Birdwalk Newsletter 5.21.2017 Walks Conducted by Perry Nugent Newsletter by Jayne J
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Magnolia Plantation and Gardens BirdWalk Newsletter 5.21.2017 Walks conducted by Perry Nugent Newsletter by Jayne J. Matney Photo above by Ricardo Adami “Have you ever observed a hummingbird moving about in an aerial dance among the flowers – a living prismatic gem…it is a creature of such fairy-like loveliness as to mock all description.” W.H. Hudson ______________________________________________ A bird of the Americas, hummingbirds, are our little fairies of the gardens and forests; they are almost anywhere in the western hemisphere where you can find mild weather with flowers offering nectar. Classified under the family Trochilidae, these magical gems of the air usually only measure between 7.5 and 13 cm (3 to 5 inches) in length, yet they rapidly beat their wings at up to 70-80 times Photo by Cary McDonald per second, and have the highest metabolism of any animal besides the flying insects! The manner in which they eat, fly, and look are only the beginnings of the traits that capture our fascination. These birds eat insects rich in nutrients and nectar rich in sugars, for energy. Tree sap and pollen are other supplemental treats. The beaks are usually long, slender, and curved downward and can be quite flexible. According to the Defenders of Wildlife website, the long tongues which they possess can lick up to 13 times per second. “Flight” and “hummingbirds” seem to be synonymous. Flight is one of their specialties. They can outfly them all! There is not a direction they cannot move, they can even fly upside down, and they can start and stop on a dime. Their notorious hovering technique is studied by scientists and engineers alike. With the use of slow motion photography, the hovering technique illustrates a figure eight pattern of their wings. So their wings tend to be small, but can rotate in the socket in specialized patterns without harming or stressing the joint and the needed muscles. Hummingbirds are, after all, named for the humming sounds they make due to these rapid wing beats. Unlike most birds, they do not “launch” themselves off of branches; their wings do all of the work. Photo by Cary McDonald Hummingbirds tend to be colorful birds, showing an iridescence to those feathers. The magnificent coloring of hummingbirds, especially the males, is primarily for courtship and territorial reasons. Colorations range from bright emeralds, reds, purples, golds, and blues. Whether to attract their mate or to discourage others in their territory, these colors are used for cues to the others in their area. In addition to color cues, behaviors are very distinct when it comes to hummingbird interaction. Territorially, hummingbirds can be very aggressive to other hummingbirds and to birds of different types as well. They have even been seen chasing of falcons if they feel the need. Of course, the males are going to take advantage of their expert flying skills to attract females. Male hummingbirds are known to dive over prospective mates at outlandish speeds (see fun facts) and using aerial displays for her while making vocalizations such as chirps, squeaks, whistles, and buzzing, and feather sounds such as chirps and high pitched sounds coming from the feathers. Many of the high pitched sounds are made by tail feathers or wings due to airflow at such a great speed. Photo by Cary McDonald Besides their eating practices, incredible flight speeds and patterns, and gorgeous coloration, these birds have proven to have incredible eye sight. Since they cannot waste any time and extra energy in locating food, their vision along with exceptional brain processing function, due to speed at which they fly, they can maneuver quickly with intense spatial resolution. These birds can also see parts of the ultraviolet spectrum of light and they make use of cues and landmarks along the way. Therefore, their flight for food is not a random or chaotic method for hunting their food. Don’t be surprised if the same hummingbirds come back to your feeder or garden from past years expecting the same prize. It has been told that they may appear before you are ready, looking for your feeder in the same location it was presented in past years. They will show up at old haunts expecting the feeder to be ready and available when they arrive! In South Carolina, it is recommended to put out feeders by mid-April. While watching hummingbirds, you may only hear parts of their song because much of it may be out of our hearing spectrum or range. They also produce ultrasonic waves which are thought to aid these birds in catching insects in mid- air. Even though hummingbirds have so many wonderful aspects to their morphology and behaviors, there are a few disadvantages for hummingbirds. Because their metabolism is so high causing their heart rates, oxygen intake, breathing rate and body temperature to be high as well, their life expectancy is lower than many other birds. The hummingbirds of our state are generally expected to have a life span of 3 to 5 years, if they live past the first year. Depending upon the specific species, longevity records are somewhere between 9 and 12 years. In addition, hummingbirds have a disadvantage when it comes to their feet and legs. They have short legs and small feet, which only allows for perching and shuffling around on a branch. So they will not hop or walk by normal standards. Contrary to what most people believe, these tiny birds actually perch most of their day. Another disadvantage for them is the fact that they must have ways to conserve energy since they expend so much in food gathering. So they have adjusted by going into torpor states which can decrease their metabolic rate and therefore other bodily functions to “give it a rest”. This is a sort of daily hibernation for them. A limitation for these tiny birds is winterizing which is very important. Because they are so incredibly small and metabolize at high rates, they cannot have a range that includes cold weather at any time. They would not survive harsh winter weather. Therefore, most winter in the tropics. Our more prominent hummingbird, the Ruby-throated Hummingbird, winters between Mexico and northern Panama. Photo by Cary McDonald There are over 300 species of hummingbirds and 12-17 of those are known to summer in North America. According to the Cornell Lab of Ornithology, the Ruby- throated Hummingbird is “eastern North America’s sole breeding hummingbird.” Hummingbirds range from latitudes of southeastern Alaska and southern Canada to southern Chile depending upon the species. They are found all across the U.S. and in the Caribbean. They are lone travelers, so you will not see them migrating or living in flocks like many migratory birds. This also affects the tendency to see them in wide ranges, but few and far between unless they are enticed with food products. Some of the southern South American birds actually migrate northward during the summer months. Hummingbirds look for habitat that will provide constant supplies of food and good temperatures. Their favored habitats are tropical and subtropical forests, open deciduous or mixed forests, meadows, grasslands, parks, gardens, and backyards. There is much talk about destruction of these habitats affecting the overall population of these birds. Once the hummingbird finds a suitable place for nesting, the pair will mate, then the male migrates away while the female is left to do the nest building, incubating, and rearing of the young. Typically the nest is a cup-like structure of mosses, lichen, small soft plant fibers, and leaves and the mother will press and smooth the surfaces with her neck and chest. Sometimes spider webbing is used as well to give the nest some flexibility in size and shape. They are typically located 10 to 90 feet above the ground and are camouflaged and can take anywhere from 6 to 10 days to complete. The gestation period is anywhere from 13 to 22 days and the clutches are small (1-3 eggs). Egg size and color vary from species to species. Once the young hatch, they are fed small arthropods and nectar from the beaks of the mother. The young will start to show an interest in flying between 18 and 30 days. In South Carolina, the most prominently seen hummingbirds are the Ruby- throated and Rufus Hummingbirds. However, other hummingbirds have been seen here as well. According to “Hummingbirds Found in South Carolina” by Beauty of Birds’ website, those which have been the more sighted here in South Carolina are: Ruby-throated (native), Rufus, Broad-billed (accidental vagrants), Buff-bellied (accidental vagrant), Blue-throated (rare vagrant), Black-chinned (rare vagrant), Calliope (rare vagrant), and Allen’s (rare vagrant). Where do hummingbirds fit in to our world? Upon close examination of fossils, a few have been recovered despite the fact that their bones are so tiny and fragile. Fossils have been recovered in Brazil and the Bahamas from the Pleistocene. Two hummingbird fossils were recovered from the same clay pit south of Heidelberg, Germany and tucked away until a scientist by the name of Dr. Gerald Mayr located it in a drawer at a museum in Frankfurt. It was estimated to be 30 million years of age. There are differences in the taxonomy placement of these birds. Traditionalists prefer them in the order Apodiformes with the swifts while many current taxonomists prefer them in their own order- Trochiliformes. Either way, they have captured our interest and hearts. Historically and culturally, hummingbirds have symbolized vigor, energy, fertility, skill, and the warrior spirit- especially in the Aztec culture.