General Ecology

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!

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.

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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

acorns

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?

mice2

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

By Derek Stoner, Seasonal Program Coordinator

A Wood Frog makes its way down to the marsh at Ashland on March 1, 2011.  What day will they emerge this year?

A Wood Frog makes its way down to the marsh at Ashland on March 1, 2011. What day will they emerge this year?

Spring officially begins today–  Friday, March 20th.  The weather outside may still not look like Spring, but the season has been pushing the envelope recently as Winter slowly relinquishes its grip and gives way to the inevitable arrival of true Signs of Spring:  the plants and animals that we count on as true signals of the changing season.

Just in the past week at Ashland Nature Center, keen observers have noted emerging Skunk Cabbage, Groundhogs running about, and Snowdrops in full bloom.   With warmer temperatures and rain in the future forecast, the big movement of amphibians to the wetland habitats will get underway.

To preview photos of Signs of Spring that are on the way, we invite you to view this video.

The twenty plants and animals shown in the video are the unique Signs of Spring selected to be part of our fifth annual Delaware Nature Society Signs of Spring Challenge.  Wherever you are this Spring, keep an eye out for these interesting sights and make a note of when you first observe them outdoors.  See how quickly you can tally up the full twenty!  Will it take you through the month of May or will you find them all by the end of April?  Only time will tell, and you can share this challenge with your fellow naturalists and family members.

To participate, click here:   Signs of Spring Challenge 2015

Download and print this form to keep track of your observations this Spring.  The challenge is free and just for fun– and you are the winner since you’ll be enjoying a more rewarding experience afield this Spring.

Please photograph and document the Signs of Spring that you see and share them with us by email at derek@delnature.org .  We will post a collection of the best photographs and stories from Spring 2015 in a follow-up post at the conclusion of the Spring season.

By Lori Athey, Habitat Outreach Coordinator

What are birds eating right now in your backyard habitat?  If you have trees or shrubs in your yard that hold fruit all winter, American Robins, Cedar Waxwings, Eastern Bluebirds, and even European Starlings are probably enjoying whatever fruits that are remaining. 

Winterberry is a native shrub that holds its fruit all winter, or at least until hungry birds eat it.  Eastern Bluebirds, American Robins, and Hermit Thrush are species that will be attracted to this in your landscape.  Photo by Lori Athey.

Winterberry is a native shrub that holds its fruit all winter, or at least until hungry birds eat it. Eastern Bluebirds, American Robins, and Hermit Thrush are species that will be attracted to this in your landscape. Photo by Lori Athey.

If you haven’t yet cut back your asters, coreopsis, and coneflowers, seed-eating birds will be pecking at the old flowerheads and on the ground beneath for fallen seeds.  When there is extended snow-cover, it is especially important for birds to be able to access seeds on old flower-heads above the snow, since they can’t get to the ones on the ground.  American Goldfinches are famous for this type of behavior, but others that can be found doing this in the yard include Dark-eyed Juncos, Field Sparrows, American Tree Sparrows and Pine Siskins.

Standing stalks of seed bearing plants like Purple Coneflower provide food for a number of bird species such as American Goldfinches.  Photo by Lori Athey.

Standing stalks of seed bearing plants like Purple Coneflower provide food for a number of bird species such as American Goldfinches. Photo by Lori Athey.

How do you provide food for birds that do not eat seeds or fruits?  Lately, I have seen birds digging through the fallen leaves in my landscape beds.  Did you know that leaf litter is full of insects, spiders, and other goodies that your birds can eat in winter? In addition, toads, fireflys, some butterflies, and other beneficial insects winter in those leaves.  Often, flocks of American Robin, Common Grackle, Northern Flicker, Carolina Wren, Eastern Towhee and other sparrow species can be seen digging through leaf-litter for protein-packed overwintering insects and spiders.  

Consider leaving leaf litter on your flower beds not only as mulch, but to provide habitat for insects, spiders, crustaceans, snails and other small organisms that birds will seek out.  Photo by Lori Athey.

Consider leaving leaf litter on your flower beds not only as mulch, but to provide habitat for insects, spiders, crustaceans, snails and other small organisms that birds will seek out. Photo by Lori Athey.

So next year, rake those fallen leaves into your landscaped beds for the wildlife. Forget about shredding them –that kills beneficial insects and takes away that nice warm blanket that toads and others crave for their winter rest. Delay cutting back your seed bearing perennials until spring. And yes, add more fruiting shrubs and seeding wildflowers to your landscape next year for the birds too –you can get them all at the Delaware Nature Society Native Plant Sale, May 1-4.

 

Some plants to consider for providing late-winter bird food:

Chokeberry (Aronia species)

American Holly (Ilex opaca)

Winterberry Holly (Ilex verticillata)

Bayberry (Morella species) – Yellow-rumped Warblers love it!

Virginia Rose (Rosa virginiana)

Pines (Pine species) – (Red-breasted Nuthatches seek out pine nuts)

Cone flowers & Black-eyed Susans (Rudbeckia species)

Purple Coneflowers (Echinacea purpurea NOT doubles)

Tickseed & Coreopsis (Coreopsis species)