5 Environmental Factors that Affect Turkey Populations Mary Jo Casalena, PGC Turkey Biologist Revised 11 /2020 WHY are turkey populations declining in many areas of PA and throughout its range ? 5 Reasons, and the ir interactions have changed over the last 25 years. Habitat, weather, predation, disease and hunting mortality. What Changed? During the 1990s turkey populations expanded rapid ly due to : • restoration (trap & transfer , which is complete ), • suppressed predator populations (much more trapping than today, rabies was more evident & fewer predator species), • short fall hunting seasons, and • a more diverse landscape than exists today. The INTERACTION of these factors, such as poor summer poult pr oduction due to adverse spring weather with poor habitat quality coupled with a fall harvest , normal predation and minor disease, impact populations. Several consecutive years of this add up to reduce the population. Some examples of how the 5 factors ha ve changed causing turkey population declines: 1. Landscape level habitat changes: that is, a decline in: • amount of interspersion of different habitat types (too many monocultures ), • habitat quality (particularly due to exotic species replacing native species), • mast - producing trees (particularly acorn producing Oaks & Cherry - hard mast is a vital overwinter turkey food source), • younger age - class forests (therefore, less food diversity for wildlife), • nesting/brood cover for turkeys (due to the above & to declines in shrubby/herbaceous cover) 2. Unpredictable weather (climate change), which has caused more extreme weather events with more spring rain which can devastate nesting/brood rearing. 3. Increased predator densities & their distribution - Predation typically limits local turkey populations. H igh predation rates may be symptomatic of a landscape with poor habitat quality causing turkeys and their young to be more vulnerable to predation 4. Unforeseen effects from disease – such as disease effects on turkey productivity, immunity, energy assimilat ion, and how disease may interact with other population influences, such as habitat & weather 5. Harvest – PA’s spring season opens after breeding has occurred & once the majority of hens are incubating their nests , this type of harvest is sustainable. How ever, fall harvest can affect populations due to harvest of hens. Our recent 5 - year study showed that shortening the fall season by 1 week effectively decreases hen fall harvest rates What ’s the new ‘normal’ turkey population ? We’re not yet sure.. What t he PGC is doing : 1. Managing SGL habitat to improve turkey habitat, but SGLs comprise a minor portion of the PA landscape. 2. Studying how climate change is impacting the environment & wildlife & mitigating those impacts where possible. 3. Promoting our hunti ng/trapping heritage and how it is an important tool in conservation. 4. Studying disease impacts: West Nile virus does not impact turkey poults. Our new Penn Wildlife Futures Program , a partnership with University of Pennsylvania’s School of Veterina ry Medicine , allow s more in te n se disease surve illan ce & studies 5. D ecreasing fall season length in WMUs with turkey population declines to promote higher turkey survival to the next breeding season to help stimulate population growth. What can YOU do to help turkey populations? • improve habitat quality (thi s helps buffer the negative effects of the other factors), • help protect existing habitat, • report any potentially diseased turkeys so we can monitor disease more intensely, • begin trapping furbearers (selling furs can provide some income too or consider i t another management tool like planting food plots). This won’t eliminate predation but may help at a local level, • and during fall turkey season, if given the opportunity, harvest a young - of - the - year bird - the adult s are the most success ful breeders/nesters the next spring.