Lake Havasu

Survey Citation:
Jenness, D. 2020. Extreme water level fluctuations limit breeding of western and Clark's grebes at San Carlos Lake, Arizona. Arizona Birds - Journal of Arizona Field Ornithologists. Volume 2020. Arizona.; Corman, T. E., and C. Wise-Gervais. 2005. Arizona Breeding Bird Atlas. University of New Mexico Press, Albuquerque, NM.

• Time period
  1966
• Source
  Article
• Both Western and Clarks?
  Y

Count Type	Range	Max	Year
Max Adults	1 to 100	presence	2006 or prior
Most Recent Adults	1 to 100	presence	continued after 1966
Max Nests	1 to 100	presence	1966
Most Recent Nests	1 to 100	presence	2006 or prior
Max Chicks	N/A	N/A	N/A
Most Recent Chicks	N/A	N/A	N/A

Comments:

Not a survey but a statement that Western grebe nesting was first recorded at Lake Havasu in 1966 (Rosenberg et al. 1991) and continued from then but does not state for how many years. Prior to the atlas, Clark's grebes were noted to only nest here (Rosenberg et al. 1991). Rosenberg et al. (1991) also noted Western and Clark's grebes nesting on the north end of the lake and carried their chicks to Bill Williams River arm 31 miles away. Highest concentration of Clark's grebes is here and at Topock Marsh. See California's entry for Lake Havasu for additional Lake Havasu grebe data. California and Arizona entries for Lake Havasu combined in the Summary Table.

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 Unpublished technical report.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/A

Count Type	Range	Max	Year
Max Adults	>1000	~3750	?
Most Recent Adults	>1000	~3750	?
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. There were ~3750 adult grebes in Lake Havasu and noted as colony site, some year-round, but no year given and no other details (Garrett and Dunn 1981, Rosenberg et al. 1991).