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.

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!

  

Avian generations in the making – part 1: courtship

The tragedies being faced in the Caribbean islands after hurricanes Maria, Jose and Irma are horrible and other than donate cash to help alleviate the needs, I’m not in a position to offer more assistance. I’m grateful for all those who can and hope government assistance will be forthcoming to help all the people in those nations recover.
The effects of the hurricanes also will be noticeable for the wildlife. Many of those living on land will drown or die of hunger; some birds may be a little luckier – able to shelter against the winds if they are native to a place or able to change their migratory pattern (e.g., delay arrival on wintering grounds) for a time. But when the effects of the storms are immense with lots of habitat destruction, the birds, too, will lack places to shelter and not have sufficient food supplies to survive.

It’s thought that some birds endemic to the islands may be severely endangered as a species. On 22 September, birders were happy to hear that eight Barbuda warblers (Setophaga subita) had been spotted on that island; not a lot but they may help ensure this tiny bird doesn’t become extinct.  At the time of writing this blog, the fate of some other bird species was still unknown. I hope that all the Caribbean bird species survive and will be thinking of them as I share this series with you on how birds take measures to ensure future generations. (It might seem odd to write this series now, but some birds are still feeding their young here.)

So, the process begins with courtship. Some birds mate for life, or at least form long-term (multiple-year) bonded relationships. They include bald eagles, black vultures, blue jays, Canada geese, white-breasted nuthatches, brown-headed nuthatches, Northern cardinals, Carolina chickadees, American crows, pileated woodpeckers and my favorite raptor shown above, the osprey (Pandion haliaetus).

Those who form ongoing bonds may have a courtship period that consists of the male bringing the female some food to indicate it’s time to get ready for nest-building. This was the case for these lovely Northern cardinals (Cardinalis cardinalis).

The American crow (Corvus brachyrhynchos) has a similar behavior; in my yard, I sometimes throw out bits of apple or bread for them in the spring as these seem to be considered real treats. The female will sit on a branch overhead calling until the male brings her some – and sometimes almost shoves it down her throat!

The Northern mockingbird (Mimus polyglottos) males will sing their repertoire in the spring to entice female mates – often they perch on the top of trees and fly up and down with spread wings in a beautiful display while singing.

        

   

The yellow-billed cuckoo (Coccyzus americanus) seeks new mates each year but has an interesting courtship behavior described by All About Birds: “A receptive female perches with its head up, pumping its tail slowly up and down…Just prior to mating, the male Yellow-Billed Cuckoo snaps off a short twig that he presents to the female as he perches on her back and leans over her shoulder. Both birds then grasp the twig as they copulate.”

 

     

 

The downy woodpecker (Picoides pubescens) females and males may both flutter between trees with slow wingbeats. Two females may also compete for the attention of a single male, a behavior I observed this past spring and which surprised me.

 

     

The male brown-headed cowbird (Molothrus ater) will vocalize for the female while spreading his wings in a display.

The killdeer (Charadrius vociferus) has a somewhat prettier courtship dance, bending forward and spreading its tail feathers to show off the colorful underside.

  

Next year, I hope to see more of the birds courting as it gives me a happy feeling.

The next step for the birds is nest-building. We don’t have the bowerbirds in North Carolina, who build elaborate nests as part of their courtship. But the species we have do spend a good deal of time on their nests and I’ll share some of their efforts in the next part of the series. (But one or two blogs on another topic will come first.)

 

Credit map: By Kmusser (Own work, all data from Vector Map.) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons