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HomeMy WebLinkAbout3184; CANNON ROAD WEST; LIGHT-FOOTED CLAPPER RAIL ISSUES; 1999-09-20I S Li 09/20/99 MON 10:00 FAX 619 560 5465 3)(34 , 002 !EEE\ Merkel &, Associates, In c. 3944 Murphy Canyon Road Suite 006 • San Diego CA 92123 Ph (619) 560 5465 • Fax (619)-560o7779.- E-mail Merkel1ncaol corn September 20,-.1999 II Ms Julie Vandeweir U. S. Fish and Wildlife Service -'Carlsbad Fish and Wildlife Office . . . . .. . . . 2730 Loker. Avenue West Carlsbad, California 92008 Re Light-footed Clapper Rail Issues at the Cannon Road / Kelly Ranch Site Dear Julie, The following Letter is a summary, of observations and relevant information on the light-footed clapper rail as it relates to proposed construction activities at the Cannon Road/Kelly Ranch site in Carlsbad Based on a review of the information available regarding the clapper rail occurrence and the project construction activities, we believe that the proposed continuation of construction of Cannon Road, as designed and proposed for implementation, would not result in:a significant adverse effect on this species The following portions of this letter summarize what is known about clapper rail bolcigy and occurrence within Agua Hedionda Lagoon, as well as the pertinent elements we believe support our best professional judgement on this issue CLAPPER RAIL BACKGROUND INFORMATION Biology The light-footed clapper rail (Rallus longirostris levipes) is predominantly it. resident of coastal salt marshes in southern California and Baja California Norte It is the only clapper rail in southern California Historically, the range of the light-footed clapper rail extended from Carpinteria Marsh in Santa Barbara County, California, south to San Quentin, Baja California Norte Many marshes, including the Carpinteria Marsh, have ceased to suppo rail populations, and the species' current distribution is restricted to small, isolated sub-population . s (Zembal 1992) The spnng counts in'! 997 revealed 307 pairs of rails in 16 marshes in California Of this total, 49'.5% were in one marsh, Upper Newport Bay, Orange County, California (Zembal, unpublished data, 1997) In San Diego County, Tijuaria Marsh National Wildlife Refuge has usually had the greatest numbers of mated pairs since censuses began in 1980 (Zembal and Massey 1988) The light-footed clapper rail has been listed as an endangered subspecies since 1973 Its population decline is mostly due to a dramatic loss of coastal wetland habitat in southern California over the last few decades Of an estimated 26,000 acres of coastal wetlands once present in southern California, fewer than 8,500 acres remains (Speth 1971, from Zembal 1992) Recently, rails have been found in less than half othis potential, habitat.. Marshes that are occupied by rails generally ha low population densities (Zembal 192) The defining feature of good clapper rail habitat Is the presence of dense cord grass (Spartinafoliosa) (Unitt 1984) This salt-tolerant grass grows 60-150 cm tall, in salt marshes, mudflats and along shorelines This cordgrass is tolerant of regular saltwater inundation, and occurs most often below Biological Consulting • Environmental Permitting • Habitat Restoration • Ecological Management (A 09/20/99 MON 10:01 FAX 619 560 5465 (it 003 Light-footed'Clapper Rail Issues at cannon Road/Kelly Ranch Site September 20,1999 the mean higher high water line (Merkel 1997).. Rails observed in- the Tijuana Marsh spent most'of their time in lower salt marsh habitat, particularly in cordgrass if it was available When water covered the tower marsh, rails foraged on higher ground in low to mid-marsh habitats of pickleweed Salicorniá virginica, saitwort, (Batis maritima), and jaumea Vaumea' carnosal, and on floating mats of reeds.: Reed,patches including cattails and buliush,were also extensively used for roosting and sunning during high tides. When' these were not available, most rails roosted in the upland fringe of the marsh during the highest.tides (Zembal et. a!: 1989).. .. . ' Rails nest preferentially in•• cordgrass in 'the lower salt marsh. Where or when cordgrass is not available, the birds still nest preferentially in low marsh, using tide-deposited materials as nesting cover. Nests"are also built in -common pickleweed and other upper salt marsh plants on hummocks of high ground 'surrounded. by low marsh (Massey et.. a!'. 1984). Clapper rails are also 'observçdin' freshwater and brackish marsh habitat. 