Rodents (rats, mice, moles, voles, etc.) have long been a challenge for humankind. They are highly adaptable to human development, cause damage to our crops and homes, carry diseases that can make us sick and are capable of reproducing at a significant rate.

For as long as humans have been living with rodents, we’ve been developing ways to control them.

There are many methods available today to control nuisance rodents at home. Such methods include excluding them from buildings by closing up gaps, removing food sources by picking up fallen fruits and keeping pet food indoors,  setting traps and using chemical poisons (rodenticides). All of these methods are effective at controlling nuisance rodents, but there has been a trend toward greater reliance on the use of rodenticides—poisons intended to kill rodents.

Rodenticides are often considered the most cost-effective method to control rodents, but they also present the greatest risk to public health and the environment. Rodenticides are often the cause of unintentional poisoning via direct ingestion by domestic pets or children, and indirect secondary poisoning of non-target species including domestic pets and predatory wildlife. Secondary poisoning most often occurs when a non-target species eats a rodent that has eaten rodenticide. 

While all rodenticides present a public safety and environmental health risk, certain rodenticides known as Second Generation Anticoagulants (SGAs) are of particular concern. Second generation anticoagulant rodenticide products contain the active ingredients brodifacoum, bromadiolone, difethialone and difenacoum. These products cannot be legally purchased or held by the general public and can only be applied by certified pesticide applicators. These chemicals prevent the clotting of blood in animals that have ingested it causing internal hemorrhaging and death. Animals (including humans, pets and non-target wildlife) that eat the chemical or eat rodents that have eaten the chemical will become sick and die.

Second generation anticoagulant rodenticides are known to be a significant cause of secondary poisoning of non-target species. Since the early 1990s, SGA rodenticide residue has been detected in liver tissue samples of 70 – 90% of non-target wildlife species screened. In 2014, the California Department of Pesticide Regulation restricted the use of SGAs, only allowing licensed pesticide applicators to use them.  While this had reduced the application of SGAs, they were still widely used by pest control companies at homes and businesses, and we continued to see lethal and sublethal effects to non-target wildlife in Davis and throughout the state.  In 2020, AB 1788 was signed into law, placing a statewide moratorium (with a few exceptions) on the use of SGAs. This ban will remain in effect until the Department of Pesticide Regulation can reevaluate the chemicals and determine if they are safe for non-target wildlife.

The City of Davis recommends that residents avoid using any rodenticides to control rodents and employ alternative methods instead. If you use a pest control company, communicate with them your desire to control rodents without using rodenticides. Finally, share your concerns about secondary rodenticide poisoning with your neighbors.

• Managing pests in the home and garden: rats
• Our Water Our World: Rats and mice UC IPM - Rats
• UCANR: Barn Owls as effective IPM

Resources:

• California Department of Fish and Wildlife 
• Raptors are the Solution (RATS) 
• U.S. Environmental Protection Agency

Sick or injured wildlife should be approached with caution. Animals that are sick or injured are particularly defensive and likely to bite if handled. Bites from wildlife are painful and may transmit harmful diseases. Depending on the species of animal, the following contacts should be able to lend assistance:  

• Skunks and foxes - Yolo County Animal Services
• Bats -NorCal Bat Rescue
• Hawks, owls, or other birds-of-prey - California Raptor Center
• Everything else - Wildlife Care Association

Is a young animal abandoned? Often times an "orphaned" animal is safe, but perhaps a bit out of place.

Was the animal brought to you by a pet? Is it naked and shaking? If yes, it likely needs help. Otherwise, leave young animals alone and let their parent(s) provide the best care possible.

When birds are nesting, we may see more young birds out of the nest as they learn to fly and feed on their own. Does the bird need help? Not necessarily! Most young birds are perfectly fine and do not need our help. Here is some useful information on what to do when you find a young bird.

Featherless/Newly Hatched (Hatchling) Birds (Picture A): If the bird is not injured, locate the nest, and place the young bird back inside. Birds are unable to detect your scent on their young. After you leave, they will quickly forget your intrusion. Be sure to place the bird in the correct nest (as parents may toss out unfamiliar babies).

Downy/Incompletely Feathered (Nestling) Birds (Picture B): These are older birds, not quite ready to fly. Find the nest, and place the young back in it unless the bird is injured. If you cannot locate the nest or it is out of reach, the bird should be placed in wildlife care (see contact info below).

Fully Feathered (Fledgling) Birds (Picture C): These birds are completely feathered, can hop about and may be able to flutter or fly short distances. Leave them alone unless they are being attacked by a dog or cat. They should be left on the ground (to be fed and protected by their parents) unless they are injured or in imminent danger.

If a bird is sick, injured or orphaned, you can contact the Wildlife Care Association at 916-965-9453 for assistance.

Keep pets on a leash at all times unless you are within a designated off-leash area. Off-leash use is never permitted within open space or habitat areas. City of Davis Leash law webpage.

Regardless of how well behaved your dog may be, they should always be on a leash when they are out in public if they are not in designated off-leash areas. Off-leash dogs can wander off paths and into habitat areas, frightening off wildlife and making them move out and away from these protected areas. Remember that your dog is perceived as a predator by other animals. Leashing your dog will also keep your pet safer by making sure it doesn't eat or drink anything unhealthy while out on a walk.

