Great Blue Heron
Scientific Name: Ardea herodias
Thresholds:
- La Grande Île (QC118)2,354 (max.)
- Pelee Island Archipelago (ON014)1,850 (max.)
- Boundary Bay - Roberts Bank - Sturgeon Bank (Fraser River Estuary) (BC017)1,000 (max.)
- English Bay, Burrard Inlet & Howe Sound (BC020)366 (max.)
- Pacific Spirit Regional Park (BC018)364 (max.)
- Holden Lake (BC053)324 (max.)
- McFadden Creek Heronry (BC001)276 (max.)
- Sidney Channel (BC047)200 (max.)
- Baynes Sound (BC057)136 (max.)
- Little Qualicum Estuary to Nanoose Bay (BC056)112 (max.)
- Lambert Channel/Hornby Island Waters (BC061)110 (max.)
- Comox Valley (BC014)106 (max.)
- K'ómoks (BC272)106 (max.)
- Cowichan estuary (BC048)100 (max.)
- Tofino Mudflats (BC002)100 (max.)
- Creston Valley (BC179)60 (max.)
- Squamish River Area (BC023)55 (max.)
- Somenos Marsh Wildlife Refuge (BC051)50 (max.)
- Glenfinnan Island (PE018)1,014 (max.)
Global
1% of the global population estimate. This threshold is used to identify trigger species and IBAs under categories A4i/ii and A4iv.
Regional/Continental
1% of the regional/continental population estimate.
Sub-regional/National SAR
The sub-regional/national SAR threshold = 1% of the COSEWIC population estimate for the region (provinces/territories) in which the species is listed as being at risk. This threshold is used to identify trigger species and IBAs under criterion C1.
| La Grande Île (QC118) | ||
|---|---|---|
| Number | Year | Season |
| 2,354 | 1992 | Summer |
| 1,900 | 1991 | Summer |
| 1,688 | 1986 | Summer |
| 604 | 1980 | Summer |
| Pelee Island Archipelago (ON014) | ||
|---|---|---|
| Number | Year | Season |
| 500 | 1997 | Summer |
| 574 | 1991 | Summer |
| 1,040 | 1988 | Summer |
| 1,850 | 1983 | Summer |
| 800 | 1981 | Summer |
| 1,000 | 1980 | Summer |
| Boundary Bay - Roberts Bank - Sturgeon Bank (Fraser River Estuary) (BC017) | ||
|---|---|---|
| Number | Year | Season |
| 200 | 2021 | Fall |
| 120 - 250 | 2021 | Summer |
| 300 - 350 | 2021 | Spring |
| 41 - 60 | 2021 | Winter |
| 35 - 225 | 2020 | Winter |
| 55 - 150 | 2020 | Fall |
| 179 - 400 | 2020 | Summer |
| 40 - 300 | 2020 | Spring |
| 37 - 269 | 2019 | Fall |
| 80 - 310 | 2019 | Summer |
| 35 - 500 | 2019 | Spring |
| 35 - 75 | 2019 | Winter |
| 40 - 86 | 2018 | Winter |
| 39 - 335 | 2018 | Fall |
| 70 - 250 | 2018 | Summer |
| 40 - 350 | 2018 | Spring |
| 38 - 62 | 2017 | Winter |
| 37 - 80 | 2017 | Fall |
| 200 - 440 | 2017 | Summer |
| 38 - 340 | 2017 | Spring |
| 42 - 264 | 2016 | Winter |