'Examples of freshwater marsh known to support clapper rails include the lower Sweetwiter. River (just east'of south San Diego Bay), at GuajOme Regional Park. as well 'as a clapper rail pair consistently, found at Agua Hedionda,- at a 'location to the northwest (along Park Drive) and well, distanced from the construction activities of Cannon Road. In these instances where clapper rails are known to occupy dense (cattail/bulrush) freshwater marsh, these habitats are typically quite extensive. " ' •,' ' ' . ,'.' S . , .,,,, , . Uritt' (1984) reports egg dates from March 6 to May 23; hOwever, Jorgenson obseved active-pests with eggs as late as July 15 in the Tijuana River estuary (in Unitt 1984) Zeiner et a! (1990) report thatciappér rails in San,Francisco ,Bay breed from mid-March through July, with peaks observed in early May and late June.. Incubation* is reported 'tO be 20-23 'days in Ehrlich et a! (1988) and from 18- 29 days in Zeiner et a! (1990)..Hatchlrng rails are covered in black down and are able to follow along after the adults in the marsh within a 'few hours' Of hathing. The young rails are dependent on the adults for several weeks and are still being fed occasionally up to at least 6 weeks of age (Zembal 1989). Inter-marsh movements by adult rails are rare. Within-marsh movements are small., usually of, no greater distance than 400 m. Mature rails with established 'territories have very small home ranges. Two banded adults, one male and one female, were observed no more than 70 in from their capture site over a period of a year and a half. This female's home range was approximatOly 0.5 hi (1.2 acres), and she maintained this home range with three different 'mates Young rails trayel larger distances, sometimes- leaving the marsh'of their birth when chased away by mature,. established 'rails, The longest movements by immature rails are 'in late' summer and fall, and 'the longest 'of these ever recorded 'was 21.7' km. However, if there is room, 'there is a strong. tendency for young rails to establish home ranges near their natal territories, and to'remain.there once.established (Zembal 'etal. 1989; Zembal and Massey 1988). clapper Rail Status at Agua Hedionda Lagoon ' ' .' ' .• . ' One pair of light-footed clapper rail's occupied the cattail marsh east of the open water of the lagoon in 1997 (Zembal '1997, unpublished data). Since censusing of rail' p9pulations began in 1980, the Agua Hedionda Lagoon rail population peaked at 7 pairs in'1983, but- dropped off to 'zero pairs in the late 1980s and early 1990s (Zembal 1992, Zembal etal. 1.996). The reoccupation' of this marsh by one pair may 'result in the re-expansion of this subpopulatiOn; The Agua Hedionda raila were detected in the cattail 'marsh, which currently covers 24, acres' in' the area 'east of the 'lagoon.. Assuming the home ranges reported by Zembal (1989) to be comparablefor the habitat available within Agua' Hedionda Lagoon, and an equal suitability of 'all cat-tail habitat at the lagOon,, an :. M&A #99-064-01 • ' ' ' • ' • . . . . • 2 09/20/99 MON 10:02 FAX 619 560 5465 , . Li 004 Light-footed Clapper Rail Issues at Cannon Road/Kelly Ranch Site. . S September'20, 1999 estimated carrying capacity of the, system would be approximateLy 20 pairs of rails. This capacity has not ever been approached' in the 17 years of monitoring this species.. The highest reported 'density 'for Agua HediOnda Lagoon was during' 1983 and 1984.when 7 and 6 pairs, respectively, were recorded. While it is not believed-that the cattail marsh'within Agua HediOnda LagOon serves as optimal nesting habitat,' this assessment would suggest that available cattail marsh habitat is not presently. limiting rail populations in this system. The single pair of light-footed clapper rails (Rallus longirostri.s levipe.$) present within the lagoon during the 1997 survey (Zèrnbal, unpublished data) occupies 'cattail'habitát located at the' ouffall of an urban drain on the north side of .the lagoon. Whi1e recent pros surveys have not, detected' pair.s in Agua Hedionda Lagoon Since 1985, clapper rails' were present 'at, this location' during the late 198OS' and early 1990s and were' detected intermittently from approximately 1988 through 1992 (K; Merkel, pers. obs;). 1999 Clapper Rail Status At Cannon Road Habitat occupied by light-footed clapper rails at the Cannon Road site consists of dense freshwater marsh comprised of cattails (Typha spp.) and bulrush (Scirpi&s spp.). Habitat quality may. be somewhat reduced by its particularly narrow configuration supported in part by an artificial berm on the south side of the drainage On the north side, the marsh habitat is bordered by high quality willow riparian woodland To the south, it is flanked by disturbed, ruderal fields and non-native grasslands. Light-footed clapper rails have had an inconsistent record of occurrence, or at least detection, at the Cannon Road location. The -species- was initially identified in May 1999. Several 'sightings and/or vocalizations were recorded over the* course of the next several weeks. The clapper rail, was then -not detected for 2-3 months, until it was again sighted on August 21,1999. It has not been detected since the August21 date. During recent surveys'and a prior survey' in this area by M&A biologist, David. Mayer, a Virginia rail (Rallus.lirnicola'limicolq was identified in the same location as 'that where the clapper rail has been' previously. identified. The Virginia rail, which emerged from the vegetation, was noted. by Leo Todd, Shea Homes, constuction representative, tube significantly smaller than the rail 'which has been observed in this area in the past. Furthermore, clapper rails were clearly detected by qualified biologists earlier in the season (.LFancher, USFWS',.pers. comm.). The breeding status of the detected rail is uncertain. No more than one rail has been detected. at any given time, 'and there have been no recorded incidence of courtship vocalizations throughout 1999, (i.e., 'duet calls'); hOwever, the aggressive behavior observed in* May 1999, during which periods, a, rail emerged from'the vegetation in response to calls, was believed to be indicative of potential nesting (Doug Gettiriger, 'Ogden, personal. communication). 