Coast Live Oak Falls Prey to Gophers

You know it’s dry when gophers start taking down trees.

Why is that? Well, normally tree roots make up part of your standard gopher diet. They’ll tunnel down to a tree’s root ball, chow down for a little while, and then move on. But as long as they only eat part of the roots – which is usually how it goes – the tree can still get plenty of nutrients and water from the soil, so it remains healthy. 

That’s why Jim Hardie, TreePeople’s Director of Park Operations, was surprised when he noticed that a roughly 20-year-old coast live oak (Quercus agrifolia) in TreePeople’s park was “browning out.” Over the course of a week, the tree went from seeming completely healthy to “literally lying on its side – it had toppled over.” The coast live oak is a native species, which means it’s generally well adapted to dry conditions, though three years of drought have taken a toll. Still, this was a surprise.

And an even bigger surprise: when TreePeople’s park employees pulled the tree up, the entire root system was gone. Thanks to teeth marks left behind on the root stubs, the culprit was clear. Gophers.

Jim believes it’s a result of the drought. Since gophers eat roots and many of the types of trees they usually eat are ailing due to lack of water, the gophers are “eating a species that they typically might not favor, but it’s what’s available given the drought’s depletion of their normal landscape.” This depletion is likely to make its way up the food chain, too. If gophers aren’t getting enough to eat, then there will be fewer available for animals that prey on them, like bobcats. The same can be said for other herbivores, like rabbits and deer, and the carnivores they feed.

This is the second coast live oak in our park to fall to gophers this spring, and according to Jim, this, along with the fact that many of the native species in TreePeople’s park seem to be suffering, “shows that we’re in a rather dire period.” Because this year may turn out to be an El Niño year, it’s possible that we’ll have a wet winter to bring some respite. But as Jim points out, even if we do – and there’s no guarantee of that – we still have five or six of the hottest, driest months of the year ahead of us.

Given that, over the coming months it will be crucial for us to take care of trees so that they in turn can support the area’s wildlife. To find out how you can help, visit our Drought Response page. From capturing water at home for tree care to volunteering at our drought response events, there’s plenty you can do to help our trees – and those gophers! – thrive while we wait for the rain to return.

By Elizabeth Weinberg

Elizabeth Weinberg is TreePeople's Social Media Specialist, a DC-based writer, and a lover of trees.