Tag: Bill Duncan

Bird nests are my favorite photographic subjects and I was ever so fortunate this spring to have an ideal situation land in my lap. Many thanks to my friends and neighbors, Larry, Sheryl and Beth for telling me about this and allowing me to setup camp in their yard for quite a few morning hours. This nest was right across the street from our St. Louis County, Missouri home, making this an easy target to get to in the early minutes of daylight. Due to a very busy year at work, I have had less flexibility in my schedule and this opportunity helped save my sanity. I can’t imagine what early morning passersby must have thought, seeing me sitting there with my long lens pointing in the general direction of a neighbor’s upper windows.

Northern Flicker nesting behaviors
Like most woodpeckers, the Northern Flicker excavates their nesting cavities in the dead or dying wood of tree trunks or large limbs. Where this nest cavity was located was quite fortuitous. Dead wood is difficult to find in the suburbs where we live. Many suburbanites immediate cull dead limbs and whole trees as soon as they show the first signs of decline. This is both for safety of life and property as well as what many consider the poor aesthetics of the imperfect tree. I’m thankful for the neighbors who put up with a dead bough of their silver maple that gave this pair of beautiful Flickers the opportunity to nest. I’m hoping they let it be! This is because Flickers are one of a few woodpecker species that will use the same nest cavity in successive years. I really hope for a replay of this one!

Unfortunately, I missed all of the interesting pre-nesting courtship behaviors that this species is well known for. By the time I was turned onto the nest, eggs were well into their development and I believe the eggs hatched shortly before or right when I began my observations. Northern Flickers can have a large range in clutch size, laying between three and 17 eggs, depending on things like nest latitude, food availability and nest cavity size. The more typical range is six to eight eggs per clutch. In this case, the pair had three male chicks that hatched and fledged. After hatching, chicks may take 24-30 days before fledging and they will typically spend another six weeks with the parents before going their own way.

As in most bird species, the Northern Flicker exhibits bi-parental care. Both parents take part in nest excavation, brooding the eggs and young, feeding of chicks and protection. Because there is a lot of down time when sitting at a nest and waiting for that decisive moment, I was happy to collect some of my own minimal data on the nesting behaviors of this particular pair.

My observations
Because woodpeckers use tree cavities to raise their brood, this somewhat limits the opportunities for those wonderful photos of parents bringing food to their young. In addition, the habits of Flickers and most woodpeckers is to feed their young via regurgitation. I did not witness a single event in which a parent brought food in its bill to handoff directly to a chick. When the developing chicks are young and small, the parents will enter and spend their time in the nest, each parent taking turns feeding and brooding. At a certain point, the chicks are developed enough to climb the inside walls of their cavity and reach the entrance. Due to this and the more considerable space the larger chicks occupy, the parents cease entering the nest and will visit only to feed and presumably check on the welfare of their developing brood.

In this case the change was quite rapid. From one day to the next, the parents quit entering the nest regularly and I have broken down my observations into these two parts. I began collecting data on May 19^th, although I did visit the nest to photograph a few days before this. After the early morning hours of June 4^th, the parents quit entering the nest. During the period where the action was taking place inside the nest cavity, I spent my efforts on the challenging task of getting sharp enough photos of the parents coming and going.

May 19^th – June 3^rd (Table 1)
Between the 19^th of May and the 3^rd of June, I observed the nest mostly during early morning hours on nine days. During these nine days, I spent a total of 18 hours and 55 minutes at the nest. The number of times visited and time spent by each parent in the nest was pretty similar, with the male visiting a couple of times more but averaging slightly less time per nest visit.

June 4^th – June 9^th (Table 2)
Between June 4^th and June 9^th, I observed the nest for six straight days, again mostly during early morning hours. During the 16 hours and 56 minutes I spent observing during this period, the female visited the nest to feed 30 times (1.8 feedings per hour) compared to the male who visited the nest to feed 25 times (1.5 feedings per hour).

My observations described above and in the accompanying tables are in agreement with published data suggesting that overall provisioning rates do not differ between the sexes in the Northern Flicker.¹

The fascinating case of momma dominance
Copulations are common during the egg laying phase of nesting in this species. Unfortunately, I missed this portion of the show. However, I did witness “copulations” that mostly took place at nest duty changeovers between the two parents during the brooding phase.

