By Kristen Travers

Snowy, icy days can make us thankful for the salt applied to make our roads safer yet road salt has a less safe side for our waterways. When ice and snow melt, the salt goes with it, washing into our streams and groundwater. As with people, streams are healthier on a low-salt diet as high salt concentrations can harm plants, fish and other wildlife. And considering how easily salt can corrode our cars it’s not surprising that high salt levels can impact infrastructure including roads and pipes and municipal and industrial processes that use water from streams.
Salt visible on a roadway

To understand the potential issues with road salt, volunteers and staff from the White Clay Wild and Scenic Program, Delaware Nature Society, and the Nature Conservancy have been monitoring our local streams.

On Mill Creek – a tributary of White Clay Creek – in Hockessin, average conductivity (a measure related to the level of dissolved salts) have shown large spikes over the winter season as melting snow and rain have flushed salt into streams and groundwater.
Graph showing average conductivity

These high peaks – which correspond to winter rain & snow events – are not seen during other times of the year.

Larger spikes were also documented on Hurricane Run, a small stream near Talleyville DE, which flows into the Brandywine Creek. The high spikes are probably correlated to snow melt and rain washing salt off the many roads and parking areas around Concord Pike.

Chloride concentrations over 250 ppm can make water taste salty and levels over 800 ppm are harmful to aquatic life.

While there are no easy solutions to the road salt quandary, municipalities and homeowners can consider smart salting practices including:

  • Consider using sand and alternate products for sidewalks and driveways
  • Reposition downspouts and snow piles so that water and melting snow isn’t refreezing on paved surfaces
  • Keep salt piles covered
  • Proper calibration of salting equipment and training programs for salt applicators

To learn more and get involved with other projects contact:





Ian Stewart

The global Great Backyard Bird Count took place from February 16th to the 19th and was a huge success. Despite its misleading name, participants counted every bird they saw no matter how far they were from home, with more than 6,000 bird species recorded across the world from over 160,000 checklists! Delaware Nature Society played its part with 10 people joining Joe Sebastiani and Matt Babbitt on a bird-filled tour of Port Penn Wetlands, the Aquatic Resources Education Center, Bombay Hook NWR, and Port Mahon Road, finding over 50 species in the process including a rare Tree Swallow.

Although the global comparisons are fun, what’s really fascinating is to sift through the species and checklist totals from each US state (https://ebird.org/gbbc/region/US/regions?yr=cur&m=). The top 3 in terms of species seen were California (370), Texas (358) and Florida (288) with Delaware coming in 24th with a very respectable 145 species. The top 3 in terms of checklists submitted were again California and Texas (8,113 and 6,389 respectively) and New York (6,154) with Delaware coming in 37th with a decent 709.

DNS Members enjoying a duck extravaganza at Port Penn

But wait, I hear you cry! Surely this is unfair! California, Texas and Florida are all large states with extensive oceanic coastlines and inland water bodies and because of their southern latitude have resident tropical birds that we can only dream of. Furthermore, large parts of these states have mild or even warm winters so their birdlife gets supplemented by migrants that summered much further north. California, Texas and New York all contain huge numbers of people which presumably translates to lots of birders so it’s hardly a surprise that these 3 states produce the largest numbers of checklists.

I decided to see how Delaware fared during the GBBC once you take into account our small population (ranked 45th in the nation) and size (ranked just 49th!). To do this, I simply divided the number of species seen and checklists submitted from each state by their population (in millions) and size (total land area).

Sure enough, once you control for population size (as a crude estimate of the number of birders) we jump to second in the nation!

State Species per 1M persons
1. Alaska 158
2. Delaware 152
3. Wyoming 147
50. New York 9

And when you take into account our small size, Delaware recorded the second highest number of species in the country.

State Species per 1000 square miles
1. Rhode Island 74
2. Delaware 58
3. Connecticut 24
50. Alaska 0.2

The number of checklists is also an interesting statistic although obviously they aren’t all created equal. One checklist may summarize birds seen by a large group of experienced birders during an intense 6-hour search of a large, rural, mixed-habitat wildlife preserve while another could be birds seen at an urban backyard feeder by a relative novice during a 15 minute coffee break. Still, when you account for population size, we generated the third highest number of checklists in America.

