It’s also the time when birds of all kinds make their nests. As much of a part of spring as that is, if you’re a homeowner you need to stay alert so that birds making their cozy homes don’t disrupt your cozy home.

Some of the same people who would be horrified to learn of a family of rats living in their basement, don’t think twice about birds nesting in their eaves.

Some birds, such as starlings, pigeons, seagulls and crows are exceptional opportunists and should be discouraged from living at your house.

At best, they might only roost on all the roofs in sight of somebody’s regular handout, all the while depositing prolific amounts of acidic droppings on each roof. (This creates ideal conditions for a healthy crop of roof moss.) At worst, they can spread harmful disease and create expensive structural damage.

The Starling: A European export

In this area one of the worst pest birds to the average homeowner is the starling. It was introduced to America from Europe in the 19^th century. With the prolific habitat of the South, they soon became noisy, swarming menaces, in flocks of millions. If you don’t remember them from your youth, that’s because they didn’t reach us on the West Coast until the last several decades.

Starlings are dark and muscular and can be distinguished from other blackbirds by their oily sheen, short tail and long and slender yellow bill.

They are a prolific bunch, with each pair having two broods and averaging eight offspring a year. They often travel in huge flocks numbering in the hundreds or thousands.

If you have encountered a starling pair creating a nest in your house, you will recall the extraordinary persistence and dedication to their task. Starlings are even known to stand by and watch a pair of other birds make a nest and then kick them out.

As we said, starlings are prolific and aggressive – often driving out native birds not just out of their nests but out of their territories.

If you’re a bird watcher, you probably already think of starlings as the enemy.

As a homeowner, you’ll want to do what you can to discourage them from building a home in your house. For one thing, they use copious amounts of straw, twigs and grasses to make their nests, making a fire hazard for you.

Gutters and drainage pipes clogged with starling nests often backup, which can cause extensive water damage.

In addition, bird nests built in chimneys and ventilation systems not only spread diseases through the system, but also can block airflow.

Bird droppings, being very acidic, can actually eat away at many substrates, especially tar-based roofing materials, eventually causing leaks. The uric acid in the feces will also corrode stone, metal and masonry and do great damage to siding, insulation, air conditioning equipment and machinery.

For most people, it’s common sense to rid their house of a colony of rats or mice. The same thinking needs to apply to pest birds. The bacteria, parasites and fungal agents in their feces can pose a serious health risk.

Besides direct contamination of food or water, airborne spores from drying feces in air ducts and vents can settle on exposed food and transfer disease.

Pest birds also harbor ticks, fleas, mites and other parasites, which are great transmitters of several hundred viral and bacterial diseases.

Keep that in mind when you’re trying to remove their nests or disinfect their messes – you may want to wear gloves and even a facemask.

So, how do you discourage starlings from nesting at your house, especially if you would like to encourage other birds to nest nearby?

As with all other aspects of keeping a healthy house, you must be observant, vigilant and more persistent than the pests that seek to invade.

First, imagine you are a bird looking for a nesting place in a warm, dry place. Tour the exterior of your home, paying close attention to the eaves and gutter areas, as well as where the siding meets the roof and all your exhaust fan vents.

You’re looking for any kind of 1 inch to 1 ½ inch holes, open spaces between trim boards, missing roofing or siding materials and especially nesting material protruding from you house. Maybe you will find what you had suspected last spring, an old nest site.

Since starlings and many other birds use the same nest for generations, you will want to remove any nesting materials from the cavity and seal the hole. Look for a secondary entrance.

In your inspection, look closely at the roof ventilation holes or vent strips under your eaves. They are critical to the health of your home, so you don’t want to seal them.

At the same time they are the premium nesting sites in your home, providing shelter, heat, ventilation and a view.

If there is a damaged or missing vent screen or just open vent holes, we suggest securing some heavy gauge, galvanized hardware cloth with a ¼ inch wire-mesh over them. That should effectively let the air in while keeping the birds out. If the birds have created holes, block or replace the wooden material.

Starlings, when nesting someplace else, aren’t all bad. They eat massive amounts of crane fly larvae and aerate your lawn in the search. Other birds have similar benefits.

Hang the right-sized bird box with proper hole and you will reap the reward of the living near one of nature’s best mosquito eaters and most amazing air shows—the cute little tree swallow.

Here are some other tips to attract native species while discouraging pest birds:

• Block the entrances to birdhouses until desired native species arrive.
• Hang suet, rather than posting it. This will keep starlings and rats from eating it, but still make it available to native birds.
• Put up nest boxes with holes no larger than 1 1/8 inches to favor native songbirds and tree swallows. The hole size and box requirements are specific for each kind of bird. The library and internet are great resources for this information