Middle Run Natural Area

All posts tagged Middle Run Natural Area

By Derek Stoner, Conservation Project Coordinator

Jim White leading a bird walk, scanning the skies for birds at Middle Run Natural Area during the Fourth Annual Middle Run Bio-Blitz. Image by Derek Stoner, August 26, 2012.

On  a morning where the weather forecast showed rain was a strong possibility, we had not a drop of precipitation for our Fourth Annual Middle Run Bio-Blitz.  We did have some incredible gray clouds and much-welcomed cool breezes to enjoy on the bird walk that kicked off at 7:00am.   Without even leaving our starting point at the Middle Run Native Plant Garden, we tallied some great birds:  Common Nighthawk, Eastern Kingbird flocks (12 in one tree!), and a family of four Pileated Woodpeckers.  From multiple directions we heard the cu-cuu-cu-cuu calls of Yellow-billed Cuckoos, living up to their nickname of “Rain Crow” as the gray clouds passed by.

Jim White led the group of birders along the Middle Run Birding Trail, with close encounters with Black-and-white Warbler, American Redstart, and Eastern Wood-peewee.  A true surprise was the juvenile Little Blue Heron that flew right over our heads while we stood in the meadow!    

Round Two of the bird walks, led by Jim White and Amy O’Neil, held more good sightings like Blue Grosbeak, Brown Thrasher, and Field Sparrow.   A total of 27 birders joined this walk, including some very avid youth birders.

An excited group of insect enthusiasts joins Sheila Vincent on a foray into the field to capture butterflies, dragonflies, and other “things with wings.” Image by Derek Stoner, August 26, 2012.

Our insect guru Sheila Vincent led a wonderful butterfly and dragonfly walk for an enthusiastic group of families, most of who were first-time visitors to Middle Run.   Right away, they caught a female Black Saddlebags– a large and showy dragonfly.  Green Darners and Blue Dasher dragonflies were flying all over the meadow, but proved hard to capture.   

A Common Buckeye gathers nectar from a Queen Anne’s Lace (Wild Carrot) flower at Middle Run. This is a classic late summer butterfly found in local meadows. Image by Derek Stoner, August 26, 2012.

The butterflies put on a show, and the youngsters captured them with great skill.  Species like Common Buckeye (above), Eastern-tailed Blue, Summer Azure, Sachem Skipper, Tiger Swallowtail, and Clouded Sulphur all made their way into the nets and camera lenses of these “bug enthusiasts.”  Notable butterfly species captured include the Little Glassywing and the Variegated Fritillary. 

Hana gets a close-up look at an egg-laden female European Mantid at the Middle Run Native Plant Garden– the prize find of the Bio-Blitz! Image by Jim White, August 26, 2012.

The creature that “stole the show” was a female European Mantid with an egg-swollen abdomen.  This docile insect climbed on our hands, posed for photos, and found plenty of appreciative admirers in our group of outdoor enthusiasts.  This species of mantid is not commonly seen in our region, and as the name indicates, is native to Europe.

With nearly 50 people participating in the event, and many taking part in their first-ever bird or bug walk, we all enjoyed sharing a wonderful morning outdoors.   Thanks to all the participants! 

If you are interested in visiting Middle Run Natural Area, the parking lot is centrally located in the middle of this 860-acre park and its 12 miles of trails.  The driveway to the parking lot is located on Possum Hollow Road, just before the entrance to Tri-State Bird Rescue.   To get GPS directions to the site, use this address:   110 Possum Hollow Road, Newark, DE 19711.   

Once at the parking lot, you may want to explore the Middle Run Birding Trail.  Use the  Middle Run Birding Trail Map 2012 as your guide as you explore the area.  Enjoy!  

By Derek Stoner, Conservation Project Coordinator

A male Prairie Warbler sings from his perch in an Autumn Olive near Trail Marker 5 on the Middle Run Birding Trail. Image by Derek Stoner, April 28, 2012.

