You can read all of the observations people have submitted here. These are some highlights:

Fewer Males in the North
Males leave first, yet a few are still being seen in the north as August ends:

"We had a half dozen hummingbirds at our feeder this evening, most of them females, but also one male. We observed the females being rather aggressive and chasing off the other females, even to the ground," reports a surprised third-grade teacher from Iowa.

"One male, one female and one juvenile constantly feeding at the four feeders. Numbers dramatically down from 2011," writes an Elliot Lake, ON observer.

"Number of birds are significantly less than last week," comments a South Mountain, PA observer.

"Have not seen a male since Aug. 27. Only a half dozen or so females left," writes a Phelps, WI friend.

Hungry Migrants Arriving in the South

"They are coming in each day. They eat all day long, starting at sunrise. I have to fill feeders up in the morning and evening both. They have done this consistently all summer long. I notice a lot more females or yearlings instead of males. I'll sure miss them," writes Teresa Young from Missouri.

"Adult male was chasing a female or an immature male away from our feeder in our school's butterfly garden. My students & I watched them fly around the garden from 11:00 am - 2:00 pm," came the news from Oakview Elementary in Greenville, SC.

"We have a hummingbird feeder at school. We have seen 4 hummingbirds come and go since school started on August 8. At home, our teacher has about 20 at 3 different feeders," report third graders from Cub Run, KY. "They eat a lot!!!!"

Tropical Storm Isaac Hits

Each year, migratory birds cross the Gulf of Mexico during the hurricane season. Several observers mentioned concern about Isaac, which was downgraded from hurricane to tropical storm on Aug. 29 when the storm stretched more than 400 miles across the Gulf Coast. Diana from Baton Rouge, LA reported 30 hummingbirds on August 27, saying:

"Starting yesterday morning, I noticed a dramatic increase increase of the number of hummers and their activity. Of course Tropical Storm Isaac is headed our way. These little wonders obviously know this and are gearing up for flight. I have 6 feeders out right now and each has 5 or more hummers fighting and feeding at the same time."

Click here to see Diana's next comments on August 29 and 30, along with Isaac-related comments from ornithologist Laura Erickson. (Keep your feeders up!)

Ruby-throated Hummingbirds are one of over 300 species of hummingbirds, and the only breeding hummingbirds in eastern North America. Month by month, where are Ruby-throated Hummingbirds and what are they doing? Facts and photos in this week's slideshow describe their annual cycle. See how these tiny birds respond to the seasons. Then create a quick reference by writing month-by-month verbs on the calendar handout that is this week's journal page:

• Slideshow
• Journal Page
• More Teaching Suggestions