Los Angeles & Orange County Western Snowy Plover Monthly Report for December 2014

Transcription

1 Los Angeles & Orange County Western Snowy Plover Monthly Report for December 2014 Prepared for Nancy Frost California Department of Fish and Wildlife 3883 Ruffin Road San Diego, CA Prepared by: Los Angeles Audubon P.O. Box Los Angeles, California Contact: Thomas Ryan December 26, 2014

2 Los Angeles County During December 2014 biologists Thomas and Joyce Realageno detected 157 snowy plovers at roosts in Los Angeles County on December 20 and 24, This total is less than the numbers of plovers observed in December 2013 and in November The reduction is mostly due to heavy beach erosion at Malibu Lagoon removing the plover s previous roosting area, and fewer plovers present at Dockweiler State Beach, Tower 47 enclosure. During the December survey, biologists observed and noted the continued presence of a volleyball court and large berm placed in the historic roosting area of the snowy plovers at Zuma, north of lifeguard tower 9 (see November 2014 report). The establishment of this court contradicts our recommendation of locating recreational facilities away from known plover roosts. The sand berm at Malibu Lagoon has much greater erosion than the prior month. The entire southern end of the sandy beach, where the plovers have previously been roosting has eroded away and the entire beach showed signs of overwash during the December high tides. Only two plovers were observed foraging on the north end of the beach and no roost is present. This partially accounts for the unusually low numbers of plovers this month. The enclosure at Santa Monica was intact. The plovers continue to roost just north and east of the enclosure in an unprotected area where vehicles drive on the beach. We recommend extreme caution be used within 500 ft of the enclosure for the remainder of the winter months. The enclosure at Dockweiler State Beach is intact but few plovers were present during the survey on December 20. The roost was checked again on December 28 and the same number of plovers was present on both counts. Sand has been deposited on this beach and the enclosure is father back from the shore than normal, but no other obvious cause explains the decline here. We did see an increase by 26 plovers at Santa Monica this month, and this may be where these plovers have moved. We observed 42 plovers at Hermosa Beach. They remain in two distinct flocks in front of 24 th and 26 th Streets. Table 1. Number of Snowy Plovers Observed in Los Angeles County, Location Dec Nov Dec Notes Zuma Volleyball court and berm placed near historic roost Malibu Heavy beach erosion, overwash, Right-orange/yellow; left green/blue Santa Monica DSB DSB Hermosa Total

3 Orange County In Orange County, biologists Ross Griswold, Rich Boulter and, and Josh Weinik detected 211 plovers on December 17, 19, and 23, This total is less than the number detected here in December 2013 (274), but is an increase over the previous month s surveys (183). Potential explanations for the decline include heavy beach erosion narrowing all beaches, possible movement to new roosting locations, construction of a new sidewalk beside the roosting fence at Balboa, and installation of berms at Surfside/Sunset Beach and Bolsa Chica. If a new roost has formed, we hope it will be detected during the beachwide surveys in January. The largest declines are at Huntington State Beach and Balboa Peninsula. Table 2. Number of Snowy Plovers Observed in Orange County, Dec Nov Dec Location Seal Beach NS 0 0 Notes Surfside Bolsa Chica SB Huntington SB Balboa AG:OB Dec 17 Crystal Cove NS Salt Creek AG:OB Dec 23 Trestles/San Clemente SB Total

4 Photographs. Photograph 1. Reduced beach area at Malibu Lagoon. Photograph 2. Overwash at the Santa Monica Beach Enclosure.

5 Roost Maps. Figure 1. Map of Zuma Roost Figure 2. Map of Santa Monica Roost.

6 Figure 3. Map of Dockweiler State Beach Tower 47 (DSB 47) foraging location. Figure 4. Map of Hermosa Beach Roost.

7 Figure 5. Map of Surfside Roost. Figure 6. Map of Bolsa Chica State Beach Roost.

8 Figure 7. Map of Balboa Roost. Figure 8. Map of Crystal Cove Roost.

9 Figure 9. Map of Salt Creek Roost. Figure 10. Map of Trestles/San Clemente State Beach Roost.