San Carlos Lake

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.

• Type
  shore
• Time period
  2003, 2019
• Source
  Article
• Both Western and Clarks?
  Y

Count Type	Range	Max	Year
Max Adults	501 to 1000	<=600	2006 or prior
Most Recent Adults	501 to 1000	<=600	2019
Max Nests	1 to 100	100	2015
Most Recent Nests	1 to 100	100	2006 or prior
Max Chicks	1 to 100	12	2015
Most Recent Chicks	1 to 100	3	2017

Comments:

More than 150 visits have been made to this lake by surveyers but evidence of nesting (observed nests and/or chicks) were found only in 2005, 2015, and 2017. Water level is a major issue, according to the author, and these three years were considered to have somewhat stable water levels for at least 3 months from March to May. The "up to 600" grebes that can be found in summer months is cited to eBird 2019 but is uncertain how many of those breed.

Survey Citation:
Jenness, D. Unknown year. Birding Arizona: Birding San Carlos Lake. AZFO. azfo.org/birding/locations.html

• Time period
  2005, 2015
• Source
  factsheet
• Both Western and Clarks?
  Y

Count Type	Range	Max	Year
Max Adults	1 to 100	presence	2005, 2015
Most Recent Adults	1 to 100	presence	2015
Max Nests	1 to 100	100	2015
Most Recent Nests	1 to 100	100	2006 or prior
Max Chicks	N/A	N/A	N/A
Most Recent Chicks	N/A	presence	2015

Comments:

Estimate, at least 10 nests were Clark's. First report of Western and Clark's grebe broods in 2005. There is a year-round population of grebes reported there with the highest numbers in winter. There were estimated hundreds to over a thousand seen on the lake but does not state which season nor what year.

Survey Citation:
Manning, A. 2006. Colony list, unpublished data.

• Time period
  2006 or prior
• Source
  Summary
• 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	2006 or prior
Max Nests	1 to 100	presence	2006 or prior
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:

Unpublished data from Ann Manning with the Utah Division of Wildlife, forwarded by Gary Ivey. Ivey said year saved was 2006 but otherwise unknown when this list was determined by Manning, hence year noted as 2006 or prior. This is on a list of known colonies of Western and Clark's grebes. No year nor other info provided.