2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...
2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...
2008 Annual Monitoring Report (pdf 10.9MB) - Bolsa Chica ...
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<strong>Bolsa</strong> <strong>Chica</strong> Lowlands Restoration <strong>Monitoring</strong><br />
<strong>2008</strong> <strong>Annual</strong> <strong>Report</strong><br />
Bay, NS2 is located within Zone 42 of the southern MTB, and NS3 is located in Zone 14 of the FFTB.<br />
Western snowy plover nest sites included all tern colonies listed above but also included the Seasonal<br />
Ponds (Zones 1 through 37).<br />
The principal survey effort for California least tern and western snowy plover was undertaken by<br />
CDFG seasonal staff member, Peter Knapp and assisted on NS1 by Kelly O’Reilly, CDFG. Merkel &<br />
Associates biologist, Bonnie Peterson, participated intermittently in the survey efforts as support and to<br />
aid in collecting data for report preparation. STI and NS1 were surveyed by vehicle from the West<br />
Levee Road prior to arrival of the least terns and then on foot. NTI was used primarily by nesting<br />
elegant terns and black skimmers and therefore required minimal monitoring for least terns and<br />
plovers. Observations were made from the West Levee Road. NS2 was surveyed by vehicle from the<br />
East Levee Road weekly using a spotting scope and once a month on foot. NS3 was surveyed by<br />
vehicle from the north end of the site. The large majority of suitable western snowy plover nesting<br />
habitat in the Seasonal Ponds was visible from the road network. The observer(s) would slowly drive<br />
along the roads that subdivide this area. Frequent stops were made to examine specific areas adjacent<br />
to the road with binoculars or spotting scope without exiting the vehicle.<br />
NS1, NS2, and NS3 are sectioned by markers, which form the basis for data recording. NS1 is<br />
sectioned south to north from A though CC in a regular grid. Each least tern and snowy plover nest<br />
located on NS1 was marked with a numbered tongue depressor and mapped for ease of relocation on<br />
subsequent visits.<br />
Beginning in late-March, surveys for nesting western snowy plovers were conducted at least twice a<br />
week, sometimes 4 or 5 times a week, until the beginning of September. Data collected included the<br />
gender of the incubating adult, length of incubation (days), number of eggs in the clutch, condition of<br />
the nest (e.g. signs of disturbance), and the fate of each nest (hatched, predated, or abandoned). Close<br />
examination of nests was usually conducted only once or twice per nest. As snowy plover nests were<br />
located they were protected by Mini-Exclosures (MEs), which were placed over the nest.<br />
Observations of snowy plover broods were made 3 to 5 days per week. It was usually possible to<br />
follow the movements and determine the fate of the chicks from each brood since there was sufficient<br />
dispersion over space and time to differentiate between broods. These regular brood observations were<br />
conducted to determine chick survival or fledgling production, as well as to detect movement between<br />
zones and use of specific zones for brood rearing.<br />
California least tern monitoring began as soon as the terns started arriving at <strong>Bolsa</strong> <strong>Chica</strong> in mid-April<br />
and continued until the terns fledged and left the breeding grounds in late August. The observers<br />
would walk active tern colonies and mark and record the section of all new nests. This activity<br />
typically occurred between 0800 and 1200 hours, 1 to 2 times per week. Observers would record any<br />
hatched, abandoned or depredated nests. Any signs of disturbance within the tern colonies were also<br />
recorded. At other times during the week, observations on the status of the colony were made from<br />
observation points outside of the colony. Observations of least tern chicks and fledglings were made<br />
every 1 to 2 days to determine hatching and fledging success.<br />
In <strong>2008</strong>, monitoring of nests on NS1 was very difficult due to the large number of nesting birds besides<br />
the western snowy plover and California least tern, including elegant tern, black skimmer, royal tern,<br />
and Caspian tern. These species previously nested primarily on NTI. By the end of June, monitoring<br />
Merkel & Associates, Inc. 92