With April almost finished and May on the way, the activity level of birds is really picking up.  Many birds are already nesting, and a visit to the Middle Run Birding Trail this morning showed Tree Swallows gathering nesting material, Carolina Chickadees on seven eggs, and Eastern Bluebirds feeding three fledglings. 

Recently-arrived neo-tropical migrants like Prairie Warblers are on territory and singing, trying to attract a mate for the nesting season.   The “Meadow Mosaic” area on the Middle Run Birding Trail between Markers #4 and 6 had three different male Prairie Warblers singing.

A male Blue-headed Vireo shows himself briefly as he goes about the business of finding food. Image by Derek Stoner, April 28, 2012.

Other birds are passing through the area on their way to nesting grounds further north.  The Blue-headed Vireo is a bird that breeds primarily in the Boreal Forest of Canada, and stops by Delaware on its north-ward migration.  Vireos and all other species of migrant songbirds depend upon an abundance of insects (primarily caterpillars and flies) that are found on native plants.   At this time of year, trees in the Oak, Cherry, and Poplar family are good bets to attract birds.

A Warbling Vireo pauses in a Tulip Tree while feeding on caterpillars. Image by Derek Stoner, April 28, 2012.

The Warbling Vireo is a species of vireo that breeds locally along streams, and is often found nesting in Sycamore trees.  This bird I observed today was gleaning caterpillars from a young Tulip Tree, in the slow and steady manner that is characteristic of vireos.  Perhaps it will stay to nest at Middle Run!

What Spring migrants and bird activity are you seeing in your area right now?

By Derek Stoner, Conservation Project Coordinator
A male Pileated Woodpecker excavates a cavity (potentially for a nest) at Middle Run Natural Area. Image by Derek Stoner, March 6, 2012.

The inspiration for the famous Woody Woodpecker laugh used to give voice to the cartoon character is a bird that lives in our local woodlands:  the Pileated Woodpecker.  After leading a bird walk at Middle Run Natural Area this morning in which several participants made wishful requests to see a Pileated Woodpecker, we ended the walk at the parking lot without yet adding this bird to our checklist.   While we discussed the walk’s highlights, I heard a distinctive “laughing” call not far away.   Training binoculars on a nearby dead tree, we came upon the scene above:  a male Pileated Woodpecker actively excavating a cavity.  What luck!

March is prime time for our local woodpeckers to be creating nest cavities and beginning the process of laying eggs in these protected holes.  We watched the male Pileated through the spotting scope, and soon he was joined by a female Pileated who seemed to be inspecting the hole-making project.   Pileateds also build large cavities to roost in (sleep) at night, so we may have witnessed the creation of a bedroom rather than a potential nursery.

Sharon and her grandson Karl enjoying great views of a perched Northern Flicker. Image by Derek Stoner, March 6, 2012.

During our walk we enjoyed good looks at other woodpeckers, including a perched Northern Flicker that seemed to be basking in the sun, and a female
Hairy Woodpecker that quietly chipped bark off an oak tree in search of insects.  Red-bellied and Downy Woodpeckers were heard but not seen.

A male Eastern Bluebird perches in a Red Maple tree bursting with spring color. Image by Derek Stoner, March 6, 2012.

At the beginning and end of our walk, we observed the classic behavior of Eastern Bluebirds hunting from perches.  Sitting atop posts or on the tips of branches, they cocked their eyes towards the ground and looked for the movement of insects.  If a chilled cricket made a feeble hop or a lethargic caterpillar twitched, the bluebirds swooped to the ground to nab these easy prey items.  The morning’s temperature started below 32 degrees, but we actually saw plenty of insect activity.  Our best sighting was an adult Winter Stonefly, freshly emerged near a tributary stream.   Future food for another bird!

By Derek Stoner, Conservation Project Coordinator

The stream of blackbirds passing overhead at Middle Run Natural Area on February 20, 2012. How many can you count? Image by Derek Stoner.

There are a lot of natural spectacles for which Delaware is known:  Horseshoe Crabs spawning en masse,  hordes of  Snow Geese whitening the sky, and clouds of mosquitoes blackening your skin (kidding about that last one).  But one of the most notable and least well-known of the First State’s nature shows is that of the immense blackbird flocks wintering here.

Every winter evening in Northern Delaware, observers can see flocks of blackbirds heading back to their traditional roosting areas along the Christina River south of Wilmington.   Streams of birds flow through the sky, meeting up with other flocks and forming rivers of birds.   Eventually the flowing flocks mass into one mega-flock in the vicinity of the Route 7/Route 58 intersection.  At this point, the flock may be more than a half-mile wide and flow overhead for more than one hour before dusk.   In the past, research featured in The Birds of Delaware has placed estimates on the size of this wintering blackbird flock at more than 300 million.
My challenge this past Monday night: could I devise a way to count the blackbirds at one point in their flight path and come up with a conservative count of one of these blackbird masses? 

Yet another segment of the blackbird flock photographed on February 20, 2012 at Middle Run Natural Area. How many are in this frame? 386 to be exact! Image by Derek Stoner.

Arriving at the Middle Run Natural Area parking lot at 5:15pm, I found a constant stream of blackbirds flying directly overhead and flying to the Northeast.  A half-mile to the north, another stream of blackbirds flowed by on the other side of the Middle Run Valley.  Positioned near a tree, I set about observing the way the flock was flowing by.   I used my digital SLR camera to take photos of sections of the flock directly overhead, and found that every frame captured about two seconds of the flock’s passage– meaning that an individual blackbird travelled directly overhead through my camera’s field of view in two seconds ( By looking at unique clusters of birds I could follow them through each photo frame). 

Another section of the blackbird flock streaming overhead at Middle Run on February 20, 2012, this time with 323 blackbirds counted. Image by Derek Stoner.

To count the number of birds in each section of the flock, I took a series of 5 images two seconds apart.  This helped to establish a sample of the birds passing by during a period of 10 seconds.  I repeated this series three times at random points throughout the blackbird flight, to end up with a total of 20 sample images. 

The blackbird flight ended at 6:06pm, meaning that for 51 minutes the stream of blackbirds had flowed overhead (with a second, equal-sized flock to the north as well) continuously.   There was no break or interruption in the flight.

I headed back to the lab (my desk at Ashland), printed out each photo, and painstakingly counted every bird in each image by using a yellow highlighter to mark the individual birds.  The first series was revealing, with frames showing blackbird totals of 323, 296,386, 386, and 311 ( I would have guessed more like 150-200 birds per image).  The second series yielded 387, 353, 364, 342, and 384.   The third and fourth series were very similar, and yielded an overall average of 340 blackbirds per frame.   

At a rate of 340 blackbirds every 2 seconds, this equates to an average of 10,200 blackbirds per minute.  Over a total of 51 minutes of continuous flight, this calculation equals 520,200 blackbirds.  Multiplied by two to account for the other similar flock to the north, this equates to a total of 1,040,000 blackbirds passing by during the period of observation at Middle Run. 

Here is where the story gets interesting (in case you’ve been lulled to sleep by all the math so far!).  My camera only captured some of the flock passing overhead, so not all blackbirds could be sampled and counted.  This fact, in my opinion, helps ensure that I am under-counting and being conservative in the final flock estimate.   Careful evaluation of the images helped me discover that an average of 26 Common Grackles were in each flock section, which extrapolates to about 80,784 total Common Grackles in total.    Noting that the rest of the flocks consisted of almost exclusively Red-winged Blackbirds (with a few Brown-headed Cowbirds thrown in), this results in an estimated 959,616 Red-winged Blackbirds in the two flocks.

I dutifully entered my observations and carefully calculated numbers to the Great Backyard Bird Count, knowing that the numbers would be “flagged” as abnormally high.  Who really “counts” a million birds at a time?  But I know without a doubt that I vastly under-estimated the blackbird numbers that evening, and that if we could view all the blackbirds at once in northern Delaware, there would be many more millions to observe!

Do you have other ideas or suggestions on how to count the individuals in blackbird flocks?  Please share your thoughts in our Comments section!