Bucktoe Creek Preserve

Ian Stewart

American Goldfinches are one of my favorite birds. Their scientific name, Spinus tristis, translates as ‘Sad bird of thorn bushes’ and derives from their mournful rubber-duck like ‘squeak’ call. Personally, I think this name is unfair, as Goldfinches always seem such happy, colorful characters (like the female pictured below) with their jaunty, bouncy flight and excited twittering. They are common birds which can lead to them being overlooked and yet they have two major surprises under their wing.

The first is that they breed very late in the summer. Once you get past mid-August only a handful of birds are still breeding in Delaware but the Goldfinch is one of these select few, along with the related Indigo Bunting and Blue Grosbeak. The main reason we think Goldfinches breed so late is that they feed their young entirely on seeds, rather than invertebrates like almost all small birds, so they have to delay breeding until the seed heads begin to appear. The favorite food of Goldfinches includes Purple Coneflower (Echinacea purpurea) and Wild Bergamot (Monarda fistulosa), as well as a range of native and unfortunately, non-native, thistles.

Goldfinches build beautiful, densely-woven nests of fibrous materials such as thistle down and grasses in which they lay 2-5 bluish-white eggs (nest photographed at Bucktoe Creek on July 23).  The nestlings develop in around 2 weeks and fledge resembling duller versions of their parents with brownish wing bars and dark beaks (nestlings photographed in a different nest on August 5, just before they fledged).

The Goldfinches’ second surprise is that they are the only finch that molts their body feathers twice a year. Both sexes are a drab yellowish-green in the fall and winter, perhaps to avoid being seen by predators like hawks, but become brighter yellow in the summertime. The males are especially striking with their lemon yellow body, jet-black wings and cap, and white tail flashes.

The sight of a flock of Goldfinches feeding in a field of native thistle is enough to gladden the heart of any birdwatcher, and luckily Goldfinches are quite easy to attract to your yard, even in fairly urban areas. You can buy sock feeders of nyjer seeds or tube feeders made specifically for Goldfinches with thin seed ports. Since Goldfinches have such small pointed beaks they are the only common bird in our area that can reach inside and pick out the nyjer seeds. They will also happily eat black oil sunflower seed from a generic tube or platform feeder which has the added benefit of attracting other birds too. Better still, try planting some patches of Coneflower or native thistle in your yard and watch them feed how nature intended!

By Ian Stewart, Ornithologist

Orioles are a type of blackbird that are famous for having both beautiful plumage and a lovely musical song and we are fortunate indeed to have two of them breeding around our area.

Baltimore Orioles build distinctive hanging basket nests along the edges of forests and usually remain quite high in the trees where they feed on berries, nectar and insects, especially tent caterpillars. However, while bird-banding in May we were pleasantly surprised to find a male in one of our mist-nets!

Male Baltimore Oriole

Male Baltimore Oriole

The male Baltimore Oriole is a stunning bird with a jet black head and wings that seem to enhance the brightness of its orange body and shoulders. It was so named because these colors were similar to the coat of arms of Lord Baltimore, the first Governor of Maryland. When seen up close the breast feathers are particularly deeply colored.

Deep orange breast of the male Baltimore Oriole

Deep orange breast of the male Baltimore Oriole

The Orchard Oriole is quite a lot smaller than the Baltimore (only 20 grams vs 35 grams) and is more common in open areas with low trees and bushes where it feeds on insects and an increasing amount of fruit later in the summer. We caught and banded several of them recently in the meadow at Bucktoe Creek Preserve where they were probably feeding on blackberries. Older male Orchard Orioles have a black head and wings but their body and shoulders are a rich chestnut.

Male Orchard Oriole

Male Orchard Oriole

Interestingly, first-year male Orchard Orioles closely resemble the greenish-yellow females but have a distinctive black patch on their throat.

1st Year Male Orchard Oriole

1st year Male Orchard Oriole (if you look carefully you can see a few chestnut feathers on the breast)

Another curious oriole feature is easiest to see up close – they both have a peculiar grayish-blue base to their lower beak.

Blue lower beak of male Orchard Oriole

Blue lower beak of male Orchard Oriole

Both orioles spend the winter in the tropics and Orchard Orioles are already leaving, with most being gone by mid-August, at which point Baltimore Orioles also start to slink quietly away. Try to get outside and see these flaming songsters before it’s too late!

Visit the Bird Banding Stations at Ashland Nature Center (Monday 8am-11am) and Bucktoe Creek Preserve (Wednesday 8am-11am) to join Ian Stewart as he bands, measures, and documents the birds at these locations.

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 Dr. Ian Stewart, Ornithologist and Naturalist

Thanks to a generous donation, Ashland Nature Center and nearby Bucktoe Creek Preserve are hosting a bird banding project that the public is welcome to visit. Bird banding is an important tool for scientists and conservationists since tagging individuals helps us figure out if they remain in the same site year-round, or in the case of long-distance migrants, where they spend their summers and winters and which routes they take. Basically, birds are caught in fine nets erected along trails then carefully removed and fitted with a uniquely numbered metal band before being released. Because the birds’ welfare is the highest priority, we check the nets every 10-15 minutes and do not operate them on very windy or rainy days. Also, it requires many years of practice with extracting and banding birds before one can be granted a federal license to do so.

A Wood Thrush in a mist-net.

A Wood Thrush in a mist-net.

With the help of a crew of volunteer assistants (Steve, Angie, Kelley and Carol), we have caught over 150 birds from 25 species, primarily Gray Catbirds, Tufted Titmice and Northern Cardinals (and yes, they bite!), but also some really neat birds like Brown Thrasher, Willow Flycatcher and Northern Flicker. We obtain as much data as we can from each bird including its age, sex, body size and molt status to answer questions about how these vary between sites and different habitats. It’s much easier to work out the age or sex of bird species if you are actually holding them, and banding birds helps you notice many things you’ve never seen before. For example, the Tufted Titmouse in the top photo below is an adult, but the one in the bottom photo is a juvenile, as can be told by the yellow eye ring and yellow flanges (the fleshy corners of the beak left over from when it was a nestling).

An adult Tufted Titmouse.

An adult Tufted Titmouse.  Can you see the small tick just above the right side of the eye?

A juvenile Tufted Titmouse.

A juvenile Tufted Titmouse.

Also, the male Eastern Towhee in the bottom photo below was likely hatched last year (2014) since it still has some brown juvenile feathers on its head while the one in the top photo was likely hatched in 2013 or even earlier as it has a solid black head. Look at those amazing red eyes!

An adult Eastern Towhee.

An older adult Eastern Towhee.

A juvenile Eastern Towhee.

A younger Eastern Towhee.

Some features on certain birds are only evident when you see them up close. For instance, the bright red eye of this Red-eyed Vireo is hard to see in the wild because they usually forage quite high up in the trees. In the hand, the red eye is striking and you can also the see the small hook at the end of the vireo’s bill, a feature that distinguishes them from warblers.

A Red-eyed Vireo up close, where it is easy to see the red eye and the hooked bill.

A Red-eyed Vireo up close, where it is easy to see the red eye and the hooked bill.

Note that mist-netting is an unpredictable business and so if you visit the banding station, we can’t guarantee you will see a bird being caught and banded. Cooler mornings can produce over a dozen birds though we catch fewer birds on hot, humid days, probably because the birds are less active. Nevertheless, even on quieter days, several lucky visitors have seen some great birds, including Downy Woodpeckers and a Northern Flicker. Woodpeckers are especially interesting up close, as one can see their unusual toe arrangement with 2 toes pointing forward and 2 pointing backward, unlike the standard arrangement of 3 toes forward and 1 back. This helps woodpeckers climb up tree trunks, as does their stiffened, spiky tail feathers.

The underside of a Flicker showing its distinctive toe arrangement and spiky tail feathers.

The underside of a Flicker showing its distinctive toe arrangement and spiky tail feathers.

In addition to its scientific value, bird banding is a fantastic educational tool, allowing for both adults and children to see birds up close.  By providing this experience, the Delaware Nature Society is helping people better appreciate key bird characteristics like their feathers and differences between species in plumage color and the shape of their feet or beak.  We are also banding nestlings of a variety of species found breeding in our nest boxes, including Eastern Bluebirds, Tree Swallows, and House Wrens, but also Tufted Titmice and Carolina Chickadees. If we are lucky some of these may turn up as adults next year! Dozens of children attending our summer camps have enjoyed checking out the nest boxes for eggs and nestlings, and some have been lucky enough to hold a baby bird!

Happy campers at Ashland Nature Center holding baby Eastern Bluebirds.

Happy campers at Ashland Nature Center holding baby Eastern Bluebirds.

Banding takes place at Ashland Nature Center on Monday and Tuesday 8am -11 am, and at Bucktoe Creek Preserve 8am – 11am, and will run through September. There is no charge to attend the banding, but for non-DNS members visiting Ashland, a trail fee applies.  We hope to see you at the banding station soon!  Songbird migration has started, and you never know what will turn up in the nets.