December 2, 2022

The Legacy of One Bear – Sara (ID #225)

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Written by Randy Cross, Biologist

Wildlife biologists have been monitoring black bears in Maine since 1975. Over the course of this monitoring program, a few bears have been monitored for over 20 years. This is a short account of the legacy of one of those bears – Sara (#225) –who started her life in January 1972.

Sara was born in a warm den in January, just as hundreds of other bear cubs are born in Maine. This den would be her home for 3 months, where she would nurse, gain strength, and develop from a 12 ounce, nearly hairless creature; into a bright-eyed 8 pound miniature bear. When she left the sanctuary of her den that spring, she would follow her mother throughout the summer and den with her again through the next winter. Most likely, in June of 1973, weighing only 30-40 pounds, she left her mother for good and took on the challenges of surviving alone in the vast forest lands of northern Maine.

At the same time Sara was becoming acquainted with the woods of northern Maine, efforts were being made by the Maine Department of Inland Fisheries & Wildlife (MDIFW) to start a research project to gain a better understanding of bears in Maine. The section of woods that Sara bear was born into was chosen to be one of the study areas for the bear project. Biologists began capturing bears to monitor their survival, general health, and reproduction in 1975. MDIFW used this information to develop a bear management system and a monitoring program that is still used today to monitor the status of Maine’s bear population.

Although MDIFW wildlife biologists began capturing bears in 1975, Sara managed to escape capture until August 11, 1980. On that day she was captured with a cable foot restraint, given the study identification number of 225, and named Sara. She was the 225th bear captured since the study began. By this time, Sara was eight years old and had grown to 150 pounds. She was fitted with a radio collar that emitted signals that could be used to locate her either from a plane or on the ground. From this point forward, Sara, as well as many other female bears, would be visited in her den each winter by biologists who would document her successes and failures at producing and raising cubs.

The following winter (February 19, 1981), researchers found Sara with two offspring just over a year old (yearlings) that had been born in the previous winter’s den. . In the 1980’s, bears in Northern Maine typically didn’t begin having cubs until they were 6 years old and then continued to have cubs every other year thereafter. So, this was likely Sara’s second litter of cubs. One of these yearlings was a female (ID 236) who weighed a remarkable 63 pounds, which is strong evidence that natural foods for bears were in great abundance during the preceding summer and fall. This yearling received a radio collar of her own so that when she left her mother in June, she could also be followed through her life, contributing valuable information to the monitoring project.

The next summer and fall (1981) was not nearly as productive for natural bear foods in this part of Maine. At this time, beechnuts were a very important food source for bears in northern Maine in the fall. Unfortunately, the nuts were not abundant that year, forcing bears to den very early and in poor condition. When biologists visited Sara in her den in March of 1982, they found her to be very thin, weighing just 100lbs and had no cubs with her. At 10 years old, Sara was entering the prime years of her life. Other mature females were experiencing similar struggles. Very few cubs were born this winter in the forests of northern Maine.

Bears are well adapted to being able to survive lean times and take advantage of plentiful food sources when they are available. As is often the case, the extremely lean year of 1981 was followed by an extraordinarily bountiful year for these bears. The next fall, they foraged on an abundant crop of beechnuts late into the fall and entered dens in remarkably good shape.

When recaptured on March 24, 1983 Sara had nearly doubled her weight in the year since she had last been seen in the den. Snuggled under her were 3 healthy female cubs Clara (Id 454), Belle (ID 455), and Karen (ID 456). All 3 were radio collared as yearlings the following winter and a matriarchal dynasty began to take shape.

Karen and all her cubs were studied over the next 20 years until 2003 when her radio signal failed due to a faulty battery connection installed by the manufacturer. That was a tough loss to the research team and efforts to recapture her the following spring were unsuccessful. She may still be roaming those woods at 32 years old.

Karen’s sister, Belle (ID 455), gave birth to her first litter of 2 cubs in 1989 when she was 6 years old. One of these cubs was a female, Josie (ID 1048). This bear, the granddaughter of Sara, has provided reproductive information the next 26 years of her life. By the time she was in her teens, Josie grew to become the largest female bear in the study area. The biologists were able to document 11 of her litters, including one male (ID 3390) this winter (2015), setting a record for the oldest female to give birth in the study (a record previously held by 2 females at 25 years old).

Over 3000 research bears have been handled between the time of Sara’s first capture and when Josie and her young male cub were handled on March 20, 2015. Sara had 11 offspring which produced 18 “grandchildren” (2 are still being monitored); 32 great grandchildren (5 are currently being monitored); 31 great-great grandchildren (7 are currently being monitored); and 13 great, great, great grandchildren (2 of which are being monitored). 105 different bears have been tagged that are direct descendants of Sara, representing 6 generations of bears. Sixteen of these, now equipped with radio collars, are providing reproductive information in this study area. Unlike males, who instinctively will roam many miles from where they were raised, females reside very close to where they were born. All of these females in this family line live within a few miles of where Sara was first captured back in 1980.

Click her for a chart of Sara’s family tree: