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All posts by Joe Sebastiani

By Ian Stewart, Ornithologist

Bird banding is in full swing at both Ashland Nature Center and Bucktoe Creek Preserve and our mist-nets are becoming dominated by Gray Catbirds! Gray Catbirds (Dumetella carolinensis) are grouped with Northern Mockingbirds and Brown Thrashers as ‘mimic-thrushes’ as all three are slender thrush-like birds with long tails and loud, elaborate songs. Indeed, catbirds get their name because of the peculiar cat-like ‘miaow’ call they often give while hidden low in a bush! Catbirds are by far the most common of the three mimic-thrushes however, and can be so abundant that many birdwatchers don’t give them a second glance. This is a pity, because catbirds have several interesting features which are particularly obvious when you are holding them during the banding process.

The first of these is the conspicuous rictal bristles around the base of their bill. Several other groups of birds have rictal bristles (especially flycatchers) and although their exact purpose is unknown they are thought to either have a sensory function or to prevent captured insects from scratching a bird’s eyes while they are being held in their bill.

Four rictal bristles can be seen at the base of this Gray Catbird's bill.

Four rictal bristles can be seen at the base of this Gray Catbird’s bill.

The second distinctive Catbird character is their crimson ‘crissum’. This is the patch of feathers underneath their tail which isn’t always easy to see in the field as Catbirds tend to stay fairly low to the ground. The third interesting plumage character of Catbirds, which can also be seen in the picture below, are the fairly obvious growth bars in their outer tail feathers. Growth bars appear as alternating light and dark bands and each pair of bands represents one 24 hour period of feather growth.

Underside of a Gray Catbird showing the crimson crissum and growth bars in the outer tail feathers.

Underside of a Gray Catbird showing the crimson crissum and growth bars in the outer tail feathers.

Not surprisingly, Catbirds were by far the most frequently caught species during the pilot banding project we conducted last summer at Ashland and Bucktoe. In just 3 months we caught 152 catbirds, of which 87 were juveniles likely hatched locally. So far this year we have recaptured 3 of the catbirds we banded last year and hope to recapture even more as the season progresses. It’s truly amazing to think that these 3 birds spent their winter over a thousand miles away in the south-eastern US or the Caribbean and yet came back to the same few hundred acre spots in DE and PA the following year!

The number on this metal leg band showed that this Gray Catbird was banded the previous year.

The number on this metal leg band showed that this Gray Catbird was banded the previous year.

So be sure to take a longer look at a Gray Catbird next time you see one. They are more interesting than you might think!

Public bird banding sessions are held at Ashland Nature Center on Monday and Bucktoe Creek on Wednesday, both from 8am – 11am, though banding does not take place if it is raining or windy, out of concerns for the birds’ safety.

Note that there will be no banding this Monday (May 30th) due to the Memorial Day Holiday.

By Guest Blogger: Martha Corrozi Narvaez

Associate Policy Scientist, Water Resources Agency, Institute for Public Administration, University of Delaware

On an unseasonably warm Sunday in February I walked hand-in-hand with my 4-year old son along Wilmington’s riverwalk that parallels the magnificent Christina River. As we walked we passed by couples, families, runners, and people of all types with the musings of ice skaters in the background. My son and I talked about the ducks swimming by, the swift current carrying sticks and other debris and the “mean people” that littered their bottles and trash in the river. I couldn’t help but think that just a few years ago I would not have been able to share this experience with him. I am fortunate to share such an experience with him and I also feel fortunate that I understand the complexity and state of this river.

Christina River on a warm winter day.

Christina River on a warm winter day.

It is easy to see that the Christina River has undergone an urban renaissance resulting in the Chase Center, Tubman-Garrett Riverfront Park, Christina Riverwalk, a variety of restaurants, high-rise residential buildings, the Blue Rocks stadium, and the DuPont Environmental Education Center’s wildlife refuge. This growth is spurred by people’s desire to be near the water and the aesthetic qualities it provides, yet beyond this beauty there is a complex, natural system at work.

The headwaters of the Christina River lie within the state of Maryland and enter Delaware west of Newark. The White Clay, Red Clay, and Brandywine creeks are tributaries of the Christina River. The Christina River is freshwater yet tidal from just south of the town of Christiana to its confluence with the Delaware River at Wilmington. Extensive tidal freshwater wetlands, including Churchmans Marsh, exist along the lower Christina. The majority of the Christina River watershed is located in New Castle County (DE). The Christina River is a mostly urbanized watershed with over 50% of the land cover developed. The watershed is the site of the Port of Wilmington, an important shipping link, and one of the largest importers of orange juice, Chilean grapes, bananas, and automobiles nationally.

Wilmington's Christina Riverfront

Wilmington’s Christina Riverfront

The Christina River has its share of historic contamination. There are numerous contaminated sites bordering the river. Samples have indicated that there are toxics present at elevated levels in the water bodies of the Christina River watershed and fish consumption advisories have been posted for the river. According to the USEPA’s water quality standards the Delaware portion of the Christina River requires varying levels of pollution reduction for nitrogen, phosphorus and bacteria.

Although the Christina River has fallen victim to years of industry, improper land use and anthropogenic influences the story of the river is a positive one. The state is working diligently to clean up and redevelop the toxic sites along the river. The Christina River is also demonstrating improving trends for many water quality parameters. According to a recent article on water quality trends in Delaware’s streams by Gerald Kauffman and Andrew Belden, water quality trend analysis for long term (1970/1980-2005) and short-term (1990-2005) trends show improvement in the Christina River for numerous water quality parameters including: dissolved oxygen (DO), total suspended sediment (TSS), total phosphorus (TP), and total Kjedahl nitrogen (TKN). Positive trends for these parameters indicate improving conditions in the river. Additional parameters, including bacteria, which levels have historically been increasing, show a leveling off for long-term and short-terms trends over this same time period, another good news story.

