Late Summer and Early Fall Hummingbirds

Wow! My hummingbird feeders have been working overtime for a week and a half now. Yesterday evening my wife and I estimated approximately 50 hummingbirds swarming the 5 visible feeders on our back porch. This morning we saw the same thing. It was hovering room only. There is no doubt that we are experiencing the peak of hummingbird activity which means we will soon begin to see numbers of hummingbirds dwindling with each day that passes. As the days grow shorter hummingbirds will instinctively feel the urge to go. For now, though, we are thoroughly enjoying the action. And I am paying very close attention in case a different kind of hummingbird appears. Recently, a friend of mine in the western most part of Bellevue had a confirmed Rufous hummingbird at her feeders.

Rufous Hummingbird

The Rufous is a summer resident of the west coast, mainly from central California all the way up into northwest Canada. Like the Ruby-throated hummingbird they migrate back to Central America and Mexico and along the Gulf coast to Florida for the winter. However, each year small numbers of Rufous hummers appear in southern states including TN. Late August and September are the months they tend to appear, or at least be seen. Some Rufous hummers have been known to stay in mid TN most of a winter.

The adult male Rufous is quite distinguishable with its rufous (reddish brown) back, flank, rump and tail. The head and crown are even darker brown to red, a red face, and bright red gorget and white breast. Pic of Male and Female Rufous

Adult females have a green back and crown with hints of rufous on the flanks. A central grouping of red spots may be visible on the white throat. Juvenile males and females will look very much like the adult female with the exception of the red spots. A lone juvenile Rufous would be difficult to notice amongst a group of Ruby-throated hummingbirds.

Rufous hummers are reportedly even more aggressive about guarding a food source than Ruby- throats, if you can imagine that.

The video was taken on my back porch this morning. Most of you do not get to see multiple hummingbirds on a feeder at the same time. In more rural areas it is quite common to see. Continue to keep your feeders clean and nectar fresh. You might be the next one to see a Rufous hummingbird.

Bat Houses and Placement Strategies

I have invested a fair amount of time researching bats the last month or so trying to learn more about the fascinating creatures sharing my yard this summer.

After last week’s blog about my recent success with bats a few customers had questions.

One customer asked “why do you think you have more bats this year. What did you do to encourage them”? The fact is I’ve done nothing different and I wish I knew why we have this surge in numbers. The bat house has been in the same place for several years. The only thing about the “Rocket” style house that’s different is Downy woodpeckers have pecked a couple of holes in it ranging in size from about 1 ½” to 3” in diameter. I hardly think that would increase the chances of a box being used.

Bats have to find new roosts on their own. They investigate new roosting opportunities while foraging at night, and they are expert at detecting crevices, cracks, and nooks and crannies that offer shelter from the elements and predators. Bats are not blind as the saying goes but in fact have sharp eye sight.

BCI (Bat Conservation International) indicates 90 percent of occupied bat houses were used within two years (with 50 percent occupancy in the first year). The rest needed three to five years for bats to move in. So, perhaps it was just time needed for bats to locate my house. Now that I’ve attracted bats to this house I am planning on putting up at least one more before next spring.

There's a lot of information about success rates of various types of bat houses and, perhaps more importantly, how they are presented. I am merely going to summarize some of the more pertinent information and would encourage you to visit www.batcon.org if you want to learn more or have enough interest to construct, or buy, a bat house to install in your yard.

Below are some basics of presenting a bat house.

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Three chamber bat house.

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Rocket style bat house.

Facts, Tips and Suggestions

Bat houses installed on buildings or poles are easier for bats to locate, have greater occupancy rates and are occupied two and a half times faster than those mounted on trees.

Tall designs like the multi-chamber (nursery) and rocket-style houses perform best

Occupancy in rural areas is over 60 percent, compared to 50 percent for urban and suburban areas.

According to BCI maintaining proper roost temperatures is probably the single most important factor for a successful bat house. They say interior temperatures should be warm and as stable as possible (ideally 80º F to 100º F in summer) for mother bats to raise their young. Some species, such as the Big Brown bat, prefer temperatures below 95º F, while others, such as the Little Brown bat, tolerate temperatures in excess of 100º F. This is very interesting because we always think of bats in relation to the coolness of caves but this is mostly during the hibernation months, fall through winter.