| 35 - 200 | 2016 | Fall |
| 60 - 400 | 2016 | Summer |
| 250 - 332 | 2016 | Spring |
| 40 - 180 | 2015 | Fall |
| 47 - 300 | 2015 | Summer |
| 35 - 170 | 2015 | Spring |
| 44 - 175 | 2015 | Winter |
| 35 - 317 | 2014 | Winter |
| 35 - 60 | 2014 | Fall |
| 40 - 375 | 2014 | Summer |
| 40 - 266 | 2014 | Spring |
| 38 - 184 | 2013 | Winter |
| 36 - 105 | 2013 | Fall |
| 40 - 190 | 2013 | Summer |
| 51 - 268 | 2013 | Spring |
| 85 - 245 | 2012 | Winter |
| 50 - 62 | 2012 | Fall |
| 60 - 400 | 2012 | Summer |
| 35 - 157 | 2012 | Spring |
| 125 - 212 | 2011 | Winter |
| 50 - 81 | 2011 | Fall |
| 53 - 223 | 2011 | Summer |
| 44 - 278 | 2011 | Spring |
| 35 - 258 | 2010 | Winter |
| 35 - 70 | 2010 | Fall |
| 35 - 37 | 2010 | Summer |
| 38 - 150 | 2010 | Spring |
| 158 - 258 | 2009 | Winter |
| 41 - 100 | 2009 | Fall |
| 34 - 125 | 2009 | Summer |
| 50 - 158 | 2009 | Spring |
| 35 - 95 | 2008 | Fall |
| 40 - 168 | 2008 | Summer |
| 45 - 202 | 2008 | Spring |
| 202 | 2008 | Winter |
| 36 - 279 | 2007 | Winter |
| 34 - 75 | 2007 | Fall |
| 34 - 128 | 2007 | Summer |
| 40 - 86 | 2007 | Spring |
| 38 - 279 | 2006 | Winter |
| 40 - 90 | 2006 | Fall |
| 37 - 250 | 2006 | Summer |
| 55 - 90 | 2006 | Spring |
| 37 - 293 | 2005 | Winter |
| 43 - 168 | 2005 | Fall |
| 75 | 2005 | Summer |
| 262 | 2004 | Winter |
| 34 - 96 | 2004 | Fall |
| 452 | 2004 | Summer |
| 36 - 70 | 2004 | Spring |
| 114 - 254 | 2003 | Winter |
| 37 - 50 | 2003 | Fall |
| 64 - 145 | 2003 | Summer |
| 150 | 2003 | Spring |
| 35 - 297 | 2002 | Winter |
| 50 - 197 | 2002 | Fall |
| 91 | 2002 | Summer |
| 50 | 2002 | Spring |
| 162 - 297 | 2001 | Winter |
| 35 - 72 | 2001 | Fall |
| 80 - 110 | 2001 | Summer |
| 41 - 75 | 2001 | Spring |
| 109 - 269 | 2000 | Winter |
| 35 - 86 | 2000 | Fall |
| 34 - 120 | 2000 | Summer |
| 36 - 57 | 2000 | Spring |
| 121 - 150 | 1999 | Winter |
| 50 - 194 | 1999 | Fall |
| 36 - 400 | 1999 | Summer |
| 94 - 171 | 1998 | Winter |
| 34 | 1998 | Fall |
| 120 | 1998 | Summer |
| 45 | 1998 | Spring |
| 35 - 96 | 1997 | Fall |
| 35 - 139 | 1997 | Spring |
| 74 - 139 | 1997 | Winter |
| 692 | 1997 | Summer |
| 100 | 1996 | Winter |
| 50 - 77 | 1996 | Fall |
| 84 - 206 | 1995 | Winter |
| 50 - 60 | 1995 | Fall |
| 51 - 1,000 | 1995 | Summer |
| 88 | 1995 | Spring |
| 128 - 155 | 1994 | Winter |
| 35 - 40 | 1994 | Fall |
| 409 | 1994 | Summer |
| 46 - 200 | 1994 | Spring |
| 82 - 200 | 1993 | Winter |
| 50 - 150 | 1993 | Fall |
| 75 - 200 | 1993 | Summer |
| 150 | 1993 | Spring |
| 36 - 218 | 1992 | Winter |