We know that the Christina River is not a pristine, natural river system yet research shows that there are positive signs for the health of the water body. The efforts by so many locally, state-wide and regionally to improve the water quality has had a positive impact. And as the riverfront becomes more popular and a destination in the region, it is my hope that individuals will learn more about the river and help protect this valuable resource through individual stewardship. And over the years as I continue to walk along the riverfront I will feel fortunate to be able to share this river, which inspires and motivates me, with so many people, especially my son.

Join us at DEEC on April 16 at 3:30pm for National Water Dance to celebrate the Christina River through dance performances and exploration of the marsh for the wildlife calling it home.

To find out more about efforts to improve and protect our waters or how you can have impact, check out the Clean Water: Delaware’s Clear Choice campaign website, Facebook, or Twitter!

By Derek Stoner, Seasonal Program Team Leader

A male Wood Frog makes his way to the breeding pools near the Ashland Marsh. Photo by Derek Stoner.

A male Wood Frog makes his way to the breeding pools near the Ashland Marsh. Photo by Derek Stoner.

The days are getting warmer, and all around us, Signs of Spring abound.   The first wildflowers of Spring are popping through the leaf litter layer, while amphibians like Wood Frogs are emerging from their Winter lair to make their way to wetlands for breeding purposes.

You are invited to take part in the Sixth Annual Signs of Spring Challenge through the Delaware Nature Society.  Each week for the next nine weeks, you encouraged to get outside and look for signs of plants emerging and animals arriving.  The species we selected as classic Signs of Spring are found widely throughout most of Delaware and southeastern Pennsylvania.

Clusters of Snowdrops-- a non-native wildflower- are emerging as the weather warms. Photo by Hilary Stoner.

Clusters of Snowdrops– a non-native wildflower- are emerging as the weather warms. Photo by Hilary Stoner.

The challenge is to find all 20 of these plants and animals, and make a note about the date that you find them.  Many are already out there and ready to be seen in this first full week of March, while others (like Barn Swallows and Trout Lily) are likely still weeks away from appearing.

Here is the link to open the Signs of Spring Challenge spreadsheet : Signs of Spring Challenge 2016

Enjoy exploring the outdoors this Spring, and please come out to one of our Delaware Nature Society-managed properties to explore and search for Signs of Spring with us!

Check out the upcoming programs through the Delaware Nature Society that will connect you with Signs of Spring during the month of March:

Early Spring Frogs and Woodcocks at Coverdale Farm,  Wednesday March 16, 5:30 to 8:00pm

Spring Equinox Hike and Campfire at Ashland, Sunday March 20, 5:00 to 7:00pm

Call 302-239-2334, extension 0 to register for these programs.

By Derek Stoner, Seasonal Program Team Leader

A young Two-toed Sloth nestles on its mother as she hangs upside down in a tree at our lunch stop. Photo by trip participant Rod Ellingsworth.

A young Two-toed Sloth nestles on its mother as she hangs upside down in a tree at our lunch stop. Photo by trip participant Rod Ellingsworth.

The Delaware Nature Society led a trip to Costa Rica recently, journeying from coast-to-coast in this verdant Central American country for twelve days in late October and early November of 2015.  The group, led by Derek Stoner and Judy Montgomery, began our adventure in the capital city of San Jose.  Aboard a tour bus with 20 participants, two trip leaders, a tour manager (Jose Saenz of Collette Travel) and our jovial bus driver Juan Carlos, we quickly exited the big city and headed into the wilds.  Here is the first installment in a series of five posts detailing our discoveries…

How often do you get to have lunch with a sloth?  After a delicious meal at Restaurant Ceibo, we turned our attention to the riot of wildlife that surrounded the building.  Right beside our tour bus, four different Two-toed Sloths could be observed in classic sloth-pose:  hanging leisurely upside-down and half-asleep.  A female with a young baby stole the show, as the youngster (showing very pale blonde hair on its head) changed positions on the nursing female.

Blue Jean Frogs, a species of poison dart frog named for its blue legs on a bright red body, clamber around the base of a Kapok (Ceibo) tree. Photo by trip participant Rod Ellingsworth.

Blue Jean Frogs, a type of poison dart frog named for its blue legs on a bright red body, clamber around the base of a Kapok (Ceibo) tree. Photo by trip participant Rod Ellingsworth.

Soon we loaded up in the bus and continued our day’s journey towards to Caribbean coast.  At the end of a dusty, bumpy road we came to the “boat ramp” which consisted of an eroded bank plunging into the crocodile-inhabited waters of the Tortuguero River.  Jumping aboard with our luggage into a 40-foot long, shallow-draft boat, we held onto the sides of the vessel as we rocketed down the narrow channel of the river.

A Basilisk lizard lounges along the Tortuguero River in Costa Rica. Photo by Derek Stoner.

A Basilisk lizard lounges along the Tortuguero River in Costa Rica. Photo by Derek Stoner.

Along the high banks of the river, we spied droopy-eyed Brahma cattle– the type of bovine that thrives in the heat and humidity of the tropics.  Around one bend we came across a large American Crocodile (12+ feet long) hauled out on the sunny sandbar.   Cattle Egrets, Little Blue Herons, Great Egrets, and other wading birds flushed and swirled away as our boat encroached on their zone of comfort.

But the real excitement came when we began spotting the beautiful Basilisks, a species of large golden-green lizard that is most famous for its ability to skip across the water on its hind legs.  The moniker of “Jesus Christ Lizard” is what makes this species most famous, and the question in our minds was:  Would we get to see these amazing reptiles actually walk on water?

Stay tuned for the answer to that question and more highlights from our Costa Rica adventure…