Friday, May 31, 2013

A Rose by Any Other Name

My wife and I spotted this unusual looking plant in the woods on the edge of our driveway. I have never seen anything quite like it. Although I looked through a lot of plant identification books as well as online, I wasn't able to learn it's name. Finally, I emailed a photo to the Maryland Department of Agriculture. They were able to identify it for me. It's common names are Strawberry Bush, Bursting Hearts or John Baptiste - Percival, which all refer to the fruit it will eventually produce. The scientific name is Euonymous americanus.

What initially attracted our attention was the overall look of a leaf with a flower centered in each. Not every leaf has an associated flower (especially the terminal leaves), but most do.

As you can see in this image, the flowers sit up off the leaf sort of like a tiny umbrella.

Notice how most flowers have a second bud that hasn't opened yet.

The five-petaled flowers are fleshier than the petals of regular flowers and have been blooming for a couple of weeks at least. It looks like ants are a main pollinator.

Is it a tree or a bush? The plant is only five or six feet tall and I assume mature if it is putting out these flowers. That argues against it being a tree. But I always think of a bush as being multiple stems and this only has one main stem. I thought that maybe I was wrong about that since I can think of a couple of bushes that can grow on one stem, crepe myrtle for one. 

As it turns out, it is neither one. It is a forb. A forb is any herbaceous flowering plant that is not a grass. Unlike trees, forbs do not have any woody tissue. Unusual in this plant is the fact that the stems as well as the leaves carry on photosynthesis. The stems stay green throughout winter.

I took this image earlier today, two weeks after some of the earlier images and you can see the second bud finally opening up. I'll come back to it in future posts as the plant has an interesting cycle of development over the course of the season.

Thursday, May 30, 2013

A Love-Hate Relationship

I am rather ambivalent regarding the gray squirrels in our little corner of the world. They are sometimes cute and sometimes pesky; sometimes extremely interesting and at other times extremely vexing. Some years we are overrun with them. This is one of those years. It's just a guess but I'm thinking this is a male although coloring for both sexes is pretty much the same.

When we moved to this house surrounded by woods, I began to notice white branches on trees in the winter time. What I mean is the bark was being stripped off certain branches. After a few years of wondering what caused it, I finally witnessed a squirrel peel a long strip of bark off a branch, roll it up in it's mouth so that it wouldn't trip on it or get tangled up in it as it moved through the trees, and take it back to it's nest.

We all know bark isn't soft, but the inner layer, the cambium layer beneath the bark is soft. Somehow the squirrels remove the bark, leaving only this cambium material and use this as the bedding for their new family. This mass of bedding fell out of a nest that had been abandoned after the nesting season was over.

Squirrels have their young early. Like January/February early. So, the babies are ready to leave the nest right around the time that an abundance of food becomes available. In this photo, the mother of the babies seen in some of the other images, is eating the inflorescence (flowers) on the sweetgum tree where her nest was built just after the leaves emerged (and also her babies).

Her three babies emerged from the nest at about the same time.

They stayed near the nest, not leaving the home tree for about a week. They were not out all the time, but were still doing a lot of sleeping. When they were out, they would spend a lot of time playing together.

One watches while the other samples buds on the same sweetgum. Their nest is in the foreground. As time passed, they became braver and braver, leaving the home tree and exploring the area a bit more.

They were branching out on adventures at just about the time the blossoms on the wild cherry were beginning to emerge and true to form for a baby, they had to try those too.

We associate squirrels with nuts, but nuts are only available during one season (and over the winter when they eat the reserves they have stored. The rest of the time, they eat other vegetation, seeds, mushrooms, fruit, bird eggs and the occasional bird chick...

Wednesday, May 29, 2013

An Age-Old Question

We've all seen robins catching earthworms on a lawn. They are amazingly successful at it. Ornithologists (and others) have long wondered whether they are keying in on the worms by sight or by hearing, and they seem to be divided on the answer. Is the bird in this image using it's sight to locate a worm or is it listening? It appears it could be using either.

I personally believe they can hear the worms (and some studies support this). I have a couple of reasons why I believe this. Have you ever watched a movie where the camera perspective is a flyover of a city? Directly below, you can see the individual city streets, but as you look further into the distance, you cannot see any streets because so many buildings are in the way. From the perspective of a robin, the lawn is pretty much the same kind of situation. It may be able to see the dirt directly around it, but it cannot see the dirt only a few feet away because too much grass is in the way. Hearing, however, would not be impeded in this type of scenario. 

I know. That isn't completely convincing, but it does still leave open the possibility that they use hearing to key in on worms. One scientist described what a worm sounds like as similar to a person walking through gravel. This particular robin had some babies to feed and was piling up pieces of worm to take to them.

This is what really convinces me, though, and it doesn't actually involve a robin, but rather, a starling. I was watching a starling parent and it's chick one day that were feeding in the mulch around some flower beds. I could see them very well because I was looking through a window which kept them from being frightened away and yet they were only a couple of feet away. The parent and chick were both hunting for grubs underneath the mulch. The chick would scratch in the mulch and come up with nothing most of the time. The parent, on the other hand, found a grub every time it scratched through the mulch. I was amazed as time after time, it would hop to a spot, scratch a little bit, and produce a big fat grub. The bird could not have been using it's sight. It was only after digging down with it's beak that the grub would appear. So, I had to conclude that it was hearing the grubs under the mulch and that the chick was also learning how to locate grubs.

I was surprised by the male Red-bellied Woodpecker flying in and landing where the robin was on the lawn. I think it was hoping the robin would drop the worm it had in it's beak. Red-bellied Woodpeckers probably do not have the same ability as the robin and was resorting to thievery. But, he wasn't early enough to get the worm.

Tuesday, May 28, 2013

mycoplasmal conjunctivitis

I thought it was a little unusual. A newly fledged House Finch was perched over the same hanging basket on the porch where another pair had raised their brood earlier this season. I had moved the hanging plant to another spot and removed the three nests this pair had built. After that, they didn't come back. What was unusual was that the baby stayed in the same place for over an hour. I took this photo after it had been there all that time, but I didn't really look at it in the camera.

I happened to look out the window a little while later and saw both parents with it on the hanging basket, then they flew into the trees on the edge of the yard. The chick followed, but it appeared clumsy in flight and had trouble landing on a branch. It was only then I began to suspect something was wrong with it. 

After taking a couple more photos and looking at them on camera, I realized the chick had an eye disease I had seen on a couple of finches a few years ago. It is called mycoplasmal conjunctivitis, a bacterial infection that renders the bird all but blind. It actually is transmitted as a respiratory infection.

The parents would fly in to feed it every so often followed by the other young from the same brood. These other chicks seemed to be unaffected. The chick mostly sat on a tree limb, occasionally scraping it's eyes on the branch to try to clear them.

The disease was initially seen in House Finches in the winter of 1993-94 right here in Maryland and in neighboring Virginia. It has since spread throughout the East Coast. It mainly effects this one species although it has occasionally been seen in a few other finch species and is also found in domestic turkeys and chickens. The disease, rampant at first, has stabilized over time. Birds that have had the disease and survived do not appear to build up an immunity to future infection. It is estimated that 5-10% of the population has the disease at any one time.

Monday, May 27, 2013

Five-lined Skink

The five-lined skink, also commonly known as the bluetail skink, is found throughout the Eastern United States. They can reach about eight inches in length. These two are a fully mature female (on the left) and a breeding male (on the right). As the female matures, the stripes fade from yellow, their main body color fades from black to the brown, and she loses the bright blue in her tail. The male turns a coppery brown and, during mating season, the male's head turns orange-red, helping to attract a female.

They are true reptiles with the claws and ear openings of a lizard. Salamanders are amphibians without ear openings. They are also poisonous to pets, so you want to keep that in mind. Our Peke, Annabelle, loves to sit out on the porch and look for them in the cracks between the decking. The skinks are very fast, so I don't think she would ever catch one. They have a tail that is easily broken off as a defense mechanism. If a predator attacks, they can leave the tail behind which continues to wiggle wildly while they escape. The tail will grow back, but it always looks a little stumpy and never attains it's original length.

I'm pretty sure these two lovebirds (or should I say, lovelizards) were aware of my presence out on the porch when these photos were taken. They seemed undisturbed by my being close by. They consume many insects (spiders, crickets, roaches, moths, ants and more), so they are beneficial to have around your home - just not inside. 

They nest in rotting logs and leaf litter, laying anywhere from 4-15 eggs. The female guards the nest until the young are born, but they are left to their own after only a couple of days.

Mating is actually a slow motion, non-violent affair. All of these photos were taken during the process, but much of the time, they were simply resting motionless. I finally got so bored, I walked away. The porch must be a pretty good habitat for them because we have plenty of them around. In the more urban area we lived in several years ago, we never saw this species.

Sunday, May 26, 2013

Mining Bees

One of our neighbors has a stretch of lawn where I noticed a lot of mining activity last year and again this year around the same time (early May). I could tell they were ground bees of some sort since you could see them flying and hovering around the mounds of dirt. We pretty quickly determined they were harmless when the dogs walked through an area we thought was free of them, but turned out to have some holes. The bees didn't try to sting the dogs (unlike those sweat bees that sting the heck out of you if you accidentally mow over their nest). It seemed to me the area they covered this year had doubled over last year and they were definitely much more densely packed than last year. The entire area covered maybe fifteen by thirty feet.

Unlike honey bees, mining bees do not have nests containing many bees, but live in individual burrows. I guess you can still call it a colony even though the bees live in single family homes instead of condos. They must burrow fairly deep because the soil around their holes is not topsoil, but the red clay from deeper down in the ground. They also must have some means of gluing dirt particles together into larger packages because the dirt around their nests was not single grains as you see around ant holes, but granular balls of dirt.

Mining bees range in size from about the size of honey bees to much smaller. The larger bees are furry and usually darker in color than honey bees. Some are brightly striped, while others are a shiny metallic green. Here, you can see one emerging from the entrance which is about a quarter inch in diameter.

Notice how many different "looks" there are to the bees in these photos. I'm not sure if some are male and others female, or whether several species were nesting in the same area. They also varied greatly in size. One odd thing while I was photographing them - when the sun was out, you would see them flying or hovering around the nest. When the sun went behind the clouds, you couldn't hardly find one.

Their tunnels consist of a vertical shaft with side chambers where the females deposits an egg on a food mass consisting of nectar and pollen collected from flowers. Some of these bees are very specific pollinators and if the plant they rely on disappears, so do the bees. The larva hatches, consumes the food mass and goes into a pupal stage, finally hatching into an adult bee early the following year. The bees overwinter in the ground, emerging the following spring to mate and start the entire cycle all over again.

One question that comes to my mind is, How in the world do they relocate their nest once they fly off? With hundreds of nest, all looking alike, they must have a unique "gps" system in order to get back home. 

Some females can be distinguished from males by a velvety patch of hair on the forehead at the base of the antennae.

Perhaps one of these two bees, which appeared to be fighting, went into the wrong nest. All activity ends after about three or four weeks and they disappear for another year. There are something like 1300 different species of mining bees altogether. They are beneficial as pollinators and as aerators of the ground and not being prone to stinging, I would hope there would be little incentive to try to eliminate them if they happen to nest in your area.

Saturday, May 25, 2013

Made in the USA

Since I had described what I was seeing as the Wood Thrush built her nest and since I found it after a predator had gotten it, I thought maybe you would be interested in taking a closer look at it's construction. Two things leap right out at me right from the start. How skillfully and carefully it was made given the knowledge God invested in this creature for living in her little corner of the world. And, secondly, how she could construct such a remarkably intricate nursery using only her beak and breast.

This is the underneath surface of the nest which was placed first. As I said in another entry, early construction was done rapidly with seemingly little thought to careful placement and it shows in this view. One thing to consider, however, is that the bird is fighting the wind and the faster the nest can be built up, the heavier, and therefore the harder, it is to blow away.

Notice how the leaf stems are all facing outward. I would see her forming the cup of the nest with her breast, pause, fuss with a leaf, and press some more. She was constantly evaluating her progress. Two pieces of cellophane are also visible, one on either side of the bottom of the nest.

I think I was most amazed with how nicely formed and how deep the inner cup of the nest was. From watching her build the nest, I had no idea it was going to be that deep. She would press with her breast, then turn in another direction and repeat over and over again, especially toward the end.

If you remember, I said I kept waiting for her to bring in some mud, but never saw her do that. Instead, towards the end of construction, she was bringing in some fuzzy looking stuff I couldn't identify. That is what the lighter material is where the arrow is pointing in this image. I don't know how she got it to consolidate into a solid wall of material.

