San Diego Shorebird Survey Tijuana River Survey Areas

Transcription

1 San Diego Shorebird Survey Tijuana River Survey Areas Legend Survey Area North McCoy South McCoy Helicopter Airfield North River Mouth- Beach North River Mouth-Marsh South River Mouth- Marsh South River Mouth- Beach µ ,000 Meters

2 Shorebird Survey Protocol and Site Description The Tijuana River estuary is a tidal river mouth and marsh in southern San Diego County just north of the U.S. Mexico border. Because this site is a mile or two south of San Diego Bay, it is likely that there is some interchange of birds between the smaller river estuary and the larger bay. For that reason, it would be preferable to schedule surveys of the river estuary at the same tidal cycle on the same day as surveys of San Diego Bay. NUMBER OF SURVEY TEAMS To survey this site adequately requires 2-3 teams: one to survey the north side of the estuary and adjacent beach, one to survey the south side of the estuary and beach, and another to cover some ponds and the upper reaches of sloughs on the east side of the marsh on the north side of the estuary. If a third team is not available, the ponds and upper sloughs could be surveyed by one of the two estuarine teams after they have completed the survey of their area. Teams should include 1-2 counters, with the largest numbers of shorebirds likely to be counted by Team 1, fewer by Team 2, and the least by Team 3. COORDINATION Regardless of whether 2 or 3 teams are used, it is important to coordinate the teams to ensure the most accurate count and to minimize over- or undercounting, particularly with respect to bird movement over the course of the survey. All teams should start at the same predetermined time and they should allow time to drive and/or walk to their starting location. The two teams covering the beach and outer estuarine sections, will need to walk out to the mouth of the river, one team starting from the north the other from the south. The areas to park a car on each end are about mi from the mouth of the estuary, so allow at least minutes to walk out to the river, where both teams will begin counting at the same time. Teams should be in contact by cell phone to coordinate when to start counting when both teams have reached the river mouth and are set to go. Team 2, coming from the south, should talk to staff at the estuarine reserve office prior to the survey date to enquire of current conditions on roads within Border Field State Park, which when wet requires a 4-wheel drive vehicle and/or parking well short of the beach. If the latter is the case, additional walking time will be needed to ensure reaching the river mouth at the designated time. If a third team is available, they should get to their starting location (see below) at about the same time as the other teams reach the river mouth; then all three teams should start counting at the same time. If only two teams are available, one of them, as noted above, should count the ponds and upper sloughs after completing their primary area. Developed December 2011

3 ACCESS AND SURVEY ROUTES BY TEAM Team 1, north side of estuary Access: From north (San Diego), take I-5 south to Imperial Beach and turn off on Exit 4 for Coronado Ave. (not Coronado Bridge) and head west; Coronado will turn into Imperial Beach Blvd. After about 3 miles, the road will hit a T intersection with Seacoast Dr.; turn left (south) and continue about 0.7 mi to park at the end of Seacoast. From the city of Coronado, take Hwy 75 south, turn right (south) on Rainbow Ave, right (west) on Palm Ave, and left (south) on Seacoast Dr. to the end. From the end of Seacoast, you can walk south along a sandy berm or levee, where you can casually scout the estuarine and slough habitat to the east and the beach to the west while walking to the river mouth. Or, if you are already familiar with the area, you can walk down to the hard-packed sand and continue south to the river mouth where the survey begins. Survey Route: From the river mouth, this team should walk back north counting shorebirds both on the estuary and beach sides of the sandspit. This team should aim to count all shorebirds on the north side of river mouth and should be in contact with the team to the south in case any questions arise about who should count certain birds or to alert them to any shorebird flocks flying their way. Team 1 will have the best views looking farther up the river, where they should count any birds seen on either side; again, coordinate with Team 2 if any questions on who is counting what. To the north, Team 1 will attempt to count any and all shorebirds on either side of Oneonta Slough, on islands in the slough, on the sandspit, and on the beach. The sandspit is widest to the south toward the river mouth, and it may require walking up on the west side of the slough (east side of sandspit) and crossing back toward the beach to obtain views of all shorebirds. Some are likely to be roosting up in the sand, so scan ahead to plan your route to minimize flushing birds. Further north the sandspit narrows and there is a raised berm to walk along that allows views into the slough to the east and the beach to the west. It may be possible to scope and count birds a long distance down the beach; not likely to be many birds, other than near the river mouth, as the beach is relatively narrow at high tide and human and dogs may flush birds. Because the slough bends and has steep banks in some places, at certain points it may require walking down off the berm to scan up the slough to count. Signs indicate that this area is closed, but contact Refuge Manager (Brian Collins) or Refuge Operations Specialist (Kurt Roblek) at Tijuana Slough National Wildlife Refuge at (619) , two weeks before your proposed survey date, to get a Special Use Permit to access this area. If you can persuade USFWS personnel to accompany you, you can avoid the extra step of obtaining a Special Use Permit. Some areas of saltmarsh may harbor roosting or foraging large shorebirds. Also, a wide flat of sandy/gravely substrate with sparse dune vegetation may conceal flocks of roosting Killdeer. 2

4 Team 1 should work their way back to where they parked on Seacoast Dr. From there they should drive north on Seacoast and stop at appropriate spots to look for shorebirds in the slough or in the saltmarsh. There is no access out into the marsh because of the presence of the endangered Light-footed Clapper Rail, but marsh vegetation is tall and thick so unlikely to be many shorebirds, and those should be mainly in the slough, which narrows in its upper reaches. Team 2 (south side of estuary) Note: Team 2 should be aware that they are in the immediate vicinity of the International Border, and exercise caution and vigilance. Access: enter via Border Field State Park, which weather permitting, is open to vehicle traffic Saturday, Sunday, and holidays (or by advanced permission on weekdays). From I-5 south/north, take Exit 2 for Dairy Mart Rd. and head south and west on Dairy Mart, which will curve right onto Monument Rd. Continue west on Monument until you reach the park entrance. From Imperial Beach, head east on Imperial Beach Blvd./Coronado Ave., and just before the freeway turn right (south) onto Hollister St. Continue down Hollister until you reach Monument Rd., then turn right (west) on Monument until you reach the park entrance. A park gate that blocks Monument Road at this point can be circumvented if necessary by bearing left (south) and making a short loop around the building. Continue straight west on Monument Road, and pull to the edge of the road to park about yards short of the beach, behind the dune. When parking be aware that though this road appears little used, border patrol personnel drive on it frequently and rapidly, so stay out of the way. It also would be advisable to display a copy of your Special Use Permit on the dashboard for the benefit of the border patrol (see under Team 1 above re. who to contact and when to obtain the permit). Walk west on the Horse Trail/border patrol road to the beach, then north to the river mouth where the survey starts. Survey Route: From the river mouth, observers should cover the tip of the spit; see Team 1 description for thoughts on coordination and areas of potential overlap. From the tip, observers should work back south along the slough on the east side of the spit until it curves left (east); from there scope up the slough as far as possible to count any shorebirds visible. At this point it may be necessary to backtrack to the tip of the spit to ensure that no shorebirds were missed down along the ocean shoreline or roosting up in the upper beach. Then work back south along the beach scanning and scoping well ahead to look for flocks of Snowy Plovers and other shorebirds roosting in the upper beach or foraging along the shore. Periodically walk up to where you can see the saltmarsh to the east and scan for shorebirds; few, if any are likely to be there because there is little water and marsh vegetation is thick. Continue south on the beach until you can scope or scan with binoculars to see any shorebirds as far as a pier on the Mexican border. Take the Horse Trail back to your car; there are some ponded areas along this trail that may hold some shorebirds. 3

5 Team 3 (ponds and upper sloughs) Access: As per initial instructions for Team 1 above, go west from freeway on Coronado Ave./ Imperial Beach Blvd. a little more than 2 miles to 5 th St., where you turn left at a stop sign. Follow 5 th south to its end at the intersection with Iris Street. Park there and walk south on the refuge trail just west of the helicopter landing field. In approximately 700 yards turn right (west). In approximately 200 yards, bear right (north) again. In approximately 150 yards the ponds will be on your left (to the west). When contacting Tijuana Slough NWR staff regarding a Special Use Permit (see above under Team 1), ask about the potential to drive from the gate at 5 th and Iris to the river mouth. If accompanied by Refuge staff, you may be able to drive and save a bit of time. Survey Route: On the way south on the River Mouth Trail, look east across to grassy edges of airfield where it is possible to see roosting Black-bellied Plovers and other shorebirds. Cover all trails, but no need to go down to the river mouth itself given that is being covered by two other teams. Most suitable shorebird habitat will be in some ponds to the west or east of South McCoy Trail; will need to walk off the trail to get closer to the ponds to the west or to find a suitable vantage point to scan them with a scope and binoculars. The last place to look for shorebirds is the slough at the north end of the South McCoy Trail; look both up and down the slough. Finally backtrack to the visitors center. When finished with this part of the survey, drive north on 5 th to Imperial Beach Boulevard, turn left (west) and go about 500 yards, turn left (south) on 3 rd, and follow it around to the Visitor Center of Tijuana Slough NWR. Park there and walk south on the North McCoy Trail, which is a short out-and-back jaunt. 4