ENVIRONMENT
Teachers, scroll down for a quick list of key resources in our Teachers Toolkit, including today’s simple MapMaker Interactive map.

Photograph by Alan Vernon, courtesy Wikimedia. CC-BY-2.0
Discussion Ideas
- Burrowing owls, an indigenous species in western California, are quickly disappearing from protected parkland in Mountain View. Are burrowing owls endangered?
- No. Burrowing owls are actually a species of least concern. There are healthy populations of burrowing owls in their species range throughout the prairies and drylands of South America, North America, and the Caribbean.
- In California, burrowing owls are a “species of special concern.” Species of special concern describe organisms that do not meet the criteria of endangered species, but are particularly vulnerable in a state or region. In California, burrowing owls are a species of special concern due to “experiencing, or formerly experienced, serious (noncyclical) population declines or range retractions (not reversed) that, if continued or resumed, could qualify it for State threatened or endangered status.”
- Shoreline Park’s declining owl population is directly associated with booming feral cat populations in Silicon Valley neighborhoods surrounding the park. Are cats an invasive species?
- Yes. Domestic cats are thought to have evolved from the Near Eastern wildcat and are considered indigenous to the Old World. As both pets and hunters of vermin such as mice, domestic cats traveled the world with human explorers. Learn how cats conquered the world with our study guide here.
- As cats were brought to the Americas, Australia, and Oceania, they decimated native populations of small birds, mammals, reptiles, and amphibians. According to one study, “We estimate that free-ranging domestic cats kill 1.3–4.0 billion birds and 6.3–22.3 billion mammals annually. Un-owned cats, as opposed to owned pets, cause the majority of this mortality.” The Global Invasive Species Database ranks cats #38 on their worst invasive species list.
- Yes. Domestic cats are thought to have evolved from the Near Eastern wildcat and are considered indigenous to the Old World. As both pets and hunters of vermin such as mice, domestic cats traveled the world with human explorers. Learn how cats conquered the world with our study guide here.

- Google’s headquarters, nicknamed the Googleplex, abuts Shoreline Park. It is one of the local neighborhoods with a significant feral cat population, and some Google employees have formed a volunteer group (GCat Rescue) dedicated to managing the feral cat community. Why are these feral cats associated with the dwindling owl population?
- feeding. GCat maintains feeding stations around the Googleplex, including some just feet from the park entrance. Although “Google understand the cats are not supposed to cross the line into the park,” herding cats is practically impossible.
- tracking. GCat regularly traps feral cats, and “cats that are released are implanted with tracking chips, and an ear is notched so they can be identified.” The tracking chips allow animal control groups to see how many of the GCat cats are venturing into the park and preying on burrowing owls.
- “The city’s wildlife preservation biologist said he was worried about the cats’ ‘significant impacts’ on protected species, ‘especially burrowing owls.’” In one instance, a cat returned to the park at least three times: “One of the cats was trapped, turned over to the Silicon Valley Animal Control Authority, released to Google, trapped again in the park and released again to Google. Last August, it was found dead in the park.”
- The primary way GCat and community members manage the feral cat population around the Googleplex is through a process of trap-neuter-return (TNR). What is TNR?
- Trap-neuter-return is just what it sounds like.
- trap. Feral cats are humanely trapped.
- neuter. The trapped animals are surgically neutered, meaning their sexual organs (ovaries in females, testes in males) are removed. Neutering—also called “fixing” or “sterilizing”—makes the cats unable to reproduce.
- return. Neutered cats are put up for adoption or returned back to the Silicon Valley wild.
- Trap-neuter-return is just what it sounds like.
- Why are environmentalists critical of trap-neuter-reutrn?
- “Cats that are fed still hunt,” says one researcher. “Even neutered cats and spayed cats hunt.”
- The animal advocates at PETA are also critical of TNR. “Obviously, cats that are neutered and then released outdoors are not going to breed, but they are likely to suffer far more than indoor cats (and those unadopted ones kept in enclosed sanctuaries) from injuries and disease, kill wildlife, and pose a public health risk from some of the diseases they can transmit to humans.”
- Is the trap-neuter-return policy the only human activity threatening Silicon Valley’s burrowing owl population?
- No. Habitat destruction is always a threat, as more land is developed for housing, industry, and leisure. In fact, one of the biggest threats to burrowing owls is the nearby Shoreline Golf Links. “A bleak Mountain View report three months ago noted there have been [owl] deaths ‘due to direct contact between golf balls and burrowing owls.’”
TEACHERS TOOLKIT
New York Times: As Google Feeds Cats, Owl Lovers Cry Foul
Nat Geo: Shoreline Park and the Googleplex
Nat Geo: Why Australia Has to Kill 2 Million Cats
Nat Geo: How Cats Conquered the World
Nat Geo: TNR Is Dangerous Both to Cats and to Other Animals
(extra credit) Nature Communications: The impact of free-ranging domestic cats on wildlife of the United States (2013)