Back in 2014 and 2015, IBP’s Black-backed Woodpecker survey crews working in the Moonlight Fire spent some extra time observing nests through a scope to record data on parental behavior. They recorded how often parents delivered food to their nestlings, the size of the food delivered, and which parent made the delivery. This work was part of IBP’s larger project, conducted in partnership with the US Forest Service, studying how changing wildfires and forest management practices affect this post-fire specialist.

But while the Black-backed Woodpecker project has produced over a dozen research papers by IBP authors and associates since 2015, the parental provisioning dataset didn’t find a home in any of these publications. It was summarized for the Forest Service and then left unused until 2019 when John Loverin, an undergraduate at the University of Connecticut, went looking for an honors thesis.

Loverin was working in the lab of IBP research associate Dr. Morgan Tingley (who has since moved to UCLA) and was mentored by Andrew Stillman (now a fully-fledged Ph.D.) who studied Black-backed Woodpeckers in partnership with IBP. He was interested in the intersection of animal behavior and statistics, but he needed some data to get started on a study of his own. Stillman put his head together with Bob Wilkerson, the IBP staff biologist and Black-backed Woodpecker guru who manages the larger woodpecker project. They remembered the orphaned parental provisioning dataset and an honors thesis was born.

Earlier this month, that thesis was published as a research paper in the Journal of Field Ornithology. Loverin and co-authors from the Tingley lab, the US Forest Service and IBP examined the relationship between parental provisioning behavior and the habitat characteristics of fires and post-fire management. In addition, they looked at how provisioning differs between male and female parents and how it varies across the breeding season.

They found that parental provisioning behavior did not differ between the sexes and that variation in this behavior is better explained by temporal variables – such as nestling age and nest initiation date – rather than habitat variables such as burn severity and distance to unburned or low severity burned areas.

We talked to John Loverin and his co-author and mentor Andrew Stillman about this work.

John: I was surprised that the habitat variables related to fire did not affect provisioning rate or prey size. I thought these would be important because Black-backed Woodpeckers in the western United States are strongly associated with post-fire habitats, however it seems that this did not matter because all the nests were in high-severity burn, and there was not enough habitat variation to see the effects of different burn severities.

Andrew: We were initially surprised to see that temporal variables, like days since hatching, better explained provisioning rates than characteristics of the burned habitat. However, a closer look revealed that there was precedent for this finding in the literature and previous studies conducted by IBP (for instance our 2019 paper on nest site selection). What we learned was that this finding likely points to the idea that the birds we observed had all arrived at a good place to nest and find their favorite food in the charred forests of the Moonlight fire – especially compared to the nearby unburned forests where dead trees are scarce. Elsewhere in California, Black-backed Woodpeckers have been found nesting in unburned forests, such as areas with large numbers of trees killed by bark beetles. If nests from unburned areas were included in a similar analysis, I would expect to find a strong effect of habitat – especially burn severity or snag density – on provisioning rates.

John: For my master’s degree, I am studying how forest management affects resilience to disturbances such as wildfires, insects, and drought, and how these forests and these relationships will change in the future due to climate change. I am also researching what the optimal density is in forests affected by drought and climate change, and how to achieve that density through management actions such as thinning and prescribed burning. Coincidentally, the dataset I will be working with is from same area in northern California where the Black-backed Woodpecker data was collected!

Andrew: The more we work with Black-backed Woodpeckers, the more surprises we find. Spending hours watching behavioral observations at nests gives you a lot of appreciation for the behavioral differences between individual birds, and we enjoyed seeing evidence for this in the fieldnotes from IBP’s nest observers. Just like human parents, some Black-backed Woodpeckers seemed relaxed and unconcerned, while other birds seemed especially tight or wary. Others showed signs of agitation if observers came into view. In order to record unbiased provisioning data, observers would sometimes have to slowly sneak into the forest stand and crouch 60 meters away from nests while recording data through a birding scope! We are grateful for the hard work and dedication of the IBP field technicians who located Black-backed Woodpecker nests and collected the data used in this study. This project also would not have been possible without support from Plumas National Forest.