Archive | June 2020

IS THE RED-TAILED HAWK A THREAT TO FEEDER BIRDS?

Jun28

      Recently while I was standing in the yard of my home, I spotted a red-tailed hawk gliding across my front yard. A northern mockingbird trailed the hunter. As I stood motionless, the hawk slowly descended before finally flaring its rusty-colored tail and landing out of sight just beyond the trunk of a water oak tree. Apparently, the red-tail missed its target as it immediately rose up without anything dangling from its talons and flew toward the back of my yard. As I stood spellbound watching the wild drama play out, the aerial hunter disappeared from sight, with the mockingbird still trailing close behind.

       Whenever a hawk appears in our yards, we often assume it is a threat to the birds using our feeders. If such is the case, is this assumption correct?

       While I did not see what the red-tail I was trying to catch, the evidence suggests, in this case, it was a mammal and not a bird. I never did see a bird fly away. However, eastern chipmunks and gray squirrels are regularly seen around the tree. If the hawk was pursuing a chipmunk, the small mammal could have escaped into a burrow. Whereas, a gray squirrel could have sought refuge climbing up the trunk of the tree.

       Studies of the red-tailed hawk’s food habits suggest that I could be right. When biologists evaluated the results of 27 food habit studies conducted on red-tailed hawks in North America, they found mammals made up the bulk (65.3%) of the 500 prey species that showed up in the diets of the birds examined. Birds were the second most important food item. A little more than 20% of the predator’s diet consisted of birds.  

       Rodents and rabbits proved to be the mammals most often eaten. Rabbits and hares proved to be the most important mammals in the diet. However, gray and fox squirrels, chipmunks, ground squirrels, and rodents such as voles, mice were eaten too.

       The list of other animals consumed included reptiles, invertebrates, amphibians, and fish.

       Although some 200 species of birds were recorded in the 27 surveys, the species most often taken by red-tails were pigeons, doves, European starlings, and woodpeckers. The woodpecker most frequently captured by this hawk was the flicker.

       Based on these findings the argument could be made that the red-tailed hawk is not a significant threat to the birds that commonly dine at our backyard bird cafes.

BACKYARD SECRET–PURPLE MARTINS HELP CONTROL FIRE ANTS

Jun24

       Purple martins are known to eat at least 79 species of insects including dragonflies, flies, bees, moths, and butterflies. However, I would be willing to guess you did not know they also dine on fire ants.

       It seems purple martins target mating male and queen fire ants. One group of researchers studying the feeding habits of purple martins found fire ants were captured during 32 percent of the birds foraging trips. The ants accounted for 31 percent of the insects taken. In addition, fire ants comprised 27 percent of the biomass consumed by the birds and their young.

       Based on these data, the scientists estimated purple martins consume some 1.7 billion fire ants annually across the United States.

MOUNTAIN MINT IS A GREAT PLANT FOR POLLINATORS

Jun21

       Over the years, my wife and I have been planting a diversity of nectar/pollen-producing plants in our gardens. This has been done in an effort to provide our backyard pollinators with sources of food throughout the year. This approach has offered us the opportunity to watch pollinators feed at a parade of plants from week to week as well as season to season. As the blossoms of one plant wither and die, pollinators redirect their attention to plants that are currently blooming. Right now, many of these pollinators are visiting mountain mint (Pycnanthemum sp.), one of the more recent additions to our landscape.

       Mountain mint is a native perennial herb that grows two to three feet tall. Eight species of this hardy plant are found in the Southeast. Plants grow two to three tall. They exist in a variety of soil conditions, including the dry clay soil found in our yard. While the plant does best in moist soil types, it is drought tolerant. Mountain mint will grow in partial shade as well as full sun.

    Mountain mint has a unique, eye-catching appearance. What makes this plant stand out is the fact that the leaves growing just below its flowers look like they have received a dusting of powdered sugar. In fact, to me, this foliage is far more attractive than the plant’s small white-purple blooms. In fact, these blossoms or so small you might overlook them if they were not arranged in clusters.

       However, though mountain mint plants won’t win any awards for beauty, the fact that it blooms from June into October makes it an important source of food for wild pollinators.

       Speaking of awards, in 2013 the Penn State Extension Service evaluated 88 pollinator-rewarding perennial plants for their importance to pollinators. At the end of the trial, mountain mint (P. muticum) received the highest rating for longevity of flowers, diversity of pollinators that use the plants, and the most insects attracted during the trials. In one trial, 76 insects visited the plants in just two minutes.

       I am not surprised at these findings. When my wife and daughter found our mountain mint blooming a few days ago, they saw a stand of mint being visited by three species of butterflies (juniper hairstreak, red-banded hairstreak, and pearl crescent). They competed with the likes of thread-waisted wasps, hornets, and bumblebees.

       One thing I like about mountain mint is that it is easy to grow. A friend gave us some mountain mint plants two summers ago. We set them out and kept them watered. The very next year the plants produced a crop of flowers.

       If you like to create dried arrangements, you will love mountain mint. Each fall after the flowers have disappeared, you are left with scores of unique prickly, round, brown seed heads displayed on long stems.

       Mountain mint is a plant that definitely deserves a place in your flower gardens.

HOVER FLIES–OFTEN MISTAKEN FOR STINGING INSECTS

Jun17

      The hover fly (also commonly called the flower fly) is one of our most often misidentified backyard residents. When one suddenly appears out of nowhere and hovers close to our face while making a buzzing sound, many panic and begin swatting at it fearing it is a bee or yellowjacket. Actually, the hover fly is not a bee, not a yellowjacket, nor hornet or wasp. Instead, it is a fly and is harmless to humans.

