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.

Avian generations in the making – part 2B: nesting in nature

My last blog looked at birds’ nests in man-made structures and there are plenty of birds who take the opportunity to use such sites. Most birds, however, make their homes out in nature – in shrubs, trees and on the ground. This is a bit of a long blog but I want to share views of different species at work.

There are different types of nests; a few types that we see in North Carolina include:

  • Cavity nests – holes in trees, made by the parents themselves or adopted as a home when birds like the cavities made by others
  • Simple scrapes – these are shallow depressions scratched out on the ground and they may be lined with materials or left to look like the rest of the surrounding ground
  • Cup-shaped nests – these structures are like small bowls and may be lined with materials like those used in nest box nests. They can be made of varied materials – swallows use mud while American robins and other birds use plant materials.
  • Platform nests – these nests are usually quite large and comprise large twigs and small branches
  • Plate nests are a bit similar to platform nests but much smaller and less organized; they may consist simply of a few twigs arranged in a shallow bundle
  • Pendant nests hang from branches.

When birds look for a cavity site, they may seek out a new spot on a tree trunk or investigate already existing cavities. These Eastern bluebirds (Sialia sialis) at Sandy Creek Park were examining one particular hole with interest, but a downy woodpecker was interested as well so there was some rivalry. The female bluebird chose to just sit on a nearby branch while her mate looked at the hole numerous times trying to make a decision.

    

Red-headed woodpeckers (Melanerpes erythrocephalus) excavate larger cavities in tree trunks to raise their broods. They may visit various trees before deciding on a spot.

      

Pileated woodpeckers (Hylatomus pileatus) may use the same holes year after year. They make holes for resting as well as for nesting and often include a “back door” so they can make a quick escape if a snake shows up.

          

Brown-headed nuthatches (Sitta pusilla), like this one at Jordan Lake, can be very industrious in excavating their nest cavities. You can watch them pecking away at the wood of a tree trunk or branch, scattering wood shavings and removing bigger bits of softened wood in their beaks to achieve a hole of the right depth for their babies. (See a short video of one at work here.)

   

I also saw nuthatches making nests on the edges of a farm and near the NC Botanical Garden. The pair working on a nest at the Garden were doing this with a great horned owl on a branch overhead, as well as a red-tailed hawk and crows who were raising a racket. Their presence didn’t bother the little birds; these nuthatches also appeared to have help from a previous year’s youngster willing to help the parents raise the new siblings.

 

 

    

Carolina chickadees (Poecile carolinensis) also dig out small holes in trees and snags.

      

Killdeer (Charadrius vociferous) use scrape nests which may look exactly like the surrounding area; their eggs then blend in really well with the environment and can be difficult to see.

When I first saw this nest suspended from a tree near a bridge, I had no idea which bird had built it. A birding friend had fortunately seen the parent bird fly to the nest – it belonged to a Northern parula like the one shown below (Setophaga americana).

    

I was lucky to see a female orchard oriole (Icterus spurius) collecting nice soft lining materials for its nest this past spring.

         

A red-winged blackbird (Agelaius phoeniceus) was doing the same with cattails – an obviously appropriate source for bird bedding!

       

Mourning doves (Zenaida macroura) and Northern mockingbirds (Mimus polyglottos) make fairly shallow, twiggy nests (“plate nests”). It makes you wonder if eggs ever roll out of them through cracks in the loose, low walls.

   

Many birds make cup nests and spend a good amount of time collecting the materials to produce them. Here you see American robins (Turdus migratorius) gathering grasses – they tend to fill their mouths as much as possible before flying off to the nest-in-the making.

      

Red-eyed vireos (Vireo olivaceus) will also attempt to get several pieces of bark into their beaks before flying back to the home site. The photos here are dark as the bird was deep in shrubs where little light was penetrating.

        

Blue grosbeaks (Passerina caerulea) weave what looks like a cross between a pendant nest and a cup nest; they also add man-made materials such as rags, cellophane, newspaper and bits of plastic.

    

Great blue herons and ospreys are builders of platform nests.The great blue herons (Ardea herodias) carry large twigs and branches to furnish a nest. At Sandy Creek Park they have been using the same tree-top platforms for several years now.

     

Last year, I saw this osprey pair (Pandion haliaetus) build their first nest from scratch; they weren’t enthusiastic about me being in the vicinity and would perch or fly overhead to give me “the evil eye” – sometimes calling to one another to sound the alert that they had spotted me down below.

 

 

This year, they were busy refurbishing the nest – these birds with longer-term mates may use the same nest year after year. Again, they would stop their work to stare me down.

