Friday, June 29, 2012

Singing the Wrong Song

At the nature preserve - a Feild Sparrow belts out the typical song of his species  

You might think that sometimes birds are deliberately trying to deceive you, but really, it could just be the way that they were raised.

A male Prairie Warbler sings at the preserve in 2011

In 20 years of identifying birds by their songs, I have been fooled many times. I recall being deceived by a Field Sparrow that instead of singing the typical Field Sparrow "bouncing ball" song, he performed a perfect rendition of a Prairie Warbler's song. Interestingly, the normal songs of the 2 species are not in the least bit similar. The Field Sparrow's song is a series of clear whistled notes that become increasingly short as it progresses (hence the bouncing ball effect). The Prairie Warbler, by contrast, sings a toneless song that consists of short buzzy notes given in a rapid volley.

One thing that these 2 unrelated birds have in common is their habitat, which is overgrown pasture land. It is thought that during a particularly impressionable time in his development, a juvenile songbird can be greatly influenced by the songs of other birds that are nesting in his immediate neighborhood. So it’s possible to imagine a young Field Sparrow, that instead of growing up to sing his father's traditional song, rebels and proudly belts out some kind of bohemian rhythm –like that produced by the freewheeling warblers in the next bush over. That's the way to break your father's heart, boy!
Who are you to tell me I'm singing the wrong song?
Well, probably not, but trying to secure a mate of your own species when you’re not speaking the same language is at best problematic. It’s likely that a female Prairie Warbler would be as confused as I was when she gets a gander at who is singing. And a female Field Sparrow would have no incentive to even get close enough to find out that this confused soul is one of her own kind. However, it has been shown that birds with aberrant songs can succeed in holding territories and even securing mates of their own species.

The Golden-winged Warbler that sang the wrong song for 5 years

For about 5 consecutive breeding seasons we had a male Golden-winged Warbler at the nature preserve that sang exactly like a Blue-winged Warbler. This is more understandable than the former case with the Field Sparrow, since the Golden-winged and Blue-winged are so closely related, and In fact the 2 species regularly interbreed. Their standard songs are also quite similar and the notes are of a similar pitch and quality. The Golden-winged Warbler sings (typically) 4 hearty buzz notes, while the Blue-winged’s song consists of just 2 buzzy notes.

A male Blue-winged Warbler
Most recently we’ve had an Eastern Towhee whose song is very strange indeed. To me it sounded ever so vaguely like a Red-winged Blackbird’s song, and definitely nothing like a Towhee’s normal song (often characterized by the phrase: “Drink… your… tea”.) Based only on the habitat that I was hearing the song emanate from, I had thought it possible that a Towhee was producing the song, but I couldn’t be sure on the identification until I actually saw the bird singing.
This Eastern Towhee will not be having any tea this morning

In this case, I don’t think the Towhee had been influenced by neighboring birds to sing this aberrant song. I think it’s more likely that this bird’s syrinx (voice box) is not working properly. Or maybe this is just his far out interpretation of the classic Drink...your…tea. Hey, it’s also possible that he just might not want any tea.
His rendition may ultimately catch on. Perhaps someday in Central New York, all of the Towhees will sing like him –and the great towhee tea boycott will begin.

Unlike most female songbirds, the Female Northern Cadinal does sing

Regional accents occur with some bird species. A resident Cardinal singing in New York State may not be singing precisely the same song as its cousin in Michigan. Regional accents can be even more local. For years I noted a peculiar sounding alarm call given by Baltimore Orioles living around the Utica Marsh and Mohawk River floodplain area. Orioles in other parts of the County, though they give an equivalent alarm call, do not give the same calls as their lowland counterparts.
The male Baltimore Oriole

Sunday, June 24, 2012

Disaster at the Beaver Pond

The 20 foot gap in the dam that drained Sarah's Pond
Somewhere between last Wednesday night and Thursday morning, disaster struck our main beaver pond when a 20 foot section of its dam collapsed. The Pond drained very rapidly and the resulting torrent of water destroyed other canals, ponds and dams located downstream. Such a rapid draining of a pond containing hundreds of thousands of gallons of water has the potential of killing beavers, but so far I have found no evidence that any of the colony were killed. I still have yet to account for all of the members of the colony –but that’s not too unusual even in normal circumstances.

