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DO BACKYARD BIRDS PRACTICE MONOGAMY?

        Up until a few decades ago, biologists believed that as many as 93 percent of songbird families practiced monogamy.  However, since the development of DNA fingerprinting in the 1980s, we now know some birds that appear to be devoted mates will stray.

        This earth-shattering realization came about quickly.  For example, by 2002, researchers discovered that up until that time a meager 14 percent of the songbirds tested were truly monogamous.  Research has shown 19 percent of the nests of supposed monogamous birds are home to at least one nestling that was sired by a father different from the rest of its nest mates.

        A few of the backyard birds that are promiscuous are the eastern bluebird, ruby-throated hummingbird, house finch, and red-winged blackbird.

        It would appear that some of our backyard feathered neighbors live soap opera lives.

PROVIDING NESTING MATERIAL FOR HUMMERS

       Have you ever given any thought of trying to provide nesting hummingbirds with a source of nesting material?  I must admit while I have placed pieces of cotton in a wire suet feeder in the spring hoping it might be used by nesting birds, I never considered the possibility the white fibers might be used by a ruby-throated hummingbird.  However, three events have caused me to change my mind.

        Several years ago, I presented a hummingbird program to a garden club in southwest Georgia that met in the home of one of its members.  While I was setting up my projector and screen, the host asked me if I ever heard of a hummingbird using cotton to build a nest.  I told her although I had not, I could see how hummingbirds might incorporate cotton in a nest. 

        She then went on the explain that she had seen a female hummer collect cotton in her backyard.  It seems she planted a cotton seed in a pot that sat near her house.  The seed germinated and grew into a healthy plant festooned with balls of cotton.  Since the plant looked attractive, she left it in pot throughout the winter.

        The following spring while she was standing in her living room, looking out across her patio a female hummingbird flew down, plucked some cotton fibers from a cotton ball, and flew up to a nearby tree.  The bird repeated this behavior several times.  Although she never actually saw the bird using the cotton to build a nest, she surmised that is what the little bird was doing.

        I was reminded of this homeowner’s experience last week when I received an email from a man relating that he had witnessed a female hummingbird collect a bit of cotton from a suet feeder filled with cotton batting.  This prompted him to search for a nest.  Remarkably, his efforts paid off and he discovered a hummingbird nest close by.

        Earlier this week I mentioned this event to a cousin.  He was so intrigued by the story he went out and bought a wire suet feeder, filled it with cotton, and hung it out near his home.  Unbelievably before the sun set he spotted a female hummer pulling strands of cotton from the  feeder.  Now he is looking for a nest.

        With this kind of success, perhaps this is something we should all try.  Even though a hummingbird might not avail itself of the cotton we offer, chances are other nesting birds will.  

EXPECT TO FIND CAROLINA WREN NESTS IN ODD PLACES

        Although the Carolina wren is considered to be a cavity nesting bird I must confess I have never found a Carolina wren nest in a natural cavity or nesting box.  In fact, when it comes to Carolina wren nests, I have learned to expect the unexpected.

        I have found Carolina wrens nesting in my well house, beneath the cover of a propane tank as well as in a cardboard box sitting on a shelf in my garage.  Others have discovered Carolina wren nests is strange places too.

        For example, their nests have been located among the rocks of  stonewalls, clothespin bags, hanging baskets, open paper bags, mailboxes, buckets, as well as in old hats and shoes.

        One year Carolina wrens nesting in North Carolina chose as their nesting site a Jeep Wrangler.  They constructed their nest where a shock absorber was attached to the frame of the vehicle.  What makes this nesting so fascinating is the fact the vehicle made three trips before the nest was discovered.

        Carolina wrens apparently have no problem nesting in vehicles that are driven about.  Decades before the famous Georgia ornithologist, Thomas Burleigh reported that, in 1928, a pair of Carolina wrens nesting in Athens chose as their nesting site a touring car.  The vehicle was left near a sawmill for two days.  During this time, the wrens began building their nest beneath the hood of the car.  When the car was driven away and returned the next morning, the unperturbed birds resumed construction of their nest.

        If you have never located a Carolina wren nest on your property, perhaps you have been looking in the wrong places.  This year focus your search on places you would never expect a self-respecting wren to nest and you just might find the nest that has been eluding you for so long.  

        Good luck!

LEAD CAN AFFECT MOCKINGBIRD AGGRESSION

          We Georgia homeowners are well aware of the fact the northern mockingbird is one of our most aggressive backyard birds.  In fact, if you are like me, it is hard to believe you would want them to be any more aggressive.  However, the results of a study published by Stephanie McClelland in the journal Science of the Total Environment suggest that the amount of lead found in the soil within a mockingbird’s territory can affect its aggressiveness.

    The study was conducted in neighborhoods scattered across New Orleans, Louisiana.  The data collected during the study found mockingbirds living in areas where high levels of lead are present in the soil are more aggressive than those inhabiting neighborhoods where soils are not contaminated with this pollutant.

         Now that I know lead can affect the level of aggressiveness displayed by mockingbirds, I cannot help but wonder if this element is affecting the mockingbirds living in my yard.  I hope that is not the case.

