Notes on Ticks

If you’re a naturalist on the Eastern Shore, encountering ticks is inevitable. Since moving here from a more urban area, I’ve learned the importance of daily tick checks, especially in warm weather. Adkins Arboretum, like any healthy, naturalized habitat, has its fair share of these pesky arachnids. Dog ticks, black-legged ticks, and Texas Lone Star ticks thrive in thickets, leaf litter, and grassy areas. Each of these species can transmit diseases. 

Luckily, there are ways to enjoy nature and avoid bringing ticks home with you. Repellents, both chemical and natural, can be helpful. Staying on the path, keeping canine friends at your side, wearing closed-toed shoes, and tucking your pants into your socks are also good defensive measures. Above all, check…and check again. 

“Why ticks?” many of us wonder. “What good are they?” As it turns out, ticks have many environmental benefits. According to Land Steward Kathy Thornton, ticks “benefit the moist, dark ecosystems in which they live by serving as a food source for many reptiles, birds, and amphibians. They also help control wild animal populations. Scientists even use them as an indicator of an ecosystem’s overall health and stability.” 

Healthy ecosystems have built-in control mechanisms to keep the spread of pathogens in check. Studies show that high animal diversity is key to limiting tick-borne disease. The presence of red foxes has a negative correlation with the incidence of Lyme disease, most likely because foxes feed on white-footed mice, which are carriers of Lyme bacterium. Opossums can eat up to 4,000 ticks a week, and guineafowl, though not native, likewise consume massive quantities of ticks. 

Ticks have been on Earth since the Cretaceous period, 145-66 million years ago. Given their long history, it’s unlikely they’ll be going away anytime soon. We might not like them, but we can learn to accept them. Because the alternative–not venturing into nature at all–poses an even greater risk to our physical and mental health.

by Jenny Houghton
Assistant Director

Parenting in Nature

For me, the hardest thing about this pandemic is missing my extended family. Masked over-the-fence meetings can’t take the place of leisurely gatherings with grandparents, uncles, aunts, and cousins. In the past three months, we’ve missed out on birthdays, Mother’s Day, picnics, and graduations. A longing for loved ones is something most of us share, even as our individual family structure varies. Family structure in the animal world varies, too, and is endlessly fascinating.

For turtles, good parenting means finding a safe place to lay eggs. After that, turtle young are on their own. Risks to hatchlings are numerous, which is why many turtle species produce several clutches of eggs each year. Mating takes place in the spring and summer, since turtles hibernate in cold weather. Interestingly, female box turtles can produce fertile eggs up to four years after mating!

Eastern bluebirds also produce several clutches of eggs a year. Fledglings from the first two broods leave the nest permanently once they’re able to fly, but those from the last clutch will overwinter with their parents. Birds go to great lengths to keep a tidy nest, consuming their babies’ droppings after each feeding. I’m all for a clean house, but this is parental devotion to the extreme.

Eastern bluebird

Another devoted animal parent is the beaver. Dome-shaped beaver lodges are home to monogamous parents, young kits, and the yearlings that were born last spring. Once the weaning process begins, both parents gather twigs and leaves for their kits to eat, and older siblings help groom and care for younger ones. When adolescent beavers finally leave the family home, they usually settle nearby.

If you’ve seen squirrels with bald patches on their backs and shoulders, you might suspect mange. But fur-depleted squirrels are usually females who have used their own fur to line their nest. Rabbits do the same. Unattended baby rabbits are no cause for alarm: mother rabbits nurse their babies only five minutes each day. When not feeding their young, they’re off grazing on clover and other plants to fortify their rich milk.

Like rabbits, does leave their fawns unattended for hours, hiding them in tall grass or brush. Newborn deer weigh in at only six to eight pounds; their spotted fur provides camouflage against the sun-dappled forest floor. Unlike their mothers, fawns have no scent, so being on their own actually keeps them safe from predators. Which just goes to show: whether in the animal or the human world, sometimes the best way to share our love is through social distancing.

by Jenny Houghton
Assistant Director

Photos by Kellen McCluskey

Nature Notes

My dog could spend hours in pursuit of frogs. One of my greatest pleasures during stay-at-home is watching her chase them in our local drainage pond. She’s never successful, which makes for a guilt-free spectator sport. Green frogs are her favorites, and over the past few weeks I’ve learned to differentiate their high-pitched alarm call from their territorial “plink.” 

Of the fifteen species of toads and frogs found at the Arboretum, I love bullfrogs the best. Nothing beats the serious heft of a golf ball-sized bullfrog tadpole. Adult frogs can weigh in at well over a pound and reach a length of up to eight inches. For me, the throbbing “baroom, baroom” of a male bullfrog signals spring as surely as the first daffodil. 

Bullfrogs and green frogs are common sights in the Arboretum’s wetlands, and visitors find them difficult to tell apart. Color is not a foolproof method: both species sport some green, and individual color variation compounds the confusion. I often explain that bullfrogs grow to the size of a dinner plate and green frogs to the size of a cake plate. Since many consider bullfrogs a delicacy, this culinary metaphor seems logical. 

