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Ian Stewart

These are the opening words of the poem ‘To a mouse’, written by the legendary haggis-eating Scottish poet Robert Burns in 1785 (which also contains the famous line oft-paraphrased as ‘The best-laid schemes of mice and men go often askew’). Although this is an apt description of mice it is also used to refer to all manner of small, obscure and reclusive animals and feather mites fit perfectly into this category.

Most people have never heard of feather mites which is hardly surprising. They are tiny brown arthropods which spend most of their lives flattened along the vanes of bird wing feathers where they were assumed to scavenge on feather debris and oily secretions and perhaps even rasp away at the feathers themselves. However, a remarkable study published last summer (Doña et al. 2018) examined the contents of mites’ stomachs using high-power microscopy and DNA analysis and found that their main food was fungi, and perhaps also bacteria and oil produced from the birds’ preen gland. Whether this means feather mites harm their hosts or are simply commensal remains to be seen.

Birds are assumed to acquire feather mites through physical contact with their parents while they are still in the nest, although they could also pick up mites from bumping into other birds at feeders or sharing the same dust bathing sites. Mites are quite easy to see if you are holding open a bird’s wing although with the naked eye they just look like a cluster of small dots (shown below).

We gained a whole new appreciation for these creatures when Shannon Modla of the University of Delaware kindly photographed some Gray Catbird feather mites under a light microscope. The magnified views show that they are long and thin with two pairs of legs at the front of their body and two pairs at the back (image below). The darker mites on the left and below are probably older mites with a hardened exoskeleton while the paler one on the right is probably a younger mite that has just molted.

Shannon was then able to view them under a powerful electron microscope and got some incredible images of their head as well as an egg (below).

To try to gain some insights into the biology of these enigmatic creatures we have been scoring the number of feather mites present on birds handled during the Delaware Nature Society’s Bird Banding project. Our simple questions were which bird species are most likely to have mites and whether the number of birds with mites varies according to the time of year.

Our first finding was that feather mites are quite common. We examined 448 birds belonging to 48 species and found that almost half of them (203 birds from 37 species) had mites on at least one of their wing feathers. We also found the proportion of birds with mites varies a lot between species. Over 75% of the Slate-colored Juncos, House Finches and Downy Woodpeckers that we examined had feather mites yet fewer than 15% of Ruby-crowned Kinglets, Common Yellowthroats or House Wrens had them. We also found that the proportion of birds with mites stayed quite consistent across the year with a noticeable peak in May.

This year we will be gathering more data on mites from the birds we band and then try to figure out why some birds are more likely to have mites than others, and why some have lots of mites while others have very few. Is it related to their body size perhaps, or how social they are, or maybe whether their beak is small and pointed enough to preen away the mites? So watch this space for updates on this new and fascinating DNS research project!

DNS has plenty of birding opportunities coming up soon, so sign up and enjoy the outdoors!

The Great Backyard Bird Count ~ Coverdale Farm Preserve

The Great Backyard Bird Coount: Kent County Tour ~ Abbott’s Mill Nature Center

Owls and Other Winter Raptors ~ Ashland Nature Center

 

Ian Stewart

Jewelweed is a colorful native annual wildflower that is common in damp marshy areas where it grows as a thin bush about 4 feet high. It is also known as ‘touch-me-not’ because of its curious habit of expelling its projectile seeds when the flowers are handled or brushed against. Jewelweed is a classic folk remedy because the juice of its leaves and stems is a well-known antidote to stings and rashes from stinging nettle, which it often grows close to.

Jewelweed growing along the boardwalk at Ashland

Many Delawareans are familiar with jewelweed as it is often found in shaded suburban gardens and parks, but few people realize that there are two species and they usually grow right next to each other! The most common is spotted jewelweed (Impatiens capensis), which is also known as orange jewelweed. This has bright orange petals densely covered with red spots and a long ‘nectar spur’ which curls along the bottom of the flower. The second, less-common species is yellow jewelweed (Impatiens pallida), which is also known as pale jewelweed. This has larger, yellow flowers with only a smattering of red spots and a shorter nectar spur which dangles downward. The leaves of yellow jewelweed have more veins and are more deeply toothed than those of the orange jewelweed. In my experience, spotted jewelweed outnumbers yellow by about 5 to 1.

Side by side views of spotted (left) and yellow (right) jewelweed showing the differences in petal pattern, the length and angle of the nectar spur, and leaf venation

Jewelweed is pollinated by both hummingbirds and bees and watching these insects crawl into the depths of the flower to access the nectar pooled up in the spur is a fun way to spend a sunny afternoon! If you’re very lucky you may get to see a hummingbird feeding from the nectar spur.

A bee burrows into a jewelweed flower in search of nectar

The bee’s back is now coated in pollen from the pollen stalk dangling above it. The bee may now pollinate the next jewelweed it enters!

Both jewelweeds have a long blooming season from late spring through the early fall and are an attractive native wildflower to plant in a damp, shaded corner of your yard to attract pollinator insects and hummingbirds.

Learn more about how you can garden for native plants and wildlife by certifying your yard as a wildlife habitat through the Delaware Nature Society

https://www.delawarenaturesociety.org/what-we-do/protecting-habitats-wildlife/garden-for-wildlife/

 

By Annalie Mallon, Ashland School Program Coordinator

Waterfalls, wild blueberries, black bear warnings, and winner of the 2018 Pennsylvania River of the year! What more could you possibly ask for on a summer trip into the Pennsylvania wilderness? Every summer the Delaware Nature Society’s Teen Naturalists head out for a week-long adventure, and these are just some of the things that were encountered on this year’s trip.

Teens enjoying lunch at the Canyon Vista Summit

Teens enjoying lunch at the Canyon Vista Summit. Photo by Annalie Mallon

Earlier this month, the teens and leaders (Courtney McKinley, Lauren Powell, and myself) embarked on a 4-day backpacking trip through the Loyalsock State Forest in northern Pennsylvania. After stuffing our packs to a full 40 pounds each with food, supplies, and gear, we were excited to see what this week in the wild would bring us. Our plan was to hike a popular section of the Loyalsock Trail, a rugged trail weaving its way through the state forest for 59 miles. We were going to hike the trail starting at Dutchman falls, branch off of it to hike the Link trail that travels through Worlds End State park, and then reconnect with the Loyalsock, circling back to where we started, thus creating a 25 mile loop (DCNR map below). Department of Conservation and Natural Resources Map

Prior to the start of our trip we had been persistently checking the weather forecast in hopes of seeing nothing but four days of gorgeous sunny skies and no humidity. Instead what we were presented with was a forecast for severe thunderstorms, heavy rain, and damaging winds. During our drive up the PA turnpike it occurred to us that we may not want to get stuck in the backcountry in heavy rain and damaging winds with nothing but the gear on our backs. Our plan for day 1 was quickly rearranged and we decided to start our trip in Worlds End State Park at a group campsite and cross our fingers that the forecast would change so we could start backpacking on Tuesday.

When we arrived at Worlds End we were greeted by a gorgeous valley full of pines and ferns snaking its way along the Loyalsock Creek. We set up camp and decided to find a place along the creek to swim and eat. Cheerful that we did not yet have to carry our heavy packs on our backs, we found a sunny spot next to the roaring creek scattered with smooth stones and perfect sitting rocks. We swam in the cold mountain water and created small rock cairns while we ate our hoagie dinners. A perfect start to our week!

Exploring the Loyalsock

Exploring the Loyalsock and building rock cairns. Photos by Annalie Mallon.

