Lucas A. Ferrara in New York Times Real Estate Section, A PROBLEM WITH PIGEONS, May 28, 2006.  

Q.  We live in a rent-stabilized apartment on the Upper East Side, and our terrace is unusable because it's infested with pigeons. We have to deal with their droppings, and the pigeons also attract bugs, which at one point made their way into the apartment. Is the owner responsible for remedying this situation? ... Laura Siegel, Manhattan

A.   "Landlords are legally required to ensure that rental apartments are fit for habitation," said Lucas A. Ferrara, a Manhattan real estate lawyer and editor of The Landlord-Tenant Monthly, a newsletter.

The "implied warranty of habitability," Mr. Ferrara said, provides that rental apartments — and areas used in connection with them — must be free of conditions that could be dangerous, hazardous or detrimental to life, health or safety.

"Typically, it's a tenant's responsibility to keep a terrace clean and free of debris," Mr. Ferrara said. "But since eliminating the infestation may require modifications to the exterior of the building, the landlord may be responsible for correcting the problem."

So, if the landlord refuses to act, a court will probably have to decide who is responsible. "The tenant can withhold rent and/or commence a court case to compel the landlord to make the necessary repairs," Mr. Ferrara said. If it turns out this is the landlord's responsibility, the tenant may be able to demand a rent abatement for the time the pigeon problem was not addressed.