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.

The birdy breeding cycle 2020 – 1: courtship and mating

Although we in the Northern hemisphere are already a little more than a month into summer, many species among our avian friends have not yet completed their breeding cycle. In my yard, many parents are still feeding begging (sometimes almost adult) children. Others are feeding young ones in the nest and some appear to be busy constructing new nests for a second or third brood. So, after a long hiatus in blogging, I decided to feature some of my bird friends, including the American goldfinch pair below (Spinus tristis) as they have worked on their new family lives in 2020.

American goldfinch P7130178 © Maria de Bruyn resSome of these photos go back to early spring. A series of misfortunes (including a crash of my laptop hard drive, a broken camera, loss of Internet) meant that I had a backlog of photos to process and then suddenly a large gap in photos taken. But I managed to recuperate some of the work and hope you enjoy the coming series of posts about the birds’ breeding and family life!

belted kingfisher

Breeding season is heralded by increasing bird song in the meadows, forests, fields and our yards. Males especially sing to attract mates and establish territories, but females treat us to songs and calls, too. This makes it easier to spot birds as the tree foliage gets thicker, especially if you have good hearing!

pine warbler P4175086© Maria de Bruyn                     white-eyed vireo P4123164 © Maria de Bruyn res

Pine warbler (Setophaga pinus)            White-eyed vireo (Vireo griseus)

Eastern meadowlark P4279816© Maria de Bruyn res            Orchard oriole P4279889© Maria de Bruyn res

Eastern meadowlark (Sturnella magna)     Orchard oriole (Icterus spurius)

Carolina wren P3316544 © Maria de Bruyn res                 blue grosbeak P4291500© Maria de Bruyn res

Carolina wren (Thryothorus ludovicianus)      Blue grosbeak (Passerina caerulea)

summer tanager P4291520© Maria de Bruyn res

Summer tanager (Piranga rubra)

Indigo bunting P6308502© Maria de Bruyn

Indigo bunting (Passerina cyanea)

Courtship is usually a sweet behavior to watch in my view. The male Northern cardinals (Cardinalis cardinalis) are especially devoted suitors, seeking out nice morsels to present to their intended mates, while among the American crows (Corvus brachyrhynchos), it’s the females who loudly call to their mates for some tasty bites.

Northern cardinal P4164873© Maria de Bruyn res

American crow P4080661 © Maria de Bruyn res

A fact that perhaps many bird lovers do not know is that few male birds have a penis. Like the female birds, most species’ males have a cloaca, a cavity externally located just under the bird’s tail and internally at the end of the digestive tract. Feces, urine, sperm and ova are all deposited in the cloaca. Birds who reproduce with this organ briefly rub their cloacae together (an activity called the “cloacal kiss”) whereby sperm from the male bird’s testes are transferred into the female’s cavity to unite with her eggs. During breeding season, the cloaca is slightly swollen and protrudes a bit from the bird’s body, facilitating the transfer. In the photo of this Carolina wren, you can see a slightly darker area under the tail indicating where the cloaca is found.

Carolina wren P7059955 © Maria de Bruyn res

red-headed woodpecker P4217162© Maria de Bruyn res

When ready for mating, the red-headed woodpeckers (Melanerpes erythrocephalus) seem to focus mainly on chasing away rivals and then snatching a quick mating session. The female woodpecker then takes a break from the chase to rest and have a bite to eat.

Some cliff swallow males (Petrochelidon pyrrhonota) seem to take advantage of females who are preoccupied with gathering mud for their nests for a quick tryst.

cliff swallows 2G0A3283© Maria de Bruyn res

The brown-headed cowbirds (Molothrus ater) seem to take their time for mating. This pair was occupied for at least 5-10 minutes in preparing for the upcoming production of eggs. At times, it seemed like the male was giving the female instructions on what to do once “the deed” was done!

brown-headed cowbird P5097676 © Maria de Bruyn res   brown-headed cowbird P5097677 © Maria de Bruyn res

Many birders do not like the cowbirds because they are parasitic nesters, i.e., they lay an egg in another bird’s nest so that the other bird will raise the young. Since the cowbird baby usually hatches before the other eggs, they either monopolize the food that the foster parents bring or they may even destroy the eggs laid by their foster mother.

