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What Time is it in Nature: Summer Storms on the Prairie

Museum Blogs - September 19, 2014 - 4:18pm

If you’ve lived in the Triangle Area for almost any length of time, you know that the weather can change rapidly without a lot of warning. A perfectly sunny day can devolve into a nightmarish storm in the blink of an eye. Prairie Ridge is subject to the same sorts of storms that you see anywhere else in the area and weather changes like rain, high winds, and cooler temperatures can impact the species living on and using the grounds. If a storm is big enough, it can even cause damage to trees or structures on the grounds. Let’s take a look at the sorts of things we see during and after storms, when few visitors are here to see them!

Before I do, however, let me say that in the event of severe weather or lightning, we encourage our visitors to seek shelter or leave the grounds immediately. There’s simply no reason to risk your safety by remaining on the grounds during storms! Pay attention to all weather alerts on your phone and please keep an eye on the sky while you’re here. Make immediate preparations to leave before storms, such as this, set in:

Storm over the prairie

Summer storms at Prairie Ridge vary from light sunshowers that drizzle a bit of water over everything while the sun is still out to intense storms where the blackened sky unleashes a fiery deluge of rain and lightning. Some animals might stay out during some of the lighter storms, such as the squirrel in this admittedly terrible photo:

Soggy squirrel

You’ll see soggy birds, soggy squirrels, soggy rabbits, and other wet animals emerging from whatever shelter they sought and return to their normal activities shortly after a storm passes by. If the rain lasts a while, you might even see an increase in animal activity immediately after storms as they make up for the time lost while they sheltered from the rain. If it’s safe to be outside, a trip to Prairie Ridge soon after a storm passes through can yield some interesting wildlife sightings!

In the more severe storms, the ground becomes quickly saturated and you’ll start to see the excess water runoff. The water runs downhill, over the slopes and into the low areas of the grounds, such as the stream and the pond. In the case of severe storms, the water can knock over plants and move mulch. In fact, immediately after many bad storms, you can often see evidence of little river systems that formed in the mulch as the water rushed downhill toward the stream:

rivulets in the mulch

If a storm is big enough to start pushing mulch around, it’s also big enough to make the stream flood, and you should not be there to see it! Our stream drains a huge amount of impervious surfaces in our area (parking lots, roads, and buildings primarily), and a lot of the water that runs off these surfaces ends up running through our grounds. The normally calm, clear, and shallow stream can turn into a roiling, muddy mess capable of carrying large rocks downstream and knocking whole trees over.  These floods develop quickly and can occur after only a few minutes of hard rain, but they also pass quickly. The water may look muddy for several hours after a storm:

Stream before and after a storm

… but the water levels will return to nearly normal within a few hours. After a few days, you probably won’t be able to tell it flooded at all!

While some of these storms can cause damage and might drive you away from your planned outdoor recreation, they are also responsible for a lot of the beauty you see at Prairie Ridge. The rain helps keep the pond full for frogs, insects, snakes, and birds and helps the flowers in the Nature Neighborhood Garden grow. The prairie is wholly dependent on rain for its water, and some species use rains as cues to reproduce or feed, such as Spadefoot Toads, fireflies, and dragonflies. Everything is clean and alive after a storm, and the light glittering off every surface can be quite stunning. You’re likely to see some of the best views as soon as the sun comes back out after a storm.

We do not encourage anyone to remain on the grounds during storms, but after a storm has passed and it is safe to go outdoors again, consider making a visit to Prairie Ridge! You can often see things that you might not see on your average nice day as storms disrupt the everyday activity of many species. You might get wet and muddy on a post-storm visit, but that’s all part of the fun, especially if you see something amazing!

What Time is it in Nature is a weekly feature highlighting the current plants, animals, and other wildlife at the Museum’s public outdoor facility, Prairie Ridge Ecostation. Find out more about the natural happenings at Prairie Ridge at our What Time is it in Nature Archive!

Photos by Chris Goforth


What Time is it in Nature: Eastern Cottontail

Museum Blogs - September 13, 2014 - 2:09pm

It’s been an interesting summer at Prairie Ridge this year. The Purple Martins arrived a little early and migrated southward early this year. We normally find mostly Eastern Bluebirds in our observation nests, but this year we saw mostly Carolina Chickadees. We’ve had a greater than average number of Eastern Box Turtles spotted on the grounds. One species that been incredibly abundant this year can still be regularly seen on the grounds, the Eastern Cottontail (Sylvilagus floridanus). Let’s explore the lives of these furry prairie dwellers!

