PROTECTION FROM PREDATORS - Limiting Predator Access

Proper box depth, roof, and entrance hole design will help minimize predator (raccoons, cats, opossums, and red squirrels) access to birds living in your birdhouses. Sometimes all it takes is an angled roof with a three-inch overhang to discourage mammals.

The entrance hole is the only thing between a predator and a bird house full of nestlings. By itself, the 3/4" wall isn't wide enough to keep out the arm of a raccoon or house cat.  Add a predator guard a 3/4 inch thick rectangular wood block, to thicken the wall, and you'll discourage sparrows, starlings, and cats.

Cats  
Nesting birds are very vulnerable to cats, as are fledglings and birds roosting for the night.  Bell collars on cats offer birds little protection.  Nailing a sheet metal guard or cone to a tree trunk is unsightly, but it may deter less agile felines.  Birdhouses mounted on metal poles are the most difficult for predators to reach, especially if you smear the poles with a petroleum jelly and hot pepper mixture.

Dogs
Pet dogs are a hazard to nestlings in the spring and summer.  All it takes is one swift bite and the baby bird is gone.  Don't let your dog run loose during nesting time.

Squirrels 
Red squirrels, and sometimes gray squirrels, can become a serious menace to bird houses and the birds themselves.  If you find your nest hole enlarged, chances are a red squirrel is the culprit. Once inside the box, squirrels make a meal of the eggs and young.   Adding a predator guard of sheet metal to the entrance hole is usually enough to keep squirrels out.

Raccoons and Opossums
Raccoons and opossums will stick their arms inside nest boxes and try to pull out the adult, young, and eggs. Adding a predator guard to the bird house or to its pole support is a simple solution.

Snakes
Snakes are an important part of the natural balance between predator and prey.  If you find one of these reptiles in your bird house, please don't kill it.  Snake-proof your house by putting it on a metal pole lathered with a petroleum jelly or hot red cayenne pepper.

European Starlings and House Sparrows  
If you don't discourage them, these two pest species introduced from Europe will bully or kill cavity-nesting birds.  Since house sparrows and starlings are not protected by law, you may destroy their nests.  But, remember, other birds are protected by law.

 

House Wrens
Sometimes house wrens interfere with the nesting success of other birds by puncturing their eggs.  But unlike the sparrow and starling, these birds are part of the natural system. They are protected by law.  Don't be tempted to intervene.

 


Insects
Many insects lay their eggs and pupate in bird houses. You should inspect your bird houses for signs of gypsy moths, blow flies, wasps, ants, gnats, and bees.  You can keep bees and wasps from attaching their nests by coating the inside of the roof with bar soap. In areas where gypsy moths abound, avoid placing boxes in oak trees, which are favored by the gypsy moths.

Pyrethrin and rotenone insecticides are recommended for killing fly larvae, bird lice, and mites.  Use only after the birds have finished nesting for the season.

I hope the information we have been providing in our blog has helped you to enjoy your bird watching.  Please feel free to add any tips or tidbits of information for our readers. If you have an interest in adding to your birdhouse or bird feeder collection, visit our website at www.aboutbirdhouses.com. 

Part 5: Birds You Can Attract to Your Bird Houses and Nest Boxes

This is a continuing series on attracting birds to your yard.

Flycatchers

The great crested flycatcher and its western cousin, the ash-throated flycatcher, are common in wooded suburbs. Their natural nesting sites are abandoned woodpecker holes.  Flycatchers may nest in a birdhouse if it's placed about ten feet up in a tree in an orchard or at the edge of a field or stream. 

Woodpeckers

You can attract all kinds of woodpeckers with a suet feeder, but only the flicker and the red-bellied are likely to use  birdhouses. They prefer a box with roughened interior and a floor covered with a two-inch layer of wood chips or coarse sawdust. Flickers are especially attracted to birdhouses filled with sawdust, which they "excavate" to suit themselves.  For best results, place the box high up on a tree trunk exposed to direct sunlight. 

Owls

Most owls seldom build their own nests. Great horned and long-eared owls prefer abandoned crow and hawk nests. Other owls (barred, barn, saw-whet, boreal and screech) nest in tree cavities and birdhouses. 

Barn owls are best known for selecting nesting sites near farms. Where trees are sparse, these birds will nest in church steeples, silos, and barns. If you live near a farm or a golf course, try fastening a birdhouse about 15 feet up on a tree trunk. 

Screech owls prefer abandoned woodpecker holes at the edge of a field or neglected orchard. They will readily take to boxes lined with an inch or two of wood shavings. If you clean the birdhouse out in late spring after the young owls have left, you may attract a second tenant--a kestrel. Trees isolated from larger tracts of woods have less chance of squirrels taking over the birdhouse.  Check out the supply of birdhouses available at www.aboutbirdhouses.com.

Part 4: Birds You Can Attract to Your Bird Houses and Nest Boxes

This is a continuing series on attracting birds to your yard.

Purple Martins

Many people want martins because, it's been said, these birds "can eat 2,000 mosquitoes a day." While it's true that they eat flying insects, don't expect purple martins to wipe out your mosquitoes. Martins actually prefer dragonflies, these insects prey on mosquito larvae. 

Mosquitoes are most active after sunset. If you want to rid your yard of mosquitoes, put up a bat roosting box.  One bat can eat thousands of mosquitoes a night.  But don't cross martins off your prospective tenant list because they don't live up to their "bug zapping" reputation. If you need a reason for attracting them, these gregarious swallows put on a show that's better than any television soap opera. 

You have the best chance of attracting martins if you put a birdhouse on the edge of a pond or river, surrounded by a field or lawn. Martins need a radius of about 40 feet of unobstructed flying space around their houses. A convenient fence or telephone wire nearby gives them a place to perch in sociable groups. 

Martins nest in groups, so you'll need a bird condo with a minimum of four large rooms -- 6 or more inches on all sides, with a 2-1/4 inch entrance hole about an inch and a half above the floor. Ventilation and drainage are critical factors in martin house design. Porches, railings, porch dividers and supplemental roof perches, like a TV antenna, will make any bird house more appealing. 

Gourds may also be made into houses by making an entrance hole and providing drainage. If you use gourds, it's not necessary to add railings and perches. Adult martins will perch on the wire used to hang the houses. 

Before you decide on a house, take the time to think about what kind of pole you're going to put it on. Martins will occupy a house that's between ten and twenty feet off the ground. Some poles are less cumbersome than others. 

Gourd houses are the easiest to set up. You can string them:

• from a wire between two poles
• from a sectional aluminum pole
• on pulleys mounted to cross-bar high up on a pole.  

Light-weight aluminum birdhouses can be mounted on telescoping poles, providing easy access for maintenance and inspection. Because of their weight (well over 30 pounds), wooden birdhouses cannot be mounted on easy-access telescoping poles. You'll have to use a sturdy metal or wood pole attached to a pivot post. The problem with this "lowering" technique is that you can't tilt the house without damaging the nests inside. If you put your house on a shorter, fixed pole, ten to twelve feet high, you can use a ladder to inspect and maintain it. 

Please check out the vast array of bird houses at www.aboutbirdhouses.com.

Part 3: Birds You Can Attract to Your Bird Houses and Nest Boxes

This is a continuing series on attracting birds to your yard.

Tree and Violet-green Swallows

Tree swallows prefer bird houses and nest boxes attached to dead trees. Space the birdhouses  about seven feet apart for these white-bellied birds with iridescent blue-green backs and wings. The ideal setting for these insect-eaters is on the edge of a field near a lake, pond, or river. 

Violet-green swallows nest in forested mountains of the west; birdhouses placed on large trees in a semi-open woodland will attract them. 

Barn Swallows and Phoebes

If you have the right habitat, barn swallows and phoebes are easy to attract. It's their nesting behavior, not their plumage or song, that catches your attention. These birds tend to nest where you'd rather not have them: on a ledge right over your front door. To avoid a mess by your door, offer the birds a birdhouse  nearby where you'd rather have them. 

Please check out the vast array of bird houses at www.aboutbirdhouses.com.