'Conversely, although rails would. be expected to be less vocal, during periods of incubatiOn, the comp1ete'.absnce of detection between late June through August seems unusual if a pair was in fact,resident at -this 'location. Additionally, there were no 'observations of adult rails being followed by 'either young fledglings or dependent 'juveniles at any period during the past several months. ' '. . • : ' No nest searches were made of the cattail marsh in which a rail has been observed. While this can be done in some habitats, searching for a nçst in dense freshwater marsh vegetation would be' difficult and destructive to this limited habitat. Moreover, because of the low potential for observing .a nest and high' potential for an adverse impact in the event that. an active nest occurs, such a nest search is not advisable. ' ' S ' 'S • ' , • • • S ' ' ' M&4 999-064-01 ' ,, ' ', S. • • , , , ' ' S ' ' ' 3' 11 09/20/99 MON 10:03 FAX 619 560 5465 005 Light-footed Clapper Rail issues at Cannon Road / Kelly Ranch Site ', '.September 20, 1999 While, it is not possible to determine with certainty whether a breeding pair exists at this site, or whether nesting was performed during 1999;. it is likely that either no nest was ever constructed and the bird was an individual attempting to establish a territory and attract a mate, or a nest was established and failed and renesting was not attempted Either of these circumstances could explain the intermittent survey findings and long period of non-detectkin. Based on conversations regarding the circumstances at this site, Jack Fancher has suggested that it would not be surprising to make intermittent observations of an individual at this site if regular censusing was performed. He'pqints out that the narrow fringing marsh serves .as a connector that links habitats' in this extensive wetland. The area in which the rail has been observed is an ideal travel corridor, albeit not ideal breeding habitat. PROJECT CONSTRUCTION STATUS '1 ''. ': •. . . At present, no additional direct impact is' 'expected to 'occur to marsh 'habitat at thó location of the previous clapper rail sightings. 'The remaining construction activities to' be completed in proximity to the locatiOn in which the rail was observed involve sewer and roadway improvements located approximately 50 feet, or greater frOm the, edge of the marsh. No direct impacts, 'are anticipaied to wetlands in this vicinity. 0 '' DIscussioN. The primary issue of concern' is that of a potential for..indirect effects in the form of noise and proximity disturbance on breeding activities of clapper rails. The clapper rail's inconsistent detection in the late spring and- summer is puzzling. While. the aggressive behavior exhibited 'by,a bird earlier in the year maybe indicative 'of breeding, there have' not been any. indications of two birds being present and the limited late season occurrences have not been suggçstive of breeding activities.' In light of the very narrow nature of the freshwater marsh, the habitat is believed to be of relatively' marginal suitability :for nesting by' this species; however, it is reasonable to expect 'that any clapper. 'rails that occur at the 'lagoon, even on a temporary basis (including periods of dispersal), 'would occasionally utilize the habitat at the Cannon Road site. The potential for clapper rails to be incubating'a: nest, at this time (late-September).is believed to. be very low.. Even assuming' the latest recorded egg dates were early in the incubation period, any nesting activity would. be expected to, be completed' by early. September. While an active nest would be very unexpected, it is possible that any adult rails, if pTesent, could still be caring for dependent young. However, clapper rail young are extremely precocious and may follow adults within ,a few hours' of hatching 'While. observations in,other systems indicate that 'adults. may" feed dependent young for .at least six weeks, ,the 'young are mobile and follow the adults through the marshes. and may move to alternative day nests away from the natal' nesta. Noise .and diturbance are known to adversely affect some species' breeding behavior by causing site' abandonment. There is also some si:ggestion that.noise may adversely impact some communication' between birds or 'impact a bird's