The 6 foot tall dam was built up by our beaver colony over the course 12 years

The Pond (named Sarah’s Pond after one of the original beavers that created it) had been steadily increasing in size during the last several months as the beavers worked to heighten its dam and at the same time dredge its bottom. The increasing amount of water in the pond exerted a greater and greater amount of pressure on the earthen dam and caused it to finally give way. More typically, these dam failures happen during significant rain storms.

Visible for the 1st time since they were originally laid down - a line of the dam's foundation stones
The pond is now largely empty of water, with the exception of the wide stream channel and a relatively small pool in front of the remaining dam. Now in only about one foot of water, stranded fish are easy prey for Great Blue Heron and Belted Kingfisher, which have increased their presence following the disaster. Newly exposed mud flats now bring in Killdeer and even some songbirds like Robins and Grackles that are looking to pick off the invertebrates that are lurking in the mud. Butterflies also gravitate to the mud, but their interest is to imbibe water and minerals.
A Belted Kingfisher finds easy hunting at the small pond that remains

The lodge at Sarah’s Pond is completely intact, but all of its normally underwater entrances are now exposed to the air. This means that the lodge is no longer safe from predators and the beavers will be forced to quickly build a new lodge or to refurbish an old one. This lodge had just been expanded to accommodate a larger family and a deeper pond. New beaver kits had been recently heard inside the lodge, but no new kit had been seen outside of it. That is until Thursday, when one of them was finally seen at one of the lodge's exposed entrance tunnels.
The beaver lodge with its entrance tunnels exposed

The beavers wasted no time in getting one of their ponds back into shape. On Thursday afternoon, shortly after I discovered that there had been a disaster, I found 2 of the one year-old beavers down at the 4th pond (called Secret Pond) working on the dam. The water level of that pond had already risen fairly high, and though this pond is much smaller than the one that they lost, it would adequately serve the beavers’ immediate needs.

May Apple works to restore the dam at the 3rd Pond
There is no lodge at Secret Pond, but there is an old dilapidated lodge in the 3rd pond –one that was originally build around the stump of a large Black Willow tree. In order to use this lodge, work began immediately to repair the 3rd Pond’s pulverized dam. The beavers' objective is to raise the pond level and resubmerge that lodge’s entrance tunnels.

Beavers take these kinds of disasters in stride. Certainly none of them were moping around or even caught without some ready plan to implement. Julia, the adult female appeared as calm as ever as she rhythmically munched on a care package of poplar branches that I had brought to her new home pond. This disaster served to bring out this year’s new beaver kit(s) a little prematurely. Normally, the kits would not be seen outside of the lodge for at least another week. There may in fact be only one new beaver kit this year, but I have yet to determine the litter size for certain.
A single new beaver kit is seen climbing over the dam to join his mother

Other animals were quick to make the move to Secret Pond. On my visit there, I saw that a Mallard family, and several of the resident muskrats where already there. Frogs and dragonflies were also there –as was one of our mink.

Secret Pond is a relatively small pond - and quite a shady place

Back in 2006, during a July rain event, Sarah's Pond's dam gave way in a similar manner . In that instance the beavers did begin repairs on the broken dam nearly immediately following the breach. But their main response was to shore up the dam at Secret Pond and at the 3rd pond and to move into to the lodge at 3rd  Pond -which is essentially the same thing that they are doing this time.
Julia enjoys her care package of Quaking Aspen boughs

It may or may not be be a long time before the beavers resurrect
Sarah's Pond. For sure, beavers are difficult to predict. Whatever they do, the pond bed's appearance is sure to change. If the beavers leave it alone, it will quickly begin to sprout grasses and within a month it will look more like a grassy meadow and less like a brown impact crater. Often beavers wait until the grass grows in thick and lush before they flood the pond again. In this way they can feed on the submerged grasses. This is one way that beavers farm their land.
The stream now flows relatively unencumbered through the remains of several dams

A Mink bounds over a half-downed willow trunk at Secret Pond

Friday, June 22, 2012

Cedar Waxwings and The Spiderwort Meadow

A Cedar Waxwing hunts for flying insects at the beaver ponds
Lately, the Cedar Waxwings have been common at the nature preserve. Their soft trilled songs can be heard just about anywhere on the property –in all different habitats.