Eastern cottontail

Eastern Cottontails are found throughout the eastern and southern US, Canada, and even parts of Mexico and South America. They are compact members of the rabbit group and sport the large hind feet and long ears common to their relatives. They are reddish or greyish brown on top and white underneath and have a short and fluffy white tail, the “cottontail” in their common name. They often become more drab in the winter and replace their brown fur with grey that blends in with the bleak surroundings more effectively.

Like other rabbits, Eastern Cottontails prefer open grassy areas and old fields surrounded by brushy habitat. They like to forage in open areas, but because they do not dig burrows, they require brushy areas to protect themselves from predators and will dash into shrubs, hedges, or brushpiles when threatened. They are known to eat a variety of food, though they are largely herbivorous and only occasionally eat insects or other animals. During the summer, Eastern Cottontails feed primarily on grasses and other herbaceous plants, and are sometimes known to venture into agricultural fields to feed on crops. In the winter when most of the green plant material disappears for a few months, they will switch their diet and feed on the twigs, buds, and bark of woodier plants. Regardless of the season, rabbits do not digest their plant-based diet very effectively and they produce two types of fecal pellets to ensure proper digestion. The green pellets consist of partly digested plant matter and are re-consumed by the rabbits so that they can complete digestion of the materials they contain. Brown pellets are mostly waste and are not eaten by the rabbits after they have been expelled.

Most rabbits do not live very long and Eastern Cottontails are no exception with an average lifespan of just 15 months in the wild. The primary source of mortality for Eastern Cottontails is predation and they are fed on by many animals, including foxes, coyotes, bobcats, domestic dogs and cats, raccoons, owls, hawks, and snakes. Rabbit meat is enjoyed by some people and they are one of the most commonly hunted animals in the US. Because many open fields are along roads, they also frequently succumb to collisions by cars.

Scientists have estimated that only 20% of the entire Eastern Cottontail population survives each year, though the rabbits that do survive are more than capable of rebuilding the population. Like other rabbits, Eastern Cottontail breeding is promiscuous and the males are not involved in rearing young. After a brief mating, the male rabbits will move on, often mating with other females. Once pregnant, a female Eastern Cottontail will dig a small, shallow hole in a protected space in a brushy area and line it with soft plants and fur. After a 28 day gestation period, a litter of blind, fine-haired kits are born. Their eyes open in less than a week and they are weaned and become independent after another 3-4 weeks, dispersing from the nest just 7 weeks after their birth. Most females will breed the spring after their birth, but some that are born early in the year will begin producing litters the same year. Female Eastern Cottontails can have up to 7 litters of 12 kits in a year, but more typically have 3-4 litters with an average of 5 kits each.

You’re most likely to see Eastern Cottontails shortly before Prairie Ridge closes in the afternoon as they are crepuscular (late afternoon-early evening) or nocturnal feeders, but you can often see them other times as well. Look out for medium-sized brown shapes on the trails alongside the prairie and you may see a rabbit munching on grasses. Step too close and it will dart into the prairie and disappear! They are on the grounds all year and you could potentially see an Eastern Cottontail even in the middle of winter, but this has been a boom year for bunnies at Prairie Ridge. Now is one of the best opportunities you’ll have to see one, so wander down the Prairie Trail soon to have a great chance to see one!

What Time is it in Nature is a weekly feature highlighting the current plants, animals, and other wildlife at the Museum’s public outdoor facility, Prairie Ridge Ecostation. Find out more about the natural happenings at Prairie Ridge at our What Time is it in Nature Archive!

Photo by Chris Goforth


What Time is it in Nature: Common Green Darner

Museum Blogs - August 30, 2014 - 1:01pm

It’s the time of year where many animal species start to move about the world. Some very long and impressive migrations are about to happen or are currently in progress, but most people tend to think about birds or mammals on the move if they consider migrations at all. There are some impressive insect migrations as well, and one species, the Common Green Darner (Anax junius) is currently making its way through North Carolina as it moves from its cooling summer habitats to more favorable climes further south.

Green darner dragonfly

Common Green Darners are dragonflies in the insect order Odonata (dragonflies and damselflies) and family Aeshnidae (darners). Within the US, they are one of the larger and more distinctive dragonflies. They have huge yellow-brown or greenish eyes that wrap around most of the top and sides of their heads with an eye or bullseye-shaped mark on the face just in front of the eyes. The thorax, the middle section, is vibrant green. Depending on whether you are looking at a male or a female, the abdomen can be a variety of colors. Males have a bright blue abdomen while the females have a green or purple-brown abdomen. The differences in colors make the Common Green Darner sexes easy to distinguish, even from afar.

