ACTIVITIES A Problem of Numbers This activity aligns with the following National Science Education Standards' Content Standard C: Life Science– Populations and Ecosystems According to most estimates, the wild horse and burro population grows at a rate of around 18 percent per year. Encourage students to use their mathe-matics skills to extrapolate the population of wild horses or burros in one or more of the states listed below. The figures used show the 1999 population of wild horses and/or burros. Have students determine what the population would be in 10 years if no intervention took place. Depending on their mathematics abili-ties, students could make a chart or graph to illustrate their findings. Arizona 3,055 California 5,225 Colorado 755 Idaho 814 Montana 176 Nevada 23,905 New Mexico 55 Oregon 2,551 Utah 4,561 Wyoming 6,279 The Bureau of Land Management intervenes in the situation by gathering excess animals and putting them up for adoption, which helps maintain healthy herds and healthy rangelands. Encourage students to consider what natural factors might limit the population growth of wild horses and burros. (Among the answers students might come up with are: harsh weather, such as drought or extremely heavy snowfall; disease; introduction of a predator.) "Mane" Assortment This activity aligns with the following National Science Education Standards' Content Standard C: Life Science– Diversity and Adaptations of Organisms Wild horses are well adapted to their life on the western range. Among the adaptations that help ensure their survival in the wild are heavy muscles, tough hooves, a large lung capacity, and acute senses of hearing and eyesight. Ever since humans began domesticat-ing animals more than 10,000 years ago, they have selected certain traits in ani-mals and attempted to reproduce these traits in offspring. As advancements were made in the science of genetics, humans developed various animals (and plants) that meet particular needs. Cats, dogs, and horses are just a few examples of animals on which humans have used controlled breeding to produce desirable characteristics. Students are probably familiar with a variety of horse breeds, including Arabians, Clydesdales, Morgans, Pintos, Quarter Horses, and Thoroughbreds. Compile a class list of horse breeds on a chalkboard or a pad of easel paper. Next, divide students into groups, and have each group research and report on the origin and development of a particular breed of horse. Among the questions the reports should answer are: When and where was the breed originally developed? What particular traits does it have? How have humans made use of these traits? A Class Act This activity aligns with the following National Science Education Standards' Content Standard C: Life Science–Characteristics of Organisms; Biological Evolution Collect pictures of various animals cut out from magazines. Students should bring in some from home. Try to include pictures from each of the animal classes, including insects, reptiles, birds, amphib-ians, and mammals. Make sure there are at least a few pictures of different horse pictures on a bulletin board. Scientists classify animals according to their body traits. The more traits they have in common, the more closely the animals are related. Students should look at the animal pictures and divide the ani-mals into groups. What traits did they use to make their groups? Students might use color, size, number of legs, where the ani-mals live, or what they eat. Discuss their "classification systems" and reasons why some might be better than others. Challenge students to name more than one characteristic that links the members of each of their groups. (For instance, what besides coloring do a zebra and a penguin have in common? Is it likely that they are related?) Then ask students to make a guess: Name three animals that are most closely related to horses and burros. To deter-mine this, start by dividing the animals into the classes mentioned above and turning students' attention to mammals. How do scientists divide them further? By asking a series of questions, the teacher can help students narrow down a list of relatives of the horse and burro. A horse is a horse, of course, and a burro is a burro. But a mule? This sterile offspring of a female horse and a male burro is another, less common member of the genus Equus. JOEL HANSON, WILDHORSEPHOTOS.COM All mammals, for instance, have hair and feed their young with milk. But which mammals in the pictures have four legs and hooves? Encourage students to look up this information in encyclopedias or on the Internet if they are not sure. Even if they are sure about hooves, the next question may require some research: Which hoofed animals have an odd number of toes? By answer-ing this question, students will come up with members of the order Perissodactyla, a name derived from Greek words meaning "odd" and "fingers." Besides horses and burros, stu-dents will discover that zebras, rhinocer-oses, and tapirs are Perissodactyls. In their research students may also learn about members of the order Artiodactyla. These hoofed mammals, with an even number of toes, include sheep, cattle, deer, and pigs. To further define the relatives of the horse and burro, encourage students to research the family of animals known as Equidae and the genus known as Equus. Once they've completed their research, students could draw—or use their cut-out pictures to create—a horse and burro family portrait.