An example of high-quality Florida scrub habitat, where the scrub jay makes its home.
A Florida scrub jay perches atop a scrub oak.
A biologist bands and measures a Florida scrub jay.
A translocated Florida scrub jay is released by researchers.
Beloved by birders, the gregarious Florida scrub-jay (Aphelocoma coerulescens) continues to decline due to habitat loss, habitat fragmentation, and management challenges related to fire-maintained habitat. A recent assessment of this endemic species found that more than 90% of remaining Florida scrub-jay populations contain fewer than 25 family groups. Florida scrub-jays are non-migratory and typically only disperse across short distances in their native scrub habitat, which increases the likelihood that restored habitat often remains unoccupied or is occupied well below its carrying capacity. Additionally, emerging evidence suggests that small and isolated populations, like at Jonathan Dickinson State Park, may have low genetic diversity, which is a problem. Due to these challenges, federal and state agencies have proposed conservation translocation, which is the human-assisted movement of wild animals from one location to another location, as a strategy to increase population growth, to maintain landscape connectivity, and to maintain genetic diversity.
Although the first conservation translocation of Florida scrub-jays occurred two decades ago, it is still experimental and has rarely been attempted, partly owing to the lack of information about its impact on source populations. Most previous translocations moved small numbers of scrub-jays from encroaching urban development. This study is unique in that it is the first study translocating scrub-jays from one conservation area to another conservation area, with careful monitoring of both source and recipient sites. The long-term goal of this project is to develop techniques that are effective in order to establish a program that is long-term, sustainable, and state-wide.
This project would not be possible without incorporating the largest and most stable population of wild Florida scrub-jays, which is found in the Ocala National Forest. In January 2017, FWRI biologists initiated a translocation research project in Ocala National Forest as a cooperative effort between the FWC and the U.S. Forest Service (USFS).
Biologists have two main research objectives. First, they need to understand how to conduct translocation from conservation lands with minimal impact to the source population. And second, they want to learn how to increase the effectiveness of translocation efforts at recipient sites. Translocation success can be influenced by many factors, including the age, sex, and number of individuals released, the timing and number of release events, and the release protocols that are used. Previous experiments have provided general guidance about the timing of translocations and the criteria for selecting recipient sites, but many questions remain unanswered. For example, it was generally accepted that translocated birds should be placed in acclimation cages at recipient sites before release. However, this study has produced data that indicate this is unnecessary, and that direct release for scrub-jays – without cages – is equally, or more, successful. Direct release also reduces the number of times that birds are handled and puts the birds through less stress.
Biologists have translocated both family groups and scrub-jays known as helpers, which are jays that cohabitate with other jays and demonstrate cooperative breeding, helping to supply food and defend the territory. Helpers are usually, but not always, related to the jays they “help”; males usually stay with their parents, while females tend to be the ones that disperse to find a new family group. Results indicate that short term measures of translocation success are comparable to, or greater than, previous translocation experiments with Florida scrub-jays. The jays are establishing breeding territories, have built nests and laid eggs, and their behavior and apparent survival is comparable to resident jays which were already there.
This project began in January 2017 and is expected to end in December 2021. The principal investigator on this project is Karl Miller, with the Wildlife Research section of FWRI. Other individuals who assist with this project include Jay Garcia (U.S. Forest Service), Ralph Risch (Florida Forestry Service), Paul Lammardo and Jason DePue (Florida Park Service). The FWC sections which assist with this project are the Wildlife Research section, the Center for Spatial Analysis, and the Center for Biostatistics and Modeling.
Florida scrub-jays face many challenges in the evolving future, but projects like this help to bolster the remaining populations and add to the body of research for one of Florida’s most distinctive and imperiled avian residents.