brown-headed cowbird P5097682 © Maria de Bruyn res      brown-headed cowbird P5097686© Maria de Bruyn res

It’s been posited that the cowbirds evolved to use this strategy because they followed the bison in migration and therefore couldn’t stay in one place to raise their young. Others believe, however, that the birds developed the practice because dispersing their eggs over several nests gave their young a better chance of reaching adulthood.

brown-headed cowbird P5097689© Maria de Bruyn res

chipping sparrow P6256620© Maria de Bruyn sgd resThe quickest mating scenario I’ve witnessed came from a pair of sweet little chipping sparrows (Spizella passerina). I’d seen the two fluttering together at the feeders and had noted one sparrow chasing another away – which I now think was the victorious suitor driving away a rival. Then one July afternoon, the two flew to a dying cedar and sat close to one another on a branch. Suddenly, Mr. Victory mounted his mate but for what only seemed a few seconds – really very quick work indeed! She sat there with her rear end elevated for a bit and then the two went back to feeding – and soon after I saw them collecting nesting materials.

chipping sparrow P6256622© Maria de Bruyn res    chipping sparrow P6256623© Maria de Bruyn res

The birds in which the males do have a penis include some duck and swan species, ostriches, cassowaries, kiwi and geese. They differ from other birds in that development of the penis is NOT stopped in the male bird embryos during development (the case in cloacal birds).

The mallard males (Anas platyrhynchos), like some other ducks, unfortunately do not treat their partners well. They may mount the female very roughly. During a mating, she may be dunked underwater repeatedly and at length; occasionally, this results in her drowning. This behavior has been the subject of various studies and some newspaper articles with sensationalistic headlines (e.g., “The horrible thing you never knew about ducks)”.

Mallard duck P1232837 © Maria de Bruyn

Mallard duck P1232839 © Maria de Bruyn     Mallard duck P1232840© Maria de Bruyn

Once the actual mating is over, the birds devote most of their energy toward building a nest. While female ruby-throated hummingbirds (Archilochus colubris) must construct her nest and tend her babies alone, many other birds cooperate in the venture, like the Eastern bluebirds. Their efforts are featured in the next blog. (And if you’d like to see a previous post on courtship, it is here.)

ruby-throated hummingbird 2G0A4084© Maria de Bruyn res

Snowy portraits – part 2

The larger birds were very obvious at the feeders during our North Carolina snowstorm in early December, but they weren’t the only ones taking advantage of the fact that I spent considerable time knocking snow off feeders and a bird bath, filling feeders up multiple times daily and spreading seed repeatedly on the snow for the ground-feeding wildlife.

The Carolina wrens (Thryothorus ludovicianus), who live in the various yard woodpiles, mostly stayed on the ground but occasionally flew up to a feeder. They also spent time clinging to the brick walls of the house, I assume in search of spiders and other small insects that stay there.

Their slightly larger brethren in shades of brown, the Eastern towhees (Pipilo erythrophthalmus), have taken up residence in the holly shrubs and a privet bush near the front-yard feeders. From there, they can emerge to hop around under the feeders (sporadically flying up to perch on a feeder, too) with a place close by to which they can escape when feeling threatened.

 

 

Both house finches (Haemorhous mexicanus, left) and pine siskins (Spinus pinus, below) came to eat seeds at the platform feeders. Though the finches are larger than the siskins, the female finches and siskins look very similar to me and I usually need to look through my zoom lens to see them clearly.

 

 

 

The photo below is a nice one for differentiating them. The female finch on the left has a thicker bill and a slightly larger and bulkier size. The pine siskin on the right has a thinner bill and hints of yellow on its slender flanks.

Another pair of birds that can be difficult to differentiate are the male house and purple finches. The purple finch (Haemorhous purpureus, below) looks like it has been dipped in raspberry juice to put color all over its body. While some male house finches also have very bright red hues, the color does not spread everywhere on their bodies.

   

The tufted titmouse (Baeolophus bicolor, below) and dark-eyed junco (Junco hyemalis) are both subtle beauties in shades of gray but easily distinguishable.

   

The junco’s pink bill gives it a delicate look in my opinion.

