I Wish You Bluebirds in the Spring

This is such a busy time of year for our Bluebirds. Fortunately, Creasey Mahan Nature Preserve has over 20 nest boxes on the property which are favorite nesting sites for Bluebirds, Tree Swallows, Chickadees, Tufted Titmice, as well as House Sparrows and House Wrens. We don't mind sharing with the first birds on the list, but House Sparrows and House Wrens are bullies, and will kill other chicks in the nest, so any time we see them building in a Bluebird box, we pull that nest out. After 5 or 6 attempts, they will give up and go someplace else.

 

Bluebirds are wonderful parents. I think the same pair return to the same nest box year after year, although I admit, it is hard to tell them apart! In this photo, notice the male bringing a nice worm for the chicks, while the female removes a fecal sac. A fecal sac is a clean, tough mucous/gelatinous membrane/film containing the excrement of nestling birds. Yes, baby birds poop in diapers! Nestlings usually excrete one sac after each feeding, especially as they get older. The parent grasps the sac by the middle with their beak. They may take out 60-70 bundles a day! Usually both parents help with this task. For hatchlings and very young nestlings (e.g., up to 4-5 days old), the parents may eat the sacs, as the baby's digestive tracts are not very efficient and the sacs may still contain nutrition. Otherwise, they drop them outside of the box, usually some distance away to avoid leading predators back to the nest.

If you are interested in learning more about Bluebirds, Sialis.org is the source of all knowledge relating to them. The safe way to observe eggs and chicks is to use a mirror, for example. The nests have a deep cup, and it's hard to see the inside sometimes. The mirror ensures that you don't accidentally break an egg while exploring with a fingertip.

Not all cavity nesters are as tolerant as Bluebirds, who will wait patiently on a nearby branch while you visit their youngsters. Just be careful not to take too long. After all, those babies are growing fast and always hungry! Only 3 weeks after hatching, they will be ready to "fledge," or fly out of the nest. We see pictures of eagles and other birds flapping their wings in preparation for fledging. But cavity nesters don't have room for this. Remember, there may be 5-6 chicks crammed inside that box, but when it's time to fly, they jump out of the hole and never look back.

Both parents will feed the nestlings. What bluebirds eat depends in part on what is available. On average over the seasons, 68% of a Bluebirds' diet is made up of insects: grasshoppers, crickets, beetles, spiders, and caterpillars (usually spied from a perch and then caught on the ground.) They also eat ants, wasps and bees, flies, angleworms, snails, sow bugs, moths, weevils and termites. Bluebirds love mealworms, and you can put them out in a dish to attract nearby Bluebirds. Occasionally they catch insects in flight, especially when its warmer and flying insects are abundant. The proportion of insects in the food bluebirds collect during nesting season is probably significantly higher than 68%. That is because their growing young need lots of protein. The rest is mostly small fruit - e.g., flowering dogwood, holly, mulberry, wild grape, Virginia creeper, pokeweed, and Viburnum, gleaned from plants or foraged on the ground. In winter, I have watched them eating mistletoe berries and poison ivy berries, since Kentucky Bluebirds usually spend the winter here instead of migrating.

As the saying goes, "May all your blues be birds." Hope to see you at Bluebird Day, May 18, from 10 - 2.

Naturally yours,

~denapple

Never Say Never in Nature

One of the first things you learn about nature, and birding in particular, is never to say never, as in "You will never see a Western Grebe in Kentucky." You see, birds don't read the field guide on which people rely for knowledge. We humans tend to assume the correctness of an authority in any field, but the birds do not. When I saw the posting on the Kentucky Bird List about a rare Western Grebe sighting on the Ohio River in Jeffersonville, I immediately jumped in the car!

 

A large, elegant, black-and-white grebe, (yes, the adult has red eyes) the Western Grebe breeds in lakes and ponds across the American West and winters primarily off the Pacific Coast, but we rarely see it in Kentucky. The Jeffersonville Overlook, just across the river from downtown Louisville, seems to be a magnet for lost birds. Last month a White-winged Scoter (from the Atlantic coast) was sighted there. When storms rage in the normal territory of a bird, it may be blown far away. Just imagine them saying "I don't think we're in Oregon anymore, Toto."



