The American black bear (Ursus americanus) is the smallest of the North American bear species. It is the only bear found in the eastern United States, inhabiting the vast forested landscapes that define Maine. Black bears are highly adaptable omnivores, and their presence indicates a healthy, diverse ecosystem. The Maine Department of Inland Fisheries and Wildlife (MDIFW) employs rigorous scientific methods to estimate the size and dynamics of the current bear population.
The Current Population Estimate
Maine supports the largest black bear population in the Eastern United States, reflecting the state’s extensive forest cover and conservation efforts. Recent estimates from the Maine Department of Inland Fisheries and Wildlife indicate the state is home to a population ranging between 24,000 and 36,000 black bears. This figure is an estimate derived from scientific modeling, not a precise count of every individual animal. The population has grown substantially over the last few decades and is considered stable. Biologists monitor this number closely to maintain a population level that can be tolerated by both the natural environment and human communities.
Scientific Methods for Counting Bears
Wildlife biologists employ sophisticated, long-term scientific techniques to estimate the population size and monitor its health. Maine’s bear study is one of the longest-running in the country, dating back to 1975.
Mark-Recapture Studies
One primary method involves a long-term mark-recapture study. Researchers capture bears, collect biological data, and fit them with ear tags and permanent lip tattoos before release. Recapturing these tagged bears in subsequent years allows biologists to estimate population density.
Monitoring Reproductive Rates
Researchers also monitor female bears fitted with radio or GPS collars, tracking approximately 85 to 110 females annually across three study areas. This allows researchers to locate the bears during winter denning periods. By visiting the dens, biologists gather data on reproductive rates and cub survival, counting the number of newborn cubs and yearlings to measure recruitment into the population.
Age-at-Harvest Model
The age-at-harvest model is central to population assessment. It relies on the mandatory submission of a premolar tooth from every harvested bear. Analyzing the cementum rings of the tooth provides the bear’s exact age. This data is integrated with information from collared and tagged bears to reconstruct the harvested population’s age structure and estimate total statewide abundance.
Geographic Distribution of Maine’s Bears
The black bear population is not uniformly spread across Maine; density varies significantly based on habitat suitability and human development. The vast, remote, and heavily forested regions of Northern, Western, and Downeast Maine hold the highest concentration of bears. These areas contain large blocks of mixed conifer and deciduous forest that provide necessary cover and abundant natural food sources.
Maine’s extensive bear habitat covers approximately 69,050 square kilometers, consisting mainly of second-growth timber. Conversely, the heavily settled Southern and Central-coastal regions, particularly the areas from Portland north to Penobscot Bay, see the lowest density. Fragmented habitat and high human population density in the south limit the bears’ sustained presence.
Population History and Management Strategies
The black bear population in Maine has undergone a significant reversal since the mid-20th century. Bears were historically considered vermin and were bountied until 1957; they were designated as a game species in 1969. Historical estimates from the late 1970s placed the population at a much lower figure, approximately 6,000 to 9,000 animals.
The MDIFW maintains the population at sustainable levels through science-based management policies. The primary tool used to regulate bear numbers and mitigate human-bear conflicts is a structured, regulated hunting and trapping season. This management is necessary because black bears have a slow reproductive rate, making their population sensitive to mortality rates.
The regulated season typically runs for three months in the fall. Methods utilized include hunting over bait, hunting with hounds, and trapping, all highly regulated by the state. Mandatory registration and the collection of biological data allow the MDIFW to adjust regulations, ensuring the long-term health of the bear population while managing impacts on agricultural interests and residential areas.