| 36 - 158 | 1992 | Fall |
| 47 - 50 | 1992 | Spring |
| 140 - 215 | 1991 | Winter |
| 80 - 150 | 1991 | Fall |
| 40 - 47 | 1991 | Spring |
| 34 - 222 | 1990 | Winter |
| 35 - 110 | 1990 | Fall |
| 41 | 1990 | Summer |
| 110 - 178 | 1990 | Spring |
| 251 | 1981 | Winter |
| English Bay, Burrard Inlet & Howe Sound (BC020) | ||
|---|---|---|
| Number | Year | Season |
| 50 - 60 | 2021 | Summer |
| 60 - 75 | 2021 | Spring |
| 40 - 50 | 2020 | Summer |
| 40 - 74 | 2020 | Spring |
| 40 - 42 | 2020 | Winter |
| 50 - 100 | 2019 | Summer |
| 40 - 180 | 2019 | Spring |
| 48 - 50 | 2018 | Summer |
| 35 - 74 | 2018 | Spring |
| 70 - 100 | 2017 | Spring |
| 40 - 100 | 2016 | Spring |
| 52 - 61 | 2016 | Winter |
| 50 - 200 | 2015 | Spring |
| 80 - 85 | 2015 | Winter |
| 70 | 2014 | Summer |
| 35 - 75 | 2014 | Spring |
| 42 - 90 | 2013 | Summer |
| 60 - 200 | 2013 | Spring |
| 40 | 2012 | Spring |
| 224 | 2011 | Summer |
| 52 - 248 | 2010 | Summer |
| 40 - 70 | 2010 | Spring |
| 50 - 80 | 2009 | Spring |
| 290 | 2009 | Summer |
| 302 | 2008 | Summer |
| 71 - 366 | 2007 | Summer |
| 40 - 70 | 2006 | Spring |
| 356 | 2006 | Summer |
| 352 | 2005 | Summer |
| 140 | 2004 | Summer |
| 42 | 2003 | Summer |
| 36 - 40 | 2002 | Summer |
| 12 | 2001 | Summer |
| 51 | 1997 | Spring |
| 40 | 1990 | Summer |
| Pacific Spirit Regional Park (BC018) | ||
|---|---|---|
| Number | Year | Season |
| 364 | 1985 | Summer |
| Holden Lake (BC053) | ||
|---|---|---|
| Number | Year | Season |
| 52 | 1999 | Summer |
| 42 | 1998 | Summer |
| 32 | 1997 | Summer |
| 144 | 1996 | Summer |
| 180 | 1995 | Summer |
| 324 | 1993 | Summer |
| 200 | 1991 | Summer |
| 200 | 1989 | Summer |
| 200 | 1988 | Summer |
| McFadden Creek Heronry (BC001) | ||
|---|---|---|
| Number | Year | Season |
| 276 | 2000 | Summer |
| 236 | 1996 | Summer |
| 2 | 1990 | Summer |
| Sidney Channel (BC047) | ||
|---|---|---|
| Number | Year | Season |
| 43 - 48 | 2021 | Summer |
| 37 | 2021 | Spring |
| 35 | 2020 | Winter |
| 36 | 2019 | Summer |
| 43 | 2018 | Fall |
| 35 | 2012 | Fall |
| 35 | 2007 | Summer |
| 38 | 2000 | Summer |
| 35 - 38 | 1998 | Fall |
| 35 - 52 | 1998 | Summer |
| 42 | 1997 | Fall |
| 35 - 42 | 1997 | Summer |
| 36 - 46 | 1996 | Fall |
| 34 - 46 | 1996 | Summer |
| 40 - 51 | 1996 | Spring |
| 35 - 53 | 1995 | Summer |
| 50 | 1995 | Other |
| 40 | 1994 | Fall |
| 74 | 1994 | Spring |
| 0 | 1994 | Summer |
| 35 | 1993 | Summer |
| 62 | 1993 | Spring |
| 55 | 1991 | Fall |
| 38 | 1990 | Fall |
