Bird-Friendly Tree Trimming & Gutter Cleaning

Originally published in the Thousand Oaks Acorn—March 20, 2026

Many birds nest between January and August, making tree trimming, shrub removal, and even gutter cleaning potentially harmful if done at the wrong time. Following bird-friendly tree care practices helps protect nesting birds while keeping trees healthy.

A simple rule of thumb: schedule tree and shrub trimming, and gutter cleaning, during the months that end in “BER”: September, October, November, and December.

Quick Tips for Bird-Friendly Tree Care

  • Trim trees September–December
  • Look for active nests in trees and shrubs
  • Survey the ground for nesting birds
  • Check gutters and downspouts before cleaning
  • Delay work if active nests are present
  • Hire a qualified, licensed tree professional

Trim Trees in Months That End in “BER”

Spring is here, and nesting season is in full swing for our local birds. One way we can help protect them is by scheduling tree and shrub trimming during months that end in “BER”: September through December.

This timing is better for both birds and trees, as most birds nest between January and August, and trees go dormant in the fall. Trimming or removing vegetation in fall greatly reduces the chance of destroying active nests or disturbing breeding birds. This includes songbirds, hawks, owls, and other important native species that share our neighborhoods.

Of course, birds do not always follow the calendar. Owls and hummingbirds may nest early, so check carefully for nests before starting any work, regardless of the season.

Be sure to conduct a thorough ground-level survey before clearing brush, since many species, such as California Quail, are ground nesters.

Also check gutters and downspouts before cleaning them, as some birds nest in these sheltered locations too.

If trees, shrubs, or groundcover must be cleared or removed during the active bird nesting season, a qualified bird expert should conduct a nesting survey within 3 days before work begins. If nesting birds are found, work should be delayed until nesting is complete, at least within a 300-foot radius of the nest.

The Benefits of Healthy Bird Populations

Healthy bird populations provide many benefits to our community:

  • Insect control: A single Black Phoebe may consume up to 1,000 insects in one day.
  • Rodent control: During nesting season, an owl may take up to 16 mice in a single night.
  • Pollination: A single hummingbird may pollinate up to 2,000 flowers per day.

Protecting birds is not only good for nature, but also helps maintain the balance of our local environment.

Choosing a Qualified Tree Professional

Homeowners should also take care in choosing qualified professionals.

Tree trimming and removal should be done by people who understand proper pruning, tree health, and wildlife protections—both state and federal. Poor trimming practices can weaken trees, attract beetles, increase fire risk, and lead to costly damage over time.

Licensed professionals also carry insurance, which helps protect homeowners from liability. Tree trimming and removal can be hazardous work, and cutting corners on cost may lead to serious consequences if a job is done improperly.

Healthy trees add tremendous value to the landscape and to property values. Treating them as an asset helps ensure they are cared for properly.

Poor trimming practices can:

  • Weaken trees
  • Attract beetles and pests
  • Increase fire risk
  • Lead to costly long-term damage

Defensible Space and Responsible Tree Care

Many residents in our area are thinking about defensible space and home hardening for wildfire safety.

If trimming or plant removal is part of that effort, fall and early winter are the best times to do the work responsibly, helping protect both wildlife and tree health.

Trimming trees and shrubs in months that end in “BER” is a simple practice that benefits birds, trees, and our entire community.

Frequently Asked Questions

Q: When should trees be trimmed in California to protect birds?

A: In California, most birds nest between January and August. To avoid disturbing active nests, the best time to trim trees and shrubs is during the months that end in “BER”: September, October, November, and December.

Trimming during fall and early winter is also beneficial for tree health because many trees are dormant during this time. Always check for nests before starting any work, since some species such as owls and hummingbirds may nest earlier than others.

Q: What should I do if birds are nesting in my gutters?

A: Some birds choose sheltered places like gutters and downspouts for nesting.

If you find an active nest:

  • Do not remove the nest. Many bird species are protected under federal and state wildlife laws.
  • Delay cleaning until the nesting cycle is complete and the young birds have left the nest.
  • Observe from a distance to avoid disturbing the birds.

Scheduling gutter cleaning during fall months (September–December) helps reduce the chance of interfering with nesting birds.

Q: Is it illegal to remove a bird nest in California?

A: In many cases, yes. Most native birds in the United States are protected under the Migratory Bird Treaty Act, which makes it illegal to disturb or remove active nests that contain eggs or young birds without proper permits.

California also has additional protections under the California Fish and Game Code, which protects native birds, their nests, and eggs from being harmed or destroyed.

Once a nest is no longer active (no eggs or chicks present), it is generally permissible to remove it. However, if you are unsure whether a nest is active, it is best to wait or consult a qualified wildlife professional.

Q: What if my HOA schedules tree trimming during bird nesting season?

A: Homeowners’ associations sometimes schedule landscape maintenance during spring and summer, which may overlap with the peak bird nesting season in California (generally January through August).

If tree trimming or vegetation removal is planned during this time:

  • Ask the HOA or landscaping company if a nesting survey will be conducted before work begins
  • Notify the HOA if you observe an active nest
  • Request that trimming near the nest be delayed until nesting is complete
  • Share this resource with your HOA

Most birds and their active nests are protected under the Migratory Bird Treaty Act and the California Fish and Game Code. Responsible landscaping practices include checking for nests and postponing work when birds are actively nesting.

Many HOAs are willing to adjust maintenance schedules or delay work in specific areas once they are aware of active nests.

Additional Resources

Learn more about bird-friendly tree care:

Author: Jennifer De La Torre
Board Member, Conejo Valley Audubon Society