ability to detect predators' or prey. However, there are no relevant observations or published literature identified for this species, thus a definitive statement regarding the clapper' rail's relative tolerance or intolerance to noise is not possible. "However, assuming observations from other species' are applicable, 'it has been noted that noise impacts are much more likely to be, detrimental in the 'initial stages of breeding, such as territory' establishment, nest, construction, or immediately following egg' laying. Adult birds are much less likely .to abandon nestlings or dependent flOdges when significant investment has been made in the offspring.. . In addition, the opportunity 'to relocate with young further reduces the potential for adverse noise M&A 99-064-01 ' . . . . , . 4. 09/20/99 MON 10:04 FAX 619 560 5465 Ej 006 a Light-footed Clapper Rail Issues.at Cannon Road/ Kelly Ranch Site . September 20. 1999 impacts in the event that a pair of rails does occur adjacent to Cannon Road and did successfully nest in. 1999, and. still, maintains dependent young. . . . . . . . . . . . . CONCLUSIONS . .. '. . . . .. . . . :.. . : If a take were to occur to clapper rails as. a' result of continuing construction of Cannon Road at the present time, the w take ould be in the form of "harassment". Under the Endangered Species Act, harass means an.-intentional or negligent act or-omission which creates the likelihood of injury .to wildlife by annoying It to such an extent as to significantly disrupt normal behavior patterns which include, but are not limited to, breeding, feeding, or sheltering (50CFR 17.3). In..the current circumstances, the principal concern is that construction in areas near • clapper rail habitat and associated noise and activities may harass clapper rails to the extent that significant disruption of normal breeding behavior occurs. . . . . . . . . . . . . . . Despite relatively frequent observations, of the habitat being made by a qualified biological.observer,. it is still unknown if: 1) apair of rails exists at the subject site; 2)if a pair does exist, that breeding activities were ever initiated, 3) if breeding activities were successful in hatching eggs and if hatching occurred at the latest possible time of the breeding season, 4) if viable young were produced and 'Continue-to persist under the dependence of adult birds, 5) if adults and young remain at or near the natal nest; and 6) if noise at late stages of breeding,.-.or any stage. of breeding. activity, has an. adverse effect on clapper rails For harassment under the ESA to occur, all of these outstanding questions must be answered affirmatively Absent any supporting evidence that a pair of birds exists or that y outig 'Were produced, there is. little to support a reasoned determination that nesting activities occur at: the Cannon Road site at the present time, 'although one cannot rule-Out the potential that. early nesting did occur. As a result, it is out judgement that the proposed construction at this time would not result in a significant adverse affect on the clapper rail Please review this letter. and let me know what your thoughts are on the subjecL I understand that the City and developer for Cannon 'Road 'are anxious to completethe work as soon as possible to avoid significant prOblems during the rainy season. If you have .an' additional'.questions regarding-'this letter, please call ma. ' 1•1 Cc Jack Fancher, USFWS Sherri Howard, City of Carlsbad Russ Haley,' Shea Homes Greg Poñce, Shea Homes Dale Greenhaigh, Consultant to 'Shea Homes AI&A #99-064-01 . .' . ' : ' ' . . . . . ., 5 09/20/99 MON 10:04 FAX 619 560 5465 0007 Light-footed Clapper Rail Issues at Cannon Road / Kelly.Ranch Site September 20, 1999 .. LITERATURE CITED Ehrlich, P.R.; D.S. Dbbkin, and D. Wheye. 1988. A Field Guide to the Naturüi History of North American Birds.. Simon and Schuster, Inc. ... Massey et a! 1984 Referenced in letter to Keith Takata Merkel, K. 1997. Predicted Habitat Effects of Tidal Prism Enhancement Within the Inner Agua Hedionda Lagoon.. Speth, J.W. .1971:. The status.of coastal wetlands in southern California. Cal-Neva Wildlife, Western Section Wildlife Society Transactions: 51-59. • . . Unitt, P 1984 The Birds of San Diego County. San Diego Society of Natural History, Memoir 13 276 pp Zerner, D C, W F Laudenslayer, K E Mayer, and M White, 1990 California's Wildlife, Volume Birds California Department of Fish & Game November 1990 Zembal, R 1989 Referenced in letter to Keith Takata Zembat, R 1992 Status and management of light-footed clapper rails in coastal southern California. . Transactions-of the Western Section of the. Wildlife S66ety28:1-5. .. .• . :•;, . Zembal R and B W Massey. 1988 Light-footed clapper rail census and study 1988 UnpubLshed Report. Zembal, R, B W Massey, and J. M Fancher. 1989 Movements and activity patterns of the light- footid clapper rail. Journal of Wildlife Management 53(1);3942. 0 •• .AI&A #99-064-01 •. . 0 • 0 • 0 0• • • • 0 :0 •. • . • 6