Bullfrog

The metamorphosis of bullfrog tadpoles can take several months in warm climates and up to three years in colder ones. In their tadpole stage, bullfrogs thrive on aquatic plants, algae, and insects. Adult bullfrogs will eat more or less anything that fits in their mouths. Hunting at night, these ambush predators have sticky tongues and powerful jaws for engulfing their next meal. 

Another quality that makes bullfrogs such great hunters is the musculature of their back legs. Expert lungers, bullfrogs can jump up to ten times their body length! I haven’t been able to find similar statistics on green frogs, but judging by my dog’s continued failure to catch one, I must assume they are similarly adept.

by Jenny Houghton
Assistant Director

Photo by Kellen McCluskey

Small Wonders

Working from home (as are most of us), Assistant Director Jenny Houghton has been working on Nature Notes to share in our weekly email newsletters (email us to sign up!).

This was a week of small wonders.

Friday turned up two treasures: the feather of a vulture and a robin’s egg. Both had fallen from great heights, the robin’s egg intact, though far from any nest. Later in the day, a skink left its iridescent tail on our front sidewalk. We took it to the porch for closer observation, marveling at the shiny scales and at the skink’s ability to evade danger. Strength, vulnerability: these are two sides of nature’s coin.

A Sunday walk led us to a meadow flecked with small white flowers, similar to bloodroot but with narrow, grasslike leaves. “Star-of-Bethlehem,” Land Steward Kathy Thornton said when I checked in, an “escaped bulb” native to Europe. Alongside the starry flowers, buttercups grew. Native or not? I checked—many are, but not all. Our chins glowed yellow; everyone liked butter.

On Tuesday, we spotted a box turtle digging a hole for her eggs, prompting several subsequent visits to mark her progress, which was slow. By the time we trudged home for the final time, the moon was out. A barred owl called from a tree; we could see its bulky silhouette overhead. The call was answered from my neighbor’s yard, where a similar black shadow hunched among the branches. The owlish conversation ended when my dogs joined in. We went inside.

After a bath and a book, I tucked my youngest into bed. “Mom,” she said drowsily, “when you start looking for nature, you see nature everywhere.” Yet another small wonder.

Originally published May 7, 2020

Virtuoso

Working from home (as are most of us), Assistant Director Jenny Houghton has been working on Nature Notes to share in our weekly email newsletters (email us to sign up!).

Recently, I had a rare break from “stay at home” orders to help with plant sale pickups at the Arboretum. My job consisted of standing at the service gate welcoming arrivals. Despite gray skies and chilly temperatures, my spirits were lifted by the cheerful sound of a bird singing lustily from the top of a nearby pine tree. His repertoire was truly impressive, consisting of melody after melody with no break in between.

Fast-forward two hours and lots of cold drizzle later, and the bird, who, by then I’d nicknamed Mr. Noisypants, was still singing. With mixed feelings of awe and exasperation, I pulled a pair of Bushnell binoculars from the golf cart to take a closer look.

Brown thrasher. Photo by Kellen McCluskey.

Mr. Noisypants was a fine specimen. A tad larger than a robin with a narrow, somewhat curved beak and a white chest streaked with brown, he was obviously no mockingbird. I committed his appearance to memory and decided to call my dependable birder friend, Mr. Wilson, as soon as I got home.

“Brown thrasher,” said Mr. Wilson, without a moment’s hesitation. He proceeded to share an impressive number of facts about this species, some of which I retained and more of which I had to look up later on Wikipedia.

Brown thrashers are members of the Mimidae family, along with catbirds and mockingbirds. I was correct in labeling my thrasher “Mister” since it is the male birds that are most conspicuous, especially during mating season. Brown thrashers are purported to have a song repertoire of 1,100—perhaps the largest of any North American bird—with each individual singing up to 3000 song phrases. Males sing loudest when seeking a mate in the spring. Charmingly, interested females will exchange a leaf or twig as part of a courtship ritual. Males will likewise present a twiggy gift, and nest-building soon begins, followed by mating and the laying of two to three blue-green eggs with reddish brown spots.

The word “thrasher” does not refer to a call but rather to the sound these omnivores make when foraging for food among leaf litter. Brown thrashers live in dense thickets and along woodland edges, where they build grass-lined nests in low branches. Males can be quite protective of their nests and will attack much larger species, including humans. Luckily, Mr. Noisypants was still in courtship mode and seemed oblivious of my presence.

I am a very poor birder, but I’ve found that the birds I do remember are not ones I’ve looked up in a book but ones I’ve looked at—and listened to—closely and at length. This is the wonderful thing about being a naturalist: learning is best achieved through direct observation, with book or internet research following only later. Many of us have more time now than ever to head outside and observe nature closely and at length. May we all grow in knowledge, health, and awe in the days ahead.