Thursday, July 23, 2020

All About Nuthatches

Here is a recent post from the Union Bay Watch Blog published by Larry Hubbell, long-time local photographer and birder.

Here also is an in-depth article about Larry and his work.

Social Distancing

A Red-breasted Nuthatch is a small, beautiful bird with a loud voice which sounds like a toy trumpet. They are roughly the size of Black-capped Chickadees - except for the abbreviated tail. They are cavity-nesters. They build their nests by carefully excavating minuscule chunks out of dead branches or trunks.

2016 was the first year they nested inside this dead branch in the Arboretum.

They are also tool users. They collect resin from living trees and transfer it to the area surrounding their nest sites. It is easy to see the increasing amount of resin between this 2017 photo and the previous one. 

This particular branch had been dead, and slowly decomposing for many years. The resin did not seep out of the wood.

The resin may catch bugs or deter predators. Facing the nest hole down may also be a deterrent.

In 2018, the Nuthatches built a new nest about a foot and a half north of the old one. Once again you can see minimal resin in the first year.

In 2019, the nest was reused and the amount of resin increased.

Nuthatches are very skillful flyers. The resin does not bother them because they can fly into the nest e.g. collapsing their wings and shooting through the opening at high speed.

Even when reusing a previously excavated nest site, the Nuthatches will often spend time making or expanding nearby holes. Maybe they just have an urge to excavate that demands satisfaction regardless of the need or lack thereof. This particular hole is about a foot or so below the 2019 nest site.

In March of 2020, for the third year in a row, the Nuthatches considered reusing the same nest site. 

Although, they did seem to reevaluate the unused hole below the nest.

Nonetheless, the old nest worked its magic and drew them back.

After four years, the relative privacy of their neighborhood was shattered. A Downy Woodpecker, roughly twice the weight of a Nuthatch, took a liking to the same dead branch. (The male Downy has red on the back of the head. The female does not.)  

The Woodpecker made sizable new holes very close to the Nuthatch nest site. The Nuthatches' displeasure and harassment eventually motivated the Woodpecker to observe a little social distancing.

About six feet below the Nuthatch nest, the Downy Woodpecker began his nest building. By mid-May, the Nuthatches had been actively nesting for several weeks. 

Here is an earlier mid-April photo showing one of the Nuthatches feeding its offspring.

The Downy was on a different schedule. His nest was just getting started. Even if he had a mate they were a long way from having a safe place for eggs to incubate and young to hatch out.

Due to a well-placed curve in the branch, the Nuthatches could hear the Downy at work but at least they did not have to watch. Minimizing distractions was a good thing.

The young in the nest were hungry and the Nuthatches had work to do. They were in constant motion e.g. 'Hunt for food. Fly to the nest. Deliver the food. Repeat.'

Young birds require proteIn to feed their growth. Here the adult supplied an insect. 

Here, it is a short-changed, 'inch' worm.

Later in the year, once the young are out on their own, Nuthatches may be more inclined to focus on seeds and nuts - as their name implies.

But at this point, their lives were completely focused on the young. This included removing fecal pouches, which are sealed little packages that contain their offspring's poo. 

Just when it seemed like the Nuthatches were out of the woods, the female Downy appeared. She basically landed on top of the Nuthatch nest. You can just see the entry hole below the branch.

Luckily, she Ignored the neighbors and hopped down the branch until she was directly above the male Downy. Somehow, even though he could not see her, the male Downy knew she was there. He stopped excavating and climbed out of the nest hole to check out his visitor.

He must have interpreted her stance as an invitation and being inspired immediately took to the air. 

No doubt flying was faster than climbing, as he normally would have done.

Having a tail can get in the way.

However, birds have had plenty of time to figure out how to work around the challenge.

With mating accomplished the male Downy's motivation may have increased. In any case, the chips flew!

It looked like the female even helped out a bit.

Outside the Nuthatch nest, a young bird appeared.

The pristine beauty of new feathers puts an exclamation point on the bird's youth.

Adults, who have spent weeks working at high speed, look much more frazzled and worn.

One would think, at this point the Nuthatch nesting story is nearly finished for the year. All About Birds says they only have one brood per year. Birds of the World* says only once, in the wild, has a nesting pair of Nuthatches been observed raising a second brood of young and yet...

...the Nuthatches began emptying the nest.

Nonstop. Faster than the feeding process.

Every five to ten seconds, the Nuthatches came flying out of the nest with another load of used nesting material.

Typically, they flew to a branch on a nearby tree and dropped the used bedding, before flying directly back to the nest and repeating the process.

The process must have become tiring and at least one of the birds decided that throwing the chips out of the entryway was an adequate time-saving solution. Normally, cleaning a nest site is a prelude to nesting. 

Are these Nuthatches preparing to have another brood? If so, will their new neighbors be willing to coexist in the same area, using similar flight paths while caring for young on a nearly identical schedule? 

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