State Checklists per 1M persons
1. Vermont 1503
2. Maine 918
3. Delaware 745
50. Nevada 119

And when you take into account our small size, Delaware produced the third highest number of checklists in the US!

State Checklists per 1000 square miles
1. New Jersey 325
2. Connecticut 292
3. Delaware 285
50. Alaska 1

Admittedly, trying to boil down differences between state bird lists based on just their size or population is simplistic. The dramatic differences between states in their habitat diversity and latitude and longitude means you are never comparing like with like. For example, birders in coastal states see large numbers of seabirds and shorebirds which are hard to find further inland. Freshwater lakes or marshes in the south will have more waterbirds than those in the frozen north. Plus, even though some states are huge a large proportion of their area is inhabited by very few people let alone birders, and so only a small proportion receives coverage. I’m sure there are many more bird-related differences between states you can think of yourself.

But it’s these exact same caveats that make Delaware such a fantastic place to live if you like birds! Because we are mid-latitude we get a sprinkling of unusual birds from further north plus a few rarities from further south. We have freshwater, seawater, estuaries, lakes and ponds, marshes, plowed fields and pasture, pine woods, deciduous woods, urban habitats, suburbs and a big open sky. This diversity of habitats was probably the main reason the Delaware GBBC produced such an amazing diversity of birds despite our small population and size. To all the Delaware birders who contributed to the GBBC (and you know who you are) I say well done! We’re in the Top 3!

If you want to continue to enjoy birds, why not come along on these upcoming DNS events and bird walks?

Dinner and Owls

February 28
Coverdale Farm

Led by Jim White and Courtney McKinley. Get close up looks at the rare Long-eared Owl, and search for other owls like Screech and Great Horned Owls. Dinner and an owl presentation are included too!

Frogs and Woodcocks

March 28
Coverdale Farm

Led by Jim White.Take a walk in the evening to find chorusing frogs and see the amazing display of the American Woodcock.

Tuesday Bird Walks (April/May)

8am, Middle Run Natural Area
Free, just meet in the parking lot

Thursday Bird Walks (April/May)

8am,Ashland Nature Center
Free, just meet in the parking lot


By Shannon Giordano, Public Relations & Social Media Coordinator

Fall is a prime time for planting trees, and Delaware Nature Society has planted quite a few in the last three weeks. Planting trees in the fall can be the best time because the trees are going dormant for the winter and the ground is often very moist, which means when spring comes and the soil starts to warm, the trees will be ready to grow.

In the past several weeks, Delaware Nature Society has planted over 600 trees at three locations. On October 27 at Coverdale Farm Preserve, the planting of 12 enormous Red Oaks and Bicolor Oaks with 9 foot root balls and full canopies began. They were brought in one at a time by truck and are being placed in a section of field that is currently used for feed hay. This planting is part of Coverdale’s 10-year Master Plan. The field the trees were planted in will be turned into a grazing pasture that will house movable animal shelters. These trees were planted in a specific area in order to create a buffer for the Farm’s neighbors, and provide shade and forage for the livestock. All 12 of the trees have been put into the ground and other areas of the farm are designated for reforestation in the future. A big thank you goes to Hank Davis who not only funded the purchase of the trees, but hand selected the trees and is also funding their installation. Hank is a true champion of Coverdale Farm Preserve, and for that we are ever grateful.

Last weekend, two large tree planting events were held on Saturday morning. The first event took place at Middle Run Natural Area where approximately 150 volunteers helped to plant 400 trees. The tree planting is just one aspect of the biodiversity management project that Delaware Nature Society manages at Middle Run under contract with New Castle County. Jim White, DelNature’s Senior Fellow for Land Biodiversity Management, heads up the planting efforts each year. “We are working to increase the park’s forest habitat as well as to increase stream buffers next to Middle Run, which is a tributary of White Clay Creek,” says Jim. Increasing forest habitat provides food and shelter for a wide variety of native wildlife. Stream buffers slow down and filter pollutants and help to reduce erosion. Tree planting also has many other benefits, including making a positive impact on climate change. County Executive, Matthew Meyer also attended the event, lending a hand with the planting. Since 1991, thousands of volunteers have helped to plant about 55,000 trees at this New Castle County park, which is located near Paper Mill and Possum Park roads in Newark.

