August 24, 2020
This month’s species spotlight looks at a native animal species and an invasive plant species — which both interact with ticks: The native Virginia Opposum and the invasive Japanese Barberry. While the Opposum loves to eat ticks, the Japanese Barberry provides tick habitat.
By WVLT Intern: Kathryn Nohilly
For many, the thought of an opossum stirs a feeling of immediate disgust. With their scavenging habits, rodent-like features, and nocturnal activity, opossums have developed quite a bad reputation. But while these creatures have come to be viewed as unclean and dangerous, they are simply misunderstood.
There are more than sixty different species of opossum worldwide. The one native to the U.S. and the Hudson Valley region is the Virginia Opossum. Despite its rat-like tail and a tendency to enjoy a good Dumpster dive, opossums are not a part of the rodent family. They are in fact, the only marsupials found in the United States.
As a marsupial, an opossum gives birth to a helpless litter that immediately crawls into the mother’s pouch to continue developing. Baby opossums, or Joeys, are about the size of a jellybean at birth. As they mature they begin to travel back and forth from the pouch. This often includes riding on the back of the mother opossum until they are ready to begin reproducing and surviving alone at around five months.
Opossums are typically 12 to 14 pounds once fully grown or about the size of a small dog. They are avid tree climbers and have thumb-like fingers on their feet along with a prehensile tail both of which help them climb.
Opossums are perhaps most infamous for their ability to play dead. When they sense danger, they collapse onto their side with a vacant stare and sometimes even have their tongue outside of their mouth. This confuses a predator enough to give them a chance to escape.
A lot of an opossum’s negative connotations may be associated with the fact that they are scavengers. The nocturnal animal is attracted to human garbage and dead meat such as roadkill. However, opossums are particularly immune to diseases and cannot carry rabies. They also consume grass, nuts, mice, snakes, and worms.
Most notably, opossums readily consume ticks. Far from being harmful, this makes them a benefit to us as we are overrun with Lyme disease-carrying black-legged ticks (a.k.a. deer ticks).
Invasive: Japanese barberry (Berberis thunbergii)
The same harmful ticks that are eaten by the native opossum are aided by the invasive species Japanese Barberry that provides an ideal habitat for them to thrive. The presence of Japanese barberry has been linked to an increase in Lyme disease. At about five-feet tall, the shrub stands at the perfect height for adult black-legged ticks to latch on to a white-tailed deer.
Japanese barberry was introduced to the United States as early as 1875 as an ornamental plant. The shrub was valued as a hedge thanks to the fact that it requires minimal care to thrive, has no pest or disease issues, and is not eaten by deer. All of these characteristics also make it a perfect storm to invade forests and outcompete native plants as it grows unchecked in large thickets.
Japanese barberry is round in shape with green leaves and yellow flowers in the spring. It is deciduous and, in the fall, will turn to orange, purple, and red. The shrub has bright red berries that stay on throughout the winter. Another distinguishing feature is its sharp thorns. This pricker bush will surely leave you with scratches if you happen to wander off of a trail in the New York region.
Removal of Japanese barberry can be done mechanically by digging out the shrub with a shovel or hand pulling the smaller plants with thick gloves. Cut Japanese barberry plants will resprout if the stem is not treated with an herbicide.