Photo of a rock cairn

Tuesday morning welcomed us with (shockingly) more sun. With no cell reception we took a short trip to the park visitor center to check the most updated forecast, but to our dismay it had gotten even worse! Tuesday afternoon was apparently bringing several storms and Wednesday was bringing heavy rains, winds, and possible hail. To backpack or not to backpack, that was becoming the major question. After discussing the pros and cons of the situation we changed our plans for the second time that week. We decided to hike, sans backpacks, the Canyon Vista Trail in the state park; a 4 mile loop that takes you up to an elevation of 1,750 feet with stunning views of the creek below. The climb was definitely worth it, the views were spectacular, and the trail itself meandered through a thick deciduous forest scattered with fungi, ferns, and trickling mountain springs. We enjoyed our lunch with a view at the peak and then visited the rock garden where we tested our fear of heights by jumping across crevices, and also explored caves in massive boulders.

Teens enjoying the views of the Canyon Vista Trail and Rock Garden

Teens enjoying the views of the Canyon Vista Trail and Rock Garden. Photos by Annalie Mallon.

It was around this time that the storms finally started rolling in. We quickly started to make our way back down the mountain, picking up our pace with each crack of thunder that came from overhead. I truly don’t think anyone has ever scrambled 2.5 miles down a rocky mountain trail as quickly as we did in that short 30 minute stretch. Upon catching our breaths and rehydrating at the bottom of the trail we decided that whatever the forecast did or did not predict, we certainly did NOT want to get caught in thunderstorms while in the backcountry. So instead of backpacking that afternoon….

We got ice cream and went swimming instead!!

I know what you must be thinking at this point, this is SO not a true Teen Naturalist adventure trip into the wilderness. Family campgrounds with actual bathrooms, not carrying 40-pound packs on our backs, and now Ice Cream?? Believe me, we would have LOVED backpacking those 25 miles if it wasn’t for that darn weather forecast! But alas, weather is weather, so of course we visited the Worlds End State Park swimming hole and ice cream shop. The creek water was FREEZING but oh so refreshing after our fast paced descent down the mountain. The sun had also come back out so we were quite content. While swimming, we started to brainstorm some plan C options for the afternoon and evening (remember, storms and rain still in the forecast). We officially decided to leave Worlds End and head south to Ricketts Glen State Park!

If you have never visited Ricketts Glen State Park, I highly recommend you do. It makes for a perfect weekend camping trip with beautiful trails and excellent waterfalls. We found an awesome campsite (somehow we scored a site right on Lake Jean!), and set up camp for the night. Then we found the blueberries. Oh. My. Goodness. The wild blueberries. They were EVERYWHERE. Bushes just bursting with the sweetest, yummiest, freshest blueberries. We spent a majority of our time that evening picking and devouring the little berries, and once again we were not complaining that we were not backpacking.

Wild blueberry bush and bowl of blueberries on a table

Blueberries galore! Photos by Annalie Mallon.

Wednesday morning brought nothing but clear skies once again, so we decided to hike the famous Falls Trail in the park. The full trail is a 7.2 mile loop with 21 gorgeous waterfalls ranging in heights from 11 feet to 94 feet. We hiked the smaller 3.2 mile loop that follows two separate branches of Kitchen Creek as it cuts down through the Glen Leigh and Ganoga Glen valleys and comes together at “Waters Meet”. The sedimentary rocks that are exposed throughout the hike were formed over 370 million years ago and the waterfalls that cut through the rocks are magnificent. We spent the hike enjoying the falls, looking for salamanders, and even came across a HUGE snapping turtle!

Photo of Newt on a rock and teen holding a large snapping turtle

A red-spotted newt in its juvenile Red-Eft stage and Jared holding a HUGE Common Snapper. Photos by Courtney McKinley

Teens Hiking the Falls Trail

Hiking the Falls Trail photo by Courtney McKinley

After finishing our hike we enjoyed a picnic lunch, a small catnap on a lakeside beach, and more swimming, and then (SURPRISE!) made another new plan. We now were headed to our third PA state park of the trip; Hickory Run State Park! The campsite we chose was surrounded by pines and located next to a lovely trickling mountain stream. Unhindered (okay, maybe just a tad hindered) by the park ranger’s warnings of a “major bear problem,” we enjoyed our first lovely blazing campfire of the week with some classic scary stories and marshmallows before heading to our tents for our final sleep.

