This heron seems to be announcing just that.
"The Stanley Park Heronry is one of the more awe inspiring sights in the Park in the Spring and Summer seasons. A cluster of around twenty trees has become the largest nesting site for Great Blue Herons in the region, a sight that draws many bird watchers, naturalists and visitors to the park to observe the dozens of pairs and their squawking young. The Herons will nest until their young are able to fly, leaving Stanley Park and returning the next year. The Heronry is a unique experience as these reclusive and elegant birds are never usually spotted in large groups."
Read more: Heronry http://www.venturevancouver.com/heronry-stanley-park-vancouver#ixzz3TvysY9iV