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 />
Muted Pocket Marsh<br />
The 14-ha Muted Pocket Marsh is primarily shallow open water and mudflat and therefore highly<br />
utilized by shorebirds and dabbling ducks. The Muted Pocket Marsh had a total of 3,745 individuals<br />
(88 species) during the <strong>2008</strong> surveys. Although this area appeared to have the lowest number of<br />
individuals and species, this is solely due to its size. Compared to the highly utilized FTB, which had<br />
an overall total of 161 birds per hectare, the Muted Pocket Marsh supported 268 birds per hectare. The<br />
most abundant of dabbling ducks included American wigeon and green-winged teal (Anas crecca).<br />
The most abundant shorebirds were dowitcher, which frequented the marsh in high numbers during the<br />
winter months.<br />
The rampikes of dead eucalyptus trees that ring the basin were used for perching by osprey, doublecrested<br />
cormorant, and belted kingfisher. The dead Myoporum along the shorelines were frequently<br />
occupied by roosting black-crowned night heron (Nycticorax nycticorax).<br />
Avian Distribution and Abundance by Habitat Type<br />
Mudflats were the most utilized habitat type during the <strong>2008</strong> surveys (37.5% of all birds observed)<br />
(Figure 1-18). Large and small shorebirds had the highest utilization of the mudflats for foraging and<br />
resting. During the June survey, the sand shoals in the FTB were the most utilized habitat due to their<br />
considerable size at that time and the absence of most shorebirds from the basin. The inundated salt<br />
panne was also highly utilized (19.0% of all birds), particularly by foraging northern shoveler,<br />
American coot, ruddy duck, northern pintail, and American widgeon. This is followed by usage of salt<br />
marsh habitat (13.5% of all birds) and open water habitat (12.3% of all birds). Salt marsh habitat<br />
usage, unlike the other major usage habitat types, appears to increase during the breeding season and<br />
continue to increase into the fall surveys. This can largely be attributed to breeding Belding’s<br />
Savannah Sparrow; however, during the August and October surveys there was also an increase in<br />
large shorebirds and upland birds (swallows and morning dove).<br />
25,000<br />
90<br />
20,000<br />
Number of birds<br />
Number of species<br />
80<br />
70<br />
Number of birds<br />
15,000<br />
10,000<br />
60<br />
50<br />
40<br />
30<br />
Number of species<br />
5,000<br />
20<br />
10<br />
0<br />
Salt<br />
Marsh<br />
Dist urbedFreshwat er Willow/<br />
Salt Marsh Marsh Riparian<br />
Mulefat Decaying/<br />
Scrub Transit ional<br />
Salt<br />
Panne<br />
Inundat ed<br />
Salt Panne<br />
Nest<br />
Site<br />
Open<br />
Wat er<br />
Riprap Mudf lat Sand<br />
Shoal<br />
Coast al Non-nat ive Urban/<br />
Sage ScrubVegetationDist urbed<br />
0<br />
Figure 1-18. Avian abundance by habitat type at <strong>Bolsa</strong> <strong>Chica</strong> during <strong>2008</strong> surveys<br />
Merkel & Associates, Inc. 84