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.

The birdy breeding cycle 2020 – 2: nest-building

After courtship has taken place, the various bird species get down to the work of constructing nests for their upcoming broods. Even now in July, gray catbirds (Dumetella carolinensis) have been gathering up nesting materials, as have house finches (Haemorhous mexicanus) who have been followed around lately by the members of their first brood.

gray catbird P6147926© Maria de Bruyn res

house finch P7081079© Maria de Bruyn resThe sites they choose can vary considerably. Canada geese (Branta canadensis) tend to locate their nests at the edge of ponds if possible. In one case, a pair built their nest atop a beaver lodge.

Canada goose P4269282© Maria de Bruyn res

Canada goose P4070275 © Maria de Bruyn res

Ospreys (Pandion haliaetus) like to place their nests atop tree snags and will also use special platforms constructed by people for them. A radio tower or stadium lights, such as those at the right, will also do nicely, however.

osprey P5044393 © Maria de Bruyn res              osprey P6126775© Maria de Bruyn res

Northern cardinals (Cardinalis cardinalis) often choose shrubs and bushes; this one built her nest in a Japanese honeysuckle vine that I allowed to grow along the top of a fence surrounding my berry garden.

Northern cardinal 2G0A0652 © Maria de Bruyn res

Northern cardinal 2G0A0001© Maria de Bruyn res

Killdeer (Charadrius vociferous) seem to take the least effort in securing a spot for their nest. It is not uncommon at all to find them scratching out a very shallow depression in a parking lot, pathway or bare bit of ground. This killdeer put her nest on a patch of ground at the edge of a parking lot and, admittedly, it was not very obvious (Look carefully at the center of the photo).

killdeer eggs IMG_2885© Maria de Bruyn res

Nevertheless, people were walking across this patch of ground with their kayaks and canoes that they had just unloaded and the eggs were in danger, even if the parents did their broken wing display to try and lead people away from the area.

killdeer 2G0A8192© Maria de Bruyn res

I found a couple traffic cones and marked off the area, warning someone who had just parked nearby. Then I contacted the park rangers to tell them about it.

killdeer cones IMG_2887© Maria de Bruyn res

Fortunately, the rangers added a third cone and some tape to effectively cordon off the area.

killdeer IMG_5577 © Maria de Bruyn res

Carolina wren eggs IMG_1173© Maria de Bruyn resThe prize for weirdest nest sites will, in my humble opinion, always go to the Carolina wrens (Thryothorus ludovicianus). People in birding groups often post messages about these birds having built a nest under the hood of a car, in an old boot left outside, inside a little-used mailbox or on a door wreath or plant pot. I have a full-sized spare tire atop a tool cabinet and last year, the wrens laid eggs there.

This year, on one of my walks, I discovered wrens who were feeding their babies in a very awkwardly placed nest inside an old cable or wire box on a neighborhood light pole.

Carolina wren P5086279© Maria de Bruyn res     Carolina wren P5181735© Maria de Bruyn res

When I visited some time later, the nest was empty so the babies must have been able to fledge.

Carolina wren P5181745© Maria de Bruyn res

Many birds will use both tree cavities and nest boxes, depending on what is most convenient or available. Sometimes, they make their own new nest holes in snags, like this red-headed woodpecker (Melanerpes erythrocephalus).

red-headed woodpecker 2G0A0033© Maria de Bruyn res    red-headed woodpecker 2G0A0248© Maria de Bruyn res

Northern flicker P4217370© Maria de Bruyn res

This Northern flicker (Colaptes auratus) was very busy working on a new cavity as well. I followed her and her mate for some time but was never able to see them feeding nestlings as our area had several weeks of hard rain and the nearby lake flooded. I didn’t feel like wading through the lake to get to the snag to check up on them, even after the water had receded a bit.

Brown-headed nuthatches (Sitta pusilla) chose a snag that was usually in the water at the edge of Jordan Lake. The hole faced out into the lake so the fledglings were going to have to fly out and veer left or right immediately in order to get to a resting place!

brown-headed nuthatch P4175229 © Maria de Bruyn res

Eastern bluebirds (Sialia sialis) will use nest holes built by themselves or other birds in previous years.

Eastern bluebird P4070231© Maria de Bruyn res

Eastern bluebird P7070899© Maria de Bruyn resThis year, the Eastern bluebird pair who frequent my yard chose not to use their usually preferred nest box. I believe it’s because they could see me watching them and they don’t like that at all! If they see me with my camera, it doesn’t stop them from flying up to the feeder or sitting on a branch near the porch. If I point the camera toward the nest box, however, they stare at me in dismay, remain on branches near the box, and refuse to go in until I shift the camera away. They did come to my feeders multiple times daily to feed their first brood (one of whom is pictured at right), once they had fledged from a nest in someone else’s yard.

