When it’s time to eat your own skin

Several years ago, I bought a couple hard polyethylene pond liners and dug two large holes in my clay and rock-filled back yard. I wanted to have a pond area and figured that two big tubs would be easier to manage and clean than maintaining an in-ground pond. So far, that has been the case except for the fact that I couldn’t keep any fish – a great blue heron managed to eat all the fish I had over the course of about 2-3 years.

That doesn’t mean my pond is not populated, however. Indeed, all the water sources in my yard have residents. Some are unwanted – for example, the mosquito larvae that I admittedly kill with mosquito dunk. The Cope’s gray tree frogs (Hyla chrysoscelis) have a preference for my rain barrels. Somehow they manage to crawl inside even when a lid is on and they deposit hundreds of eggs per season.

   

Fortunately, not all of the frog eggs hatch or my yard would be overrun and the sound in the evenings would be overwhelming. Even the half-dozen or so current adults manage to produce quite a loud concert series – I’m surprised neighbors haven’t asked me to do something to tamp down the sound!

I used to have bullfrogs in my container ponds but haven’t seen them this year. Instead, my neighbors have been lovely green frogs (Rana clamitans). One grew to a very large size and he was joined by two others of a bit smaller stature.

They aren’t very noisy, mostly croaking in the late afternoon. It must have been that sound that attracted another neighborhood resident whom I spotted one day sitting on a nest box next to the pond. The red-shouldered hawks (Buteo lineatus) have spent time watching the pond before when in the mood for frog legs; this was a young hawk who had obviously been in the pond as evidenced by his wet plumage.

The pond was quiet for a few days and I thought the hawk must have had a good meal. And then, slowly, the frogs began to emerge again. There are three that sit on the rocks surrounding the larger pond although one is a bit smaller. This makes me think the hawk might have gotten one but that a juvenile frog was now accompanying the larger pair.

   

When my pond “greenies” croak, they don’t seem to get very large inflated vocal sacs. At the NC Botanical Garden, fellow photographer Mary showed me a green frog that she had been photographing and he croaked a couple times. It went too fast to get a good shot so I offered to make him “talk” by croaking at him. My pathetic attempt at imitating him really was quite pitiful, but amazingly did evoke a response. His vocal sac didn’t get really large either though.

One day, I spotted one of the yard frogs sitting on a rock, opening and closing its mouth without making a sound.

 

When I looked more closely, it seemed to have some membrane hanging on its side.

Then I saw that it was partly in the frog’s mouth and the amphibian was tugging away at it. I wondered if he was sick.

It turns out that he was perfectly healthy and staying that way by eating his own skin! These amphibians regularly shed their skin because it would otherwise harden and make it difficult for them to absorb oxygen while underwater, where they spend a considerable amount of time. So periodically, they scrunch themselves together and then stretch to break the skin so that it can be pulled off, leaving supple skin behind to better enable the “breathing” method called cutaneous gas exchange.

But why do the frogs then eat their skin? It actually has many nutrients, including calcium and proteins. I have no idea if the skin has any taste and whether they enjoy ingesting it. It seemed to be a bit of a laborious process when I watched this frog go through the process. Added to that is the fact that they actually use their eyeballs to push food down their throats and you discover that our froggy friends have quite a unique digestive process!

 

Outside my yard, I’ve not seen too many frogs this year. There was a lovely little Northern cricket frog (Acris crepitans) out and about on one of my walks.

More recently, I’ve been seeing Fowler’s toads (Anaxyrus fowleri) in the woods and parks.

 

     

At the NC Botanical Garden, I had the chance to see some rather large tadpoles sharing a pond with smaller ones.

It was interesting to see that the tadpoles first develop their hind legs and then their front legs before eventually losing their tails.

Finally, one more type of interesting creature I’ve been observing lately on walks are land snails. They don’t really belong in a blog that is about amphibians but it’s unlikely I’ll be writing one about mollusks any time soon. So, I’ll leave you here with a few photos of what I thought were some snails with beautifully spiraled shells. Have a good day or evening!

 

 

 

The birdy breeding cycle 2020 – 4: growing into adult plumage

As mentioned in a previous blog, when young birds are ready to leave the nest, they don’t necessarily look like their parents. Many of the altricial birds (ready to move about and forage on their own) may resemble fluffy versions of the adults, as is the case with these hooded merganser ducklings (Lophodytes cucullatus) following their mother.

