Seasonal Bird News

Fall Migration is Underway

Fall Migration is underway and while your birdfeeders will slow down in October birdwatching in the area will be more interesting. Have your binoculars with you and ready because Warblers, Tanagers, Orioles, Grosbeaks, and Flycatchers are pouring through middle Tennessee stopping to feed in the early mornings on insects and berries. Mornings are the best time to see lots of different species, and mornings after a storm tend to be even better. Mornings are better because many of the migrants are moving at night. They settle down to rest and feed in the morning. Make time to visit one of the many great local birdwatching areas this fall to see some birds you may not have seen before. The usual hot spots include:

Radnor Lake, Warner Parks, Bells Bend, Harpeth River Greenway,

Hidden Lakes State Park, Gossett State Park, Shelby Bottoms, Montgomery Bell.

Common Nighthawk

Chimney Swift

One of the more interesting things to see in the fall is the migration of Chimney Swifts and Common Nighthawks. In the evenings, particularly in areas where there is outdoor lighting, like high school football games and downtown, these birds gather and feed on insects in impressive flocks.

For information about great places to birdwatch this fall click on the links below…

Tennessee Birding Trails

Tennessee Birding on Facebook

TOS Nashville Chapter-Radnor Lake Wed morning walks

As for birdfeeders October is a good month to do maintenance on bird feeders, cleaning and repairing. We often have, or can get, parts for birdfeeders. It’s a good time to clean out nest boxes, too, or move them to a potentially better location if they were not successful.

Why are feeders slow in October? During the spring and summer birds take great advantage of feeders while they are raising young. Now that the breeding season is over and youngsters are mostly independent a bird’s life is a little more leisurely. And natures harvest is beginning. Weeds, wildflowers, shrubs, vines, and trees are producing seeds, nuts, and fruit. Birds will gravitate to these natural offerings for a while before finding our feeders interesting again. While we miss seeing our bird visitors for a while many of you will get some relief from squirrels, chipmunks, and raccoons, as they too take advantage of natural food sources.

Keep the hummingbird feeders clean and nectar fresh. The hummers are really feeding heavily now. Go out and see some birds!

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 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.

Three chamber bat house.

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: the Tennessee Bat Working Group website.

Hummingbirds. Here We Go!

Male Ruby-throated

Female Ruby-throated

Here we are in mid-July and the time everyone anticipates. Ruby-throated hummingbirds will soon ramp up their interest in feeders and the action will be fast and furious through the end of September.

For many of you the spring and early summer months produce little if any activity at your feeders. Why? Let’s not forget Ruby-throated hummingbirds DO NOT make the long journey here from Central and South America for the sugar water. They DO NOT NEED the feeders but will take advantage of them when they are through with nesting and fattening up for migration is their foremost concern. Hummingbirds have been migrating here for thousands of years to breed and to take advantage of the abundance of insects, which is their primary food source. They would come here even if hummingbird feeders did not exist.

August through September is the peak time for us to see hummingbirds at feeders. Based on frequently asked questions at the store there's a lot of confusion surrounding Ruby-throated hummingbirds and the first few months they are here. It is true Ruby-throated hummingbirds begin migrating through and into TN as early as mid-March. At this time you may see some activity at a feeder as migrants move through, feed, and then keep moving. Or an early arrival summer resident may visit a feeder often for the first few days as it settles in after its long journey.

Although all summer resident hummingbirds of Tennessee have arrived by mid-May, most people will see very little of them and activity at feeders will be minimal and infrequent until at least mid-July when there is a sudden surge in activity.

It is thought by many the reason for this sudden surge is they have just "come back" from where they've been. Actually, it is that the summer resident hummingbirds have concluded raising one to three broods of offspring and are ready to begin taking advantage of nectar in feeders.

Ruby-throated hummers usually raise two chicks at a time so when the nesting phase concludes you may be seeing at least 6 young hummers coming to feeders.

Since hummingbirds feed on small insects an alternative way of feeding them is available.Try placing some fruit in a mesh sack and hang it near your hummingbird feeder.The fruit will draw fruit flies which the hummingbirds will readily devour.It is quite interesting to see a hummingbird dart its specialized tongue out to snag the flies. And it is their long tongue that laps up the nectar from feeders.

So, if you have been disappointed because you haven’t seen hummingbirds at your feeders that’s all about to change. Give your feeders a good cleaning and get some fresh nectar made (1 part sugar to 4 parts water). Remember, nectar is only good for about 3 days at a time in summer heat. Enjoy the action!

Where are the Goldfinches?

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.

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

Around day 5 eyes will open and feathers start to be seen.

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. Video of Baby Killdeer