       Here is how you can tell if you have encountered a stinging insect or a hover fly. All you have to do is remember this brief saying, “Two wings fun, four wings run.” In other words, flower flies possess only one pair of wings, whereas yellowjackets and their relatives have two sets of wings. In addition, while the flower fly will not sting or bite, as we all know, bees, yellowjackets, wasps, and their kin are armed with a stinger that they will use to inflict a painful sting.

       In addition, most of the flower flies we encounter in our backyards look much like yellowjackets. However, if you will look closely, you will notice the hover abdomens of flower flies look deflated and flat. The abdomens of yellowjackets, on the other hand, appear inflated.

       Also, hover flies can both hover and fly backwards, whereas, yellowjackets do not possess this mastery of the air.

THE SUMMER TANAGER’S ODD FOOD CHOICE

Jun14

       One of the many birds that inhabit our backyards during the spring and summer is the summer tanager. Although it is one of our most beautiful backyard residents, it is a bird that lives there in relative anonymity. This is because it rarely visits our feeders and regularly feeds out of our sight within the thick canopies of tall, leafy trees. If we were able to peel away the leaves and watch a summer tanager feed, we would be soon discover that this striking bird has an odd food preference.

       Like a number of our other summer avian residents, the summer tanager dines on a wide variety of foods. Its varied diet includes fruits and berries in addition to a host of various invertebrates such as grasshoppers, cicadas, spiders, moths, and butterflies. However, the thing that separates the tanager from many birds is its affinity for bees, hornets, and wasps. In fact, it is so fond of them it is sometimes called the bee bird.

       Remarkably one of the bird’s favorite foods is the paper wasp. Summer tanagers are known to eat the adult wasps and also rip open their nests and feast on the wasps’ larvae.

       More often than not, we rarely catch a glimpse of a summer tanager hunting for insects that can deliver a painful sting to bird or man alike. From time to time though, summer tanagers can be seen perched closer to the ground near a beehive waiting for the chance to snatch a worker honeybee flying to or from the hive.

       The summer tanager is able to avoid being stung by grabbing hold its prey and flying back to a nearby perch. Once there it pounds the hapless insect against the branch until it is dead. It then proceeds to wipe the lifeless insect on the branch. This removes the bee’s stinger and other body parts that are inedible. Once this food preparation is completed, it swallows the bee whole and awaits the chance to feed again.

AMERICAN GOLDFINCHES FEED ON SCARLET SAGE SEEDS

Jun10

       One lesson I learned many years ago is some of the most fascinating wildlife sightings take place when you least expect it. Such was the case last Sunday. My wife and I had just finished dinner when she called out, “Come here, you have got to see this.”

       As soon as I heard her entreaty, I rousted myself out of my favorite chair and walked to the doorway leading to our sunroom. Once there she directed my gaze to a planter full of potted plants standing alongside the rail bordering the far side of the deck.

       As soon as I was able to locate what my wife was pointing at, I was surprised to see a female American goldfinch pulling apart the seed heads of a scarlet sage (Salvia coccinea). As we watched, the bird expertly extracted each unripe seed and immediately devoured it.

       Once I saw what was going on, I retreated to the house, grabbed my camera, and returned. Since this was the first time I had ever witnessed this behavior, I desperately wanted to photograph the event. Knowing that the bird would fly away if I opened the sunroom door, I slowly moved as close to the windows as I could and took several pictures through the sunroom’s windows. Knowing full well how difficult it is to photograph birds through window glass, I realized my chances of being able to take decent pictures were low. Remarkably, when I later reviewed the photos, I was surprised to find the photographs exceeded my expectations.

       A few minutes later a male American goldfinch flew in to enjoy the feast taking place no more than 10 feet away from us. This provided me with the opportunity to photo both birds from the comfort of my sunroom. What a treat!

       As we watched the birds feed, I could not help but wonder why they chose to feed on the scarlet sage’s tiny, green seeds when a feeder stocked with black oil sunflower seeds was no more than 20 feet away.

       We watched this fascinating drama play out for several more minutes before something scared the birds away. As the goldfinches flew to a stand of trees, we were left with several super photos and memories of how a pair of goldfinches made a Sunday afternoon extra special.

       I am so glad my wife just happened to notice what was taking place just outside our backdoor.

       Keep your eyes peeled as natural dramas are taking place in your backyard every day. However, you will never see them unless you take the time to look for these special happenings.

       One final note: if you will type the words “scarlet sage” in the search engine bubble located in the upper right corner of the blog and hit return key, two other blogs I have written about wildlife use of scarlet sage will pop up.

CAN URBAN AREAS AFFECT BIRD MIGRATION?

Jun4

       Growing numbers of backyard wildlife enthusiasts share the opinion that they are not seeing as many birds visiting their backyard feeders during the winter as they did in years past. It is a widely accepted fact that the total numbers of North American birds have declined dramatically in recent decades. However, other factors may also be having a deleterious impact on the numbers of birds that winter in the Georgia. The results of a recently completed study published in Conservation Biology identified one possible reason for birds apparently altering their migration patterns.

       Accord to the study’s lead author Anne-Sophie Bonnet-Lebrun, “This showed that urbanization can have an effect on migratory behavior of birds.”  

       This conclusion was reached after analyzing banding data involving 12 partially migratory species. These species may or may not migrate every year. The researchers found that, of the species banded, the European starling, American Goldfinch, evening grosbeak, and purple finch were the birds that would most likely winter within the breeding range. However, urbanization increases the likelihood that common grackles, European starlings, house finches, and white-throated sparrows will also remain in their breeding areas too.

       The researchers suggest that warmer temperatures, coupled with food availability provided by the presence of bird feeders, and other foods found within urban areas offer birds ideal places to winter.

       Further research is needed to determine if urban areas are affecting the migratory patterns of other bird species.