Western Grebes are most famed for their elegant pas de deux courtship dance. We will have to do some traveling to see this live, but it would be exciting. Alert and covered with blackish or silvery down when hatched, the chicks leave the nest and ride on the back of the parent after hatching.

The Horned Grebe passes through Kentucky during migration, and this one was found on a lake near Elizabethtown, KY. The field guide displays large pictures of the male birds in their vibrant breeding plumage, and if that's what you look for, you are sure to be disappointed many times. This Horned Grebe, for example, breeds in Canada, so we only see it in the more drab winter plumage as it migrates.

The small Pied-billed Grebe is the one you usually see in Kentucky. When danger approaches it dives underwater and quickly swims away. It's a wonderful defense - just ask any birder trying to watch one! Observing nature is always the best way to learn about it, with some hints from the field guide. How exciting it is to discover some behavior NOT mentioned in the guide! You can have just as much fun watching birds from your kitchen window as you would be traveling afar. Give it a try!

Naturally yours,

~denapple

Sandhill Crane Migration

 

One of the most exciting sounds in nature is the "kar-r-r-r- o-o-o" of Sandhill Cranes flying overhead in their spring and fall migration. We heard some today at Creasey Mahan Nature Preserve. Sandhill Cranes are large birds which have mostly grayish feathers-- the shade of gray can vary widely. The forehead has a bright red patch that is one of the most noticeable features of the bird, while the cheeks are white. Sandhills fly with neck and legs extended.

Although the feathers are gray, sometimes they can have a reddish-brown appearance. Sandhill Cranes preen themselves by rubbing mud on their feathers. The mud can be brown or red, and comes from iron rich environments, producing the reddish tinge. As the cranes molt the red will disappear.

Sandhill Cranes are opportunistic feeders and change their diet based on what is available. They most often eat plants and grains, but also dine on invertebrates or even small mammals, amphibians and reptiles. If you are searching for them, look primarily in fields of corn stubble, rather than soybean fields.

Three subpopulations of Sandhill Cranes are migratory. The Lesser, Greater and Canadian Sandhill Cranes spend winters in the south and summers at their breeding grounds. Sandhill cranes winter in Texas, California, Arizona, New Mexico and Mexico. In the early spring, the cranes begin the migration to their breeding grounds. Throughout the spring, the cranes can be seen resting and feeding along rivers and wetlands throughout the Great Plains and Pacific Northwest. The largest congregation of Sandhill Cranes occurs from February to early April along the Platte River in Nebraska. During the late spring, summer and early fall, Sandhill Cranes can be seen at their breeding grounds, in Minnesota, Wisconsin and Michigan. Others breed in Oregon, Idaho and Alaska. Although the majority of migration routes are in the Plains states, one route passes right over Kentucky. Major stopovers for these cranes are in northern Indiana (More than 10,000 sandhill cranes stop during fall migration at Jasper-Pulaski Wildife Area.) and eastern Tennessee (Hiwassee Refuge).

In the early spring, as Sandhill Cranes are migrating to their breeding grounds, single cranes will start pairing up. A Sandhill Crane pair performs unison calling to create a bond. When the pair reaches the northern breeding grounds, they mate and build a nest. During mating, Sandhill Cranes perform dancing displays. Although the dancing is most common in the breeding season, the cranes can dance all year long. Sometimes the dance involves wing flapping, bowing, jumps and simply playing around. They might also throw a stick or some plants into the air.

Sandhill Cranes have an interesting and distinctive call. Both the males and females make a rattling "kar-r-r-r- o-o-o" sound. The call varies in length, strength and loudness depending on its intention. The loudest and most noticeable call is during the mating season. Males and females will sing loudly and in unison. You can hear them calling high above even though you can't see them.

