On Sunday, October 20th, interns from Arroyo, Castro Valley, San Leandro, and San Lorenzo high schools visited Ardenwood Historic Farms in Fremont to complete their first of four monarch butterfly habitat restoration field days.
Many students have early memories of Monarch butterflies (Danaus plexippus) from learning about the life cycle in elementary school. Some lucky students may even remember raising their own butterflies in class, feeding their hungry caterpillars until they enter their cocoon, patiently watching the chrysalis, and finally being rewarded with the sight of their monarchs taking flight for the first time. Unfortunately, lessons like these are soon to be a thing of the past because the once thriving population of monarch butterflies has been in decline since the 2010’s. This decline came to an all time low in 2020 when the western monarch population was reduced to less than 0.1% of its historic levels. This drastic decline in population is caused by a variety of factors including habitat loss, climate change, and pesticide use. This year Earth Team interns are doing their part to support monarch butterflies by restoring local overwintering habitat.
Monarch butterflies migrate an astounding 2,000 miles a year. They do this to escape the cold temperatures of winter by traveling south. The eastern population spends the winter in central Mexico and the western population ventures out to the California coast. There are over 400 overwintering sites in California that have the ideal microclimate for monarchs: partial sunlight, high humidity, fresh water, and no freezing temperatures or high winds. The Xerces Society of Invertebrate Conservation has ranked the 50 most priority overwintering sites in greatest need of support. Currently, Ardenwood is listed at number 17 on this list.
Ardenwood is a fully functioning, victorian-era farm that is part of the East Bay Regional Parks District. The park is home to goats, sheep, chickens, bunnies, cows, and a very friendly blacksmith. Upon Arriving, Earth Team interns were welcomed to the farm by the resident gardener, Diana Ramirez. She gave everyone a tour of the Ardenwood grounds, allowing interns the opportunity to see the vast array of native plants growing on site. There are many gardens throughout the Ardenwood grounds, and, after viewing them up close, it was time to get to work.
Interns were split into 3 teams and completed work in 5 areas for the park. First, program coordinator Healey and intern group 1, spent time in the eucalyptus grove on the far side of the park. Together, everyone spent time raking leaves and gathering sticks and logs to make piles tucked away by the trees. These log piles actually serve as shelter for monarchs overwintering in Ardenwood park.
Once the piles were made, group one made their way over to the nectar garden. There, interns pulled weeds and raked pathways through the garden. This nectar garden is essential for overwintering butterflies. While the eucalyptus grove may be a safe place for them to rest, they still need to eat! Interns cared for the many native nectar plants there, including this massive Mexican bush sage (Salvia leucantha).
Group 2 joined coordinator Jamie by the greenhouse. They worked to clear weeds and invasive plants from around the building and nearby pathways. Students worked together to clear out two massive invasive balloonplant milkweeds (Gomphocarpus physocarpus). Monarchs are a milkweed butterfly, meaning they only lay their eggs on milkweed plants. The caterpillars eat the milkweed after hatching not only providing nutrients for growth, but the toxins in the milkweed make the monarch caterpillars and butterflies unappealing to predators. However, this particular milkweed is an invasive species native to South Africa. This species is actually harmful to our local monarchs and can lead to developmental deformities. While removing the first balloonplant, interns learned the hard way that the balloons on the balloonplant are actually filled with hundreds of seeds attached to cotton-like strands. These allow for easy seed dispersal for the plant…and a messy cleanup for interns. Luckily, after learning from their mistakes, removal of the second balloonplant was quick and a little less messy.
Nearby, group 3 worked on weeding around the vegetable garden and preparing one of the planter boxes for new crops. Don’t worry, after all the hard work shoveling, interns took a break to make a few tik toks. Once the Veggie garden was cleared, group 3 moved on to weeding the bioswale. A bioswale is a landscape feature that collects polluted stormwater runoff, soaks it into the ground, and filters out pollution. By keeping this area free of weeds and debris, interns are ensuring a safe source of drinking water for the monarchs.
At the end of the day, Earth Team was able to remove about 100 cubic feet worth of weeds and invasives and left Ardenwood with a healthy habitat for this year’s monarchs. A few lucky interns were even rewarded with seeing a monarch flying through the newly cleared vegetable garden!
None of this work would have been possible without the help and collaboration of Diana Ramirez from the East Bay Regional Parks District. Her commitment to the interns and their education not only engaged students but connected them to their local environment. EarthTeam would also like to thank the Alameda County 2024 Fish and Wildlife Propagation Fund from the Alameda County Fish and Game Commission for providing funding for this project.