The brown-headed nuthatch babies (Sitta pusilla) look very much like their parents. Sharp-eyed observers might notice that the tops of their heads are not as brown as those of their parents.

The Eastern meadowlark juveniles (Sturnella magna) resemble their parents but lack the bright yellow and black coloring on the throat and breast.

 

The difference between adult and juvenile downy woodpeckers (Picoides pubescens) is subtle. The female woodpecker has no coloring on the top of her head, which is simply bedecked with the white and black feathers that cover the rest of her body.

The male woodpecker has a red patch on the back of his head.

The immature woodpecker has a red patch on top if the head and this is lost as the bird reaches adulthood.

The Northern mockingbird youngling (Mimus polyglottos) resembles mom and dad quite a bit except for some spotty streaking on the chest.

In other species, the babies start out looking quite different from their parents. Spots characterize many members of the thrush family, with birds like wood thrushes (Hylocichla mustelina) and hermit thrushes (Catharus guttatus) retaining the spots in adulthood.

   

The Eastern bluebirds (Sialia sialis) and American robins (Turdus migratorius), on the other hand, are only strongly speckled as immature birds, losing their spots as they mature.

In some cases, the birds undergo color changes. Male summer tanagers (Piranga rubra) start out yellow-orange with their reddish coloring appearing in patches until they finally achieve their very bright adult red hue. Some of the immature birds are really quite beautiful with their mottled colors.

 

   

The male blue grosbeaks (Passerina caerulea) start out brown and gradually achieve their dark blue feathers with some reddish/brown wing accents.

 

 

Among the birds that undergo a major change are the European starlings (Sturnis vulgaris). The young birds start out with dullish brown or gray hues with some streaking. Eventually, they begin to develop some spotting and then ultimately achieve the beautiful adult summer glossy feathering with green and purple hues mixed in.

 

 

The females of the Eastern towhee species (Pipilo erythrophthalmus) have a brown back above a white breast with reddish sides, while the males have black backs.

The young developing towhees keep you guessing as to their sex since they undergo quite a lot of color changes as they develop. They do have the white in their tails, which helps you identify them as to species.

 

  And then we come to the hawks and owls. It is not unusual for the young raptors to look nothing at all like their parents. The red-shouldered hawks (Buteo lineatus) start out looking like fluffy and then becoming gradually kind of scruffy looking.

     

As they get a little older and leave the nest, they start to resemble their parents more but have more streaking on the breast. As they near adulthood, they look much more like mom and dad.

 

And we end with an example of another raptor. There is a real difference between the baby great horned owl (Bubo virginianus) and its parent as you can see. Many birds are impressed by the adults but ooh and aah over the nestlings. It must be the combination of those big eyes and fluffy feathers that take away attention from the already formidable claws!

               

Next up – a foray into the world of amphibians and reptiles!

The birdy breeding cycle 2020 – 3: raising young

This year, most of the birds that visit my yard chose to build their nests in places where I didn’t see them. Only the brown-headed nuthatches, house wrens and Eastern bluebirds chose to use nest boxes. The Carolina wrens (Thryothorus ludovicianus) began to use a nest box but their nest was invaded by ants before I had noticed so they abandoned that site. Still, I was able to watch parents with babies, both at home and out on the nature trails.

There are two major kinds of baby birds. The altricial birds hatch as helpless young who must develop their sight and feathers, requiring parental care until they can fly from the nest. They include the songbirds that you may see often, such as chickadees, nuthatches, cardinals and bluebirds, whose babies are seen below shortly after hatching and after several days of development.

 

In contrast, the precocial bird babies can quickly move about on their own after hatching and are able to begin foraging for food themselves as they follow their parents around. In some cases, the parents may also feed them. Examples of precocial birds include killdeer, ducks and Canada geese (Branta canadensis) as seen below.

The nest I watched most closely this season was built by brown-headed nuthatches (Sitta pusilla) in a nest box. Carolina chickadees were also interested in that spot, but the nuthatches won out. Mama Nuthatch laid six eggs, four of which hatched. She and Papa were very hard workers, flying to and from the box countless times per hour. Like other seed-eating birds, they fed their nestlings insects because the babies need lots of protein for their development.

