Goose Lake

Survey Citation:
Ivey, G. L. 2004. Conservation assessment and management plan for breeding Western and Clark’s Grebes in California. Unpublished technical report. American Trader Trustee Council, California. . Accessed 15 January 2020.

• Time period
  N/A
• Source
  Conservation Assessment, Management Plan
• Both Western and Clarks?
  N

Count Type	Range	Max	Year
Max Adults	501 to 1000	598	1977
Most Recent Adults	501 to 1000	598	1977
Max Nests	N/A	N/A	N/A
Most Recent Nests	N/A	N/A	N/A
Max Chicks	N/A	N/A	N/A
Most Recent Chicks	N/A	N/A	N/A

Comments:

This entry to capture historical record of breeding grebes in CA prior to 2002. These 598 grebes were majority Clark's in 1977 and noted as colony site (Ratti 1981). Considered a major area by Small (1994).

Survey Citation:
Ivey, G. L. 2004. Conservation assessment and management plan for breeding Western and Clark’s Grebes in California. Unpublished technical report. American Trader Trustee Council, California. . Accessed 15 January 2020.

• Type
  shore; boat; air
• Time period
  28 August 2002, 17-25 August 2003
• Source
  Conservation Assessment, Management Plan
• Both Western and Clarks?
  Y

Count Type	Range	Max	Year
Max Adults	101 to 500	120	2003
Most Recent Adults	101 to 500	120	2003
Max Nests	1 to 100	60	2003
Most Recent Nests	1 to 100	60	2003
Max Chicks	N/A	N/A	N/A
Most Recent Chicks	N/A	N/A	N/A

Comments:

The 2002 field surveys were limited to August 28 via airboat. The 2003 surveys on Goose Lake included aircraft and shore scoping. Table 3 population estimate is the # of nests (60) x 2 for 120. The nests here rrepresent 0.7% of the Intermountain West (Ivey and Herziger in prep.). Clark's were only grebes observed in 2002 - 2003 and might be largest known concentration of breeding Clark's but in the late 1970s, some Western grebes were observed (Ratti 1981).

Survey Citation:
Ivey, G.L., and C.P. Herziger. 2006. Intermountain west waterbird conservation plan, version 1.2. A plan associated with the Waterbird Conservation for the Americas Initiative. Published by U.S. Fish and Wildlife Service Pacific Region, Portland, Oregon.

• Time period
  2003
• Source
  Conservation Plan
• Both Western and Clarks?
  N

Count Type	Range	Max	Year
Max Adults	101 to 500	120	2003
Most Recent Adults	101 to 500	120	2003
Max Nests	1 to 100	60	2003
Most Recent Nests	1 to 100	60	2003
Max Chicks	N/A	N/A	N/A
Most Recent Chicks	N/A	N/A	N/A

Comments:

Appendix D, Table D-2, data is 60 nests, 120 area population estimate (nests x 2), population data source is Ivey 2004. Also in Ivey Region 1 Non Game California Waterbird Atlas spreadsheet, did not re-enter.

Survey Citation:
Ratti, J. T. 1985. A test of water depth niche partitioning by Western Grebe color morphs. Auk 102:635-637.

• Type
  shore
• Time period
  1981
• Source
  Communications
• Both Western and Clarks?
  Y

Count Type	Range	Max	Year
Max Adults	101 to 500	301	1981
Most Recent Adults	101 to 500	301	1981
Max Nests	N/A	N/A	N/A
Most Recent Nests	N/A	N/A	N/A
Max Chicks	N/A	N/A	N/A
Most Recent Chicks	N/A	N/A	N/A

Comments:

Totals calculated from Table 1. This paper tested water-depth and distance from shore niches between light and dark phased Western grebes. Light-phased Western grebes fed farther from the shore than dark-phased Western grebes but were not found feed at greater water depths.