Eastern bluebird P7091193 © Maria de Bruyn resTo my surprise, a couple weeks back, the bluebirds chose to use a decorative nest box that I had bought for decoration. It hangs from a pole and sways in the wind and was not really sturdy. The roof began to let loose in the middle and the décor was curling up from the exposure to rain. But when I finally looked in the box when the parents were gone, I found four nestlings inside. They were pretty well grown already and I thought they might be fledging this past week. I didn’t see it, although I did watch a bit. Yesterday, I found one half of the roof on the ground and the nest was empty. I hope that the babies fledged and not that some larger bird plucked them out after the roof came off.

The materials used for nests can differ quite a lot. House wrens (Troglodytes aedon) make loose frameworks of twigs and the nests look pretty messy inside a box.

house wren 2G0A9598© Maria de Bruyn res         house wren P5181711© Maria de Bruyn res

They do seek out some softer materials with which to line the nest.

house wren 2G0A1982 © Maria de Bruyn res

Carolina chickadees (Poecile carolinensis) make beautiful cups of moss and line them with softer materials – plant fluff or hair from mammals that they find.

Carolina chickadee P3285249 © Maria de Bruyn res     Carolina chickadee IMG_8789© Maria de Bruyn res

Cliff swallows (Petrochelidon pyrrhonota) use mud to construct nests, often underneath bridges and rafters in more urban areas.

cliff swallow 2G0A3239© Maria de Bruyn res     cliff swallow 084A3656 © Maria de Bruyn sgd res

It is well-known that hummingbirds use spider web to help hold their nests together. Blue-gray gnatcatchers (Polioptila caerulea) are also known for doing this.

blue-gray gnatcatcher IMG_8085© Maria de Bruyn res

blue-gray gnatcatcher P4027629 © Maria de Bruyn res

I was surprised a couple years ago to find a nest-building Northern parula (Setophaga americana) also collecting spider web – it appears to be a popular construction material for the birds!

Northern parula 2G0A6727© Maria de Bruyn res

I will leave you with a couple photos from one of my favorite types of nests – that of the white-eyed vireo (Vireo griseus). The first time I saw one being built, I was quite surprised as the birds had chosen a low sapling only about 2 feet from a pathway. They weren’t fond of me watching so I took some photos and left. When I returned some days later, they had completed the nest. (The one below is a different bird.)

white-eyed vireo 2G0A5756© Maria de Bruyn res2

The nests are obviously well-made. This year, I came across an empty nest – also in a low shrub right next to a walking path. It has withstood strong winds, heavy rainstorms and other weather. Now it is a lovely decoration for walkers to see as they pass by.

white-eyed vireo P6125921© Maria de Bruyn res

Next up in the blog series: raising babies!

Some previous blogs about nesting can be seen here and here.

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.

 

An avian buffet appears!

In the town where I live, there is a private lake in a neighborhood of single-family homes. The little body of water was created by developers who dammed a local creek; now a neighborhood association levies annual fees for use of the lake for swimming, fishing and boating. In the past month, the neighborhood residents were surprised by an influx of birds that they do not usually see and some photos of the new avian visitors began circulating.

Given my interest in wildlife and birds, some colleagues passed on a couple of photos to me and one couple kindly invited me to come visit so that I could see the new arrivals in person. They were especially curious about the identity of a few ducks. When I arrived, no ducks were in sight, but at least 80 double-crested cormorants (Phalacrocorax auratus) were hanging out in crowds on two floating docks.

Their tightly-packed presence had displaced the Canada geese (Branta canadensis), who are more common lake residents. A group of 11 geese were off in the distance on shore leaving the open water to the visiting avian groups.

Some of the cormorants couldn’t fit onto the platforms, so they swam around in the company of the many dozens of ring-billed gulls (Larus delawarensis) of all ages who were swarming the waters as well.

From time to time, the gulls would begin edging their way onto the platforms, eventually taking up space vacated by the cormorants. There are both adult and immature gulls in the crowd.

From time to time, the gulls launch themselves into the air for aerial forays which end in dives down to pick up a fish, of which there still seem to be plenty. This is because the shad population with which the lake was apparently stocked is dying off as a whole.

Why is this happening? I don’t know the species of shad with which the lake was stocked, but it appears that threadfin shad (Dorosoma petenense) are common in the Southeastern USA and often introduced as forage fish for the bass and catfish that fisher-people seek. The shad are very sensitive to changes in water temperature; when it goes below about 42° F (5.5° C), they expire. In the past 6 weeks, we had an unusual early winter storm with about 8-11 inches of snow, followed by days and days of cold rains. Sometimes, it is cold 24 hours long; other days have nights and dawns below freezing and then afternoon temperatures of 50-60° F (10-17° C). The shad die-off is a result.

  

The newly arrived birds are obviously enjoying the easy pickings. When the gulls drop down to snatch a fish, they are almost always pursued by other gulls who try to make them drop the prize.

 

Even when they alight with a fish firmly held in their beaks, other gulls harass them in an attempt to make them give up the meal.

 

  

The shad often appear to be too large for the gulls to swallow. I saw several gulls try to position them to get them down their gullets but the fish just wouldn’t go down. So they drop the fish in the water and then try to pick off pieces for easier eating, while fending off neighboring gulls.

  

It is unclear to me how the birds who don’t usually populate the lake in winter knew that a spontaneous buffet had appeared. In addition to the cormorants and gulls, a group of seven bald eagles (Haliaeetus leucocephalus) was also fishing when I visited. There were some almost full adult eagles (with mostly white heads and tails) and several immature birds of varying ages (eagles reach maturity at 5 years of age). I guess that they came over from Jordan Lake, which is quite a fair distance away. Searching the Internet has not yet given me an answer to this question.

I didn’t see the eagles harass gulls who had gotten a fish but they were very carefully watching one another. When the eagle below managed to get a snack, other immature eagles closely followed him/her. A sub-adult who got a fish was harassed by an immature bird as well.

 

The eagles soared overhead and were joined at one point by a beautiful red-tailed hawk (Buteo jamaicensis). The larger raptors let the hawk fly alongside them with no problem.

It was quite a chilly morning when I got to see the visiting aquatic birds, so I only stayed a short time. But my friends invited me to return for another visit, which I hope to do soon as there is no telling how long it will take the visiting birds to eat the easily available shad. And the ducks? I was able to get one rather indistinct photo of a threesome across the lake and helpful folks in a Facebook group confirmed my guess – they are ruddy ducks (Oxyura jamaicensis). Maybe I can get a decent photo of them next time. 🙂

Signs of spring in an uncertain season

As tiny snowflakes fall gently from the sky, my thoughts have left Costa Rica for a bit and turned to the weird weather we’ve been having in North Carolina. I didn’t move to this state for its weather but in the time I’ve been here, I’ve grown to appreciate the climate – we have four seasons but the winters have not seemed overly long and the spring and autumn temperatures are often fabulous.

 

This year, much of February was unseasonably warm in our Piedmont area and people, as well as plants and animals, were enjoying the warm sun and mild temperatures. Crocuses and irises poked their blooms up a bit early and birds were checking out nest boxes.

 

 

 

Butterflies, like this question mark (Polygonia interrogationis) made an appearance (it was getting sustenance from some dog poop left on a bridge!) and Carolina anoles (Anolis carolinensis) emerged to sun in the warmth.

 

 

 

Then on 12 March, we had a day of snow. The male Northern cardinal (Cardinalis cardinalis) and Carolina wren (Thryothorus ludovicianus) sat amid the flakes between trips to the feeders.

 

 

The female ruby-crowned kinglet (Regulus calendula) didn’t seem too perturbed, but the male resident was not happy – his bedraggled red crown was in evidence, both when chasing her away from the feeders and when he was just coping with the wet snow.

 

 

 

When I left for my Costa Rican rambles, it looked like the spring weather might give way to colder temperatures; when I returned 10 days later, it was definitely more winter-like. Then, this past weekend, we had a brief respite. Despite a cold morning start, friend Karla and I visited the Guilford County Farm. The farm personnel had marked off a section of the gravel parking lot where killdeer (Charadrius vociferus) had placed a nest with four eggs. When the babies hatch, they can walk away from the nest as soon as their downy feathers dry.

 

They won’t be able to fly until about 25 days later, but they can feed themselves. The parents will continue tending to and defending them, however. In the meantime, the parents do not come near the nest so as not to draw attention to it and they will try to lead any potential predators away with a broken wing display. They do fly near the nest often, however, and keep an eye on it in between their own feeding sessions.

Karla quickly spotted Wilson’s snipes (Gallinago delicata) flying over the pond and settling at the water’s edge. As we drew closer, we could spot them occasionally, but they blended really well with the vegetation. Below are a couple photos taken at a fair distance with a high ISO and lots of grain – but you can try to see if you can spot the six snipes in the first photo and the two in the second.

Fortunately, one flew in a bit later and I got a couple more recognizable photos!

  

Some Canada geese (Branta canadensis) flew in and headed for the same corner of the pond.

Then, as I was trying to find the snipe in the grass again, I noticed a killdeer looking for insects nearby.

She was accompanied by a male, who at first seemed to be preening but who was actually trying to impress her with some courtship displays.

 

The males will show off their feathers for their (potential) mates, especially raising and displaying their bright tail feathers as a fan.

The female would walk away and he would eventually move closer in an attempt to get a response.

Nearby, we saw three Northern mockingbirds (Mimus polyglottos), two of whom seemed to be males battling over a female. Their dispute was very vigorous and lasted quite a long time. In fact, when they flew away, they were still going after one another!

 

During our continuing walk in the fields and woods near the farm, we saw many other bird species including Eastern meadowlarks, brown creepers, woodpeckers and a pair of kestrels. The woods were kind of strange in that there were very few bird nests visible in the bare trees and also no Eastern gray squirrel nests – in fact, we did not see one squirrel the entire time we were there, which was very odd. An adorable baby donkey (Equus asinus) did greet us as we walked by, though, and our long excursion (about 6 hours) gave us a nice taste of spring. Hopefully, when the snow flurries today end, we will see spring weather come back quickly and be able to enjoy the flora and fauna of this season again. Next blog – back to Costa Rica!