Habitat loss—due to destruction, fragmentation or degradation of habitat—is the primary threat to the survival of wildlife in the United States. When an ecosystem has been dramatically changed by human activities—such as agriculture, oil and gas exploration, commercial development or water diversion—it may no longer be able to provide the food, water, cover, and places to raise young. Every day there are fewer places left that wildlife can call home. The endangered Whooping Crane sometimes travels with a flock of Sandhills, but the are larger and white in color.

Naturally yours,

~denapple

Call of the Wild Goose

Have you noticed V's of geese lately? Are they migrating through Kentucky on their way somewhere else? Maybe, and maybe not. Canada Geese fly in a V formation because it's both aerodynamic and energy efficient. Each bird in the line flies slightly higher than the bird in front of it, acting as a windbreaker and reducing drag. The lineup provides easy communication between the geese while keeping track of each other. They take turns leading the formation, falling back in the line when they become tired.

Canada Geese maintain nests in Canada and in the northern regions of the United States throughout the summer. Once lakes and rivers begin to freeze over and food becomes scarce, the geese congregate into flocks of 30 to 100 birds to start their migration to warmer places. The fall migration occurs in September or October. They travel the same flight corridors called flyways every fall and spring to get to their destinations in southern parts of the United States and northern Mexico. The flyways follow coastlines, rivers and mountain ranges. Canada Geese migrate 2,000 miles to 3,000 miles, and can fly 1,500 miles in 24 hours with ideal weather conditions! The geese generally travel 40 miles per hour, but they can reach 70 mph with a good wind. The geese fly at altitudes between 2,000 feet and 9,000 feet.

Though common today, at one time Canada Geese were hunted almost to extinction. The birds had vanished from the north-central United States by 1900, and droughts in the 1930s reduced their numbers elsewhere. Since then, however, the growth of federal and state refuge systems has helped build goose populations that now probably exceed those of presettlement times. The present abundance of Canada Geese in open suburban areas like parks, airports and golf courses, and their habit of defecating almost a pound of material per goose per day, has given the bird an increasingly negative image.

People may be surprised to hear that birds learn to migrate from their parents and flock—they don't hatch with this complex knowledge. So geese hatched in Kentucky never learned to fly north and instead took up local residence year-round. We've provided food and safety right here in our cities and suburbs. The geese have no reason to go elsewhere, so they settle in and raise families.

Canada Geese are found in many types of watery habitat, including lakes, rivers, marshes, bogs and sloughs. In their breeding range, a pair usually requires at least five acres of open water plus access to upland fields or open land for grazing. In winter, geese need grazing habitat for feeding and open water for drinking. Geese are vegetarians, eating a variety of plant species and parts, especially grasses, sedges, grain and berries. They often feed in flocks, and have become fond of farm-grown grains, especially corn and shoots of winter wheat. These birds are exceedingly adaptable to human-altered habitats and are common on suburban parks, lawns, golf courses and even at Cave Hill Cemetery. So don't be surprised to see them near your own neighborhoods.

Naturally yours,

~denapple

Shorebirds at the Shore

Solitary Sandpiper

 When I hear the word "shorebirds," I automatically think of birds seen at the beach. After all, that's the "shore" right? Well, not always.  Shorebirds, or waders, are not simply birds found at the shore, but are the families of plovers, sandpipers and related forms that are part of the order Charadriiformes. Most of these birds can be found along shorelines, especially in migration, but they are also found inland, upland, on arctic tundra or at sea. They are related to gulls, terns and auks, also Charadriiformes. One of the many attractions of shorebirds is the long-distance migration of species such as American Golden-Plover  between the high arctic and southern South America.

As a birder, I find shorebirds hard to identify, since many of them look very much alike. I sent a photo of this bird to Brainard Palmer-Ball (the birding expert in Kentucky) for some help. His expert eye noticed the following: the main characters for this guy are the size (not tiny, but not large, sort of medium-smallish); the very noticeable eye-ring; and the olive colored legs. The back being mostly plain dark gray with a few smidges of white are also helpful (rather than being mottled and marbled with more browns, rufous, and beige). The bobbing you noticed is also a characteristic behavior (but it's more of a jerk of the body up in front rather than bobbing of the tail). Brainard finally took pity on me and identified this as a Solitary Sandpiper. Watch the short video below to see the bobbing motion made by this bird.