A flock of Cedar Waxwings in early spring

The song of the Cedar Waxwing seems quite appropriate for a bird with such an amiable disposition. Most of us have heard if not seen for ourselves the waxwings’ habit of sharing berries with others of its kind. They literally can be seen passing berries –beak to beak to their friends and family members. As part of courtship, the male will also frequently give tributes to his mate –usually berries.

Currently, the best place to find a flock of waxwings is down at the beaver ponds, where they gather at the end of the day. There the waxwings partake in catching insects on the wing, an activity that they are as skilled at as any of the true flycatcher species. They’ll perch on a snag right over the water, and repeatedly fly out to catch their prey.

A pair of Cedar Waxwings dissesmble an old Oriole nest for raw materials

In this activity, the waxwings are joined by several species of flycatcher (Eastern Wood-Pewee, Eastern Kingbird and the Great Crested Flycatcher) and by 2 species of swallow (Barn Swallow and Tree Swallow). Dragonflies also eagerly snatch up the insects that fly low over the water. June is a time of plenty if you’re able to eat insects.

Cedar Waxwings accept a wide range of nesting situations. I’ve found their nests placed over marshland, in overgrown pastures and in open canopy forest. I’ve seen them build a nest in a young White Pine only 5 feet high and I’ve also seen them choose a site 60 feet high in a Black Locust tree. They seem to be equally resourceful in their selection of nest building materials. I’ve seen them build (both male and female participate in nest construction) with cattail down, pine needles, poplar cotton, bark strips and also with small twigs and leaves.
A pair turns to stone when someone approaches the nest

The Cedar Waxwings often nest late in the season –even during August, when most of our other breeding songbirds have long since finished raising their last broods. Fledgling and juvenile waxwings have much more mottled feathers on their chests and are easily distinguished from their parents. 

Waxwings have red, yellow and sometimes orange spots on the ends of their wing and tail feathers. These colorful waxy projections are responsible for the species common name. The color of the “wax” at the end of their tails tend to be yellow, but depending on what the birds eat, they may change to orange.
An occasional winter visitor --the Bohemain Waxwing has even more ornate plumage

Frequently waxwings are found in flocks of 12 to 50 birds (sometimes more)especially in fall through spring. Like some of the finch species, waxwings are non-migratory and they are unpredictable visitors outside of the breeding season. They move like nomads, going wherever they find their food resources to be plentiful. Their major foods outside of the breeding season are fruit.

The Spiderwort meadow in bloom
Currently, the wildflower meadow at the nature preserve is filled with spiderwort blooms. You may or may not notice them depending on what time of day you go by the meadow. Generally, in the early morning, their flowers are open, but typically they start to close as the day progresses and the sun light becomes more intense. The individual flowers are short-lived and only last a day or 2, but each plant has numerous flower buds, so the plant itself may continue to bloom for weeks.
Spiderwort flowers

Monday, June 18, 2012

The Fawns of Spring and Beaver Multitasking

Twin Fawns wait for their mother to return 
By the end of May, while working in the reforestation fields, I was frequently coming upon fawns lying curled up in the grass. So still and so well hidden, you literally can stumble over one if you’re not careful.

A very young fawn, curled up in the grass near one of our benches
It’s normal behavior the fawns’ mothers to leave them alone like this for extended periods of time, while they are off feeding somewhere –usually in a nearby field or in the woods. After all they can’t produce milk for their young without eating a lot of salad –right?

Looking for a new place to set down

Occasionally, I’ll see a fawn become startled enough to run off, but they never seem to wander very far before laying down again to resume their vigil for their mothers. When the mother finally does return, a prolonged hello in the form of a cleaning and a long drink are in store for the youngster.
Last year I watched one fawn as it searched for a place to conceal itself. It was very young –probably born that same morning. It walked haltingly on its disproportionately long legs until it reached a grassy place underneath a young Pitch Pine. The grass wasn’t very high, but as soon as the fawn laid down, it really did disappear.
The Doe is reunited with her fawn
In that same field, some years back, I recall seeing a pair of young deer as they chanced upon a fawn that was bedded down in this manner. Their individual reactions were interesting: The young female wanted nothing to do with the little being that so abruptly popped out of the weeds and was now surveying her underside so hopefully. By contrast, the male deer strode right up to the fawn and gave it a good looking over. Next he began licking it with his long tongue. All was going well until the fawn decided to see if the amiable buck was also dispensing milk. The encounter ended with the 2 adult deer strolling off and the fawn lying down again to wait for its actual mother.
May Apple works on the roof of the beaver lodge
May Apple is the name of the adult male beaver that lives at our nature preserve. Yesterday, I watched him for about an hour in the afternoon as he near simultaneously worked on several tasks. The first thing that he was concentrating on was food procurement; he had dragged a Pussy Willow sapling out of the meadow and placed it about 10 feet out from shore, where it could be safely accessed by all members of his family.
Now it's time to work on the dam
His next task was to add material to the 2nd Pond’s dam, but after only 3 armloads of mud, he switched to searching for sticks of a particular size that he could add to the top of the beaver lodge. After doing this for only 15 minutes, he took a short snack break and then set out across the pond and toward the overland path that leads into a grove of Willows.

