Guest Post: A Closer Look at Scrub-Jay Habitat

This post was contributed by Meredith Heather, a Research Assistant in the Avian Ecology lab at Archbold Biological Station and a 2020 WOS Research Grant recipient.

a photo of a florida scrub-jay, a blue, gray, and white bird
A Florida Scrub-Jay perches in a sand live oak, taking a break from foraging to scan for predators. Photo by Meredith Heather.

Growing up, I enjoyed watching birds feeding and bathing in the backyard. It wasn’t until after I took an ornithology course that I became more interested in watching their behaviors and learning about individual species. As the years passed, I became increasingly aware of the differences in their habitat preferences, habitat use, movement, and ecological significance. When I decided to pursue a master’s degree, I wanted a research project that would allow me incorporate habitat use, because understanding how animals utilize their habitats is necessary in supporting management and policy decisions. Conducting research at Archbold Biological Station (Archbold) with Florida Scrub-Jays provided me an opportunity to do just that.

Florida Scrub-Jays are a Federally listed Threatened species residing only in Florida. Non-migratory, these jays occupy and defend year-round territories. With very specific habitat requirements in fire-dependent oak scrub, they are threatened due to habitat loss, habitat fragmentation, and habitat degradation such as fire suppression. For my thesis, I am interested in how post-fire habitat patches and variation in vegetation height affect the Florida Scrub-Jay’s foraging success and behavior at Archbold. To do so, I am combining focal foraging watches with drone habitat imagery. I also conducted arthropod abundance surveys in different structure types to get an idea of resource availability.

Meredith in the middle of a scrub-jay’s territory, pausing for a photo during one of her hour-long focal observations recording behavioral and location data of a Florida Scrub-Jay. Photo by Zach Forsburg.

Archbold is a 2100-hectare preserve located in central Florida at the southern end of the Lake Wales Ridge. The Archbold Florida Scrub-Jay population has been studied for over 50 years. The ancient, relic Florida scrub that these jays rely on is typically low and open, dominated by short scrub oaks and palmettos mixed with bare sand patches and scattered pines. Optimal habitat for a Florida Scrub-Jay is typically described as scrub that burned five to ten years ago, when the vegetation has had time to recover from a fire but before it becomes too overgrown. Once the habitat becomes tall and overgrown, it is more difficult to detect predators and there’s a lack of the bare sand patches that the jays use to cache acorns, their main food source over winter.

Fire is important to maintain and reset the scrub, and many plants and animals besides scrub-jays are dependent upon it. Until now, time-since-fire has been the metric used to map and describe the habitat after prescribed burns at Archbold. However, each fire behaves differently, influenced by many factors including fire history, intensity of the burn, weather, and slope. Therefore, time-since-fire is not always an accurate predictor of habitat structure, and it is the habitat which is important to the jays.

A charred Florida scrub landscape after an intense burn. New growth will begin to show in a matter of days. Photo by Meredith Heather.

Using drone imagery, we are mapping habitat structure in my study area and quantifying the structural diversity that each jay territory contains. Territories consist of various patches with different fire histories, and smaller territories are at a higher risk of burning completely. By overlaying the jay’s foraging locations, foraging successes, and other behaviors onto the habitat maps, I aim to get a better understanding of how the Florida Scrub-Jays at Archbold are using different habitat patches, whether they avoid or prefer some, or if their behaviors differ between patch types. With the field work portion complete, I am currently working on categorizing the habitat in the drone imagery and will proceed with the analysis once that’s finished. I predict that the habitat in larger territories will contain more diverse structure, with more resources than smaller territories with uniform habitat. I expect that this will lead to improved foraging success in larger territories and that jays will spend more time foraging in low, open habitat compared to tall, overgrown habitat.

Scrub oaks, palmetto, scattered pines, and various other plants associated with Florida scrub habitat. Photo by Meredith Heather.

Through my thesis work, I experienced the scrub in ways I hadn’t before. Rather than always looking up at the birds, I had to get down on the ground for the arthropod surveys and spend an hour thoroughly searching through a ten-meter plot. It’s a different world entirely to pay attention on the small scale. In my time working at Archbold outside of my thesis research, I’m typically only in the field in the mornings, but doing the focal watches allowed me to immerse myself in the life of jays in the evenings as well. Evening in the scrub is more still and peaceful with a softer sun. Despite the challenges and struggles that come with research and field work, this experience has made me a stronger and more confident scientist. I am very thankful to Wilson Ornithological Society for supporting my research and helping me reach my potential. I am looking forward to seeing the results of my analysis and how they can contribute to the management and conservation of Florida Scrub-Jays.

For more detail about my project’s habitat mapping with the drone and its relation to the region’s fire history, you can read the post Influence of fire on Florida Scrub-Jay Habitat on Archbold’s blog. To learn more about the Avian Ecology program at Archbold, check out our website.

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