Like other dragonflies, Common Green Darners have a complicated method of reproduction. Females choose their mates not by any merits of his own, but on the quality of the egg-laying habitat in which he resides. Males will fight with one another for the best locations and the strongest individuals with the best egg-laying habitats generally mate with more females than other males. When a female, who normally spends most of her time feeding away from the water, decides she wants to mate and approaches a pond to find a suitable place to lay her eggs, the male who protects that location will swoop in and grab her behind the head. The female will then have to curl her body up and under his to mate. After a brief mating session, they will together find a place where she will lay her eggs in the pond. In order to ensure that no other males have a chance to mate with the female before she lays her eggs, the male will continue to hold onto his mate’s head until she has laid her eggs and leaves the pond entirely.

Many dragonfly species spend the bulk of their lives in water as either eggs or immatures (called nymphs), and the Common Green Darner is no exception. After some time in the water, the nymphs will hatch from the eggs. The young dragonflies are tiny at first, but fierce! They are amazing predators that use a long, extendable mouthpart to reach out and grab prey (insects and small crustaceans, fish, or tadpoles) and pull it back to their face to eat. As they feed, they’ll grow, often going through over 20 molts over 1-3 years before they mature enough to leave the water. At that point, they’ll crawl out of the water, break open their final nymphal exoskeleton (they “shed their skin”), pull their bodies free, puff up their wings, and fly off in search of food. They’ll spend about a month on land as adults, hunting insects on the wing.

Only a handful of dragonfly species are known to migrate (though there may be others we’re not yet aware of), but Common Green Darners are one of the best known dragonfly migrants. In the fall, cues in the weather drive the dragonflies south. Scientists don’t really know where the Green Darners go once they leave the US, but they follow the east coast and the large midwestern rivers along the way, eventually striking out across the Gulf of Mexico and disappearing into Central or South America. They likely mate, lay eggs at their final destination, and die, with their children making the return trip in the spring.

We have Common Green Darners at Prairie Ridge throughout most of the late spring and into the early fall, but their numbers may increase dramatically as the migration begins. Next time you visit, take a trip down to the pond and look for the large brilliant green and blue dragonflies flying out over the open water. You’ll likely spot a mating or a duel between males, but if you’re lucky you just might get to see dozens of Darners, weary travelers taking advantage of the abundant prey in the prairie grasses as they rest on their long trip south.

What Time is it in Nature is a weekly feature highlighting the current plants, animals, and other wildlife at the Museum’s public outdoor facility, Prairie Ridge Ecostation. Find out more about the natural happenings at Prairie Ridge at our What Time is it in Nature Archive!

Photo by Chris Goforth


Getting in On the Ground Floor of Citizen Science

Museum Blogs - August 29, 2014 - 6:40pm

Black swallowtail caterpillar  One of the benefits of having a field station associated with your natural history museum is having an opportunity to get in on the ground floor of some interesting research projects. We do a lot of citizen science at Prairie Ridge, and this summer we were selected as a pilot site for a new citizen science project looking at the insect food base for birds called Caterpillars Count. We’ve been testing protocols and collecting data for the project all summer, and it’s been a lot of fun. Let me take you behind the scenes of a citizen science project that’s in development!

Caterpillars Count is part of a research effort led by Dr. Allen Hurlbert, an ornithologist at the University of North Carolina Chapel Hill. Dr. Hurlbert is interested in some big questions about birds, such as whether bird population sizes track the availability of insects and whether birds migrate to North Carolina at the same time that insects become available in the spring. These are questions that are best answered by having a lot of people on the ground who are monitoring both the bird and insect populations. So far, Dr. Hurlbert has monitored bird populations through bird banding stations, sites where researchers capture birds in mist nets, place a uniquely numbered bracelet around their leg, and track individual birds via a centralized federal database of band numbers. We have a strong bird banding program at Prairie Ridge. Insect populations are a bit more complicated to monitor as there are no big monitoring programs to track insect abundance during the year. So, Dr. Hurlbert is turning to citizen scientists for help.

aphids on hollyCaterpillars Count focuses specifically on the insects that live on or under leaves on trees, the food base for foliage gleaning birds. By having citizen scientists examine leaves on trees and report the number and types of insects they find, you get can a good census of the local insect density and compare the insect population to the bird population at that time. At a previous pilot site, Dr. Hurlbert had volunteers count insects on 400 leaves. Unfortunately, even when there are LOTS of insects out and about, the chances of your seeing an insect on any given leaf on a tree is pretty small. Volunteers would often return from their leaf surveys with no insects spotted at all.

