In April and May, 2011, California Native Plant Society (CNPS) volunteers, led by Dr. Frank Landis, searched for sensitive, rare, and endangered plants on the publicly accessible areas of Fiesta Island. This search was part of a larger 2011 effort to find rare coastal dune plants in San Diego County, focusing on beaches that had not been recently surveyed.
CNPS volunteers found five sensitive plant species growing on Fiesta Island: Nuttall's lotus, a CDFG list 1B species. Between 1,234 and 1,253 plants were found. Coast woollyheads, a CDFG list 1B species. Between an estimated 4,350 and 5,050 were found. Robinson's pepper-grass, a CDFG list 1B species. Approximately 10,000 were found. Red sand verbena, a CDFG list 4 species. Sixteen were found. Woolly seablite, a CDFG list 4 species. This shrub is abundant on berms around the southern half of the island, and was not counted.
An estimated 3,451 to 3,674 pairs of California least terns nested at 36 nesting sites in 1999
and produced an estimated 671 to 711 fledglings. These estimates result in 0.18 to 0.21
fledglings per pair, the lowest productivity recorded since statewide censuses were initiated in
1976. Statewide pair estimates decreased 11% from 1998 values, but fledgling estimates
declined by 74.9% due to exceedingly high predation and chick mortality at many sites. Over
30% of the nesting population was concentrated at two sites (Mission Bay Mariner's Point and
Santa Margarita North Beach); ten sites supported a combined total of 76.6% of statewide pairs.
One site (Los Angeles Harbor) contributed nearly 24% of the state's fledglings in 1999; Los
Angeles Harbor and three other sites (NAS Alameda, Ormond Beach and Mission Bay Mariner's
Point) produced over 50% of 1999 statewide fledglings.
Four sites that supported least tern pairs in 1998 reported no nesting in 1999 (Batiquitos
Lagoon W-1 and E-2; Mission Bay Fiesta Island, Mission Bay South Shores); four additional
sites (Venice Beach, Seal Beach, Bolsa Chica, Chula Vista Wildlife Refuge) supported nesting
but had no productivity in 1999.
1999 pair estimates were 18% lower than corresponding statewide nest numbers; in 1998 they
differed by only 9%. Renesting may have occurred far less frequently in 1999 than in 1998 due
to far higher predation (16.5% of all eggs and 7.7% of chicks hatched) and other factors
contributing to chick mortality (26.5% of all hatched eggs) in 1999. The greatest egg losses in
1999 were attributed to coyotes, crows and ravens; highest chick/fledgling losses were to
American kestrels, coyotes and peregrine falcons. Chick mortality due to factors other than
predation was 26.5%, higher than 1997 and 1998 and is believed to be related to prey
deficiencies and unknown factors.