| 200 | 1988 | Summer |
| Baynes Sound (BC057) | ||
|---|---|---|
| Number | Year | Season |
| 35 | 2007 | Winter |
| 35 | 2006 | Winter |
| 35 | 1999 | Spring |
| 35 | 1999 | Winter |
| 35 | 1998 | Spring |
| 35 | 1998 | Winter |
| 35 | 1994 | Winter |
| 136 | 1981 | Summer |
| Little Qualicum Estuary to Nanoose Bay (BC056) | ||
|---|---|---|
| Number | Year | Season |
| 112 | 2018 | Spring |
| 56 | 2015 | Winter |
| 38 | 2013 | Winter |
| 37 | 2012 | Winter |
| 45 | 2006 | Winter |
| 37 | 2005 | Winter |
| 40 | 2004 | Winter |
| 43 | 2003 | Winter |
| 35 | 2002 | Spring |
| 34 | 1999 | Winter |
| 37 | 1995 | Winter |
| 38 | 1994 | Winter |
| 33 | 1977 | Summer |
| ? | ? | Other |
| Lambert Channel/Hornby Island Waters (BC061) | ||
|---|---|---|
| Number | Year | Season |
| 16 | 2008 | Fall |
| 38 | 2007 | Summer |
| 38 | 2003 | Spring |
| 110 | 1999 | Summer |
| Comox Valley (BC014) | ||
|---|---|---|
| Number | Year | Season |
| 37 - 55 | 2016 | Summer |
| 53 | 2015 | Winter |
| 44 | 2014 | Winter |
| 41 | 2009 | Winter |
| 11 | 2009 | Fall |
| 44 | 2006 | Winter |
| 60 | 2005 | Winter |
| 55 | 2004 | Winter |
| 56 | 2003 | Winter |
| 39 | 2002 | Winter |
| 39 - 90 | 2001 | Winter |
| 44 | 2001 | Fall |
| 61 | 1999 | Winter |
| 61 | 1998 | Winter |
| 56 | 1997 | Winter |
| 43 | 1995 | Winter |
| 34 | 1994 | Winter |
| 53 | 1993 | Winter |
| 86 | 1992 | Winter |
| 106 | 1991 | Winter |
| 69 | 1990 | Winter |
| K'ómoks (BC272) | ||
|---|---|---|
| Number | Year | Season |
| 43 | 2021 | Fall |
| 56 | 2021 | Summer |
| 36 - 44 | 2020 | Fall |
| 38 - 53 | 2020 | Summer |
| 34 - 46 | 2020 | Spring |
| 40 - 59 | 2018 | Fall |
| 38 - 68 | 2018 | Summer |
| 37 - 55 | 2016 | Summer |
| 53 | 2015 | Winter |
| 44 | 2014 | Winter |
| 56 | 2012 | Spring |
| 68 | 2011 | Spring |
| 102 | 2010 | Spring |
| 41 | 2009 | Winter |
| 49 | 2009 | Spring |
| 53 | 2008 | Spring |
| 46 | 2007 | Fall |
| 38 | 2007 | Summer |
| 48 | 2007 | Spring |
| 35 - 44 | 2006 | Winter |
| 60 | 2005 | Winter |
| 45 - 76 | 2005 | Spring |
| 55 | 2004 | Winter |
| 55 - 63 | 2004 | Fall |
| 42 | 2004 | Summer |
| 46 - 94 | 2004 | Spring |
| 56 | 2003 | Winter |
| 54 | 2003 | Fall |
| 38 - 84 | 2003 | Spring |
| 39 | 2002 | Winter |
| 55 | 2002 | Fall |
| 73 | 2002 | Spring |
| 39 | 2001 | Winter |
| 44 | 2001 | Fall |
| 35 - 61 | 1999 | Winter |
| 35 - 61 | 1998 | Winter |
| 56 | 1997 | Winter |
| 43 | 1995 | Winter |
| 34 - 35 | 1994 | Winter |
| 53 | 1993 | Winter |
| 86 | 1992 | Winter |
| 106 | 1991 | Winter |
