Birds congregating in trees over a deck create noise and mess, making outdoor spaces less enjoyable. Addressing this requires a humane, multi-faceted approach focused on making the tree an undesirable location for perching, roosting, and nesting. Property owners can use physical barriers, sensory deterrents, and habitat adjustments to encourage birds to find alternative locations. These methods provide practical, non-lethal strategies to reclaim the space above your deck.
Blocking Access with Physical Barriers
The most reliable approach uses physical barriers to prevent birds from landing directly on branches above the deck. Specialized bird netting offers a highly effective solution by completely blocking access to the canopy. Commercial-grade netting, typically made from high-density polyethylene or nylon, should feature a mesh size of approximately 3/4 inch to exclude small birds without causing entanglement.
When installing, the netting must be pulled taut and secured around the trunk and perimeter of the canopy to eliminate all gaps. A continuous barrier is necessary, as small openings allow birds to bypass the deterrent. For individual, thicker horizontal branches, a non-toxic, sticky bird repellent gel can be applied to make the surface uncomfortable for landing.
Bird spike strips can be adapted for very large, flat tree limbs. These strips remove the flat landing space, though they are typically only effective against larger species like pigeons. Place the gel or spikes along the top of the branch where the bird’s feet would normally make contact.
Methods Using Sight and Sound to Deter Birds
Sensory deterrents capitalize on a bird’s natural fear and wariness, often involving visual or auditory confusion. Reflective objects are common visual techniques, as the constantly changing flashes of light disorient and alarm birds. Pieces of Mylar tape, old CDs, or reflective ornaments can be hung from outer branches, positioned to spin and catch the sunlight.
Mock predator decoys, such as plastic owls or inflatable balloons, can provide an initial scare. However, birds quickly learn that a stationary object poses no real threat. Decoys must be moved frequently, perhaps every few days, to maintain the illusion of a living predator and prevent habituation.
Auditory deterrents include recordings of predator calls or species-specific distress calls, which signal immediate danger to the flock. The sounds must be broadcast at random intervals and at a volume that avoids disturbing neighbors. Ultrasonic devices are largely ineffective against most bird species because avian hearing is not sensitive in the ultrasonic range.
Reducing Tree Appeal Through Habitat Modification
Long-term deterrence is achieved by actively making the tree less attractive as a habitat, focusing on reducing cover and eliminating nearby resources. Selective pruning of the tree canopy above the deck is an effective technique to decrease the number of protected roosting and nesting sites. Thinning dense branches allows more light and air into the canopy, removing the sheltered spots birds prefer.
Practice selective pruning, removing no more than 25% of the canopy at one time to maintain the tree’s health. Pruning during the winter (generally between September and February) minimizes the risk of disturbing active nests.
Removing attractants in the surrounding area further reduces the incentive for birds to remain near the deck. This includes securing garbage cans, removing unsecured pet food, and promptly picking up fallen fruit from nearby trees or shrubs. Additionally, removing or relocating water sources, such as bird baths, leaky faucets, or standing water, reduces the overall appeal of the area.
Following Wildlife Protection Guidelines
Before implementing deterrent measures, be aware of regulations protecting native bird species. The federal Migratory Bird Treaty Act (MBTA) protects nearly all native bird species, their eggs, and their nests. This law makes it illegal to destroy or disturb any active nest—one containing eggs or dependent young—without a specialized permit.
If an active nest is found, all activity in the area should cease until the young have fledged and the nest is completely inactive. It is permissible to remove a nest that is only partially constructed or completely abandoned. However, positive identification of the species is important, as some species, like House Sparrows, are not protected. All methods used must be humane and non-lethal, focusing exclusively on exclusion and deterrence.