Most birders in Calgary have seen Great Blue Herons along the city waterways or flying overhead as the birds come and go from their communal roosts. But many people are not aware that you can also see their smaller relative, the Black-crowned Night-heron, within the city limits.
These birds are not very common in this area. During the past five May Species Counts, between 6 and 21 Night-herons were counted, and that is within an 80 kilometre radius of the city centre. In the 2009 count, only 13 birds were seen, all of them in the prairie area and none within the city limits.
There may well be many more birds around than these numbers indicate, since Night-herons, as their name suggests, are mostly active at night. During the day they roost in trees, bushes, or reeds and can be difficult to see, despite standing about 64 cm (two feet) high.
These birds have an almost worldwide distribution and in this part of their range they are migratory. They arrive in the Calgary area during the second week of April.
The best place I know to see Black-crowned Night-herons within the city of Calgary is at a pond near Country Hills Boulevard and Deerfoot Trail in the Northeast. The pond lies in the southwest corner of that intersection. There is a gravel road (15 Street NE) that runs just west of the pond. You can park there and see the herons from the road, or walk down. I don’t recommend going near the pond until at least mid-July since American Avocets nest there and get quite agitated if you approach. We don’t want to scare them off.
I don’t know if the Night-herons breed near this pond. The earliest I have seen them there is the last week of June, so I suspect that they breed elsewhere and come to feed after the breeding season is over.
In 2008 I saw as many as seven birds there at once, including two juveniles. This year I have only seen adults.
Black-crowned Night-Herons have also been reported at the ponds near Airport Trail (96 Avenue) on the west side of Deerfoot Trail, which is about one kilometre south of the Country Hills Boulevard location. But it is very difficult to access that area safely. The best you can do is pull on to the shoulder of Deerfoot Trail to have a look.
If you know of any other reliable locations for these birds within the city limits, please post a comment.