Spatially-explicit population modeling to predict large carnivore recovery and expansion

Abstract

Despite extensive range contractions, several large carnivore species have recently recolonized portions of their former range. Since the 1990s, American black bear reports have increased in Missouri, USA, corresponding with increasing abundance and distribution. As effective management benefits from sound information on wildlife demographics and spatial distribution, we used a spatially-explicit metapopulation model built from local data to inform a stage matrix, which was used in conjunction with a previously created habitat suitability model to quantify and predict the growth and expansion of the black bear population. We collected demographic data during 2011–2021 from 162 female bears with 159 young from 70 litters. Average litter size was 1.95, 42% of cubs were female, and cub survival to yearling was, on average, 95% for females and 70% for males. The habitat suitability model identified 53 core areas most suitable for bears in Missouri. Increasing from previous local estimates of bear population size (∼280 bears in 2012), the model estimated the total bear population inhabiting core habitat patches in year 10 as 732 individuals (598–873, 5th–95th percentiles), with an average annual growth rate of 1.11. The estimated carrying capacity of the core habitat patches (excluding cubs-of-the-year) was ∼2700 bears, but adding marginal and highly marginal habitat patches increased the carrying capacity to ∼5500 bears. Population estimates were most sensitive to variations in stage matrix parameters though overall patch colonization estimates were relatively stable. Our work is an important step toward understanding the recolonization potential of black bears in Missouri and can aid future studies projecting large carnivore density in other areas as well as values and attitudes toward these wide-ranging species. Developing holistic conservation frameworks will be critical if human acceptance toward large carnivores continues increasing and carnivore recolonization of historical range continues.