 

They were devoted parents, flying to and fro with food, carrying away fecal sacs and chasing off other birds who used the nest box as a perch. All their care was no match, however, for a pair of birds who are known to be quite aggressive during nesting season.

 

I first learned of house wrens’ (Troglodytes aedon) intolerance of other nesting birds in their vicinity when they invaded the nest of a banded female Carolina chickadee (Poecile carolinensis), whom I had named Chantal. Her babies were hatching and the wrens went into the nest during her absence and killed them. That experience made me hope they would not return to my yard the next spring, but they seem to like the area. This year they visited all the nest boxes in my yard and the male began nests in several of them to keep away other birds. It is thought they may drive away other nesters in order to reduce competition for food when it comes time to raise their own young.

 

The wrens finally settled on a nest box and I thought they would leave the nuthatches alone. Their young ones got to the brink of fledging and the parents were encouraging them to fly out. Sometimes, they would fly up to the box as a youngster peered out into the big wide world and just hover with the food in their mouth.

 

 

They would perch atop the box and call. Eventually two took the leap (which I didn’t see); I thought the others would follow the next day. The parents were busy in the morning and suddenly all activity ceased. I guessed that the other two had taken flight, so in the afternoon I took a peak in the box. To my utter dismay, I found the remaining two nestlings deceased; the wrens had pecked them to death. ☹ I buried them in my flower garden with a small Buddha statue marking the site.

 

 

The nuthatches continued taking care of their fledged babies. They would follow the parents to the feeder poles, crouch down and flutter their wings rapidly as they begged for a morsel.

 

Eventually, the parents found a nearby branch in a large willow oak where they would crack nuts and feed their offspring. As you can see, the spot got a lot of use and could be easily identified by the shredded bark. The whole family still goes up there to eat their nuts from the feeders!

Many adult birds appreciate bird feeders as “fast-food” stops for themselves while they spend most of their time searching for meals for their nestlings. Even the species who mainly eat seeds feed their babies insects because the young ones need lots of protein as they develop toward maturity. The Eastern bluebirds (Sialia sialis) in my yard and other areas seem to favor caterpillars as a food of choice for their developing youngsters.

 

 

 

The pileated woodpecker parents (Dryocopus pileatus) take turns sitting on eggs and bringing food for their young ones.

The larger raptors bring in heftier meals for their offspring. This red-shouldered hawk grew up alone; those of us watching the nest didn’t know whether only one egg hatched or something happened to a sibling. The parents would bring small mammals for the baby to eat.

 

A pair of great horned owl babies (Buteo lineatus), located by Mary, a locally well-known bird photographer, appeared to be growing well the couple times I went to see them. I never saw the parents bring them food but assume they were well fed as they were venturing out of the nest the last time I saw them (a process called “branching”).

 

It seems that a young bird’s open mouth is a trigger for parents that they can barely resist. Until they mature, the fledglings have a pale white or yellow area, or in the case of American crows (Corvus brachyrhynchos) reddish, where their beaks join. This becomes very visible when they open their mouths wide to beg for food and parent birds have a hard time resisting the urge to stuff food down their throats.

The Eastern phoebes (Sayornis phoebe) at a local park were following their parents around asking for food.

They exhibited both the crouched wing fluttering and wide-open mouths as cues that they wanted to be fed.

  

The downy woodpecker (Picoides pubescens) juveniles did not seem to beg as much as the other birds in my yard. They just perched close to feeders or their parents and eventually mom or dad gave them a bit of suet.

 

The European starling young (Sturnus vulgaris) are especially demanding to judge by their behavior at my feeders. These are larger birds and the offspring are as large as their parents,

They are capable of feeding themselves but spend a good deal of time with wide open beaks demanding to be fed.

 

 

 

The starling parents usually give in, but you can almost think they look exasperated.

At least the immature starlings can demonstrate well how a bird looks with a full crop (i.e., the enlarged part of the esophagus that forms a muscular pouch in which food can be stored).

In between all the feeding, the parents have one other important nest duty – keeping the nest as clean as possible. They do this by removing fecal sacs, as this prothonotary warbler (Protonotaria citrea) was doing last year.

 

Some adult birds will actually eat the fecal sac. This is because the nestlings do not completely digest their food and the sacs therefore still contain valuable nutrients that the parents can use. I can imagine the parents are glad to be done with this duty once their young have fledged, however.

