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Small mammals play a vital role in maintaining forest health

Deep within the Penobscot Experimental Forest in Maine, a team of researchers has uncovered a fascinating phenomenon involving small mammals.

These woods, located about 10 miles north of Bangor, are scattered with hidden treasures — not gold or jewels, but eastern white pine seeds.

These seed caches were strategically placed by researchers to study the behavior of the forest’s small mammal inhabitants.

Behavior of small mammals in forests

This intriguing study is led by Brigit Humphreys, a graduate student at the University of Maine, as part of her National Science Foundation-funded research.

For the past two years, Humphreys has been investigating how the personalities of small mammals influence their behavior, particularly in the context of seed dispersal.

Her work is part of a larger, eight-year project nearing its conclusion, aimed at understanding the role of individual animal personalities in ecological processes.

Ecological importance

The point of the project was to figure out how small mammal personality and animal personality in general influence different ecological processes.

“We’re focused on small mammals because they’re abundant, we get a really good sample size, and we can conduct experiments on them in the forest. Seed dispersal is crucial to Maine’s economy, recreation, and aesthetics,” Humphreys explained.

This research sheds light on an often overlooked aspect of ecology — individual behavioral differences within species.

By focusing on these differences, Humphreys aims to highlight their significance in ecosystems, tree growth, and forest regeneration.

Catching the thieves in action

Under the guidance of Professor Alessio Mortelliti from the Department of Wildlife, Fisheries, and Conservation Biology, Humphreys and her team conducted their fieldwork from June to October 2022.

They set traps for various small mammals, including squirrels, chipmunks, mice, voles, and shrews, across a six-grid system in the forest. Each captured animal was tagged and its personality traits recorded.

After clearing the traps from each grid, the team planted artificial seed caches equipped with circular antennas to detect the tagged animals. Game cameras were also installed to capture footage of the animals pilfering the seeds.

Discovering personality traits

Humphreys’ findings reveal that the personality of small mammals significantly influences their seed-stealing success.

“We found that more exploratory deer mice were more likely to find caches to pilfer,” Humphreys notes. “They move around more and don’t consider predation risk as much, so they find these caches and steal them.”

The research also highlighted that skinnier animals were more desperate to pilfer due to hunger, and female voles were more likely to steal seeds, aligning with previous research on vole behavior.

Unexpected pilferers

Throughout the study, the team observed a variety of species pilfering the caches.

“We had over 10 different species come and pilfer the caches,” Humphreys says. “Some were unexpected, like raccoons. The other common pilferers were American red squirrels, eastern chipmunks, Sorex shrews, and jumping mice.”

Even with a small sample of jumping mice, their effectiveness was notable. “The ones that were present in our areas were very effective. They got like 10 caches in a night,” Humphreys adds.

Small mammals, healthy forests, happy planet

Humphreys’ research, recently published in the Journal of Animal Ecology, emphasizes the importance of individual behavioral diversity within species.

“The take-home message of all the research we are doing is that individuals are important,” she concludes. “There’s a big push in the science community to conserve biodiversity, but beyond biodiversity, we have to be conserving behavioral diversity within a species if we truly want to have fully functional ecosystems.”

In summary, as we delve deeper into the secret lives of forest critters, Brigit Humphreys and her team at the University of Maine continue to unravel the complex relationships between small mammal personalities and the ecosystems they inhabit.

Their research not only highlights the importance of individual quirks in shaping forest dynamics but also underscores the need to conserve behavioral diversity within species.

By understanding and preserving the unique personalities of these furry thieves, we can ensure the health, resilience, and beauty of our forests for years to come.

So the next time you take a walk in the woods, remember that beneath the tranquil canopy, a lively cast of characters is busy pilfering, exploring, and shaping the world around them, one stolen seed at a time.

The full study was published in the journal Journal of Animal Ecology.


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