The second planting event last weekend was held at DuPont Environmental Education Center (DEEC). The Rotary Club of Wilmington planted 200 trees in the Russel Peterson Urban Wildlife Refuge with staff from the DNREC Division of Fish and Wildlife.  The project was funded by members of the Rotary Club who donated $2,000 for the trees along with funding from DNREC. The tree planting is part of an effort over the past 20 years to restore the freshwater tidal marsh with native plants to provide habitat for waterfowl, song birds, deer, raccoon, beaver, and even river otter. The Rotary Club of Wilmington planted the trees as part of a challenge to all Rotary Clubs across the globe. International Rotary President, Ian H.S. Riseley challenged every Rotary club to make a difference by planting one tree for each of its members between the start of the Rotary year on July 1, 2017 and Earth Day on April 22, 2018.

A sincere thank you to everyone who was a part of each of these events!

Ian Stewart, Ornithologist

One of the best ways to connect with nature is to monitor bird nest boxes. Regularly checking the contents of an active nest box lets you watch the whole breeding cycle unfold before your very eyes! It starts with nest building, progresses through egg laying and nestling rearing and then (hopefully) ends with the young birds successfully leaving the nest.


Using an mirror to count Bluebird eggs

The Delaware Nature Society has a team of eager volunteers who monitor over two hundred boxes spread throughout several properties and every year brings more data and surprises. Our most common occupants are Tree Swallows, Eastern Bluebirds and House Wrens but most years we attract a few Carolina Chickadees, Carolina Wrens and Tufted Titmice. One year we had a White-breasted Nuthatch use one of our boxes – who knows what species might show up next?!

Chickadee on nest

Opening this nest box revealed a Carolina Chickadee sitting tightly on a nest. In these cases we leave the bird alone and retreat.

Checking boxes lets you see for yourself the many differences between each species in the way their nests are built, the shape and color of their eggs, and the appearance of their nestlings, as well as the nesting quirks of different birds. Did you know for instance that House Wrens often add spider cocoons to their nest, probably because the spider hatchlings eat arthropod pests mixed in among the nest lining?

Wren nest with spiders

House Wren nest lining dotted with spider cocoons

Our boxes remain in place year-round and provide winter refuges for both welcome and (slightly) unwelcome guests. Eastern Bluebirds roost in our boxes overnight during the winter, presumably to help them stay warm, and sometimes bundle together in the same box. Last winter one of our boxes at Coverdale Farm Preserve had an enlarged entrance hole and was filled with acorns from the huge old Red Oaks that line the driveway. This was probably a squirrel using the box to cache a supply of acorns to chomp on if a sudden snowfall made food hard to find.

chewed box


Mice also like to spend the winter in our boxes so we have to bump them out to allow the birds to nest. Can you spot the two mice jumping out of the box?


We have been cleaning out our boxes to get them ready for spring and the birds are checking them out already so nesting isn’t far away! We can always use an extra person or two to help monitor nest boxes at Coverdale Farm or the Red Clay Reservation near Greenville, or Abbott’s Mill near Milford, so if you want to get involved just give us a call on (302) 239-2334. Boxes only need to be checked once a week and monitoring them makes a great excuse for talking a walk on a summer evening or weekend at these beautiful sites. All of our data are submitted to Cornell University’s ‘Nest Watch’ scheme so we are contributing to science as well as simply enjoying nature.

If you’d rather put up your own nest boxes why not join our upcoming program (April 27th at Ashland followed by a field trip to Coverdale on April 29th) to get advice on how to design and position boxes in order to attract nesting birds to your property? Having birds nest in a box you built yourself is a tremendously satisfying experience that may be repeated for many summers to come!

Tree swallows on box

A pair of excited Tree Swallows start building their nest in a brand-new box