"A true conservationist is a man who knows that the world is not given by his fathers, but borrowed from his children." -John James Audubon
First, I want to offer a little apology. I have re-formatted this post at least three times, but every time I publish it, the changes are lost. So, I have conceeded defeat. Hopefully, the formatting issues will not detract too much from your enjoyment of your child's work.
As we have been making our way through the taxonomy of living things this year, the children recently completed a unit of study about birds. Birds are a perfect unit of study for this time of year- many children are fantasizing about Easter eggs, and they are constantly exposed to birds busily flitting about the play yard constructing their nests and rearing their young.
Birds are pretty fascinating animals to study- they can be found on every continent in the world, they descended from theropod dinosaurs, have been observed manufacturing and using tools, communicating through complex songs and symbols (attaching white bits of weeds and garbage to a nest mean babies have hatched), and participating in complex social behaviors (hunting, cooperative breeding, flocking, mobbing predators, and migrating). Additionally, teaching students about birds before reptile or amphibians, makes it easier for them to understand the lifecycle of these animals since the structures of bird eggs are more familiar, and larger.
We are fortunate to have several pairs of Ringneck Doves which build nests at the school each year and raise their young in the relative safety of our play area, in addition to the numerous crows, a woodpecker, robins, and sparrows. So the children were fortunate to have some experience with concrete examples of birds in a natural environment.
Cultural units of study are units which are largely developed to help the child adapt to their own society (learning about science, geography, art history, etc). They generally begin with concrete experiences with real things the child might encounter in their environment, and then provide the child with an understanding of the more abstract principles through carefully scaffolded interactions with their environment (not through rote memorization, lectures, or even stories).
Although providing children with an introduction to the life sciences is important in its own right, the cultural units of study serve other important purposes in a Montessori classroom environment. They provide children with the opportunity to develop their vocabulary, to apply math, geography, and formal language knowledge (reading, composition, grammar), to utilize scientific tools and instruments (measuring, weighing, using a microscope or dissection tools), and to cultivate an understanding of the scientific method (making predictions, testing hypotheses, and recording observations).
Montessori firmly believed that children this age are in a sensitive period for learning the names of the things which surround them and that it is important to provide children with the correct, precise, nomenclature for what they are observing. She developed many lessons to teach children the precise names of leaf shapes, geometric solids, and many other objects; she also created lessons in which children label everything in their environment with small labels. Personally, I always find it pretty amazing to consider the sophisticated language that these young children are absorbing through these units (in this unit alone, children learned the terms- bird, nest, talons, claw, beak, wing, feather, down, semi-plume, plumage, vaned, tympanum, blastoderm, embryo, albumen, yolk, chalaza, membrane, calcium, porous, ovoid, ellipsoid, scavenger, raptor, nocturnal, diurnal, predator, prey, vertebrates, preening, brooding, aviary, fertile, infertile, ornithology, naturalist, camoflauge, etc) and how easily they seem to remember and correctly employ the vocabulary later.
Far from merely creating precocious children, it turns out that Montessori had recognized something fundamental about the needs of young children and the optimal path to literacy. Current research in the cognitive sceinces confirms that children this age are in a sensitive period for language acquisition and shows that a child's vocabulary is one of the most important predictors of their future literacy (which in tern, is one of the most accurate predictors of their educational success). A 1998 study by the National Resource Council found that preschoolers with the largest vocabularies by 5 years of age, were the most proficient readers by 10 and 15. Obviously, the quality of the early childhood environment is a key contributor to vocabulary development. Several studies confirm that children from higher income and "enriched environments" had the highest vocabularies. In one very interesting study on the effects of early childhood environments, it was shown that children in enriched classroom environments had heard three times as many words as children in less literate early childhood settings, and by first grade those children had twice the vocabulary (Graves & Slater, 1987). Studies undertaken in home environments show similar findings. In one monumental study, conducted in 1995 by Hart and Risley, researchers tracked how often parents conversed with their children and what vocabulary they used. They found that an average low income two year old child hears 620 words per hour; by contrast, a high income two year old child hears 2,150! By age five, the low income child has heard 10 million words (knows about 3,000 words) and the high income child has heard 30 million words (and knows about 20,000)! To close the gap, would require providing the low income child with 41 hours per week of out of home language exposure as rich as those heard by the affluent children! Pretty staggering!
To begin our unit on birds, the children learned the basic structures of an egg (using the regular, hard boiled variety). Then, they learned the difference between a fertile and an infertile egg, and had the opportunity to view some mounted specimens of eggs and an assortment of particularly beautiful eggs (white, cream, brown, and blue eggs) from our community supported agriculture farm to see the diversity in differently sized and colored eggs.