 

The chipping sparrows (Spizella passerina) and white-throated sparrows (Zonotrichia albicollis) are both daily visitors to my feeding stations regardless of the weather. The “chippies” are here year-round, while the white-throated sparrows (right) are only resident in the autumn, winter and spring. The somewhat smaller chippies usually sit on the feeders, while the white-throats mostly seek food on the ground; both will venture into the others’ areas, however.

Two very different birds share a common feeding method for gathering suet. Both the ruby-crowned kinglet (Regulus calendula, below left) and yellow-rumped warbler (Setophaga coronata, below right) hover in front of the feeder as if they are imitating hummingbirds, snatching a bite to eat as they “balance” mid-air. Both will eventually alight on the feeder, though, and then eat at a more leisurely pace.

The bright little pine warbler (Setophaga pinus) also loves suet but never hovers at the feeder. S/he will wait until other birds have cleared the space and then clutch the frame to have multiple bites of the fatty food. During windy intervals of stormy weather, this plucky bird also holds its ground, clutching the feeder pole so as not to blow away.

 

The downy woodpeckers (Picoides pubescens) are never scared off the feeders by anyone. Their larger red-bellied cousins are often a bit hesitant to visit but the downies can’t be kept away. Like them, the Eastern bluebirds (Sialia sialis) also don’t let the presence of other avians put them off – they are willing to share space.

This doesn’t mean the bluebirds won’t show a bit of temper, especially toward their own species mates, but they generally get along with everyone.

And the bluebirds visit regardless of the atmospheric conditions, sometimes looking stunning with their bright dry plumage and sometimes looking a bit bedraggled when the pouring rain and thickly falling snow wet their feathers completely. Beginning birders might wonder if these are the same birds, but fortunately the bluebirds seem to dry out quickly to regain their usual beauty.

   

 

There were a few more birds that came along during the storm (one featured in the next blog!), including Carolina chickadees, Northern cardinals (Cardinalis cardinalis, left) and red-winged blackbirds. Snow and ice storms and pouring rain can be a drag in many ways for the human species but for birders, these “bad-weather” interludes can certainly be a boon for easy armchair and window watching!

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!

  

Winter wonderland – the bigger and colorful birds

In this second-to-last blog of the snowstorm series, I’d like to feature the bigger and colorful birds who demonstrated how they adapted their feeding habits to the prevailing weather. The Northern cardinals (Cardinalis cardinalis) actually didn’t change their behavior that much – they looked on the ground for fallen seeds and spent plenty of time at the feeders.

They spent some time in the snow-laden trees looking lovely, too.

  

  

The Eastern towhees (Pipilo erythrophthalmus) usually spend their time foraging underneath the feeders in search of fallen seed and they continued that behavior during the snowstorm. Unfortunately, the female was carrying a tick; I had already seen a robin and a junco with ticks on their faces – this may mean that the coming spring and summer will be an especially bad tick seasonal period for us.

 

The beautiful brown thrasher (Toxostoma rufum) looked both on the ground and at the feeders for his meals. Despite his size, s/he never bullied any other bird.

 

 

 

   

The remaining juniper berries on the red cedar trees (Juniperus virginiana) attracted the blue jays (Cyanocitta cristata).

The Northern mockingbird (Mimus polyglottos) was also seeking food there.

 

 

 

 

The cedar waxwings (Bombycilla cedrorum) and American robins (Turdus migratorius) had already been eating the juniper berries in the autumn; the waxwings had been by about a week earlier but now the robins were all over the trees, shaking off accumulated snow to get at the remaining fruit.

 

 

One robin looked as if s/he might have lost some outer feathers but it didn’t seem to affect her balance or flight. Occasionally, a robin also visited the meal worm feeder.

  

On the days following the big snowfall, as the snow melted more and more, the robins began eating it. During a previous snow event, they had joined the cedar waxwings on the roof of my house to get their drinks that way; now they were taking the snow from the trees.

They weren’t the only ones taking advantage of the opportunity. The Northern flicker (Colaptes auratus), who did not visit the feeder, spent a lot of time in an oak tree near the feeders eating snow.

 

  

There were a few birds that visit my yard who didn’t show up during the snow. They included the American crows and the hawks who often make the birds scatter from the feeders: the Cooper’s, sharp-shinned, red-tailed and red-shouldered hawks. They must have been looking for food elsewhere.

Some birds may have also avoided the feeders because of the large number of competitors who showed up, a feature of the next and last blog in this series.