 

 It's exciting to find one of these little birds in Kentucky. They breed in the taiga, nesting in trees in deserted songbird nests of northern Canada, and migrate to South America for the winter, so you can only find them here during the migration season. This Sandpiper was searching for insects along the muddy banks of the upper pond in Meadowlark Meadow. It looks like we are having more success in attracting different species of birds to the Nature Preserve! Come for a hike yourself and see what migrants you can find!

Naturally yours,

~denapple

Resident Raptors at the Nature Preserve

Last summer at the Raptor Open House Saturday, Raptor Rehabilitation of Kentucky released a bird at the Nature Preserve. A neighbor of Tavia's found this red-shouldered hawk near her home, and Mike Huff captured it to be taken to Raptor Rehab for care. They found a Dell computer box to put her in, and thus she was named Adell. Fortunately, nothing much was wrong with her, and she was ready for release in a few weeks.

When the release time came, Adell flew to a nearby pine tree, and was instantly mobbed by our resident mocking birds. This happens on many raptor releases, and we've always been puzzled about it. How do the local birds know so fast that a raptor is being released? Adell took it in stride though, and we have seen and heard her around the Preserve ever since. Go to http://www.allaboutbirds.org/guide/Red-shouldered_Hawk/id to hear the distinctive sound of the red shouldered hawk. Blue jays can mimic them, and it's easy to be fooled.

Adell found a mate, and they often are seen and heard around the Nature Preserve. This week, they couldn't resist soaring over Meadowlark Meadow, calling loudly to each other. And yes, the mockingbirds, orioles and robins still chase them around.

Female raptors are larger than males, so I might guess the bird on the right to be the male.

From below, the red shouldered hawk is easily identified by the light colored "window" near the tip of their wings which allows the sun to shine through. Since breeding season is about over, she's starting to molt. Notice that she seems to be missing a feather on each wing. Birds don't lose all their feathers at once, but a few here and there until they are all replaced. The flight feathers drop out in pairs so the bird isn't put off balance.

Last spring we saw Adell headed for what appeared to be nest in the woods near the maintenance building, so Mike decided to climb the tree and see if she had chicks. The tree climb was successful (I know who I'll call next time a cat can't get down from a tree!), but he found nothing but an empty nest. We also haven't see any hawk fledglings, so maybe she didn't have a successful brood this year. We hope she will have better luck next year though, and we keep our eyes out for her!

Naturally yours,

~denapple

Murder in the Meadow

"Get your gear," shouted Special Agent Huff. "We've got a body by the meadow."

Agent Huff skidded the crime mobile to a halt and I jumped in. He took off across the grounds of the Nature Preserve, driving at breakneck speed. Creasey Mahan Investigative Services is on duty again, investigating the latest death.

Last week, we discovered one dead bird along the meadow, and frankly, didn't think much of it. Three days later, however, we found four more feathered corpses in the same location. "It looks like a serial killer, Agent Huff," I said, snapping photos at the crime scene. "Why would there be five dead birds, apparently the same species, in the same spot, with no blood or signs of violence?" I could not take any prints, and DNA for these victims was not in the database, so I consulted the experts with the Beckham Bird Club. After referring to the field guide, they all agreed that these were young European Starlings, recently fledged from their nest. But they reached no conclusion about the time or cause of death.

Agent Huff and I returned to the crime scene. A thorough search revealed a sixth victim nearby.

Ducky, the medical examiner, was unavailable, so we had to do our own post-mortem without his special expertise. There was no blood, no apparent wounds or broken bones, no sign of burns from electrical power lines above the bodies. The mystery started to drive us crazy.

Let's review the possible suspects. Might it be a neighborhood cat? The bacteria in a cat's bite can kill a bird, and cats will kill without eating their victims. But no feathers were mussed at all. Might these young stupid fledglings land on the hot power line directly above where we found their bodies? Yes, but six of them in the same spot over the period of a week?