Bat house temperatures are influenced directly by the exterior color and direction faced. East-, southeast-, or south-facing are generally good bets. My Rocket house is, as you have seen, a darker color. Bat houses we sell are almost always a plain western cedar. From now on I will suggest staining the box a darker color.

Avoid placing bat houses directly above windows, doors, decks or walkways. Bat urine and guano would fall directly down to whatever is below. The urine is known to stain some finishes.

For more information about constructing, painting, installing and maintaining your bat house, please see:

The Bat House Builder's Handbook

Single chamber bat house plans

Four-chamber nursery house plans

Rocket box bat house plans

My Summer Bats

Bats have been of particular interest to me this summer as I’ve had great success with a “Rocket” style bat house. This box has been on a 10’ post in my yard for several years and seen only minimal success.

Most evenings my wife and I settle in to watch the bats emerge from the box which is situated in a clearing surrounded by trees. We’ve been able to count over one hundred several times. Only recently have I come to the conclusion they are the species, the Little Brown Bat, perhaps the most common, widely distributed in the U.S. They measure less than 4” in length and vary in color from olive-brown to a yellow-brown. The wings consist of naked skin, which are attached alongside the feet.

There are several bat species that are very similar in appearance, so we are still observing for more details and clues that will help definitively identify them.

During summer Little Browns often inhabit buildings, usually in hot environments like attics, where females form nursing colonies of hundreds or even thousands of individuals. Not much is known about where the males are at this time but they are likely solitary and scattered in a variety of roost situations. Colonies are often close to a lake or stream. This species seems to prefer to forage over water, but also forages among trees in open areas. Little Browns may repeat a set hunting pattern around houses or trees. Little Brown bats eat a variety of insects, including gnats, crane flies, beetles, wasps, and moths. Here is a very interesting thing I did not know about bats. Insects are usually captured with a wing tip, transferred into a scoop formed by the forwardly curled tail, and then grasped with the teeth. Because we don’t get to see them working in slow motion we would never see this action.

After doing a little more research on Southeastern bats, I learned some very interesting facts about these fascinating little nocturnal mammals. For instance, did you know that at certain times of the year we can have up to fifteen different species of bats in the southeastern United States? Or that all bats in the eastern United States feed exclusively on insects? They are the only major predator of night flying insects and may eat more than 50% of their body weight each night. Unfortunately, the amount of mosquitos they consume is not as great as once thought.

In late fall and winter the Little Brown Bat usually hibernates in caves and mines. Bats return from migration and awaken from hibernation as early as mid-March and they will be abundant throughout the summer and into early fall. By mid-October most will have migrated to more southerly states, or are going into hibernation. For more information about bats in our area please visit: www.tnbwg.org the Tennessee Bat Working Group website.

Birding on Vacation

I always recommend bringing binoculars on a vacation.  Maybe birdwatching isn’t your “main” activity but it sure is fun to see birds not seen in your own backyard.  It just adds another element of fun and discovery that can round out your vacation activities. 

I recently vacationed in St. Thomas, Virgin Islands and snorkeling in the beautiful clear blue waters was the dominant activity, and it was fascinating.  There are so many beautiful fish and other aquatic life to see.  Snorkeling and exploring the underwater world and identifying the aquatic life could easily become a new obsession, but living in TN will prohibit me from “diving” into a new hobby.

I did want to share some of the bird life encountered, though, and interestingly enough there was not a lot seen while on land.We only saw one species of hummingbird, the Green-throated Carib. Of the 5 types of hummingbirds seen on the island only two are considered common while 3 of them are considered rare or accidental. I did not actually get to go out with the intention of “birding” as I was with a group and a lot was planned.While on a catamaran excursion, though, my binos came in quite handy.

