Archives

All posts by Shannon Giordano

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/

 

By Ian Stewart

Delaware Nature Society has over 200 nest boxes spread around the properties we own or help manage which we installed to provide nest sites for a variety of birds. Every summer these boxes are monitored by a team of volunteers who track over 100 nesting attempts by 5-6 bird species (and we are always looking for more people to help with this – please get in touch if you’d like to get involved!). You’d be wrong to think the boxes stand idle throughout the winter however – it’s just that most of the action now takes place at night!

Several birds often roost in them during the winter, including Screech Owls, Eastern Bluebirds and some woodpeckers, which they probably do to protect them from the elements such as wind and rain. It is likely several degrees warmer inside a nest box than outside of it and for a small bird on a very cold night this could be the difference between life and death. Bluebirds take this a little further and are famous for ‘bundling’, where several birds squeeze into the same box for the night, probably keeping each other warm with their body heat.

A male bluebird entering a nest box

A male bluebird entering a nest box in winter

This year we’re making a special effort to check our boxes during the winter too. Sometimes it’s obvious that birds have been roosting in our boxes as they leave their droppings behind. The droppings in the photo below were almost certainly from a bluebird that has been eating Oriental Bittersweet. Bluebirds usually eat insects but at this time of year these are hard to find so they switch their diet to berries, and this exotic invasive vine is one of the few local plants that still has berries on it in February. You can help bluebirds in winter by planting berry-producing native bushes and shrubs such as Winterberry, Viburnums and Hollies. We will be following these boxes all through the year to see if bluebirds end up nesting in the same boxes that were used in winter.

Bluebird droppings inside a nest box

Bluebird droppings show they have been using this nest box

It’s also worth checking nest boxes in winter for less-desirable occupants. About 10% of our nest boxes are occupied by white-footed or deer mice during the winter. These nocturnal mice build fluffy nests inside boxes and sleep in them during the day. We always dump out mice and their nests during the winter, which may seem unkind but if left in place their urine and feces can damage boxes or carry disease, and birds won’t use boxes already occupied by mice. If you do this yourself, don’t use your hands to dislodge mice and their nests in case you pick up any disease or get bitten, but instead gently ease out the box contents with a stout stick.

Two deer mice fast asleep in this box

Two deer mice fast asleep in this box

This box at Coverdale Farm Preserve contained a furry nest with no fewer than 15 uneaten hickory nuts, which was interesting as this is not a common tree at the Preserve. These had probably been stored in the box by a Flying Squirrel, a nocturnal mammal which does not hibernate and requires food all winter. The squirrel cached the nuts here to provide a food supply for later in the winter, so to be sure the little guy wouldn’t go hungry we left the nuts below the box.

Hickory nuts cached in this nest box by a flying squirrel

Hickory nuts cached in this nest box by a flying squirrel

So just because you never see anything going inside your nest boxes in winter, don’t assume they aren’t being used!