Cases of female dominance in the pair bond of this species has been documented², but I have not yet found documentation on this particular “copulatory” behavior. I admit, it took me a while to discern that anything was out of the ordinary. I guess I was too busy with the camera. After looking at the photos in the camera a little more closely, it finally dawned on me that the female was mounting the male! This wasn’t a single fleeting bit of behavior. I observed the female mounting the male on at least 11 different occasions and I never once observed the male mounting the female.

I wonder if this has something to do with the size of the two birds in this pair. Field guides and other sources suggest that males in this species are usually slightly larger than females. In my opinion, that is not the case with this pair. In this image and in the video below, the female looks significantly larger than the male.

Trials and tribulations of suburban cavity nesters
Another behavior that was relatively easy for me to record was the interactions between the Flicker pair and European Starlings. As mentioned above, cavity sites can be difficult to find in the suburbs. As a consequence, competition for this resource can be considerable. Exotic invasive European Starlings are known to aggressively mob and dislocate native cavity nesting species. During the brooding period, I counted six times where a parent chased away a European Starling that had come too close for comfort (Table 1, 2). On one occasion, a parent chased away a Red-bellied Woodpecker that came very close to the cavity opening. Although I never observed a Starling chase while the parents were visiting the nest in the post-brooding phase, this likely occurred outside my range of viewing. Additionally, the risk from European Starlings taking over a nest cavity is probably highest immediately after the cavity construction and during egg laying. I was not on the site to make observations at this stage.

Another significant competitor for larger cavity nesting birds like these Flickers is the squirrel. My friend, Dave, told me about a similar opportunity he had from his property vantage this spring, in which a grey squirrel actually took over the nest cavity from a pair of Flickers, presumably destroying and potentially eating the eggs or developing chicks.

I was really concerned that I was going to witness something like this with my nest as well. Less than three feet about their nest cavity was a much larger, natural cavity that faced straight up and was being used by a couple of grey squirrels as a sort of day bed. The squirrels moved up and down the bough of this tree, right past the nest on several occasions but the parents never seemed too concerned about them.

Get busy Feeding
Obviously, I enjoyed myself the most during the time that the chicks were old enough to stick their heads out of the nest and be fed by the parents. This didn’t always result in good photo opportunities – often the parents would stick their heads far into the nest, blocking clear views of these interactions, but I caught enough to make me happy.

Fledging
Before we get to the details, I want to share a video of the behaviors the adults took to try and coax the chicks to leave the nest. This one is shot in normal speed with on-site audio. You can hear the adults giving the chicks their keeyer calls and the chicks responding. It was near impossible to predict when the chicks would take their dive out of the nest. I filled memory cards with video and stills in hopes of capturing this.

I guess I’ve grown used to the heartache that comes with not catching the first flights of chicks on camera. It seems there is always something that gets in the way. In this case, Miguel and I watched as the first chick took his first flight out of the nest. Or I should say, Miguel got to watch and take a series of unforgettable photos (see the GIF I put together of these below). I was busy at the time taking feeding notes… But, I was still optimistic. This was early on a Saturday morning and I didn’t have to get to work. I felt confident that the other two would be sure to follow shortly. Five hours later and a total of nearly eight hours of continuous sitting at the nest, I decided to call it a day. I had grass to mow, needed a meal and a shower. So, I packed it up, feeling confident that the other chicks would likely wait until the next day to take their leave from their wooden nursery. I checked that evening around 7:00 and the nest was dead silent. The remaining chicks were gone. I heard Flicker vocalizations coming from the surrounding neighborhood. I missed this opportunity but was warmed by the idea that all three chicks were successfully on to their next stage, learning to forage from two obviously apt parents.

And that is that. I’m glad there are a few more Flickers in the neighborhood and will anticipate and hope these two will return to their nest cavity next year. I hope you’ve enjoyed this story a fraction as much as I did telling it.

Ozark Bill

Literature Cited

1 Weibe KL. and Elchuk, C.L. 2003. Correlates of parental care in Northern Flickers Colaptes auratus: do the sexes contribute equally while provisioning young? Ardea 91(1): 91-101.

2 Kilham, Lawrence 1959. Early reproductive behaviors of flickers. The Wilson Bulletin Vol 71, No.4.