Caspian Tern
Scientific Name: Hydroprogne caspia
Thresholds:
- Little George Island (MB062)7,600 (max.)
- Spruce Island Reef (MB098)6,000 (max.)
- Lake St. Martin Islands (MB083)3,000 (max.)
- Presqu'ile Provincial Park (ON004)2,444 (max.)
- Sand Reef Islands (MB092)2,000 (max.)
- The Watchers (ON016)1,570 (max.)
- Duck Island (MB032)1,200 (max.)
- Pigeon Island (ON041)958 (max.)
- The Cousins (ON017)934 (max.)
- Limestone Islands (ON052)866 (max.)
- Hamilton Harbour Waterbird Colonies (ON020)798 (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.
| Little George Island (MB062) | ||
|---|---|---|
| Number | Year | Season |
| 7,600 | 1992 | Summer |
| 1,000 | 1987 | Summer |
| 3,000 | 1986 | Summer |
| Spruce Island Reef (MB098) | ||
|---|---|---|
| Number | Year | Season |
| 6,000 | 1999 | Summer |
| Lake St. Martin Islands (MB083) | ||
|---|---|---|
| Number | Year | Season |
| 3,000 | 1986 | Summer |
| 1,020 | 1970 | Summer |
| Presqu'ile Provincial Park (ON004) | ||
|---|---|---|
| Number | Year | Season |
| 2,444 | 2001 | Summer |
| 2,400 | 2000 | Summer |
| 932 | 1997 | Summer |
| 740 | 1994 | Summer |
| 588 | 1993 | Summer |
| 204 | 1990 | Summer |
| Sand Reef Islands (MB092) | ||
|---|---|---|
| Number | Year | Season |
| 1,208 | 2012 | Summer |
| 2,000 | 1986 | Summer |
| 900 | 1979 | Summer |
| The Watchers (ON016) | ||
|---|---|---|
| Number | Year | Season |
| 1,142 | 1998 | Summer |
| 1,356 | 1994 | Summer |
| 1,570 | 1989 | Summer |
| 1,046 | 1980 | Summer |
| Duck Island (MB032) | ||
|---|---|---|
| Number | Year | Season |
| 1,200 | 2012 | Summer |
| Pigeon Island (ON041) | ||
|---|---|---|
| Number | Year | Season |
| 958 | 1990 | Summer |
| 80 | 1977 | Summer |
| The Cousins (ON017) | ||
|---|---|---|
| Number | Year | Season |
| 260 | 1998 | Summer |
| 934 | 1991 | Summer |
| 790 | 1980 | Summer |
| Limestone Islands (ON052) | ||
|---|---|---|
| Number | Year | Season |
| 558 | 1998 | Summer |
| 866 | 1989 | Summer |
| 688 | 1980 | Summer |
| Hamilton Harbour Waterbird Colonies (ON020) | ||
|---|---|---|
| Number | Year | Season |
| 798 | 1997 | Summer |
| 492 | 1992 | Summer |