Background Knowledge & Content Objectives
This unit follows a unit on flight. Students will have read multiple texts concerning the forces of flight (i.e. gravity, drag, thrust, lift) and about how humans learned to fly. One of the assigned texts, How People Learned to Fly by Fran Hodgkins, specifically mentions that people studied birds to learn about flight. Using the flight unit as a jumping off point to begin talking about animal adaptations, students will already know that birds are special because they can fly. Students will know that people have studied birds for centuries because of this ability.
In the context of the urban environment where my students live, most students are very aware of pigeons. It can feel like that is the only type of bird that survives, living off litter and trash. However, as I learned in my research, “birds are the most species-rich group of living land-dwelling vertebrates...occupying every continent and almost every habitat on Earth.”6 After training myself to look closer, it becomes increasingly clear that the birds I encounter on a daily basis are definitely more than pigeons. Teaching students about this variety will help them to closely observe. Although we are doing this in a scientific context, training students to pay attention will help them in every aspect of their academic career.
While it may seem as if birds are similar and have similar adaptations regardless of species, especially in the eyes of a child, almost every part of their body is adapted for survival in subtle ways based on their habitat. Even if one was just to study birds within the United States of America, they would be able to find various adaptations based on the multiple habitats within this large country.
Animal Adaptations
There are four key tenets for the survival of a species: (1) acquiring food and water, (2) acquiring shelter, (3) physical safety, and (4) reproduction. For students, it is important to know these tenets so that they can expand their thinking and elaborate on their ideas. For example, an owl has soft feathers and a hooked bill, and these body parts are important because they give the owl an evolutionary advantage in acquiring food.
In my classroom, I have historically used a chart (Fig. 1) to describe these necessities for survival. The chart I use and make available for student reference is below.
Figure 1. The anchor chart I use in my classroom to illustrate the different necessities for survival
When discussing adaptations with students, it is important to remember that they must be able to explain how the adaptation meets one of the four needs.
Avian Adaptations
Bird bodies are mostly adapted for the purpose of flying. Every part of their body—their feathers, their bills and beaks, and even their skin—is adapted to be lighter so they can fly.7 Like other animals, birds are also differently adapted based on where they live, what they eat, and the presence (or lack of) of predators. Birds that do not fly mostly live in habitats where they do not have natural predators. They did not need the ability to fly because they did not need to escape. Other birds, like an ostrich, are too big to fly. Their weight makes it impossible for them to create enough lift to get off of the ground.
Through this lens, teachers can discuss avian adaptations from the general features that birds share, such as feathers and beaks, to the more specific parts of birds that tend to be different across species, such as their necks and feet. Even within one habitat, birds behave differently based on the structure of their bodies. Understanding how the form of a bird’s body determines the function will allow students to look at artwork of birds with a critical eye and a deeper understanding of the environment that bird lives in.
Wings and Feathers
The most obvious avian adaptation is wings. Most ornithologists believe feathers serve two purposes: flight and insulation.8 Feathers are important even for birds that do not fly, like flamingos. Their feathers keep them dry and warm.9 Feathers also generate thrust and lift, two forces that my students will be aware of because we will have just discussed flight.10 Knowing that feathers generate these forces, students will be able to connect their new learning to their prior learning. Students will know that to fly, these forces must be present. They will also be able to make the connection that people learned from birds, their wings, and their feathers in making it possible for humans to fly.
Based on even just the feel of feathers, you can determine the kind of habitat a bird lives in. For example, duck feathers feel waxy because they are more resistant to water than other bird feathers. Penguins have a large amount of dense feathers to keep themselves warm and streamline their bodies for swimming.11 Owls have soft, loose feathers because they need to be able to fly quietly while they are hunting for prey.12 Knowing these differences will help teachers to design experiments that lead students to the answers about the adaptation and differences between feathers rather than just telling them. It will also help students generalize knowledge and use what they know about one type of feather to understand the environment and adaptations of other birds who have similar adaptations.
While feathers mostly serve the functional purpose of flight and escape, some birds’ feathers have special coloring that makes them stand out and blend in. For example, a rock ptarmigan, a bird that lives in the tundra, is white to blend in with the snow of its natural habitat.13 Conversely, a peacock is known for its large, elaborate feathers. These feathers, while beautiful and mainly intended to attract the opposite sex, also keep the peacock safe from predators. When its tail feathers are spread out, the peacock appears much larger, not to mention that the black spots on their feathers look somewhat like eyes.
Wings allow most birds to fly. Not only do wings allow birds to travel, but they also allow them to escape from predators. Escaping from predators can largely affect the development and evolution of wings. Smaller birds that spend more time on the ground have developed wings that allow them to fly quickly in short spurts. Birds of prey have longer, more narrow wings that allow them to soar in the air while searching for food.