When you’re out walking or watching bird feeders, it can be entertaining to observe the birds as they nest and raise their demanding children. And it’s good to know that you may even see adult birds begin to drive away their babies, either because they’re tired of feeding them or because they are busy with a second or even third brood for the season.

Life on late winter-early spring farmlands

Although it’s taken me some time to process photos taken earlier this year, I’d still like to share what I was seeing in late winter and early spring when stopping at farm fields. These sometimes muddy and stubble-covered parcels of land can offer wildlife watchers nice views of birds and occasionally other animals, unobstructed by a lot of foliage. So visits to roadside farms and ponds were on my early 2019 nature-walk itineraries.

Farm fields are often bordered by stands of trees where animals can retreat if they become disturbed by humans standing around aiming long camera lenses at them. The white-tailed deer (Odocoileus virginianus) above were browsing one morning and seemed unconcerned as I photographed nearby birds. When I turned to watch them specifically though, they decided to move back into the woods bordering the field.

Many farmers put out bird boxes on fences bordering their fields; in early March, the Eastern bluebirds (Sialia sialis) were already checking out and starting to furnish potential nest sites. Here a male was flying away from a nest box while his mate was gathering pine needles.

The fences offer other birds a good vantage point for observation, too. A Northern flicker (Colaptes auratus) perched on a fence post to look around and then flew to a branch high above me.

 

A bird present in large numbers was the brown-headed cowbird (Molothrus ater). One morning, a friend and I counted some 200 birds in one small group of trees. Many people think they are an invasive species and dislike these birds intensely because they evolved a behavior that can endanger other birds. The cowbirds, who are native to America, were originally present in prairies where they followed the buffalo. This meant they did not stay in one place long enough to tend a nest, so they began laying their eggs in other birds’ nests. The young cowbirds hatch first and then may throw out the other eggs or hatchlings or they eat so ravenously that the other nest mates don’t get enough.

It certainly is disconcerting to see a small warbler feeding a large cowbird fledgling and a couple bird species have been endangered by the behavior. But I don’t dislike the cowbird because of this – they did not choose how to evolve and the behavior developed as an adaptation, not an “evil” practice. They are attractive birds. And the sounds they make are lovely, akin to water droplets falling into a pool.

 

The American robins (Turdus migratorius) were also present in abundance; they tend to flock together in the winter and early spring. One farm had a boggy area with some cyprus trees and the robins were busy looking for insects among the cyprus “knees” (Taxodium distichum). These woody structures that grow out of the roots may help stabilize the trees when they are standing in water but scientists have not yet definitively identified their purpose.

There were other trees near the cypresses; in one, the cocoon of a Polyphemus moth (Antheraea polyphemus) was hanging high overhead. It also pays to look around to see who is flying u[ ahigh above those trees and fields. It’s not uncommon to see Canada geese (Branta canadensis) flying from one farm pond to another.

Red-tailed hawks (Buteo jamaicensis) soared over different fields I visited.

Red-shouldered hawks (Buteo lineatus) also made an appearance.

And one of my favorite raptors often eluded my efforts to capture a portrait. Only a couple times was I able to catch a beautiful kestrel (Falco sparverius) speeding by in flight.

The robins were feeding in the fields as were several other bird species.

 

Yellow-rumped warbler (Setophaga coronata)

Savannah sparrow (Passerculus sandwichensis)

Pine warbler (Setophaga pinus)

A pair of Northern mockingbirds (Mimus polyglottos) was taking advantage of numerous cow patties left behind on one farm field in their search for insects. They were flashing their wings repeatedly; I’m convinced that this was behavior designed to scare up bugs so they can catch them easily.

 

 

Other birds were following them around in the field, apparently taking advantage of the insect smorgasbord. Two of them were a song sparrow (Melospiza melodia) and a field sparrow (Spizella pusilla).

This year, it was also my good fortune to see a bird new to me in one farm field, the lovely horned lark (Eremophila alpestris). Although these birds are not considered endangered, their numbers declined by 71% between 1966 and 2015.

I couldn’t get close to the larks but one day I did catch a bird taking a dust bath in a gravel and dirt road next to their preferred field. On a second visit to that farm, I again saw a lark in the road and then another lark joined it.

It turns out that female larks perform a courting display that looks very similar to actually taking a dust bath, so I got to see a mating behavior that I hadn’t expected!

