Plus: size matters for female bighorn sheep, the hidden migration of North American dragonflies, helping trees move north and the great white who drew itself

Changes to the city’s Green Standard aimed at protecting its fragile ravine network will pose challenges and opportunities for landscapers — and could kick off a national trend

Experts say global reforestation is one of our best defences against climate change, so a Toronto-based company is developing drones that can get the job done quickly

Volunteers are collecting samples from bigleaf maples to prevent illegal logging