in the central and northern San Francisco Bay area has been in a significant long-term decline since 2001 (Kelly and Robinson-Nilson 2011, Condeso 2013; ACR, unpublished data).
- Communal roost sites such as the night-heron roost in the proposed development site provide important functional benefits related to vital rates of adult and juvenile annual survival. These benefits, which include energetically efficient access to nearby feeding areas, enhanced foraging
- efficiency, thermoregulatory benefits, and reduction of predation risk can be critical in sustaining regional populations (Beauchamp 1999).
- The statement in the RDEIR (Impact BIO-4 on page 4.3-29) that elimination of the roost site “would not contribute to a significant cumulative impact on the black-crowned night heron populations,” is made without scientific justification. Similarly, the implication that ornamental landscape trees in the area—even if not near ponds or estuaries—would provide viable alternative sites for roosting is made without supporting evidence. In contrast, heron specialists Kushlan and Hancock (2005) have indicated that roost sites are particularly important habitat features for night-herons, and they have further specified that, although roosts are often established in human environments, essential habitat conditions for roost sites include adequately dense roosting cover near fresh, brackish or saltwater feeding areas. Therefore, the conclusion that removing the night-heron roost would have no impact on the number of night herons in the area is unsubstantiated.
- Elimination of the roost site and pond would impose cumulative impacts on night-herons in the surrounding region by contributing to the incremental loss of habitat and reducing the availability of suitable roost sites. The assertion in the RDEIR (Impact BIO-4 on page 4.3-29) that, if the roost site is destroyed, the birds would simply “disperse to other locations during construction and, when the trees are removed, would roost in alternative locations” is highly speculative and fails to consider impacts of incremental habitat loss and the importance of roost site quality and location. Scientific work on Black-crowned Night-Herons provides evidence that they depend on finding particular roost-site conditions among multiple alternatives within their foraging range to facilitate annual and intraseasonal adjustments in roosting behavior (Perlmutter 1992). Such conditions include changes temperature, wind, predation risk, disturbance, and increasing water levels associated local flooding and sea level rise. In addition, considerable scientific evidence suggests that roost sites near important feeding areas provides herons with important energy benefits (Beauchamp 1999).
We urge you require full protection of the valuable wetland habitat and pond area used by Black-crowned Night-Herons behind the Corte Madera Inn. Thank you for considering this comment.
Sincerely,John P. Kelly, PhD - Director of Conservation Science
Scott Jennings - Avian Ecologist
References cited
Beauchamp, G., 1999. The evolution of communal roosting in birds: origin and secondary losses. Behavioral Ecology 10:675-687.
Condeso, E. 2013. Life on the edge: The status of Black-crowned Night-Herons in the northern San Francisco Bay area. Audubon Canyon Ranch. The Ardeid 2013:4-5. [http://www.egret.org/ardeid ]
Hothem, R. L., B. E. Brussee, and W. E. Davis, Jr. 2010. Black-crowned Night-Heron (Nycticorax nycticorax), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology. [http://bna.birds.cornell.edu.bnaproxy.birds.cornell.edu/bna/species/074]
Kelly, J.P., Etienne, Katie, Strong, Cheryl, McCaustland, Mark and Parkes, M.L., 2006. Annotated atlas and implications for the conservation of heron and egret nesting colonies in the San Francisco Bay area. Audubon Canyon Ranch, Stinson Beach, CA, 94940.
Kelly, J. P., K. L. Etienne, C. Strong, M. McCaustland, and M. L. Parkes. 2007. Status, trends, and implications for the conservation of heron and egret nesting colonies in the San Francisco Bay area. Waterbirds 30: 455-478.
Kelly, J. P, and C. Robinson-Nilson. 2011. Tidal marsh herons and egrets. Pages 14-15 in M. Pitkin and J. Wood (eds.), The State of the Birds, San Francisco Bay. PRBO Conservation Science and the San Francisco Bay Joint Venture.
Kushlan, J. A., and J. A. Hancock. 2005. The Herons. Oxford University Press, New York.
Mikuska, T., Kushlan, J.A. and Hartley, S., 1998. Key areas for wintering North American herons. Colonial Waterbirds, pp.125-134.
Perlmutter, G. B. 1992. Environmental factors influencing roost arrival of Black-crowned Night-Herons J. Field Ornithology 63:462-465.
Vander Zanden, M .J., J.D. Olden, and C. Gratton. 2006. Food-web approaches in restoration ecology. Pp. 165-189, in D.A. Falk, M.A. Palmer, and J.B. Zedler (eds.) Foundations of Restoration Ecology. Island Press, Washington, D.C.