Lesser Slave Lake

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Grebe Survey Summary

Max Adults: 3742
Year: 2002
Most Recent Adults: 30
Year: 2016
Survey Type: Shore; Boat; Air
Most Common Threats Reported: Water level too high; lack of/poor nesting habitat; human/development/boat disturbance; nest abandonment; mortality from fishing/nets/barriers; cattle grazing/intrusion

Lake name:: Lesser Slave Lake
Location:: Alberta
HydroLAKE ID:: 42
Latitude:: 55.306762
Longitude:: -114.773391
Basin type:: non-reservoir
Primary vegetation for nesting:: bulrush Scirpus spp. Scirpus spp.
Management agency:: Alberta Environment; Alberta Parks; Lesser Slave Lake Wildlands Provincial Park
Region associations:: Boreal Forest; Lesser Slave Provincial Parks; Lesser Slave River Basin
Comments:: Second largest lake within Alberta, it has a diversity of habitat and is important for birds. A bird observatory is situated on its shore.

Surveys (10)

Survey Citation:
COSEWIC. 2014. COSEWIC assessment and status report on the western grebe (Aechmophorus occidentalis) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 55 pp. www.registrelep-sararegistry.gc.ca/default_e.cfm

Type
shore; boat; air
Time period
1970, 2011
Source
Report
Both Western and Clarks?
N

Count Type	Range	Max	Year
Max Adults	>1000	3742	1991-2011
Most Recent Adults	1 to 100	?	2011
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:

From Table A.2, maximum counts of breeding Western grebes from surveys mostly conducted during nesting season from June and July (sourced from Wilson, A. and Smith, P.A. 2013. Distribution and population status of Western Grebes in Canada. Unpublished report for the Canadian Wildlife Service). Stated as 20 year chunks: 1970 - 1990 and 1991 - 2011 without breaking those down into years or other details. This lake supported a large colony historically but water levels increased in 2007 and the nesting vegetation was scoured by the spring ice pack (Wollis and Stratmoen 2010). New vegetation grew but only 2 adults were observed in 2008 (Wollis and Stratmoen 2010). There were no surveys in 2009 nor 2010 but a colony re-established in 2011 (ASRD/ACA 2013).

Survey Citation:
Erickson, M. E. 2010. Persistence and abundance of the western grebe in Alberta. Dissertation. University of Alberta. Edmonton, Alberta, Canada. Same lakes and abundance estimated were checked against Erickson, M. E., C. Found-Jackson, and M. S. Boyce. 2017. Habitat associations with counts of declining western grebes in Alberta, Canada. Avian Conservation and Ecology. 12(1):12. Appendix to Erickson et al 2014 is unavailable but presumed to be the same list of lakes and abundance estimates.

Time period
19 June 2008, 14 August 2008
Source
Dissertation
Both Western and Clarks?
N

Count Type	Range	Max	Year
Max Adults	>1000	3742	2002
Most Recent Adults	1 to 100	2	2008
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:

From Table B.1 and Table C.1, survey methods and dates for 2008 field season, and latest abundance estimate from 2008, compared to maximum abundance estimate. Source of maximum abundance estimate is historical data from Wildlife Status Reports (WSR) #60. 19 June 2008 survey is colony check (no detail of this) and 14 August data is obtained from ASRD. I didn't include maximum abundance estimate as part of the survey date for Erickson's surveys.

Survey Citation:
Prescott, D. R. C., J. Unruh, S. Morris-Yasinski, and M. Wells. 2018. Distribution and abundance of the western grebe (Aechmophorus occidentalis) in Alberta: an update. Alberta Environment and Sustainable Resource Development, Fish and Wildlife Policy Branch, Alberta Species at Risk Report No. 160, Edmonton, AB. 23 pp.

Type
boat
Time period
1950, 2016
Source
Report
Both Western and Clarks?
N

Count Type	Range	Max	Year
Max Adults	>1000	3742	2002
Most Recent Adults	1 to 100	30	2016
Max Nests	1 to 100	presence	1960, 1964, 1970, 1979, 2000, 2002, 2006, 2009, 2011, 2012, 2015, 2016
Most Recent Nests	1 to 100	presence	2016
Max Chicks	1 to 100	presence?	1960, 1964, 1970, 1979, 2000, 2002, 2006, 2009, 2011, 2012, 2015, 2016
Most Recent Chicks	1 to 100	presence?	2016

Comments:

Sources are eBird (accessed Nov 2015 and Dec 2016), AESRD and ACA (2013), FWMIS (Accessed Nov 2015 including field surveys from 2015 and 2016), Hanneman and Heckbert 2001, Kemper et al. 2008, Wollis and Stratmoen 2010, Erickson 2010, and Hanus 2002. This report is an update of Western grebe distribution in Alberta based on previous provincial status reports, additional breeding records (between May 1 to August 31) through end of 2014 from new sources. Lakes were visited in 2015 and 2016 for occupancy and habitat conditions. In a given year, if there are multiple sources of data, the highest count was given. From the Appendix, I entered only lakes (67) with evidence of breeding (either chicks or nests, but doesn't specify which and no nest nor chick numbers provided). Otherwise, 318 lakes supported adult grebe populations. This report compiled a list of 35 priority lakes for grebe surveys and management actions through the provincial recovery plan based on high population and habitat scores. New lakes with breeding reveal a changing system of lake occupancy and possibly higher populations than previously thought in Alberta.

Survey Citation:
Alberta Sustainable Resource Development and Alberta Conservation Association. 2006. Status of the western grebe (Aechmophorus occidentalis) in Alberta. Alberta Sustainable Resource Development, Wildlife Status Report No. 60, Edmonston, AB. 29 pp.

Time period
1970s, 2002
Source
Report
Both Western and Clarks?
N

Count Type	Range	Max	Year
Max Adults	>1000	3742	2002
Most Recent Adults	>1000	3742	2002
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:

Data from Table 1 ("Summary of lakes in Alberta supporting western grebe colonies of over 500 breeding birds, adapted from Hanus 2002), Table 2 ("Summary of the most recently published western grebe population data for the province of Alberta"), and Table 3 ("Summary of historical and current information on breeding populations of western grebe on lakes in northwestern Alberta"). Table 1 is divided into categories of lakes with 1000+ birds and lakes with 500 to 999 birds and not specific count numbers. 500 to 999 birds were on that lake in the 1970s and 2000. Lesser Slave Lake is in the Boreal natural region. Data from Table 2 is sourced from Eadie 2002. Number of grebes is determined by nest count X2 in Table 3 and is sourced from Hanneman and Heckbert 2001, Ealey 1979 in Hanus 2002, and Eadie 2002.

Survey Citation:
Alberta Sustainable Resource Development and Alberta Conservation Association. 2013. Status of the western grebe (Aechmophorus occidentalis) in Alberta: Update 2012. Alberta Sustainable Resource Development. Alberta Wildlife Status Report No. 60 (Update 2012). Edmonston, AB. 48 pp.

Type
boat
Time period
1970s, 2011
Source
Report
Both Western and Clarks?
N

Count Type	Range	Max	Year
Max Adults	>1000	1000+	1979, 2002, 2006, 2011
Most Recent Adults	>1000	3504	2011
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:

Data from Table 1 ("Summary of lakes in Alberta supporting western grebe colonies of over 200 breeding birds, adapted from Hanus 2002) and Table 2 ("Most recent abundance estimates from known western grebe breeding lakes in Alberta based on structured surveys; at some lakes, more recent observations have been made but these were not complete counts"). Table 1 is divided into categories of lakes with 1000+ birds and lakes with 200 to 999 birds and not specific count numbers. Table 2 data is from A. Fontaine 2011 unpubl. data. Estimates of western grebe numbers are a minimum estimate for that year derived from nest counts (x2 for breeding adult numbers) or boat surveys of adult grebes, using highest estimate. According to Table 4, the 2011 count is 37% of estimated proportion of provincial population. In 2008, water levels rose greatly prior to nesting and grebes did not nest elsewhere (H. Wollis, pers. comm.). A marina was proposed to be developed nearby (H. Wollis, pers. comm.). This lake is considered a nationally important designation for breeding grebes and has a high amount of recreational activity.

Survey Citation:
Wollis, H., and C. Stratmoen. 2010. Population study of western grebes in Alberta 2001-2009: Implications for management and status designation. Alberta Sustainable Resource Development, Fish and Wildlife Division, Alberta Species at Risk Report No. 138. Edmonton, AB. 18 pp.

Time period
2002, 2009
Source
Report
Both Western and Clarks?
N

Count Type	Range	Max	Year
Max Adults	>1000	3742	2002
Most Recent Adults	0	0	2009
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 report is a continuation of a western grebe monitoring project started in 2001 to survey colonies in Alberta and assess population trends and distribution. Known and new colonies were searched for each year through 2009. This entry is from Table 2 comparing most recent estimate of # adults with highest estimate year.