| 69 | 1990 | Winter |
| Cowichan estuary (BC048) | ||
|---|---|---|
| Number | Year | Season |
| 45 - 76 | 2021 | Summer |
| 39 - 110 | 2021 | Spring |
| 62 | 2021 | Winter |
| 41 - 92 | 2020 | Summer |
| 83 - 100 | 2020 | Spring |
| 80 | 2020 | Winter |
| 46 - 80 | 2019 | Summer |
| 40 | 2019 | Spring |
| 35 - 65 | 2018 | Summer |
| 36 - 100 | 2018 | Spring |
| 41 - 73 | 2017 | Summer |
| 35 | 2017 | Spring |
| 82 | 2016 | Summer |
| 47 | 2016 | Spring |
| 51 - 80 | 2015 | Spring |
| 46 | 2014 | Summer |
| 42 | 2013 | Summer |
| 35 - 50 | 2012 | Summer |
| 35 - 57 | 2011 | Summer |
| 38 | 2010 | Fall |
| 35 - 49 | 2010 | Summer |
| 59 | 2010 | Spring |
| Tofino Mudflats (BC002) | ||
|---|---|---|
| Number | Year | Season |
| 40 | 2017 | Fall |
| 34 | 2015 | Fall |
| 37 | 2012 | Summer |
| 48 | 2011 | Fall |
| 34 - 51 | 2004 | Summer |
| 44 - 75 | 2003 | Summer |
| 56 | 2002 | Winter |
| 81 | 2002 | Fall |
| 45 - 53 | 2002 | Summer |
| 39 - 73 | 2001 | Fall |
| 50 - 56 | 2001 | Summer |
| 39 - 53 | 2000 | Fall |
| 37 | 2000 | Summer |
| 47 - 56 | 1999 | Fall |
| 100 | 1995 | Fall |
| 39 | 1992 | Summer |
| Creston Valley (BC179) | ||
|---|---|---|
| Number | Year | Season |
| 34 | 2021 | Spring |
| 55 | 2019 | Spring |
| 40 | 2018 | Fall |
| 40 | 2018 | Spring |
| 35 | 2016 | Spring |
| 50 | 2015 | Spring |
| 36 | 2015 | Winter |
| 51 - 60 | 2014 | Spring |
| 38 - 60 | 2013 | Spring |
| 40 | 2003 | Winter |
| Squamish River Area (BC023) | ||
|---|---|---|
| Number | Year | Season |
| 44 | 2021 | Spring |
| 44 | 2019 | Summer |
| 43 | 2018 | Spring |
| 43 | 2017 | Winter |
| 37 | 2017 | Summer |
| 37 - 39 | 2016 | Spring |
| 41 | 2016 | Winter |
| 36 | 2015 | Winter |
| 55 | 2015 | Summer |
| 44 | 2014 | Winter |
| 38 | 2014 | Fall |
| 40 | 2014 | Summer |
| 40 | 2013 | Winter |
| 48 | 2013 | Summer |
| 40 | 2010 | Summer |
| 35 | 2007 | Winter |
| 35 | 2007 | Summer |
| 34 | 2006 | Fall |
| 35 | 2006 | Winter |
| 36 | 2005 | Summer |
| 41 | 2004 | Fall |
| 35 | 2004 | Winter |
| 45 | 2003 | Winter |
| 50 | 2003 | Fall |
| 35 | 2003 | Summer |
| 39 - 41 | 2001 | Fall |
| 36 | 2000 | Winter |
| 34 | 1999 | Spring |
| 34 | 1999 | Winter |
| Somenos Marsh Wildlife Refuge (BC051) | ||
|---|---|---|
| Number | Year | Season |
| 50 | 1998 | Summer |
| Glenfinnan Island (PE018) | ||
|---|---|---|
| Number | Year | Season |
| 1,014 | 1997 | Summer |
| 508 | 1987 | Summer |
| 500 | 1981 | Summer |
| 364 | 1980 | Summer |
| 200 | 1977 | Summer |
| 100 | 1974 | Summer |