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By Ian Stewart

For over 4 decades Delaware Nature Society has been providing homes for birds in the form of wooden nest boxes. We currently have over 200 boxes spread across the properties we own or help manage and every year literally hundreds of young Bluebirds, Tree Swallows, Chickadees and House Wrens fledge from our boxes. In some years we are pleasantly surprised to open one of our boxes and find nests of unexpected species like Carolina Wrens, Tufted Titmice or even White-breasted Nuthatches.

Adult male Purple Martin at gourd

This year one of our long-standing volunteers, Steve Cottrell, attempted to attract a new and charismatic species to our nesting list – the Purple Martin! The Purple Martin is the largest swallow in North America, and gets its name because the adult males have purplish-blue feathers over their whole body. Females are purple above but pale below and sub-adult males (those hatched the previous summer) look like females but have purple blotches on their breast. Martins are long-distance migrants that spend the winter way down in the Amazon Basin, especially Brazil, and many people across the country eagerly await the return of these shimmering gems each spring.

Purple Martins are widely but patchily distributed across the eastern United States because they tend to only nest in colonies of artificial houses and won’t be found where these aren’t present. Martins are quite fickle however, and many people erect brand-new houses in what seems like an ideal place (away from trees and preferably near a good source of insects) and yet never attract any martins. Steve was one of those unlucky people and had tried to attract martins to his yard for 5 years without success.

Steve in front of the Ashland Purple Martin tower

He therefore decided to donate his three Purple Martin towers to us! Each of these towers is equipped with a dozen plastic nesting gourds which are made of white so they stay cool inside and a large screw cap on the side for easy checking. Steve erected one tower at Ashland Nature Center and two at Bucktoe Creek Preserve near Kennett Square, Pennsylvania.

Steve lowers the martin gourds to check contents

Steve and Delaware Nature Society staff members anxiously watched the towers throughout spring and were thrilled to spot martins perched at all three towers in late April! We had an even bigger thrill last week when we found at least one Purple Martin nest with eggs at both of the Bucktoe towers and then just today, a nest with 5 eggs at Ashland! This is the first confirmed breeding by Purple Martins at both Ashland and Bucktoe!

Steve checking the Ashland gourds for nests

Eggs found in the Ashland tower

We will be checking the gourds each week to follow these nesting attempts and see if we are lucky enough to get any more. Later in the summer we hope to band any nestlings produced to try and track their movements during migration and winter and also see if any return to our sites in 2019!

We will also be banding nestling Purple Martins at their long-established colony at DNS’s Abbott’s Mill site in Milford on June 30th and at Flint Woods Preserve in Centerville on July 11th so check out those programs if you want to see these beautiful birds up close.

And if you want to try to attract them to your own property, check out Wild Birds Unlimited in Hockessin and the Purple Martin Conservation Association’s website at https://www.purplemartin.org/. Be lucky!

By Kristen Travers

April and May showers may bring flowers but for our streams rain can also bring problems. Recent rains have resulted in our streams resembling unappetizing chocolate milk more than the clear clean water that we want to see.

Before many people lived in the Delaware region, most of our area was covered in forests, wetlands and marshes. When it rained most of the rain water would slowly infiltrate (soak) into the ground and into the groundwater. Today our landscape also includes homes, businesses, and shopping centers. Rain water can’t soak through impervious surfaces such as roads, building and parking lots but instead runs over these surfaces picking up contaminants and sediment and quickly flowing into our waterways.

Data on our local streams clearly shows how as stream flow increases during storm events, so does the cloudiness of the water as measured by turbidity – a measure of the relative amount of suspended particles such as sediment.

Bare soil, dirt exposed from poor construction and farming practices, and stream bank erosion caused by excessive flows cause increased turbidity. Muddy water harms aquatic life, smothers habitat, and increases water temperatures. It can also be a health concern to drinking water sources and recreational uses since harmful microbes found in animal and human waste bind to soil particles.

Providing opportunities for rain water to slowly infiltrate into the ground can keep pollutants and sediment out of our waters while reducing flooding

Rainwater and soil are assets that should be kept in place:

  • Soak it Up: Add native shrubs, trees or perennial plants who’s deep root systems help to break-up soil and promote infiltration, while also holding the soil in place.
  • Cover it Up: Cover bare soil with mulch and more importantly plants!
  • Prevent It: Minimize chemical use on lawns and in our houses, don’t mow right up to the creek, and pick up after your pets.

Thank you to the volunteers involved with the Delaware Nature Society Stream Watch, White Clay Wild & Scenic program, and Nature Conservancy Stream Stewards for their dedication to monitoring and improving the health of our waters.

 

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:

www.delnature.org

www.nature.org/ourinitiatives/regions/northamerica/unitedstates/delaware/index.htm

whiteclay.org/

 

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
5:30pm
$20/$25
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
5:30pm
$15/$20
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