Agent Huff added that he'd seen a raccoon in the nearby tree just this morning, and raccoons will get into a nest to kill/eat the chicks. We tracked this suspect to its lair in the tree, but couldn't decide how it would catch young birds that can fly.

"Look at this photo!" I exclaimed. "These marks in the nest box are from a BB gun! From a distance, might a BB shot might kill a young bird without leaving an obvious wound?"

"Hmm. I might have to put up some security cameras, or maybe send Agent Wheeler on a stake out. If we have BB gun traders, we are in serious trouble." Agent Huff frowned at the thought.

Back at the office, Agent Wheeler pondered the location where all six victims had been found. LG&E had come by recently to dig around the poles and sprayed some sort of chemicals there, presumably an insecticide to preserve the wood. Would that be strong enough to kill these young birds? Remember, a mother bluebird was very aggressive a few weeks ago in this same place. Maybe she was reacting to the sprayers.

It's the end of this episode. This case will be classified as "unsolved" for now. But the Creasey Mahan Investigative Services team will be on the watch for more evidence.

Mocking Bullies

You know the Mockingbird - a largish gray bird with flashy white wing bars and white on the sides of a long tail. It's best known for its ability to mock or imitate just about anything, repeating a phrase 3 or 4 times before moving on the next birdsong. They have even been reported as mimicking the ring of a cell phone!

And they will go on and on into the night, or at least the bachelors do. As soon as he wins a mate, she will put an end to those rowdy night-long parties.

Mockingbirds are very territorial. The male sits as high as he can in his territory and sings loudly to tell all other male mockingbirds to scram - this territory is taken. If some bird doesn't get the message, he will chase the intruder around until it leaves.

Once a Mockingbird claims a feeder, other species will hang back until it leaves. Of course, fledglings still follow their parents around, begging for food.

This morning, as I arrived at the Nature Preserve, I heard lots of racket in the picnic tree by the Field House. Mockingbirds were shouting and dashing in and out of the tree. In a few minutes, I found the source of their disturbance - Adell, our Red Shouldered Hawk. Mockingbirds are notorious for "mobbing" hawks. That is, they chase and bully the larger bird without mercy. Are they defending their nests? Some think so, but these hawks don't hunt birds as their first choice in prey. I think Mockingbirds are just feathered bullies.

Every time Adell and her mate moved, several Mockingbirds followed them, calling loudly. Now I ask you, how is a self-respecting hawk supposed to sneak up on a mouse in the grass with all that noise going on? Do you think the Mockingbird is really trying to protect the mice these birds normally eat? If this were a Peregrine Falcon, which does hunt birds, they would stay clear, knowing the Falcon would have them for dinner in an instant.

Naturally yours,

~denapple

Bluebird Trail

Eastern Bluebirds love living at Creasey Mahan Nature Preserve. They are cavity nesters and build in boxes which the Louisville Audubon Society gave us. People donated money as a Valentine's fundraiser that year, so some of the have people's names or initials painted with a heart. Bluebirds eat insects when available, but I've seen them chowing down on mistletoe berries in the winter, and they like open grassy areas.

The CornellLab of Ornithology at Cornell University is the online authority about birds in this country, and they promote Citizen Science. That is, regular birders collect data on birds through the Christmas Bird Count, Backyard Feeder Watch, and NestWatch programs. Very clever of them to enlist thousands of field researchers at no pay! I explored the NestWatch site, and decided that the Creasey Mahan Bluebird Trail would be a terrific addition. You study a guide to learn how to monitor nests, and take a short online exam (very easy but very informative). Then you set up your nest sites online to record the data. They recommend checking the boxes every 3-4 days - is there a nest? Does it have any eggs? Are the parents around? When do the young hatch and how many? Predation losses? Are there House Sparrows or Cowbirds? One cool trick I learned is to use a mirror to see down into the nest, instead of reaching in with your hand. The eggs are quite fragile and can break with a touch sometimes.

