Audubon Kern River Preserve has an Annual Spring Nature Festival, and in 2011 it fell on Easter weekend. Being that Audubon is about birds, we thought it appropriate to hold an Easter egg hunt with a twist. Volunteers and staff molded life-size clay eggs of seven local nesting species and then hid them for a traditional hunt.

After searching the field, the children (and adults) had to place each egg in the appropriate nest for a reward of candy and a special trading card of the correctly identified species which had been specially created for the event. In order to do this the deal was that the "eggs" stayed with the nest. (So we can do this again and again.

Replicas were made of Great Blue Heron, Western Screech Owl, Mourning Dove, Anna's Hummingbird, American Robin, Western Bluebird, and Brown-headed Cowbird. We handcrafted the molds from Plaster of Paris over egg replicas purchased from a science craft store, and then airbrushed them with a color and pattern matching the native bird egg as closely as possible.

MATERIALS

• Replica eggs from natural supply company (e.g. Acorn Naturalists, Skulls Unlimited etc...)

• Plaster of Paris

• water

• small plastic containers

Pour plaster of Paris into plastic container, place egg replica (covering the egg with Vaseline helps to keep it from sticking to the plaster) into wet plaster, covering the bottom half of the egg, to create the first half of the mold and let dry. Remove egg from mold, repeat the steps above to make the top half of the mold; except this time cover the already created first half of the mold with plastic wrap and fit it over the egg to make the mold whole in two sections.

Molding clay

Mold clay into appropriate size ball and fit it into mold halves, pushing them together and then scraping off excess wet clay. Let the whole egg set for 8 hours or so, remove from mold and then repeat until you have enough eggs for your project.

Bisque fire eggs in 1800ºF kiln for 24 hours

Sand dry eggs with fine grit sandpaper to smooth rough spots.

Acrylic paint

Buy various colors of acrylic paint to be mixed to match colors copied off of real specimens or use pictures from books. Single colors work best if airbrushed - note I applied too much paint to most of the eggs leaving them a bit on the bright side. You don't need that many coats as the eggs are generally lighter shades. The cowbird egg paint was applied with a rough artist’s sponge. No need to coat with acrylic, although it might make the eggs last longer. Most bird eggs are generally dull with a slight sheen.

It was a lot of work, but proved to be great fun and educational, too. Thanks are due to Wendy Rannals, who made the first molds, to Sarah Teed for helping to make some of the eggs, to John Schmitt who made the Screech Owl and Robin nests, to Marlene Benton for lending us the Mourning Dove nest, and to Rob Estrada who made the second molds, molded most of the eggs, and provided the material to create the eggs.