Reading about the behavior, I discovered that if male larks see a female who is dust bathing, he may mistake what she’s doing and try to mate with her when she’s not ready.

So reproductive life is a bit difficult for those males, who look so adorable when they raise those head feathers to project two little black horns.I will leave you here with a few more views of a horned lark who was singing and foraging not too very far from the road.

 

Oh, those ravishing raptors!

Numerous people who attract birds with feeders feel regret and sadness when one of their avian visitors is captured to serve as a meal for a raptor in the neighborhood. I, too, feel that pity and discomfort when I see one of the hawks or owls capture a bird or animal because my thoughts go to the pain and fear that the prey must feel. But of course all wildlife has to eat and I want members of the predator species to survive as well. And the beautiful predators can be really interesting to observe.

 

A Cooper’s hawk (Accipiter cooperii, left) sometimes frequents my yard looking for a bird to take. This particular day in November last year, the hawk flew to the front-yard feeders but came up empty-taloned. Raptors, also known as birds of prey, are not the only birds that eat something other than seed. Some smaller birds, like the shrike, do so and many songbirds eat insects. The raptors, however, often go after prey that is fairly large in comparison to their own body size. In January this year, I came across another Cooper’s hawk at a nature reserve. The bird flew soundlessly past me to land in a tree downslope and paused for a bit before flying on, providing time for me to get a gorgeous portrait.

I’ve been lucky lately in seeing barred owls (Strix varia) at the Brumley Nature Preserve North. This owl was sitting silently next to a walking path, looking out over the adjacent field.

A couple weeks ago, I was startled by this barred owl who suddenly flew in front of me from behind my right shoulder. I hadn’t noticed him/her in a tree behind me. I tried to follow its flight but lost it. I thanked the owl for letting me glimpse it and said it would be nice if s/he came back so I could get another look. Sure enough, after I had turned back to the vicinity where I originally was surprised by the silent predator, it flew in and perched on a branch. The bird had a snooze, keeping one eye partially open to keep me in view.

  

Lately, I’ve been seeing many red-shouldered hawks (Buteo lineatus). They have been flying overhead at the nature reserves. The other day, two flew by calling raucously and then they alighted at the top of a far distant tree. I couldn’t get a photo but did see them mating in silhouette against the late afternoon sky.

  

 

A few weeks ago, a pair of red-shouldered hawks began constructing a nest just down the street from where I live. One afternoon, I happened to see them and one was collecting twigs to build or refurbish a nest.

 

 

   

This pair roams our neighborhood looking for prey; sometimes, one or both will perch in my back-yard tree for a little rest.

    

When one of the red-shouldered or Cooper’s hawks pauses for some time in the tree over the small pond, I figure it is watching for frogs or one of the chipmunks that live in the rocks surrounding the pond. The chipmunks appear to be very good at eluding capture.

 

 

A couple weeks ago, our neighborhood family of American crows (Corvus brachyrhynchos) was making a racket in my yard and when I looked out the window, I could see them harassing a hawk. I couldn’t make out why they were so angry but grabbed my camera for some shots through the window.

 

  

It turned out that the Cooper’s hawk had caught one of the numerous Eastern gray squirrels that live here. The squirrels sometimes annoy me but on the whole, I enjoy watching their antics, so I felt badly for this squirrel, who obviously was not going down without some struggle.

What made it easier for me to watch was that I didn’t really see the squirrel’s head and it was not making a sound. I think the hawk had silenced it early on when it had its claws around its neck and chest.

The hawk was determined and kept hold of the rodent, eventually subduing it.

The hawk as not unscathed, however, as you can see from the wound on its leg.

When the raptor flew off suddenly with the squirrel hanging from its talons, the three crows chased it in hot pursuit. I don’t know if they were just upset that the hawk was present or if they wanted to steal the squirrel away. On walks through the neighborhood, I am now regularly seeing the hawks in trees and on power lines. They are not too shy and seem to be adapted to the human presence in their territory.

  

While I may be feeling a bit wary for the other animals and birds when the stunning raptors appear, it still is a thrill to see one up close. Only about half of the red-shouldered chicks make it through their first year of life, so I hope the hawks keep coming by. And who knows, maybe we will have some of the long-lived birds who can reach an age of 15-19 years!