At Prairie Ridge, we’re testing an expanded protocol. Instead of 400 leaves, we’re looking at 2000 leaves per week. That’s 50 leaves on each of 40 trees spread along the Forest Trail. As you might imagine, it takes some time to look at 2000 leaves, even with a group of people, but with practice we’ve gotten the time down to about an hour for our group of 4 dedicated volunteers working together each week. We make notes about what’s difficult about the protocol, what we like and don’t like about the project, and we send the information back to Dr. Hurlbert so he can consider making changes that will make his project more user-friendly. My group of weekly volunteers consists of adults, but we’re working to get kids involved as well. We’ve incorporated Caterpillars Count into our Citizen Science Saturday walks to reach a variety of ages, all the while taking notes about what works and what doesn’t to send back to Dr. Hurlbert for evaluation.

Long legged flyOne of the best things about getting involved in the early stages of a project like this is the ability to provide feedback that will help improve the project before it is released on a larger scale. Because we are on the ground doing the project every week, my volunteers have tested the protocols extensively. We know, for example, that it can easily take more than an hour to complete the whole protocol, but the work goes faster with a group. This means that to be the most successful, Dr. Hurlbert should target environmental education centers and similar facilities that get groups of people regularly. We’ve also learned that most beginners have a hard time telling a true bug from a beetle, a fly from a bee or wasp, even with the provided guide. We’ve made some suggestions for improvements to the guide to help future participants identify their insects more easily.

It’s rather special to be given an opportunity to test a citizen science protocol like this, and it’s been a good experience. My group of volunteers knows that not only are they collecting scientific data that is useful in a real research project, but they’re also helping make Caterpillars Count a fun and enjoyable project for other citizen scientists. We’ll continue collecting data for a few more weeks and then take a break for the winter. With any luck, the project will be ready to roll out in the spring, and we’ll be able to offer Caterpillars Count to even more volunteers. And if not, we’ll do more field testing. Either way, we hope to get more people involved in this interesting new project – and learn a little more about the amazing world we live in!


What Time is it in Nature: Scarlet Hibiscus

Museum Blogs - August 7, 2014 - 11:50pm

It’s mid-summer, so Prairie Ridge is a happening place!   You’ll see animals darting across the trails as you walk and there are dozens of plant species in bloom.  One plant in bloom now is quite spectacular, the Scarlet Hibiscus (Hibiscus coccineus), and can be found in several locations on the grounds.

Scarlet hibiscus plant

The Scarlet Hibiscus (also known as the Scarlet Rose Mallow, Swamp Hibiscus, or Red Water Hibiscus) is a shrubby flowering perennial plant that is native to the southeastern United States.  It typically tops out at 6-8 feet in height and sports long, narrow stems that die back in the winter and regrow in the spring.  The leaves are palmate, with 3-7 points that radiate out from the point where it attaches to the stem, and can get as big as 8 inches across.  Each leaf lobe is narrow and pointed with a serrated edge.

These plants grow best in full sun and moist soils.  In the wild, Scarlet Hibiscus are most often found growing in swamps, marshes, or ditches in wet or saturated soils.  They are also found along rivers and streams where they are often taller than the other flowering plants, such as Pickerelweed, that grow in similar conditions.

The flowers of Scarlet Hibiscus are quite showy:

Hibiscus flower

As you can see, they are brilliant red with five petals arising from the center of the flower.  The pale green sepals wrap around the base of the petals and the reproductive structures are located along a long stalk that emerges from the center.  Each flower only lasts about a day, but the plants produce many flowers over their bloom period in late summer so that they retain their showy appearance for several weeks.  If a flower is fertilized, a fruit will grow where the flower attached to the stem.  It will mature in the fall.

Scarlet Hibiscus is attractive to a variety of pollinators.  Butterflies, bees, and hummingbirds can be frequent visitors, so the plants make an excellent addition to native pollinator gardens.  You can often find other insects, such as the predatory long-legged flies and scentless plant bugs, lurking among the leaves and feeding on the seed pods.

You can find several examples of this gorgeous plant at Prairie Ridge.  Next time you visit, stop by the garden near the kiosk in the parking area to look for insects on the leaves and flowers.  You can also find fine examples of Scarlet Hibiscus in the Nature Neighborhood Garden and along the shore of the pond.  These spectacular plants will remain in bloom for a few more weeks, so make a trip out to see them before the flowers disappear!

What Time is it in Nature is a weekly feature highlighting the current plants, animals, and other wildlife at the Musuem’s public outdoor facility, Prairie Ridge Ecostation. Find out more about the natural happenings at Prairie Ridge at our What Time is it in Nature Archive!

Photos by Chris Goforth


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