We awoke Thursday to our last day of perfect weather, and with bittersweet feelings we began to say our goodbyes to the gorgeous PA wilderness and start our journey home. Reflecting on our wild week full of last minute plans and reminiscing on some favorite Teen Naturalist trips of the past, our van ride went by in a snap and we pulled into the Ashland driveway with nothing but smiling faces (perhaps due to the fact that we did not end up backpacking 25 miles).

Group photo of teens and leaders in front of the Ganoga Falls

The Teens and Leaders next to Ganoga Falls at Ricketts Glen. Photo by Courtney McKinley

If you know a teenager, who is 13 – 17 years of age, that would like to join the Delaware Nature Society Teen Naturalists, please contact me at (302) 239-2334 ext. 120. The Teen Naturalists meet once per month, study nature, adventure outside, and go on a trip like this every August.

Ian Stewart

Migration is a fascinating aspect of animal biology. Each spring and fall, millions of birds, mammals and insects fly thousands of miles to get to either their breeding or wintering grounds. Migration can be challenging to follow however, as many of these animals migrate at night and travel quickly. There are several methods scientists use to track migration but a new collaborative method has recently emerged: the Motus system.

The Bucktoe Motus tower

The Motus system is an international network of automated towers which detect any animal fitted with a special small tag within a 15km range (‘Motus’ = Latin for ‘movement’). Since each tag emits a unique signal it is possible to track the movement of individual animals as they pass by one of more towers. The great majority of animals fitted with tags are birds but tags have also been placed on bats and large insects like dragonflies or even butterflies! The Motus network allows scientists to collect data on tagged animals to help them find out how variables like weather and the animal’s age, sex, and physical condition affect the timing and speed of their movements. It also aids conservation efforts by identifying key areas where animals stop to feed and rest during migration which can then be protected.

There are over 200 towers spread across the world, most of which are in North America (see the map on the Motus homepage www.motus.org). In the summer of 2017 a team of dedicated field biologists erected a line of towers all the way across Pennsylvania. The towers are so close together that their detection ranges overlap, meaning that they would pick up every tagged animal that migrates north or south anywhere in the entire state!

Distribution of Motus towers across PA and DE

Thanks to generous funding from the Starrett Foundation and the Pennsylvania Department of Conservation and Natural Resources via the Willistown Conservation Trust, a Motus tower was erected at Bucktoe Creek Preserve near Kennett Square in August 2017 as part of this line and has been recording 24/7 ever since! In the fall of 2017 it detected 7 thrushes, 3 warblers, a woodcock and a bat, all presumably heading south for the winter. In the spring of 2018 it detected a thrush and 4 shorebirds, all likely heading north to breed.

Another remarkable feature of the Motus system is that much of the data is open-access and can be viewed by anyone with the Internet. To see what animals are being detected follow these 4 simple steps.

1. Visit the homepage at www.motus.org then scroll down to see a map of the world with a yellow dot representing each tower.

2. Zoom in to find the tower you’re interested in (e.g. Bucktoe Creek) and click the dot. A box will then open telling you the name of the tower and its location plus the contact details of the organization overseeing it. The bottom row gives the number of tags detected by that tower (if there have been any) with ‘table/timeline’ in parentheses next to it.

3. Click on ‘table’ and a new page will open with several columns including the date each tag was detected plus the ID# of that tag (in blue text) and the species it was placed on.

4. Click on the ID# to reveal the date and place where the animal was tagged, and then if you want to explore further, either click on ‘table’ in the bottom row to see a list of towers at which that bird was detected, or ‘timeline’ to see what time the animal passed by the tower and how long it stayed. My own favorite is to click on ‘map’ to show the route the animal took!

Every year more Motus towers are erected throughout North America and they are also starting to spread across other continents. The number of tagged animals is also steadily increasing and every time one is detected it adds to our understanding of animal migration. Watch this space for updates from the Bucktoe tower!