Survey Citation:
Hanneman, M., and M. Heckbert. 2001. Colonial nesting waterbird survey in the northwest boreal region – 2000. Alberta Sustainable Resource Development, Fish and Wildlife Division, Alberta Species at Risk Report No. 7, Edmonton, Alberta, Canada.

Type
boat; air
Time period
1970s, 17 July 2000
Source
Report
Both Western and Clarks?
N

Count Type	Range	Max	Year
Max Adults	501 to 1000	presumably >500	1970s, 2000
Most Recent Adults	501 to 1000	presumably >500	2000
Max Nests	101 to 500	400	1970s
Most Recent Nests	101 to 500	350	2000
Max Chicks	N/A	N/A	N/A
Most Recent Chicks	N/A	N/A	N/A

Comments:

This was a survey of colonial waterbirds based on historical records of colony locations. Western grebes were not the target species but were counted as well. Table 6 compares the 2000 survey with historical data (if available) and is entered here. These are partial surveys of the lake so may be difficult to compare as grebe colonies might move around year to year and this lake in particular is surveyed in different locations but not in all years.

Survey Citation:
Eadie, G. 2002. 2002 Lesser Slave Lake western grebe survey. Lesser Slave Lake Bird Observatory. Lesser Slave Lake, Alberta. 17 pp.

Type
shore; boat
Time period
8 May 2002, 22 August 2002
Source
Report
Both Western and Clarks?
N

Count Type	Range	Max	Year
Max Adults	>1000	3742	2002
Most Recent Adults	>1000	3742	2002
Max Nests	>1000	1871	2002
Most Recent Nests	>1000	1871	2002
Max Chicks	1 to 100	60	2002
Most Recent Chicks	1 to 100	60	2002

Comments:

The maximum adult count in 2002 is the estimated total number of nests X2. The data summary on page 28 doesn't include the Auger Bay estimate of 200 nests so I included that in the nest and adult estimated total for maximum and most recent. I used their lowest estimate of nests and adults for the minimums. Historical data is mentioned and I entered that as a seperate entry. The survey dates for 2001on page 6 are partial around the lake so I didn't use those numbers.

Survey Citation:
Eadie, G. 2002. 2002 Lesser Slave Lake western grebe survey. Lesser Slave Lake Bird Observatory. Lesser Slave Lake, Alberta. 17 pp.

Type
shore; boat; air
Time period
1960s, 2000
Source
Report
Both Western and Clarks?
N

Count Type	Range	Max	Year
Max Adults	>1000	presumably >1000	1979
Most Recent Adults	501 to 1000	presumably >500	2000
Max Nests	501 to 1000	650	1979
Most Recent Nests	101 to 500	350	2000
Max Chicks	N/A	N/A	N/A
Most Recent Chicks	N/A	N/A	N/A

Comments:

Historical data summarized on page 4 and 9 entered here. These don't have much detail so I entered to 2001 formal survey in its own entry. 1960s presence of historic colony has no #s (Ealey 1986), the 1979 and 2000 nest numbers are cited as Hanneman and Heckbert 2001, the 1978 and 1979 nest numbers are cited as Ealey 1986.

Survey Citation:
Environment and Climate Change Canada. 2021. Management Plan for the western grebe (Aechmophorus occidentalis) in Canada [Proposed]. Species at Risk Act Management Plan Series. Environment and Climate Change Canada, Ottawa. 5 iv + 52 pp.

Time period
2002, 2016
Source
Management plan
Both Western and Clarks?
N

Count Type	Range	Max	Year
Max Adults	>1000	3742	2002
Most Recent Adults	1 to 100	30	2016
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:

From Appendix B, data columns are historical high count, high count since 2000, and most recent count. Since minimum count was not stated, I entered the minimum from these columns though it might not be the actual minimum across the span of years reported. Also, there is no detail on years that were excluded from surveying so range of survey years may be inaccurate. Footnote for this lake indicates that for 2015 to 2016, breeding was confirmed, potential habitat was available, and lake was occupied by Western grebes. Sources are Prescott et al., 2018 and Alberta Environment and Parks, 2018.