The children also participated in several practical life activities involving eggs- including baking and slicing hard boiled eggs for a snack.
The children learned to identify the basic structures of an egg (shell, membrane, albumen, yolk, and
chalaza).
The children also learned to identify the basic parts of a bird using bird puzzles and by making Parts of a Bird booklets.
Then, one day, a package came to the school! Inside the package were ten beautiful chocolate colored eggs that came from Gabbard Farms. Much to the children's excitement, these eggs were fertile and contained beautiful little Marin chickens!
The children put the eggs into the classroom incubator and anxiously counted down the days until the chicks were due to hatch !
Advent- style chains are an effective way for young children to visually understand the passage of time (as well as being a fun three dimensional art project). Many of the children made their own chains to count down the days.
As the eggs were gestating, the children learned some basic embryology using sequencing cards
and this embryology set (which shows the development of an embryo during each of the 21 days in their development).
Finally, after what seemed like "eternity," or so one young man told me, there were chickens! The children named their beloved brood Dandelion (after their most beloved flower), Ginger, Tilly, and Twinkydink (characters from one of the chicken books they read). Caring for animals is an important experience for children this age. It facilitates independence and the development of responsibility. They learn how to care for something gently and compassionately, they learn about the basic needs of living things (water, food, warmth), and it helps children to develop a positive sense of self esteem (by contributing positively to their environment and community).
It was important to me that children have some understanding of the great diversity of avian life. To show children some different types of birds, we treated the children to a special presentation from the Rocky Mountain Raptor Program. The children got to see a Great Horned Owl and a Red Tailed Hawk. They learned about the basic characteristics of raptors, and the need for preserving wild spaces where they live.
After the presentation, many of the children dissected "owl castings." Generally, I am a big fan of using "real" supplies for projects, but we actually used artificial pellets for this activity. The artificial pellets have a few clear benefits over real ones- they are safer (there have been some disease outbreaks in public schools where real castings were dissected, even ones that had been sterilized), and you are guaranteed to get an entire skeleton (and to know, in advance, what animal skeleton will be inside). We dissected castings containing small birds so that the children could get the added benefit of assembling a disarticulated bird skeleton (reinforcing that birds are vertebrates). The children matched the "bones" to blackline masters of the skeleton. This turned into a great small group project!
The children also had the opportunity to examine birds nests.
The children learned about different species of birds using three part cards. Three part cards are a versatile Montessori material, used for practically every area of cultural study imaginable. Children who are proficient readers can read the labels and match the labels to the pictures; children who cannot read use the cards to perform a simple visual matching exercise in which they match identical pictures and words. These lessons increase childrens vocabulary, provide advanced students with new reading challenges, and give all students exposure to having seen a lot of words in print.
The children looked at some framed mounted specimens of different feather types (down, semi-plume, and vaned feathers). Then they created their own feather collections and labeled the parts, type of bird, and types of feathers.
Children who were proficient at reading and had been learning the parts of speech (nouns, articles, verbs, adjectives, etc) read noun labels and matched them to miniature birds.
Some of the older children also came up with the idea of sorting them into raptors and non-raptors once they were labeled. This generated some great discussions and intense debate about how best to classify some birds and about the characteristics of raptors (for example, as one student observed, pelicans eat fish like a raptor, but don't have talons and hooked beaks).
Children also reinforced their understanding of geography by correctly placing miniature birds on the continents in which they live.
Children diagrammed sentences about birds and raptors.
And, of course, the children read lots of high quality, age appropriate, literature about birds and some wonderful biographies about John Audubon.
The children also really enjoyed looking at feathers and parts of egg shells under the microscope (something I really recommend- you can see the air holes in the shell, even under very low power).
They also matched bird x-rays to the types of birds they came from (again, reinforcing the meaning of the term vertebrates).
After completing so many bird activities, many of the children processed the information in their own ways, pretending to be hens sitting on nests in the yard or Peregrine Falcons diving at prey, creating beautiful bird drawings in the style of John James Audubon (whose art they studied with books and matching cards),
chalkboard drawings,
bird cut-outs and representative modelling with clay and playdough (one child made an amazing Great Horned Owl),
and by researching and composing their own non-fiction books about birds or raptors to read to their friends during the "Author's Chair" at line time (a time when children can read aloud their own compositions to their friends).
"A true conservationist is a man who knows that the world is not given by his fathers, but borrowed from his children." 
And, of course, the children read lots of high quality, age appropriate, literature about birds and some wonderful biographies about John Audubon.
(This page reads: "Birds use their beaks to gather food.")
(This page reads: "Bald eagles feed the fish to the baby. They eat small birds too.") 
