Wildlife in the Arboretum

The Arboretum is home to at least 31 species of mammals, 7 species of fish, 3 species of amphibians, 19 species of reptiles, 45 species of butterflies, 18 species of ants, and hundreds of species of other insects and invertebrates (confirmed and expected). More than 135 species of birds have been observed nesting or roosting in the Arboretum.

The Arboretum is committed to providing wildlife habitat, supporting native pollinators, managing insect pests with beneficial insects and other biological controls, and balancing the needs of wildlife populations with the needs of the plant collections.

Currently, we face a challenge with the dramatic growth of the heron and egret colony at the Peter J. Shields Oak Grove, our most scientifically-significant collection. More than 2,500 of these large birds inhabited the grove last summer. The number of nests of cattle egrets, a prolific, non-native species, increased from 87 in 2005 to 495 in 2007. Large heron colonies are known to damage or kill the trees in which they breed and to pose health risks to humans. We are working with campus wildlife biologists to determine ways to discourage nesting without harming the birds. Researchers are experimenting with humane methods such as removing the remnants of last year’s nests and shining a bright light at the birds.

Click here for answers to frequently asked questions about the plan to address the heronry.