May Apple perceives a stranger standing on the path ahead - time to switch tasks

By this point, I had walked over to the same area in search of butterfly activity. May Apple was just starting to waddle up into the field when he noticed me. Initially, it looked like he was going to continue up the path and walk right by me, but after some minutes of contemplation, he turned around and once again seamlessly switched to another task. Still in the field, he began pulling up some assorted greens –some grass, goldenrod and ferns. Once he had collected a sizable bouquet, he swam out for the lodge, dove toward the underwater entrance and presumable brought the greens into the living chamber where they will be used for bedding.
May Apple brings some bedding material back to the lodge

Friday, June 15, 2012

Marsh Wrens at the Utica Marsh and the Ninebark Bush - an Unrivaled Bug Magnet

Marsh Wren singing
At the Utica Marsh the Marsh Wrens have been very active in the cattail beds. Marsh Wrens have a close association with cattails and are seldom found very far from them. The invasive plant, Purple Loosestrife, has taken over much of the wetland habitat at the Utica Marsh. In fact, cattails now only cover a relatively small portion of its acreage. This means that the Marsh Wren and many of the other Marsh specialty species are forced to make do with an ever decreasing amount of viable habitat.

A well concealed Marsh Wren nest

Male Marsh Wren build nests mostly out of cattail leaves. They create oval-shaped, domed nests which are placed about 1 or 2 feet above the ground (or water). Most often the nests are well hidden in the reeds, and difficult to pick out unless you know what to look for. Like the House Wren, the males usually make several “dummy” nests that will never be used. Sometimes as many as 6 nests will be built for every one that is actually used to raise young. It’s up to the female wren to decide which nest to finally lay eggs into.

The Marsh Wren male is often polygamous, so perhaps when he is making all of these nests he’s being optimistic that he’ll be able to secure enough wives to fill them all with eggs. I think that it’s more likely that nest building is a constructive outlet for all of the surplus energy that wrens seem to possess.

The Wren himself often stays hidden from view

Looking out at their breeding grounds at the Marsh, I can see 2 new Wren nests built only 10 feet apart from each other. The builder sings a rapid bubbling (or clicking) song that’s similar but not as musical as the House Wren’s song. It has been shown that a young male Marsh Wren learns between 50 and 200 different song types, but discerning the subtle differences between most of these similar sounding songs takes keener ears than mine.

Found nearby the Wrens, a Red-winged Blackbird nest with eggs
For the other resident birds of the marsh, Marsh Wrens can be antisocial neighbors. Apparently, when given the opportunity, they will sometimes peck holes in other birds’ eggs –thus destroying them. I however, found my Marsh Wren neighbor to be quite amiable. I spend a few hours in his territory observing a Least Bittern nest, and he never tried to peck at my head once! In fact he flitted about the marsh grasses, collecting materials for a nest, and pretty much behaved as if I wasn’t there. Getting pictures of him when he was singing was difficult. For the most part, he liked to sing low down in the cattail leaves, and so it was hard to get a clear view of him. He wasn’t on the best terms with the other male Marsh Wrens nesting nearby and they’d engage in singing duels at irregular intervals. However, no actual physical fighting was observed.

Nesting nearby is the rare and colorful Least Bittern

Like all of the other wren species that I know, Marsh Wrens are excellent hunters and so any insects that share a habitat with them had better beware.

Ninebark is a trurly massive native bush that grows at our nature preserve

Ninebark is in full bloom at the nature preserve. The profusion of flowers on this large native bush attract more pollinating insects than any other plant on the property. Moths and Butterflies appreciate this bush, but bees, wasps, beetles and flies seem to be its real devotees. If anyone ever wants to study the diversity of bee and fly species in this region, my advice is to stake out a Ninebark Bush. Every spring, I’m guaranteed to find several species that I’ve never seen before.

