This is the time of year in Central Minnesota when a greater number of hummingbirds are seen at once - at the feeders or out in the field especially areas abundant with the native plant Jewelweed. The high population of ruby-throated hummingbirds occurs because birds from the north are now down here feeding with the resident birds before flying the next leg south. The hummers get very territorial over their food source during this brief period and will often stake out a perch to dive bomb a competitor that flies in.