(d) Other birds
11. Birds are fascinating and amazing because:
(a) Only birds have feathers, a unique, beautiful and versatile body covering.
(b) Many birds live in close proximity to humans and allow us to observe their lives.
(c) Birds’ songs and calls add so much to our enjoyment of the natural world.
(d) Birds perform many services, some eating harmful insects, others acting as pollinators and a few even cleaning up roadkill
1. Although we can’t be certain of the reasons geese honk in flight, many researchers feel that (a) is part of the answer.
2. The answer is (c): Owls are raptors and many of them kill and eat smaller birds. Songbirds want to drive owls out of their area before night, a time when they’re asleep and especially vulnerable.
3. The correct answer is (b) — tropical songbirds began pushing northward after the last Ice Age and have built traditional migratory patterns to take advantage of abundant food and room for nesting in northern areas in summer.
4. The answer is (b), according to the Audubon Society: more than 800 species can be found at one time or another in North America and 654 species are considered native to our continent.
5. According to Partners in Flight’s population estimate database, there are around 300 million robins in North America, making them our most populous bird, so it’s (c). This estimate is based on a variety of bird surveys.
6. (b) and (c) are both correct. Birds need to stuff themselves before starting migration to fuel the early part of their journey. Some migrants add 50 percent or more to their usual weight, but they never lose the ability to fly. In fact, hummingbirds often get so tubby that they look like flying golf balls.
7. The answer is (d). Most birds raise their young, teach them to feed themselves and then they’re done. Crows, however, have very strong and lengthy family ties. In fact, they’re known for the “helper at the nest” phenomenon, in which a young crow from a previous year’s nest helps its parents raise their brood in subsequent years.
8. Mostly false. Red birds like cardinals truly are red; their feathers colored by the foods they eat, and the same rule applies to birds like goldfinches and orioles. The big exceptions are birds that are blue and those with iridescence. The brilliant blue we see on bluebirds and blue jays is really a trick of the way light strikes their feathers and hummingbirds’ iridescence is due to feather structure, not pigments.
9. (c ) These all travel amazing distances but the champ is the Arctic tern, a bird that may cover up to 44,000 miles in a year’s time, flying between Greenland and Antarctica. Caribou move up to 800 miles, green darners may travel several hundred miles and monarchs may migrate 2,500 miles to reach Mexico’s highlands.