For live links, click to: riverhouses.org/2019-anatidae-ii
Every Friday in the River Houses we invite you and your students to learn about a different group of North American birds from your recommended homeschool bird guide (riverhouses.org/books) — it’s a great way to add a few minutes of informal science, geography, natural history, and imagination to your homeschool schedule. (We started this new feature at the beginning of this month with an introduction to your bird guide.)
This week’s family is (again) the Ducks, Geese, and Swans — the Anatidae (bird guide page 14). Usually we’ll cover one or two families each week, but we’re spreading the ducks, geese, and swans over two weeks because there are so many of them: about 160 species around the world, and 66 in North America. Last week we said a few words about geese and swans; this week we’ll turn to the ducks.
With smaller children, you can take our Friday Bird Families posts as opportunities to just use your bird guide as a picture book and spend a few minutes looking at all the wonderful wildlife. For older students, one of our objectives is to help them become fluent with a technical reference book that’s packed with dense information. Here’s the introduction to this bird family — you’ll find it on page 14:
“DUCKS · GEESE · SWANS — Family Anatidae. Worldwide family. Web-footed, gregarious birds, ranging from small ducks to swans. Largely aquatic, but geese, swans, and some ‘puddle ducks’ also graze on land. Species: 160 World, 66 N.A. [North America].“
In larger families, such as the ducks, geese, and swans, your bird guide will also often have separate subheadings for notable subgroups within the family — for example, the “dabbling ducks” (page 26):
“DABBLING DUCKS. Surface-feeding members of the genus Anas: the familiar ‘puddle ducks’ of freshwater shallows and, chiefly in winter, salt marshes. Dabblers feed by tipping, tail up, to reach aquatic plants, seeds, and snails. They require no running start to take off but spring directly into flight. Most species show a distinguishing swatch of bright color, the speculum, on the secondaries. Many are known to hybridize.“
Pick a representative species to look at in detail each week and read the entry aloud, or have your students study it and then narrate it back to you, explaining all the information it contains. This week, why not investigate one of the most familiar of all ducks, a species found throughout the entire northern hemisphere: the Mallard (page 26).
All sorts of biological information is packed into the brief Mallard species description in your bird guide — can your students tease it out? How big is this bird? (23 inches long.) What’s its scientific name? (Anas platyrhynchos.) What does it sound like? (Quack! But then you already knew that. 😊) Will you be able to find this species where you live? At what times of year? (Study the range map and range description carefully to answer those questions, and see the book’s back flap for a map key.)
From the illustrations you can see that the Mallard is sexually dimorphic (“two-formed”): that is, the males and females are different in appearance, with the males having an iridescent green head, chestnut breast, and silvery-gray flanks. A little browsing will show you that most duck species are dimorphic, whereas most geese and swans are sexually monomorphic (“one-formed”): the males and females are similar in appearance, and just by looking you can’t tell them apart.
One of the most beautiful hidden features of many dabbling ducks, as noted in the description above, is the speculum (Latin, “mirror”) — the swatch of iridescence on the secondary feathers (the inner wing feathers that attach to the bird’s forearm). The speculum is plainly visible when the bird is in flight, but it’s usually hidden at rest, unless the bird happens to stretch its wings a bit.
And of course Mallards have provided the soundtrack — accurately or not — for just about every duck that has ever appeared in film and television. 🔊
Browse through the many other duck species in your bird guide and take note of (and delight in) the many wonderful duck names that enrich the English language: gadwall, merganser, pochard, eider, teal, canvasback, scaup, pintail, and more.
What ornithological discoveries have you made in your homeschool this week? 😊
❡ Homeschool birds: We think bird study is one of the best subjects you can take up in a homeschool environment. It’s suitable for all ages, it can be made as elementary or as advanced as you wish, and birds can be found just about anywhere at any season of the year. Why not track your own homeschool bird observations on the free eBird website sponsored by Cornell University. It’s a great way to learn more about what’s in your local area and about how bird populations change from season to season. 🐦
❡ Words for birds: You may not think of your homeschool dictionary (riverhouses.org/books) as a nature reference, but a comprehensive dictionary will define many of the standard scientific terms you will encounter in biology and natural history, although it will not generally contain the proper names of species or other taxonomic groups that aren’t part of ordinary English. (In other words, you’ll find “flamingo” but not Phoenicopterus, the flamingo genus.) One of the most important things students should learn to look for in the dictionary is the information on word origins: knowing the roots of scientific terms makes it much easier to understand and remember their meaning. 📖
❡ Come, here’s the map: Natural history and geography are deeply interconnected. One of the first questions you should teach your students to ask about any kind of animal or plant is, “What is its range? Where (in the world) does it occur?” Our recommended homeschool reference library (riverhouses.org/books) includes an excellent world atlas that will help your students appreciate many aspects of biogeography — the science of the geographical distribution of living things. 🌎
❡ Rivers in the sky: How many birds are migrating this week? You can find out from the BirdCast website, also sponsored by Cornell University, which offers daily bird migration forecasts in the spring and fall for the entire United States. 🦅
❡ Nature notes: This is one of our regular Friday Bird Families posts. Why not print your own copy of our River Houses Calendar of American Birds and follow along with us, and add your name to our free weekly mailing list (riverhouses.org/newsletter) to get great homeschool teaching ideas delivered right to your mailbox all through the year. 🦆