Pestipedia

Nesting Birds

**Nesting Birds** is a term covering any bird species that attempts to build nests or establish roosts on or within human-made structures. Common nuisance species include **Pigeons** (*Columba livia*), **House Sparrows** (*Passer domesticus*), and **European Starlings** (*Sturnus vulgaris*). The conflict is significant and involves **structural damage**, **unsanitary conditions** from droppings (guano), **noise**, and potential **health risks** from pathogens and associated parasites (e.g., mites, fleas).

Taxonomy and Classification

Nesting Birds belong to the class Aves. The three species listed above are generally **non-native and unprotected** in the U.S., allowing for their nests (and sometimes the birds themselves) to be legally removed or controlled. However, **native birds (like Swallows, Doves, or Robins) and their active nests (containing eggs or young) are strictly protected** by the Migratory Bird Treaty Act (MBTA) and must not be disturbed until the young have fledged.

Physical Description

Nesting Birds vary in size and color (e.g., Pigeons are stout and gray; Starlings are medium-sized and iridescent black).

  • **Nesting (Key ID):** Nests are bulky, messy piles of grass, twigs, feathers, and trash placed in sheltered structural voids (vents, eaves, signage, window ledges).
  • **Conflict Sign (Key ID):**
    • **Guano:** Accumulations of droppings on ledges, windows, or sidewalks below roosting areas.
    • **Nesting Material:** Visible nesting material blocking vents or protruding from eaves/gutters.
    • **Noise:** Constant chirping, cooing, or movement in walls, attics, or soffits.
  • **Conflict:** Structural damage, health risk, and aesthetic degradation.

Distribution and Habitat

Nuisance Nesting Birds are found worldwide, heavily concentrated in urban and suburban areas. Their habitat is any structure that provides high, protected, or sheltered platforms for nesting and roosting, especially commercial buildings, warehouses, and homes.

Behavior and Conflict

The conflict profile is severe contamination and property damage.

  • **Dropping Damage:** Guano is highly acidic and corrosive, leading to permanent damage and deterioration of roofing, paint, masonry, and equipment (e.g., solar panels, HVAC).
  • **Health Risk:** Droppings can harbor pathogenic fungi (*Histoplasma capsulatum* – Histoplasmosis) and bacteria (*Chlamydia psittaci* – Psittacosis). The nests often harbor bird mites which may bite humans.
  • **Structural Issues:** Nests can clog gutters, vent pipes, and chimneys, posing fire hazards and causing water damage.

Management and Prevention

Control is integrated pest management (IPM), with a heavy focus on **exclusion**.

  • **Exclusion (Key):**
    • **Netting:** Install heavy-duty bird netting to seal off large voids (loading docks, under eaves).
    • **Spikes/Wires:** Install bird spikes or tension wire systems on narrow ledges, window sills, and parapet walls to prevent landing and roosting.
    • **Screens:** Cover all vents (louvered, dryer, attic) with heavy-gauge screening or hardware cloth.
  • **Repellents:**
    • Use sticky gels or taste/smell repellents as a temporary measure (gels require careful application and maintenance).
  • **Nesting Management (Legal):**
    • Ensure all local and federal laws (MBTA) are followed. **Remove non-native nests only when unoccupied.** If a native bird nest is active, exclusion methods must be deferred until the young have fledged.

    • Conservation and Research

    Nuisance Nesting Birds are managed as high-priority structural pests. Research focuses on developing humane and effective non-lethal deterrents, studying urban population dynamics, and safely mitigating health risks associated with guano.