In this image, you can readily see the rootlets that she brought in as the final step in building her nest. I'm not sure why they choose this material. While it is soft when first dug up, once it dries out, it is rather stiff and scratchy.

I wanted to include two photos to give you a better idea of what I had said in an earlier post. The tree the Wood Thrush was nesting in is marked by the arrow although the branch it's nest was on is above this photo. Between the porch and woods there is a open space marked by the rectangle that serves as a flyway for the birds, mostly coming and going from the bird feeder in the back. So, you can see the odds were high that a lot of birds knew about the nest and maybe that is why so many different species were "invading" her space.

The arrow in this final image points to the location on the branch where the nest was located. I don't foresee her returning to build another nest in the same spot. I have heard them singing in the woods close by, but haven't seen either one since the nest was knocked out of the tree. The blue sky gives the impression there isn't much woods back there, but that isn't true. To the right is a swath of trees a couple hundred feet wide that leads to an even deeper and wider stretch of woods. That is why I was so surprised when she first began building 
her nest since she could have easily chosen a better site.

Friday, May 24, 2013


The failure of the Wood Thrush nest was a real disappointment to me. Seldom have I gotten to film this secretive species and I was really looking forward to watching them raise their brood. It goes to show how important siting the nest can be. While I am only an amature observer, I personally thought the site she chose to build a nest was not a good one. It seemed to me it was in too open an area. In the afternoon, the sun would be shining on the nest, which I didn't think was too good either. I also mentioned earlier that the ten or fifteen feet between where the nest was located and the side of our house creates a flyway where birds are constantly passing the nest. I think that may have increased awareness among many of the birds that visited the nest for unknown reasons.

I don't know what happened. I took a peek at the nest from the porch to see if she was sitting and when I did the same thing an hour later, the nest was gone! A day earlier, marauding crows were all through the woods around the house trying to discover where there were bird nests. They eat both eggs and babies. I don't think it was crows, however, because I was inside the house at the time and would have heard their loud calls. Plus, if it was crows, I don't think they would have knocked the nest out of the tree.

I found the nest, intact, lying amongst the ground cover (pictured above) under the river birch. That makes me think it was a squirrel that was the predator. We are having a banner year for squirrels and they are everywhere. Although they cannot get into the squirrel-proof bird feeder on our deck, they still hang around looking for stray seeds that have been dropped from the feeder.

If you remember, I posted a photo of a squirrel a couple of days ago that was on a branch at the base of the same tree. In this photo, taken just a few feet from the river birch, a squirrel is munching on a nice fat mushroom it found. Squirrels are omnivores and will eat both vegetable matter and meat, be it eggs or chicks. Makes you wonder how any bird can successfully raise a brood, doesn't it?

Thursday, May 23, 2013

Brown-headed Cowbird

Once the female Wood Thrush finished building the nest, she didn't stay in the vicinity of the tree as much. She was probably taking the opportunity to put on a little weight before having to sit on the eggs. For a few days, she would be laying one egg a day until her clutch was complete, then she would begin nesting in earnest. 

On an occasion when both the male and female thrushes were away from the nest, a female cowbird flew in and very quickly deposited an egg in the thrush nest. I don't think she was on the nest more than thirty seconds, but I'm pretty sure she laid an egg just that quick. Then she hopped out and flew away just as quickly.

Female cowbirds are brood parasites. In other words, they don't build their own nests, but lay their eggs in the nests of other birds. In fact, cowbird eggs have been found in the nests of over two hundred other host species. A cowbird female can lay up to 36 eggs in a season. Parasitism is the main reason I dislike cowbirds.

Some host females recognize the alien and use different strategies to get rid of the egg. Some birds will build an entirely new nest over the old or even abandon the nest. Some birds will break the egg while others will roll the egg out of the nest. Most, however, don't recognize the foreign egg and raise the chick as it's own once hatched. 

Cowbird eggs hatch a little sooner than most other species, giving the chick an unfair advantage since it is both larger and more mature than the other chicks. The cowbird chick out-competes for the food brought back by the parents. In this photo, you can see the female cowbird leaving the nest which is over on the right.

I couldn't tell if the female thrush recognized what happened while she was gone. She didn't seem to take notice, although I wasn't there to watch the entire time. It may be she rolled the egg out of her nest. I would not have known if she did because we have a ground cover underneath that tree and I would not have been able to see it.