The Birders Report

Purple Martin Male (Progne subis) photos by Larry Jordan, click on photos for full sized images

The Purple Martin (Progne subis) is a well known and popular bird in eastern North America where it breeds almost entirely in human-made martin houses. Only a few records of natural nestings east of the Rocky Mountains have been reported during the twentieth century¹. Here in western North America however, where Purple Martins are less common, they nest almost exclusively in woodpecker holes or natural cavities.

Purple Martin Female at Woodpecker Hole in Dead Snag

The Purple Martin is the largest swallow in North America and among the largest in the world, their diet consisting exclusively of flying insects.

Most migrate north in early spring via the Central American isthmus between North and South America.

As a secondary-cavity nester, the Purple Martin has also suffered from the introduction into North America of European Starlings and House Sparrows, which compete with it for nest sites throughout much of the eastern half of the continent. Without human intervention and management of these colony sites, starlings and sparrows can cause local extinction of martins by appropriating their nest cavities and making them permanently unsuitable for martin use¹.

The problem is certainly diminished in the western Purple Martin population since this group nests solitarily in its more traditional natural cavity in the wild.

Since these birds are rather scarce in central northern California where I live (note the tiny red splotch on the map above) , I was delighted to be informed of this breeding pair by another local birding friend.

Observing this pair from a safe distance with a super telephoto lens allowed me to get these photographs without disturbing the bird’s natural behavior. I watched as the female made several trips for nesting material.

On many of these forays, she was escorted by the male, which is considered to be mate-guarding behavior. He rarely brought back nesting material himself. At other times, the male would simply wait the few minutes that his mate was gone and welcome her at the cavity entrance.

Occasionally, after the female placed the nesting material into the cavity, in this case pine straw, the male would follow her into the cavity where they would disappear for a few moments. According to Birds of North America Online, in over fourteen years of observation pairs are rarely observed copulating. It is believed that this activity probably occurs within the nest cavity. From the look on this males face as the female departs, I think this may very well be the case.

Here the male has just returned following the female back to the nest site from a foray…

and here.

After the female had been in the cavity for awhile, she appeared at the entrance with something in her beak. Apparently she was doing a bit of housekeeping as she dropped, what appeared to be a seedpod of some sort, outside the nest cavity.

I’m not certain about his response.

I must say she certainly is a beauty…

no matter how you look at her.

And I think he enjoys showing off for her too.

I know I certainly enjoyed the show.

This is a film I shot of the pair at the nest site. Make sure you turn the sound up as you will hear not only the Purple Martin male singing but several other bird species in the background including a Common Raven and Mourning Dove. If you can identify some of the other songbirds singing and chattering, please let the rest of us know what they are.

References: ¹Birds of North America Online

Western Bluebird Nestling (Sialia mexicana) photos by Larry Jordan (click photos for full sized images)

Being the conscientious Bluebird Trail monitor that I am, I noticed Friday, on my way home from work, as I approached this nest box one of the nestlings was staring back at me out the entrance hole. I knew it had to be close to fledging time because I check the boxes often enough to know when the eggs hatch and therefore when the nestlings should be ready to fledge.

You never want to approach a nest box when it is close to fledging time because you don’t want the nestlings to fledge prematurely. Western Bluebirds usually fledge at around 20 days old.

So I waited until the next morning and went back to the nest box in question. They were still there. I set up at a safe distance hoping to watch the entire fledging process from the beginning.

When I arrived at around 7:30 am, the female adult was in the tree adjacent to the nest with food for the nestlings. In my experience, most birds seem to fledge in the morning which makes sense to me. That way the young birds have most of the day to get used to the real world!

I heard an Ash-throated Flycatcher nearby, another cavity nesting species that uses the bluebird houses. I was rather surprised when I witnessed the Flycatcher chasing the momma Bluebird away from her nest site. It worried me a little bit but then I thought maybe the Ash-throated Flycatcher had chosen a nest site in one of the natural cavities in the nearby oak trees.

Mamma Bluebird snuck back to the nest box and fed the nestlings the tidbit she had in her beak and took off, presumably for more food. At this stage in the nesting process the young are fed about 10 times per hour which, if your math is good, equates to about every six minutes.

But wait. What’s going on with all of these Violet-green Swallow (Tachycineta thalassina) images? Violet-green Swallows seem to appear out of nowhere in my experience and as I am standing there, all of a sudden, there they were! Three or four Violet-green Swallows circling me, the oak trees and the nest box!

Both Ash-throated Flycatchers and Violet-green Swallows are cavity nesting birds that will use bluebird nest boxes. I knew that they were around because I have both species currently occupying some of my other nest boxes. However, I was not aware that they were bold enough to approach and inspect occupied boxes.

At one point a swallow actually perched atop the nest box and looked down as if it was expecting to see a youngster sticking its head out the entrance hole.

In the meantime, the brilliantly colored male Western Bluebird was taking his turn bringing food to the nestlings.

At this point however, the adults were only bringing food to the nest box on some of the visits. Some trips to the nest were taken with empty beaks.

This is the point at which the adult Bluebirds try to coax the nestlings out of the nesting cavity into our world. They perch on nearby branches and call t0 them, urging them to come out of the only home they have ever known.

The young birds stick their little heads out the entrance to the birdhouse over and over again, hearing all the other birds calling around them but pinpointing that special call from their parents. Wondering if mom and dad are going to bring more food and in this case, what all those Violet-green Swallows are doing flying toward the house.

This youngster finally decided it was time and took the plunge into this big wide world. He or she flew about fifteen feet to the branch of an oak tree directly in front of the birdhouse. And, as it is always the case, as soon as the first nestling leaves the nest, another one pops its head up to look out to see where its nest mate has disappeared to.

I filmed this monumental event that goes on daily across the globe, young birds leaving their nests, depending on their parents to teach them the ways of the world. I have condensed the three hours I observed watching the first three of the five nestlings fledge into a six and a half minute video.

You will see the female Western Bluebird make a few trips to the nest with food for the chicks and then again without food. She comes back and lands on the roof of the house a few times, then perches nearby. The male also comes to the nest box without food as the nestling opens its mouth thinking it will be fed. In the meantime the Violet-green Swallow cruises by.

There is video of the first nestling perching for the first time on a tree branch and watching the swallows flying overhead. Listen for several other bird species calling in the background and see if you can identify them.

After all of this, head on over to The Bird D’pot and Wild Bird Wednesday to see all the other bird photos from around the world!

I believe that a new Wildlife Conservation Stamp is essential to advance National Wildlife Refuge enhancement and conservation of wildlife habitat in the United States. Please join the conversation at 10000 Birds and let us know what you think about this important project.