 

The Acadian flycatcher (Empidonax virescens) makes a cup nest that is well-hidden among the leaves of the tree spot it chooses. A friend saw the pair constructing this nest and it was done by the time I visited. It seemed quite a tight fit for mom to sit in while brooding her eggs.

The bird whom I enjoy seeing most during nest construction is the blue-gray gnatcatcher (Polioptila caerulea). These little birds are very active and often don’t sit still for long as they feed in shrubs and trees. When they are busy making a new home though, they take their time to do a good job. First, they locate good locations for the materials they use – leaves, spider web to hold the leaves together and pieces of lichen to cover the outside walls.

      

They affix the lichen carefully to make a really beautiful, compact and elegant little cup. The female then sits in it and moves her body to ensure it gets the right shape and dimensions for her upcoming brooding.

     

The male and female both work hard on the nests and this year I got to see three pairs at work. In two cases, it was lucky I saw them flying to and fro because their nests blended in really well with the tree.

Unlike the cavity and platform nesters, the cup and pendant nesters usually need to build a new nest each year. At the end of the summer, for example, the blue-gray gnatcatcher nest had already deteriorated considerably with the rain and wind, even though it was a fairly calm and dry season.

 

Once the nest is complete, the avian parents brood and feed their babies before fledging and this will be the third part of this series. For now, I leave you with the male and female ospreys as they watch the birdwatcher….

  

Warbler watching and migration – a shared pleasure for birders!

black-and-white-warbler-i77a3458-maria-de-bruynAutumn migration in North America has been underway for some weeks and our bird populations in North Carolina are changing in composition. Some birds stay year-round – for example, I see robins, blue jays, Carolina wrens, Carolina chickadees and tufted titmice in all seasons to my great delight. However, other birds who have been here since spring are now getting ready to leave for a southerly jaunt to a place that will be warmer for them in winter – most of the ruby-throated hummingbirds and some gray catbirds have departed already. (I have had a catbird stay year-round but others leave.) Many black and white warblers (Mniotilta varia) will be leaving, too.

american-redstart-i77a4367maria-de-bruyn-resThe Nature Conservancy has noted that the autumn songbird migration is one of the top four migrations in this state. The Audubon Society has even published a guide to this migration and when certain species usually begin their travels. (Left: American redstart male)

 

This seasonal event means that dedicated birders make special efforts to visit places where it’s likely we’ll see warblers. Many of North America’s 50 species don’t eat seed or suet, so you won’t find them visiting your feeders often. I have found, however, that pine warblers (Setophaga pinus) and yellow-rumped warblers (Setophaga coronata) are pretty social and those who are here for the winter are already joining my “regular” birds at feeding stations. The pine warblers especially like suet (female left, male right below).

pine-warbler-i77a0184-maria-de-bruyn-res        pine-warbler-i77a0409-maria-de-bruyn-8-x-10

The yellow rumps are still looking around a lot for insects; this one snagged a skipper butterfly.

yellow-rumped-warbler-i77a5552-maria-de-bruyn-res

In the autumn, many of these songbirds no longer have their beautiful breeding plumage, which is often so distinctive that you can identify them easily, especially the males. I was lucky enough to see some of those beauties during spring migration as well as in the summer for the ones that spend the warmer months here.

prothonotary-warbler-i77a2854-maria-de-bruyn-res   prothonotary-warbler-i77a9933-maria-de-bruyn-res

Prothonotary warbler male (Protonotaria citrea)

yellow-throated-warbler-img_0418-maria-de-bruyn        prairie-warbler-i77a1622-maria-de-bruyn-res

Yellow-throated (Setophaga dominica) & prairie warblers (Setophaga discolor)

american-redstart-i77a7811-maria-de-bruyn-res

 

The warblers’ non-breeding coloration is frequently duller and drabber than their breeding plumage. Often only experienced birders can tell some species apart on first sight. Added to that is the fact that young birds don’t yet have their adult plumage and the immature males often look just like adult females. So it is a challenging time for identification, especially for me, but an exciting time for discoveries.

 

blackpoll-warbler-i77a1289-maria-de-bruyn-resGetting photos of these lovely birds can be tricky since they move about a lot in search of their insect meals. It is ultimately the pursuit of those culinary delights that leads the warblers to migrate South, since the insect population declines dramatically in areas with cold weather.