OFTEN IT PAYS NOT TO MOVE

        Birds have a variety of ways to keep from being eaten by bird of prey.  For example, some birds escape into deep cover at the approach of a hawk. Others rely on the pattern and coloration of their plumage to blend in with the surrounding landscape.  There are even birds that use erratic and fast flight to stay out of harm’s way.  Another way in which birds escape the sharp eyes of an avian predator is to remain motionless.  Recently nature enthusiast Debbie Menard watched a downy woodpecker use this ploy to keep from being snatched up by a Cooper’s hawk.

        Debbie maintains a number of nectar and seed feeders close by her Monroe County residence.  This allows her to watch birds as she moves about inside her home.  Recently she noticed a downy woodpecker perched on a nearby peanut feeder.  She did not give this much thought, as downy woodpeckers are frequent visitors to the feeder.  However, several minutes later she was surprised to see the black and white bird had not moved.   When she looked about her yard it quickly became apparent, birds had mysterious vacated her feeding area.  Indeed something seemed to be amok.

        The first thing that came to mind was the Cooper’s hawk that regularly patrols her yard must be nearby.  When she heard the raucous, incessant calls of American crows and blue jays, it became obvious that the Cooper’s hawk or other predator must be nearby.

        When she checked the downy woodpecker again, she found it was still seemingly frozen to the feeder.  All told, the downy remained glued to the feeder for at least 15-20 minutes.

        Finally, when Debbie ventured out into her carport, she inadvertently flushed a Cooper’s hawk that apparently had been perched in an oak growing along the edge of her driveway.

        After the hawk departed, the downy woodpecker flew off and the regular diners at her backyard cafe returned and resumed their feeding.

        This behavior displayed by the downy woodpecker worked because many predators detect the presence of potential prey by detecting an animal’s slightest movement.  Although the woodpecker was in plain sight, the bird was essentially invisible to the Cooper’s hawk. However, if the bird had moved the slightest bit, its ruse would have been over and the woodpecker would have had to make a desperate dash to cover to avoid the sharp talons and bill of the formidable predator.

        If you would like to share an interesting backyard wildlife experience with other bloggers, please let me know.

WHY DO SOME BIRDS FORM FLOCKS IN WINTER?

       Some of the birds that inhabit our yards during the winter travel about in flocks. Among the birds that adopt this behavior are American robins, chipping sparrows, brown-headed cowbirds, common grackles, and red-winged blackbirds.

       Being a member of a flock offers a bird many advantages. A bird traveling in a flock is less likely to be captured by a hawk, owl, or other predator. This is called the predator dilution effect.

       Here is how it works. Should a Cooper’s hawk dive into a flock, it must select one bird and not be distracted by all of the others in the flock. This is often difficult to do when lots of birds are frantically trying to escape with the lives. As such, to be successful the hawk must target a single bird. If the hawk attacked the whole flock and simply lashes out trying to catch a bird, chances are all of the birds will fly away unscathed.

       Another advantage to being the member of a flock is that it is extremely difficult for a predator to approach a flock of birds when hundreds, if not thousands, of pairs of eyes are poised to detect any potential danger.

       In addition, flocks have a tendency to find food more readily than individual birds. In many cases, the older, more experienced members of the flock know the best places to find food and roost. This is a real bonus since food is often difficult to find in winter.

       In addition, birds that expend as little energy as possible trying to locate food have a greater chance of survival during frigid weather. A bird in poor physical condition can easily succumb to the cold on frigid nights simply trying to maintain its body temperature.

I am sure you are familiar with the old adage, “There is safety in numbers.” As you can see, in the case of birds that flock together in winter, this statement is indeed true.

BLOGGER OBSERVES WHITE-BREASTED NUTHATCH CACHING FOOD

In a recent blog, I noted that one of the great joys of backyard wildlife watching is sharing your observations with others. This prompted Debbie Menard to report one of her most interesting recent wildlife sightings. I found her report so interesting I thought I would share it with you.

       Debbie is one of the few folks I know that offers safflower seeds on her menu of food offerings at her backyard bird cafe. Since gray squirrels do not relish the oily seed, it is sometimes used as an alternative to sunflower seeds. For some reason, gray squirrels seem to shy away from this odd seed.

       In fact, it is a seed that only a handful of backyard birds will routinely eat. The seed appears to be eaten most often by the northern cardinal. The short list of other species that will eat safflower seeds includes the likes of downy and red-bellied woodpeckers, tufted titmouse, mourning dove, Carolina chickadee, blue jay, finch and the white-breasted nuthatch.

       One day this summer Debbie watched a white-breasted nuthatch pluck a safflower seed from a feeder and characteristically fly off with it in its bill. The bird landed on the trunk of a large white oak tree. Once there, the bird made a few modifications to the bark of the tree. Once the bird was satisfied with its handiwork, it wedged the seed in the cavity it had created and flew away.

       This was the first time Debbie have ever seen a white-breasted nuthatch engage in this fascinating behavior.

       What a great sighting!

       Keep your eyes peeled, a white-breasted nuthatch, or some other bird, may be caching seeds in your backyard right now.