Ninebark flowers are busy with pollinating insects of all kinds

We started these bushes by seed originally, and they grew pretty quickly. Now the largest of them is over 8 feet tall and is covered with thousands of blossoms.

Tuesday, June 12, 2012

Nest Failures

A Wood Thrush incubates eggs in her nest
A Wood Thrush egg thrown out of the nest by a cowbird
Most bird nests that are begun never result in young birds successfully leaving the nest –or “fledging”. Every year, of the nests that I monitor at the preserve, most of them fail for one reason or other. Most often predation is the cause, but other factors relating to weather, parasites and cowbirds (brood parasitism) can result in nest failures.
Cardinal nestlings a few days before the nest was pillaged  by an unknown culprit

This year, the number of nests that are failing to produce young is depressingly high. The primary reason could be linked to the mild winter that we just experienced coupled with the bumper crop of wild food that was produced last summer. In the forest, when the Beechnut Trees (and other nut tree species) produce a large number of nuts, Chipmunks, Jays and other nest predators do very well, and many more of them tend to survive the winter. These animals then turn to pillaging bird nests in the spring when other food is harder to come by.

The number of chipmunks in the woods this year is pretty astounding. It’s hard to imagine a nest located on the ground having much of a chance being brought to completion with these guys around. Unfortunately, so many of the woodland birds build their nests on or near the ground –not that they are that much safer in the trees.

The Eastern Chipmunk is a known bird egg and nestling thief
 The Kingbird incubates her eggs just days before the home-wrecker arrives
Out of the 15 or so nests that I’ve been keeping track of at the nature preserve, over 10 of them have failed. The Kingbird nest that I mentioned in an earlier blog post, was likely emptied out by a Red Squirrel –for few other nest predators would tolerate the pummeling that the kingbird parents can dish out. The good news is that the Kingbirds were seen rebuilding their nest in a new location. The female was even repurposing part of the old nest –using some feathers from it to put the finishing touches on her new construction. It is important to note that, like the Kingbird, most of the birds that lose their first nests will try again –most often in a new location.

I happened to be nearby when one of the Baltimore Oriole nests was emptied of its young. A Blue Jay had found the nest, and repeatedly returned to it until it had successfully nabbed all of the nestlings inside. The parent Baltimore Orioles even stopped defending the nest after the first couple of young were taken –sensing that for this brood, all was lost.

The Red Squirrel is another well practiced nest robber
Actually, a good way to determine what bird species are nesting in an area is to wait for a Jay to fly through. All the nesting birds in the vicinity will start giving alarm calls, and some will even try to mob the Jay, and attempt to force it to leave the area. Grackles, Crows and Hawks elicit similar responses from nesting birds. Kingbirds, Swallows and Blackbirds will often continue following a Crow or hawk until it is escorted far out of the breeding area.
After their eggs were destroyed, a Bluebird pair attempts a 2nd nesting

Cavity nesting birds are not safe from predation either –whether they build in a dead tree or in a man-made nest box. Mice, Chipmunks, Red Squirrels, Raccoons, and in some areas, snakes, are all skilled at infiltrating these homes and emptying them of their precious contents. Birds like House Sparrows, and occasionally House Wrens, that wish to take over a box that’s being used by a Bluebird, have been known to destroy eggs or nestlings.

An abandoned Yellow Warbler nest with only a single "tell tale" cowbird egg remaining
The most interesting case of nest-box raiding this year involved an American Kestrel. These small colorful falcons are not so common in our region anymore, but occasionally one will show up to hunt around the nature preserve. One individual learned an innovative technique for catching birds that use nest-boxes. The falcon hovers in front of a box or lands on top of one, in a manner similar to that of a returning parent Bluebird or Tree Swallow, but when the nestling sticks its head out of the hole to be fed, it instead gets seized and absconded; presumably, it is then used to feed Kestrel nestlings.  
A Tree Swallow cautiously looks out of its nest box

So songbirds have incredible challenges to overcome when trying to breed –and that’s at a protected nature preserve. In unprotected areas the challenges are much more daunting –where development destroys habitat, where mowers and chainsaws abound and where domestic cats prowl the neighborhoods. It’s a tough world out there.