Sources of Information

Eadie, G. 2002. 2002 Lesser Slave Lake western grebe survey. Lesser Slave Lake Bird Observatory. Lesser Slave Lake, Alberta. 17 pp.
Lesser Slave Lake Important Bird Area (IBA) Site Description
Lesser Slave Watershed Council (LSWC)
Lesser Slave Lake Bird Observatory
Canadian Geographical Names Database (CGNDB)
Lesser Slave Lake Provincial Park
Lesser Slave Basins Water Management Plan
Lesser Slave Basins Map

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Lesser Slave Lake

Grebe Survey Summary

Surveys (10)

Survey Citation: COSEWIC. 2014. COSEWIC assessment and status report on the western grebe (Aechmophorus occidentalis) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 55 pp. www.registrelep-sararegistry.gc.ca/default_e.cfm

Comments:

Comments:

Comments:

Survey Citation: Alberta Sustainable Resource Development and Alberta Conservation Association. 2006. Status of the western grebe (Aechmophorus occidentalis) in Alberta. Alberta Sustainable Resource Development, Wildlife Status Report No. 60, Edmonston, AB. 29 pp.

Comments:

Survey Citation: Alberta Sustainable Resource Development and Alberta Conservation Association. 2013. Status of the western grebe (Aechmophorus occidentalis) in Alberta: Update 2012. Alberta Sustainable Resource Development. Alberta Wildlife Status Report No. 60 (Update 2012). Edmonston, AB. 48 pp.

Comments:

Survey Citation: Wollis, H., and C. Stratmoen. 2010. Population study of western grebes in Alberta 2001-2009: Implications for management and status designation. Alberta Sustainable Resource Development, Fish and Wildlife Division, Alberta Species at Risk Report No. 138. Edmonton, AB. 18 pp.

Comments:

Survey Citation: Hanneman, M., and M. Heckbert. 2001. Colonial nesting waterbird survey in the northwest boreal region – 2000. Alberta Sustainable Resource Development, Fish and Wildlife Division, Alberta Species at Risk Report No. 7, Edmonton, Alberta, Canada.

Comments:

Survey Citation: Eadie, G. 2002. 2002 Lesser Slave Lake western grebe survey. Lesser Slave Lake Bird Observatory. Lesser Slave Lake, Alberta. 17 pp.

Comments:

Survey Citation: Eadie, G. 2002. 2002 Lesser Slave Lake western grebe survey. Lesser Slave Lake Bird Observatory. Lesser Slave Lake, Alberta. 17 pp.

Comments:

Survey Citation: Environment and Climate Change Canada. 2021. Management Plan for the western grebe (Aechmophorus occidentalis) in Canada [Proposed]. Species at Risk Act Management Plan Series. Environment and Climate Change Canada, Ottawa. 5 iv + 52 pp.

Comments:

Sources of Information

Survey Citation:
COSEWIC. 2014. COSEWIC assessment and status report on the western grebe (Aechmophorus occidentalis) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 55 pp. www.registrelep-sararegistry.gc.ca/default_e.cfm

Survey Citation:
Alberta Sustainable Resource Development and Alberta Conservation Association. 2006. Status of the western grebe (Aechmophorus occidentalis) in Alberta. Alberta Sustainable Resource Development, Wildlife Status Report No. 60, Edmonston, AB. 29 pp.

Survey Citation:
Alberta Sustainable Resource Development and Alberta Conservation Association. 2013. Status of the western grebe (Aechmophorus occidentalis) in Alberta: Update 2012. Alberta Sustainable Resource Development. Alberta Wildlife Status Report No. 60 (Update 2012). Edmonston, AB. 48 pp.

Survey Citation:
Wollis, H., and C. Stratmoen. 2010. Population study of western grebes in Alberta 2001-2009: Implications for management and status designation. Alberta Sustainable Resource Development, Fish and Wildlife Division, Alberta Species at Risk Report No. 138. Edmonton, AB. 18 pp.

Survey Citation:
Hanneman, M., and M. Heckbert. 2001. Colonial nesting waterbird survey in the northwest boreal region – 2000. Alberta Sustainable Resource Development, Fish and Wildlife Division, Alberta Species at Risk Report No. 7, Edmonton, Alberta, Canada.

Survey Citation:
Eadie, G. 2002. 2002 Lesser Slave Lake western grebe survey. Lesser Slave Lake Bird Observatory. Lesser Slave Lake, Alberta. 17 pp.

Survey Citation:
Eadie, G. 2002. 2002 Lesser Slave Lake western grebe survey. Lesser Slave Lake Bird Observatory. Lesser Slave Lake, Alberta. 17 pp.

Survey Citation:
Environment and Climate Change Canada. 2021. Management Plan for the western grebe (Aechmophorus occidentalis) in Canada [Proposed]. Species at Risk Act Management Plan Series. Environment and Climate Change Canada, Ottawa. 5 iv + 52 pp.