Unfortunately, cats (even well-fed pet cats), are super effective predators. Free-roaming pet cats can’t help but capture and kill various wildlife like birds, lizards and small mammals. In addition to their impacts on wildlife, free-roaming cats are also at greater risk of being injured or killed, either by accident or by other wildlife predators. For the safety of your cat and for wildlife in our community, its best practice to keep pet cats indoors.

Unwanted cats should be surrendered to an adoption agency or shelter and never be abandoned or forced out of the home.

The City's urban forest provides significant benefits to the citizens of Davis, but did you know the urban forest also provides habitat for the wide variety of wildlife that call Davis home? While maintenance of these trees is necessary to support tree health and vigor, as well as to protect near-by structures and ensure public safety, tree maintenance activity can harm nesting wildlife if not done thoughtfully.

Birds and their nests are protected by state and federal laws. The breeding season for most species is from March to August. Tree pruning or removal during this time presents a risk of killing or injuring birds, their nestlings or eggs. Nesting adult birds may even abandon their eggs or offspring if there is elevated disturbance in or nearby the nest tree.

So, what can we do to maintain our trees without harming wildlife?

• Contact the City's Urban Forestry program to make sure the tree is not a City tree, Landmark tree or has other restrictions on the maintenance of the tree.
• Anytime you need to undertake tree maintenance or removal, ensure that it is absolutely necessary and (for maintenance) at a time of year that is beneficial to the health of the tree.
• Consult an arborist to advise on tree health or public safety concerns.
• When possible, tree maintenance or removal should only occur between September and February.
• If you must conduct tree maintenance during the spring and summer months, please have a qualified wildlife biologist, or someone familiar with bird breeding behavior, survey the tree for nests. Contact the City of Davis’ Ecological Resources Program Manager at 530-757-5680 if you need help finding someone to survey for nests. Do not disturb the tree if nests are present. Nests are protected by state and federal law and destroying them is a misdemeanor.
• Hawks and owls often reuse old stick nests. Avoid removing them if possible.
• Contact the City of Davis’ Ecological Resources Program Manager at 530-757-5680 if you find injured, displaced or dead wildlife.

The City's hiking and walking paths are regularly maintained to ensure they are clean and safe. Off-path areas are not maintained for people or their pets, and there is no guarantee for safety when entering these areas. Walking off the paths can damage plant life, harm critical habitat and scare away nesting and breeding wildlife.

Some greenbelt areas are adjacent to stormwater drainage channels. While these may look like good hiking areas, drainage channels are carefully engineered to convey rainwater—not people—and are not maintained to accommodate safe passage of people and pets. Walking through these areas can cause damage to the channel, leading to erosion of the soil, increase of sediment deposits further downstream and increased flooding risk. In addition, stagnant water in stormwater channels is not treated, and can pose a risk to pets.

Regardless of the type of path, location or mode of transportation, it is important that everyone stay on the designated paths and keep dogs leashed in order to protect people, plant life and urban wildlife.

Learn more on the Open Space Program webpages.

The Barn Owl Nest Box Program is a city-wide effort to support the local barn owl population and benefit from the natural pest control they provide. Residents that wish to participate in the program may donate a barn owl box and have the city install it into a City-owned tree. Contact the Public Work Utilities and Operations Department for more information. 

Planting a wildlife-friendly garden in your yard is a great way to support wildlife. Any combination of appropriate food sources (ex. flowers, seeds, insects, slugs and snails), cover (ex. dense vegetation, artificial nests boxes, branch piles, etc.) and water will help attract wildlife. Just understand that if you provide habitat, all sorts of wildlife species will visit including potential pest species like skunks, squirrels and rats.

Pollinator gardens are a great fit for any yard. Sow a variety of native flowers to attract and support honey bees, native insects, and hummingbirds. The monarch butterfly will feed on and lay eggs on narrow-leaf or showy milkweed species. More information on monarch butterflies.

The City of Davis manages and maintains thousands of acres in and around Davis for a variety of uses. Many of these areas provide valuable habitat for local and migratory wildlife species. Many of these locations, however, are an important part of our City’s utility systems (such as North Area Pond, West Area Pond and Core Area Pond). These sites require regular maintenance, including clearing brush from stormwater drainage areas, pruning trees and mowing grasses, activities which are necessary to help reduce fire risk, control invasive species and to maintain the function of the utility.

The City takes into consideration the impacts to habitat quality when maintaining utility sites. To protect wildlife and habitat on City property and prevent potential conflict between vegetation management and wildlife, City of Davis follows a Wildlife Resource Protection Policy with specific rules for maintenance operations in areas that may also provide habitat for wildlife.

State law permits property owners to trap wildlife on their property if they are causing property damage. However, State law prohibits the relocation of trapped wildlife. Trapped animals must either be euthanized (if allowed under California law) or released back to the same location. Under the California Code of Regulations, Title 14, 465.5(g)(1). releasing wild animals at a location other than where they were caught is prohibited (unless a permit to relocate the animal has been obtained from California Department of Fish and Wildlife). Why can’t wild animals be released to another (maybe less populated) location?  Relocated animals may return or present a similar problem to someone else. Release of animals is also a major factor in the dissemination of numerous diseases to other animals including pets and humans.