San Joaquin Marsh Wildlife Sanctuary
Grebe Survey Summary
- Max Adults: presence
- Year: 2013-2020
- Most Recent Adults: presence
- Year: 2020
- Survey Type: N/A
- Most Common Threats Reported: N/A
- Lake name:
- San Joaquin Marsh Wildlife Sanctuary
- Location:
- California
- Latitude:
- 33.662842
- Longitude:
- -117.842013
- Surface area (km2):
- 1.2
- Basin type:
- non-reservoir
- Primary emergent vegetation:
- Cattails (Typha sp.) bulrush (Schoenoplectus sp.)
- Management agency:
- Irvine Ranch Water District
- Lake use:
- water treatment
- Region associations:
- San Diego Creek
- Designations:
- Wildlife Sanctuary
- Comments:
- The San Joaquin Marsh Wildlife Sanctuary are a complex of constructed wetlands used to hold urban runoff water for Irvine River Water District's Natural Water Treatment System.
Surveys (1)
Survey Citation:
Santolo, G. 2021. Ground nesting by Aechmophorus grebes in Orange County, California. Western Birds 52:173-177.
-
Type
shore -
Time period
2013, 2020 -
Source
Notes -
Both Western and Clarks?
Y
| Count Type | Range | Max | Year |
|---|---|---|---|
| Max Adults | 1 to 100 | presence | 2013-2020 |
| Most Recent Adults | 1 to 100 | presence | 2020 |
| Max Nests | 1 to 100 | 8 | 2019 |
| Most Recent Nests | 1 to 100 | 7 | 2020 |
| Max Chicks | N/A | N/A | N/A |
| Most Recent Chicks | N/A | N/A | N/A |
Comments:
Observation of ground nesting by Western and Clark's grebes (and hybrids) since 2018. Grebes have been observed there since 2004 by Sea and Sage Audubon but nesting was not observed there until 2013. Santolo conducts nest searches for various bird species there and started to observe ground nesting by Western and Clark's grebes starting in 2018. These ground nests were considered active with new eggs, incubation, and nest construction observed and photographed. They were 1 to 3 meters from the water edge, early in the nesting season, and not considered stranded by water drawdown. Floating nests were constructed in late June to July. No information on nest success. Table 1 is 2019 and 2020 nest observations but it is not clear how many nests there were in 2018.
Sources of Information
- Santolo, G. 2021. Ground nesting by Aechmophorus grebes in Orange County, California. Western Birds 52:173-177., https://www.irwd.com/san-joaquin-marsh/san-joaquin-marsh