One. Two. Tree.

By Jose Jasso

Photo Chris Parkes

It’s breeding season and with that comes birds searching for a place to nest and raise their hatchlings. If they’re a bird of prey or raptor, it will have to be a spot high up, close to the heavens, that they will call home for at least a month. The go-to tree would most likely be the eucalyptus tree, as they are abundant and are some of the tallest trees reaching up to 300 feet in height, and that can be found in canyons and open spaces. However, Eucalyptus trees are an invasive tree species, so where else could these San Diego raptors call home?

The issue is that raptors often opt to nest in eucalyptus trees due to the displacement of native trees by these invasive species, making them a predominant nesting site. Brazilian Peppers, Peruvian Peppers, and Eucalyptus trees all make it extremely difficult for our native shrubs and plants to grow under them. Brazilian peppers absorb too many resources and their canopies don’t allow enough sunlight to reach any plants that settle under them. Eucalyptus trees drop their leaves creating a carpet, and the oils that the leaves have on their exterior can seep into the soil and can prevent plants from growing. Imagine a house that was simultaneously driving away food sources.

However, this doesn’t always have to be the case. Before these invasive trees were introduced there were other native tree species that called the canyons home. Native trees support and sustain plants growing under their canopy, and are well-suited to our water culture as well. These trees can be found in our canyons, open nature spaces, and neighborhoods. Unfortunately, due to the prevalence of Eucalyptus trees, our native species are often overlooked.

A native keystone species is the Coast Live Oak that can reach up to eighty two feet tall and thirty five feet wide. Their large canopies provide great habitat for birds but also allow for understory plants to thrive. Coast live oaks are well known for their gnarled branches and leathery leaves. The leaves also provide natural mulch for themselves and the plants around. When in bloom, the flowers feed small pollinators , and their acorns feed birds like Woodpeckers and Scrub Jays. To put that in perspective, two hundred and seventy species rely on this tree for habitat and for food. 

Western Sycamores also could be found in riparian areas and can reach heights of one hundred and fifteen feet tall, which are perfect for birds of prey who prefer to nest up high. Sycamore are known for their palmate-shaped leaves and spiky seed balls that fall on the ground. Sycamores are host plants for the Western Tiger Swallowtail and can require lots of water but are undoubtedly some of the most beautiful trees when taken care of.

Lastly, there are Fremont Cottonwood trees. Usually found in riparian areas, these trees can grow up to one-hundred fifteen feet tall and provide plenty of habitat for birds and butterflies. Possibly not ideal for gardens, but in the creeks and canyons these trees are a big benefit for our local ecosystems. This plant is tough and can grow easily, when it is not competing with other plants for water and nutrients.

While thinking of birds and taking care of their habitats, other things to consider are where they call home. While invasive trees may be what they need now, what they had before was a lot better and giving that back to them would allow for more birds to be able to call canyons home. Do the birds have everything they need now? When the trees they reside are taking away food and space. What if they instead had the right groups of plants that feed them and house them. What would that look like then? What would it sound like in the canyons with everything that should be there and nothing that shouldn’t?