Our project began in 2018 as a collaboration between the the Maine Department of Inland Fisheries and Wildlife (MDIFW) and the University of Maine. The project seeks to support implementation of the wild turkey component of MDIFW’s Big Game Management Plan, which will guide MDIFW’s wild turkey management over the next 10 to 15 years. We will provide data to address the plan’s goal to “Maintain a healthy turkey population below biological carrying capacity while providing hunting and viewing opportunity.” Our research will also examine risk factors associated with a recently detected or emerging viral pathogen, Lymphoproliferative Disease Virus (LPDV), in wild turkeys in Maine; data which is important for better understanding and predicting the local impacts of pathogen infection on turkey populations.
The Field Work
To collect this data, we capture turkeys across the state of Maine for banding, sampling for infectious diseases, and deployment of radio telemetry and GPS transmitters. During the winter, we establish bait sites within our study areas to attract turkey flocks. Once turkeys have become habituated to our setup, we use drop nets or rocket nets to secure the turkeys for processing. Individuals are given leg bands, have blood and cloacal swab samples collected, and a selection are fitted with transmitters allowing us to track their survival, nesting behavior, and movements throughout the year.
A key goal of the MDIFW management plan is to improve the agencies’ ability to monitor turkey populations. An accurate understanding of what population size and structure is within Maine would reduce uncertainty in the decision-making process. MDIFW requires a cost-effect method to estimate turkey population size in Maine with greater accuracy and confidence on which to base management decisions. We will implement a method, the Lincoln Estimator, recently employed in Ohio, Pennsylvania, and New York which uses existing harvest reporting systems and band recovery models to produce estimates of population size. This method allows for the incorporation of landscape factors to account for variation in turkey harvest rates and turkey density across the state and increase the accuracy of estimates. You can help by reporting any banded turkeys you harvest or observe through our online reporting system.
The movement of individuals across a landscape has numerous implications for population management. Individual animal movements can vary according to the availability of resources and how they are distributed. For wild turkeys, a species that is able to persist in areas with varying levels of human activity, it is important to understand if and how movement of individuals is affected by activities of humans. Changes in movements between different land use types, e.g. between agricultural and forested landscapes, could impact management decisions. By identifying and quantifying patterns of movement, we will provide the information needed to create targeted management plans to achieve their desired results.
Habitat quality is an important consideration when making decisions regarding management and conservation. In an effort to make a full assessment of wild turkey nesting habitat, we will observe how hens select different nest site characteristics and how that selection affects their nesting success. We will also quantify variability among individuals by including observations of hen movement behavior to determine how behavioral traits, such as when turkeys leave their winter range or how far they travel for nesting, can impact their nest success.
Risk factors, distribution, and transmission dynamics of LPDV
We collect whole blood from each turkey to test for a virus called Lymphoproliferative Disease Virus (LDPV) that was originally detected in wild turkeys in the United States in 2009. Once turkeys are identified as either infected or uninfected, we can begin to explore the potential for individual risk factors such as age and sex. We can also identify the distribution of the pathogen and determine if infection varies across habitat and land-use gradients to identify spatial areas of concern. The blood samples will also be used to obtain LPDV genetic sequence data from each infected turkey, which will allow us to identify strain diversity to explore transmission dynamics across the landscape through strain and geographic relatedness.
Health and population impact
In other wild turkey populations, greater than 25% of morbidity or mortality cases have been attributed to infectious diseases, but little is known about LPDV in wild turkeys due to its recent detection in the species. We will be taking an additional blood sample (serum) to assess whether LPDV infection predisposes individual wild turkeys to other pathogens, which may affect individual health. Since some captured turkeys will be fitted with radio or GPS transmitters, we will be able to determine if LPDV impacts individual daily movement and/or home range size. Additionally, we can assess the relationship between LPDV infection and both survival and nest success to elucidate population-level impacts. Lastly, we also collect cloacal swabs to determine if LPDV can be detected in cloacal samples. If we find that it can be, it would provide a novel detection method that is easier to collect and less invasive for the turkey.