Nature photographer Mary had discovered a spot where the warblers could bathe in a relatively protected fashion; she kindly shared the location with some of us and a number of avid birders sat with her for hours waiting for the birds to appear. Some of our more “common” avian friends used the site, too, including a gray catbird (Dumetella carolinensis) and a brown thrasher (Toxostoma rufum).

gray-catbird-i77a4922maria-de-bruyn-res    brown-thrasher-i77a4880maria-de-bruyn-res

northern-waterthrush-i77a5013maria-de-bruyn-res

 

A Northern waterthrush (also a warbler, Parkesia noveboracensis) found the spot enticing.

The trees around the water hosted birds as they looked for insects, like the black-throated blue warblers below (Setophaga caerulescens), seen a few weeks apart.

 

 

black-throated-blue-warbler-i77a8117-maria-de-bruyn-res  black-throated-blue-i77a4426maria-de-bruyn-res

A female American redstart (Setophaga ruticilla) spent time working the shrubs surrounding the creek with some success.

american-redstart-i77a4981maria-de-bruyn-res    american-redstart-i77a4996maria-de-bruyn-res

The male redstarts hopped about the branches and rocks hanging over the creek for a while before venturing below to bathe.

american-redstart-i77a7628-maria-de-bruyn-res american-redstart-i77a4217-maria-de-bruyn-res

american-redstart-i77a4477maria-de-bruyn-res  american-redstart-i77a4480maria-de-bruyn-res

The birds appeared to enjoy their bathing spot immensely, sometimes dipping under water over and over again.

american-redstart-i77a4685-maria-de-bruyn-res  american-redstart-i77a4693-maria-de-bruyn-res

american-redstart-i77a4658-maria-de-bruyn   american-redstart-i77a4629-maria-de-bruyn-res

american-redstart-i77a4710-maria-de-bruyn-res

 

They also didn’t mind sharing the space with each other (or sometimes other species)..

magnolia-warbler-i77a2250-maria-de-bruyn-res

 

 

 

The Magnolia warblers (Setophaga magnolia) did the same, giving me some good looks and making my first in-person sighting of this species (lifer!) quite special.

 

 

magnolia-warbler-i77a5161-maria-de-bruyn-res    magnolia-warbler-i77a5184-maria-de-bruyn-res

chestnut-sided-warbler-i77a5210-maria-de-bruyn-res

 

The chestnut-sided warbler (Setophaga pensylvanica)was a very vigorous bather!

chestnut-sided-warbler-i77a5230-maria-de-bruyn-res

chestnut-sided-warbler-i77a5207-maria-de-bruyn-res    chestnut-sided-warbler-i77a5203-maria-de-bruyn-res

hooded-warbler-i77a4728-maria-de-bruyn-res

 

A male hooded warbler (Setophaga citrina) made a brief appearance one day, followed by some female and male common yellowthroats (Geothlypis trichas).

 

common-yellowthroat-i77a4431maria-de-bruyn-2common-yellowthroat-i77a4316maria-de-bruyn-res

Another water body that provided me with some excellent views of warblers was the Haw River. In the small town of Bynum, a bridge crosses the river and gives birders a great vantage point to see birds in the tree canopy close to eye level. There I was able to see two more lifers a couple weeks ago – the first was a bay-breasted warbler (Setophaga castanea).

bay-breasted-warbler-i77a1004-maria-de-bruyn-res    bay-breasted-warbler-i77a1003-maria-de-bruyn-res

blackpoll-warbler-i77a1315-maria-de-bruyn-resThis beauty was followed by another that had me confused. At first, I thought I was seeing a kinglet but this bird was a bit large and then as I got closer looks, I realized it looked like a bay-breasted warbler but had yellow feet. A search on the Internet showed I had seen a blackpoll warbler (Setophaga striata), likely a non-breeding male. Experts on an American Birding Association Internet site confirmed the ID for me.

blackpoll-warbler-i77a1320-maria-de-bruyn-res    blackpoll-warbler-i77a1329-maria-de-bruyn-res

black-and-white-warbler-i77a7204-maria-de-bruyn-resMy migration warbler watching culminated with some exciting finds in my own yard. I was surprised by several I hadn’t seen at home before, including common yellowthroats, a black and white warbler looking for insects in my willow oak and a gorgeous Northern parula (Setophaga americana), who even came to my feeders before pursuing a caterpillar in a Rose of Sharon nearby.

northern-parula-i77a7131-maria-de-bruyn-res   northern-parula-i77a7117-maria-de-bruyn-res

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I’m now hoping to see some birds that breed further North during the summer arrive here for their late fall/winter/early spring sojourn, such as a ruby-crowned kinglet who has spent time with me each winter for the last three years. Next time I’ll share some of my pollinator sightings with you, in the hope you find them as fascinating as me. Have a nice day!