So, mostly we were treated to sightings of ocean birds. Highlights include the Magnificent Frigatebird, a bird generally seen along coasts and over open water. These large, dark seabirds have the longest wingspan, in proportion to weight, of all birds. Seafarers named these aerial predators for a swift warship. Frigatebirds skim the sea snatching surfacing fish, but have also been known to harass other birds in flight forcing them to drop their catch then promptly swooping to catch the falling meal. The male is glossy black and known for the orange throat pouch that becomes bright red when inflated in a courtship display. They measure around 40” in length and have a wingspan of 90”, or roughly 7.5 feet.

Also seen were Brown Booby, Elegant and Royal Tern, Brown Pelican, and Laughing Gull. All of these birds were regularly seen hunting the water for schools of fish near the surface.

The Elegant Terns would hunt in small flocks, hovering and suddenly folding their sharp wings diving with great speed into the water emerging effortlessly with their prey. The Elegant Tern is named appropriately.  They are a very elegant bird in appearance.  They have a white and gray body with a black crest and bright orange beak.

The Brown Pelicans are always fun to watch as they skim the surface of the water together.  Pelicans are such a large awkward looking bird but in flight they are a wonder.  As Pelicans would dive into the water for a meal the Laughing Gulls would hover just over them and actually land on their heads hoping to steal the catch away. It was very entertaining. 

Where are the Goldfinches?

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We field this question a lot this time of year. Goldfinches are quite different than many of our other feeder birds in that they are frequently on the move. Goldfinches you see for a few days or a week may be miles away tomorrow only to be replaced by a new group shortly thereafter. These movements are even more prominent in the spring. We tend to see more Goldfinches concentrated at feeders in winter as northern populations move south. With migration all but over here in mid-TN we should begin to see good numbers of Goldfinches settling back in to bird feeding stations. So, don’t think that you’ve done something wrong, or think the seed in your feeder is bad, it is normal for Goldfinches to be on the move. Here are a few tips to improve your success with Goldfinches.

Ø Keep your feeders full. Goldfinches prefer to feed as a group and will not find a feeder attractive if it only has one feeder port available to feed from. Top them off regularly.

Ø Check your seed for dampness particularly after rain showers. Simply shake your feeder up and down to see if the seed is dry and loose, or gotten wet and clumped together. Remove only the wet seed. The Aspects brand Quick Clean feeders are a great choice of finch feeders for easy maintenance and cleaning.

Ø Keep feeders clean. Mold is a bad thing to have on your feeders and seed. Really dirty feeders can be detrimental to the birds and be a source for spreading disease. Not to mention making them less desirable. Keep in mind Goldfinches are totally vegetarian. They do not eat insects. So with lots of seed choices available in nature the seed at your feeder better be in tip top condition to compete.

Ø If you have multiple finch feeders we recommend grouping them. Again, they prefer to feed as a group, so it pays to give them that opportunity. The more the merrier.

Goldfinches love sunflower whether in shell or out. Check out our Finch Blend which is Nyjer seed and Fine Sunflower Chips, and the Fine Sunflower Chips which can be used in any finch feeder.Be advised, if using the Finch Blend or Fine Sunflower it is recommended you present the feeder in a squirrel proof manner, like a baffled pole system, for example.

Ornithology Vocabulary Lesson.

Since we are in the breeding season for birds here are a couple of ornithology words to expand your knowledge. They may even help you with the next NY Times Crossword.

Altricial and Precocial

Almost all of us have seen baby songbirds in a nest.We know they are completely dependent on the adults to keep them warm as they are featherless for the first few days and to bring them food while in the nest developing.They are completely helpless and mostly immobile.The adults continue to feed them for weeks even after they have fledged. This is referred to as altricial. Altricial birds include herons, hawks, owls, and most songbirds.

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Eastern Blue bird babies just hatched. No feathers and eyes still closed.

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Day 12 birds are fully feathered and still being fed. They will leave the nest any day.

Precocial means young are capable of a high degree of independent activity immediately after hatching. Precocial young typically can move about, have their eyes open and will be covered in down at hatching. They are generally able to walk away from the nest as soon as they have dried off. They will also begin searching for their own food. Examples of precocial birds include most duck species, Wild Turkey, Quail, and Killdeer.