The females will lay one egg per day when they start, and usually lay 4-5 in a clutch. This ambitious female has SIX to take care of! Sialia is the genus of Bluebirds, and Sialis is a website dedicated to them where you can learn everything you ever wanted to know about Bluebirds and other birds you might find while watching them. Bob and Judy Peak monitor Bluebird boxes around Land Between the Lakes, and they have 70-90% occupancy this year. If there isn't a hard freeze yet to come, they think we will have a record number of Bluebirds hatching! I'm not monitoring all our boxes, but of the 15 I am watching, we have Bluebird 5 of them, and Chickadees eggs in one.

For example, a pair of Tree Swallows have nested for several years in the box just outside the Nature Center. She will line her nest with fluffy feathers and pull them over the hatchlings to keep them warm. We also have a Chickadee in one of our boxes. She uses a base of moss and lines the cup with what looks like dog fur. In any event, it's very soft and warm.

Tree Swallows and Chickadees are nice birds just looking for a place to raise a family. But other species will use our boxes and not be nice about it. House Sparrows, for example, will not only nest in a Bluebird box, but will go into a Bluebird nest and kill both the young and adults there. House Wrens will put sticks and twigs in boxes they don't intend to use before actually starting a nest. They have been known to destroy Bluebird and other cavity nester's eggs by piercing them (holes of 3 mm or less, or a large ragged hole in the middle), and then often removing them from the nest. They can remove an entire chickadee nest in a matter of hours. One theory is that they are removing competition for food since they eat insects too. Cowbirds will lay eggs in the nests of other birds, so you have to keep an eye out for an egg that doesn't match the others.

The spotted House Sparrow eggs are laid in a messy nest with pieces of paper and trash mixed with other birds feathers. The recommendation is to remove the nest. Bluebirds have been know to lay 3 clutches through the summer, so monitoring will continue for months to come, and I'll share any exciting discoveries. But I ask you to please not disturb the nests and parents unless you are experienced with nest monitoring.

The Original Twitterer!

The Tree Swallows are back in Kentucky, and this pair likes to sun and preen on the power lines just outside the Nature Center at Creasey Mahan Nature Preserve. Adults have dark blue iridescent feathers on their back, with a snow white throat and breast. Males and females look alike, although females may be a little more greenish. Some adults are drab gray. They look like they are wearing a tuxedo! Their long wingtips reach the tip of their tail; they do not have a long, scissor/forked tail like Barn swallows. Two more Swallows approached the line, and the male chased the other one away, so perhaps they will look for another nesting spot.

Like bluebirds, Tree Swallows are secondary cavity nesters, meaning they depend on pre-existing nest sites like nestboxes. Although they're very social, they're also territorial with their own species. Later in the nesting season, they defend a smaller area. They have been seen removing eggs from a chickadee nest. However, they can also be quite territorial, and may not like it when humans approach the nestbox, and may swoop, dive bomb, click their beaks and make a racket, especially if eggs are in the process of hatching. It's best to leave them alone then! Tree Swallows spend a lot of time checking out and peering into a box. It seems like they put one piece of grass a day into the box! The nest is made of grass or pine needles and can be sort of sloppy. The cup, which is flatter than that of a bluebird, is lined with feathers most of which are added after egg laying begins. Downy feathers are often used in the cup, encircled by larger feathers that curl up over the eggs for insulation. Occasionally trash or bits of white birch bark, paper, tissue or cloth are used. Once the nest is feathered, it is rarely abandoned. Our Bluebird boxes at the Nature Preserve are used by Bluebirds, Tree Swallows, Chickadees, Wrens and House Sparrows.

They eat flying insects like beetles, horseflies, dragonflies, ants, moths, and mayflies. Because they rely on bugs, extended periods of cold rainy weather can be deadly. Adult Tree Swallows consume 2000 insects and feed 6000 insects to their young over a 45 day nesting period. That means that each nestbox family consumes more than 300,000 insects. Since 90% of  their hunting takes place below 39 feet, they are making a real dent in human pestering insect populations.



I think Twitter must have gotten their name listening to Tree Swallows. This bird was more interested in cleaning his wings, but listen closely and you will hear him twitter to his mate. When you come to the Nature Preserve, watch these beautiful birds and listen for yourself!

Naturally yours,

~denapple