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….

  

Woodpecker welcome!

My celebration for the arrival of 2016 happened on 21 January, when I had my first nature walk of the year. It was delayed by a hospitalization at the start of the year and home treatments for a couple weeks after that. When a relatively warm and sunny day arrived, I just had to get out there despite still dealing with some recovery-related issues. I chose the North Carolina Botanical Garden as my venue since it has plenty of benches for short rests in between walking. It was simply lovely.

pileated woodpecker I77A7321© Maria de BruynMy first bird of the day was a beautiful male pileated woodpecker (Dryocopus pileatus), a harbinger of the day’s theme – the woodpeckers were my welcome committee!

Loud rhythmic hammering had me searching the snags among the tall trees for the next greeter – it reminded me of the facts I had learned about woodpeckers and their adaptations to a pecking life.

downy woodpecker I77A7372© Maria de BruynIt turned out to be a diminutive downy woodpecker (Dryobates pubescens), whose hammering sounds were enhanced by the hollow stem with which he was busy.

Next up was a lovely female yellow-bellied sapsucker (Sphyrapicus varius) who was very industriously flitting from branch to branch in search of sustenance.

yellow-bellied sapsucker I77A7419© Maria de Bruynyellow-bellied sapsucker I77A7582© Maria de Bruyn

When flattened against tree trunks, she demonstrated how well camouflaged her back feathers make her. A male sapsucker showed it, too.

yellow-bellied sapsucker I77A7476© Maria de Bruyn

yellow-bellied sapsucker I77A7860© Maria de Bruyn res

red-bellied woodpecker I77A8242© Maria de BruynA red-bellied woodpecker (Melanerpes carolinus) rounded out the welcoming committee.

The other birds didn’t disappoint. Several species were in the woods and at the feeders near the Garden’s bird blind. A lovely Carolina chickadee (Poecile carolinensis) flitted about. A tufted titmouse (Baeolophus bicolor) was singing.

 

Carolina chickadee I77A7639© Maria de Bruyn tufted titmouse I77A7388© Maria de Bruyn

 

white-breasted nuthatch I77A8203© Maria de Bruyn

 

A white-breasted nuthatch (Sitta carolinensis) foraged on tree trunks overhead. A Northern mockingbird (Mimus polyglottos polyglottos) posed among red winter berries.

 

Northern mockingbird I77A7737© Maria de Bruyn res

hermit thrush I77A7658© Maria de Bruyn

 

A hermit thrush (Catharus guttatus) emerged near the bird blind, and then the same bird or another seemed to accompany me as I walked another part of the native habitats garden.

 

hermit thrush I77A7818© Maria de Bruyn

hermit thrush I77A7788© Maria de Bruyn res

Later, a male sapsucker (identifiable by his red throat) appeared near the Paul Green cabin, where he had been busy working on his sapwells.

yellow-bellied sapsucker I77A7858© Maria de Bruyn res yellow-bellied sapsucker I77A7854© Maria de Bruyn res

Shortly thereafter a downy woodpecker came to the same spot and sampled sap (or something else) from the row of holes left by the sapsucker! That was a nice example of how what one animal does can benefit another, too.

downy woodpecker I77A7912© Maria de Bruyn

downy woodpecker I77A7921© Maria de Bruyn res

During a plant interlude, I was surprised to see some Southern purple pitcher plants (Sarracenia purpurea) that had not yet shriveled up in the cold.

Southern purple pitcher plant I77A8086© Maria de Bruyn Southern purple pitcher plant I77A8081© Maria de Bruyn res

 

 

 

When, I was leaving, a ruby-crowned kinglet (Regulus calendula) alighted overhead,

ruby-crowned kinglet I77A8165© Maria de Bruyn ruby-crowned kinglet I77A8164© Maria de Bruyn

a red-bellied woodpecker arrived, and one more woodpecker made an appearance – a Northern flicker (Colaptes auratus) high up behind some branches in a tall tree. I was using my small zoom lens so the photo quality isn’t great, but you can see that s/he was there.

red-bellied wooodpecker I77A8234© Maria de Bruyn Northern flicker I77A8154© Maria de Bruyn

downy woodpecker I77A8006© Maria de BruynThe only woodpeckers that are common in our town that I missed were the red-headed and hairy woodpeckers – it was truly a woodpecker welcome and a really lovely start to my wildlife photography outings for this year!