The shape and size of wings serve different purposes for different birds. For example, birds with long, narrow wings travel long distances and birds with short, round wings only fly short distances.14 Birds like the kiwi, who have tiny wings, do not fly at all. These birds have no natural predators in their environment and do not need to be able to fly as a form of escape.15
Beaks and Bills
The primary function of a bird beak is to gather food or eat.16 A bird’s beak or bill is shaped differently based on their diet. The beak or bill is especially important because birds do not chew.17 Some birds, like the penguin, have adapted to this lack of teeth by developing keratin spikes on their tongue to grip food.18 This combination of lack and compromise is a helpful way to think about evolution and adaptations.
Bird beaks are specially designed and adapted for the bird’s food source. For example, a Eurasian curlew uses its “downcurved bill to extract worms [and other prey] from deep in the mud of saltmarshes.”19 Students should begin to understand that if we know what a bird eats, we can infer where they live.
In the National Wildlife Refuge System’s pamphlet, Birds & Their Adaptations, the agency includes a great diagram (Fig. 2) to help understand the function of each form of beak.20 By knowing this information, teachers can choose images and artworks that include a variety of beak forms to show the differences among bird species.
Figure 2. National Wildlife Refuge System’s beaks and bills illustration
In art, bird beaks are one of the most obvious adaptations to see and to draw. This is most likely the first thing students will notice when looking at bird art. Similarly, artists often included prey or food in their artwork like John Gould’s hummingbirds21 or John James Audubon’s Yellow-billed Cuckoo22. Viewers can see that the hummingbird’s beak is specialized to be able to go deeply into a flower to get its nectar. Alternatively, the cuckoo’s beak is specialized to grip insects like butterflies. The inclusion of the food source for the bird helps students and teachers determine the specific ways that a bird’s beak helps the bird.
Legs and Feet
Much like beaks, avian legs and feet vary based on habitat and have much more influence on survival than just for movement. Many of the birds that students will see living in urban environments will have three or four toes that allow them to grip tree branches (and light poles) when they are not flying.23 Ostriches have only two toes, and their leg and foot structure is built for speed, another adaptation that both separates ostriches from other birds and compensates for their lack of flight.24 Most birds have claws, but birds of prey (i.e. owls and eagles) have particularly sharp claws or talons to catch and grip prey while they are flying.
For birds that spend much of their time in deep water, their legs are long for them to be able to wade through water while looking for prey.25 This adaptation is relatively obvious for students to see in art and images, making it worth including birds with this adaptation in your instruction. When thinking about “obvious” adaptations like long legged birds that spend their time in water, it is a worthy thought experiment to ask students why an artist would have wanted to draw or paint this type of bird. When thinking about bird habitat, we should consider which habitats the artist’s audience would have been familiar with and which habitats they would not be familiar with.
Swimming birds often have webbed feet. Even amongst these species, there is variety based on specific environmental factors. Both a penguin and a duck have webbed feet to help them swim, but a penguin’s foot is designed more for streamlined swimming and for pushing across ice. However, a duck’s webbed foot is designed more for paddling.26 These differences are important for considering avian lifestyle and behavior as an aspect of avian adaptations.
Bird Sounds
An important part of bird identification is listening to the sound the bird makes. Birds vocalize for many reasons: warning calls, mating, defense of territory, as well as for general communication.27 Understanding these bird calls is an important part of understanding avian adaptations. For example, baby ducks peep to communicate while in their eggs so they will hatch, and therefore leave the nest, at the same time.28 This is an important adaptation for ducklings to ensure safety in numbers to help them fend off predators.
However, short of magic, there is no way for the sound of a bird to be captured in an image. Depending on how much time and space you have in your schedule, you may want to design a lesson that incorporates close listening in the same way that students will exercise close observation. While watching and listening, students should consider the purpose of the bird sound. What about the sound and what happens after the sound help us to understand the purpose? How does this teach us about this bird’s adaptations?
Reproduction
While it is inappropriate to discuss the details of reproduction with first graders, it is important to highlight that just like other animals, birds must find a mate so that they species can survive. In child friendly language, I encourage teachers to teach about the brightly colored plumage that many birds must attract a mate. Mating is important for survival, because if birds did not mate, they would not be able to continue. As mentioned earlier, peacocks are a great example of the bright, beautiful plumage necessary to attract a mate. This plumage is well known for its beauty and has been the subject of many artworks.
Examples of this kind of adaptation shown in artwork are Thomas William Wood’s Birds of Paradise from 1862 and John Collet’s Red-Plumed Bird of Paradise from 1810. It is easy to understand why artists would be interested in this kind of adaptation because it is so eye catching. These types of birds would also be out of the norm to see for the average European viewer.
Another aspect of reproduction, and particularly of protecting their offspring, is the way that birds take care of their nests and eggs.
Nests or Lack Thereof
One of the trickier parts of discussing animal adaptations with young children is talking about reproduction. However, reproduction is one of the most important aspects in the survival of a species. While having the babies is one part of reproduction, it is also important for animals to protect their babies. This is the part of reproduction and the proliferation of a species that I discuss with my students. When thinking about birds, many students have seen a bird nest whether they realize it or not. These nests function as shelter and protection for baby birds. When birds build a nest, they often conceal them with “surrounding vegetation…[and] place their nest in an inaccessible area…to provide protection from predators.”29 This behavior is part of survival for a bird and is worth discussing with children. Relating it back to their own home and parents (where appropriate) will help them understand this concept.
A bird’s nest depends on where it lives and what its needs are. The U.S. Fish and Wildlife Service describes the kinds of nests based on habitat: smaller birds with more natural predators build nests that can be more easily concealed; larger birds with fewer predators build large nests at the tops of trees that they use multiple times.30 They can afford to have nests like these because they need not worry about animals coming to harm their eggs or shelter.
Birds who do not make nests must compensate for this lack of shelter. The best and most common bird that does not have a nest is the emperor and king penguins. These penguins incubate a singular egg on their feet. While this is widely different from birds that build nests to keep their young safe, this incubation without a nest serves an evolutionary purpose. By keeping the egg on their body, they can keep the egg warm in a cold climate. They are also able to move and huddle with the flock so that they all stay warm.31
Birds In Art
Even as far back as the Paleolithic Age, birds have been depicted in art for many purposes.32 Birds, because of their flight, have stood as symbols and icons for much of written and oral record.33 As time went on, naturalists and artists alike wanted to catalogue and organize birds into some kind of taxonomy.
Art and science are often intertwined in bird art because while, yes, they are seen as beautiful and worthy of being depicted, artists also drew birds to try and understand them. Before humans began traveling, cave artists drew the birds they encountered. As people traveled and brought knowledge back, many artists painted or drew what they heard. Not very many people were traveling to see birds in their habitats and often relied on people to bring dead birds back to Europe so they could see and learn about them.34 As you can imagine, all context is lost with this practice.
This is a reason to analyze depictions of the same birds across time periods and countries. Students can begin to think critically about what has changed in the depiction of the bird and what has stayed the same. When thinking about time periods, students will consider what different artists thought were important about the specific bird. When thinking about countries, students can analyze what people from different areas noticed about the birds. For example, birds that travel to stay in warmer temperatures will have similar adaptations. Students should be able to notice that artists, regardless of where they are from, will observe that these birds have similar living conditions regardless of location. This will also allow students to see that people, regardless of living far apart, will have familiarity with the same species. This will lead them to draw conclusions about important adaptations. What did observers bring back to artists to draw? How did these observations translate into art before people were able to observe the birds for themselves?
One of the main reasons that scientists and artists sought to understand, index, and categorize birds to further understand them. Through close observation, “paintings document[ed] the transition of birds from objects of interest to subjects of organized study.”35 As science developed, so did art. As artists and scientists alike began to better understand the natural world, this understanding shows up in their works. The works became more precise and used as a tool for teaching and learning. Even just the transition from showing birds in isolation to showing them in their natural habitat shows this shift in scientific thinking.
One such scientist was Dr. Richard Brookes. Although little is known about him, his natural history volumes in 1763 served as an early science text for readers to learn from Brookes’ observations.36 Even earlier than Dr. Brookes were illustrators and woodcarvings done by Konrad von Megenberg around 1480 and Pierre Belon in 1555.37 With this transition to more of an indexical style, bird artists began to want their depictions to be as accurate as possible.
One of the most well-known bird artists is the American John James Audubon. Audubon’s main concern in his avian art was accuracy. He was insistent that his depictions of the birds he was cataloguing be so accurate and true to size that he went to the lengths of pinning the recently shot bird to his paper and tracing it.38 While Audubon’s endeavor to capture every bird in America was a scientific endeavor, it was also an artistic one. His works are undoubtedly beautiful, but they also capture the many aspects of bird behavior and bird adaptations that we want students to notice and make determinations from.
We can also apply this same thought process to birds of prey and how they were depicted over time. Birds of prey, as they are predators, will allow students to think more about adaptations from the perspective of hunting rather than adaptations to stay safe from predators. One such bird that teachers can use is the falcon. Ancient Egyptians viewed the falcon as a symbol of prosperity and protection. Many powerful figures, like King Chefron, were depicted in statues with falcons, as well as statues of falcons placed in pyramids.39 Pairing these statues with images like Benozzo Gozzoli’s fresco of falcon in the Medici-Riccardi Chapel in Florence from 145940 and Audubon’s Rough-legged falcon from Birds of America.41This exploration and observation can lead to student discussion on the adaptations that early people noticed to make them see the falcon as a symbol of protection.
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