The Nature of Delaware

by The Unknown Astronomer

I hope you all had unclouded views of the gorgeous conjunction of Venus, Jupiter, and the moon last weekend, and that you continue to observe Jupiter in decline and Venus ascendant.  Of course, the two planets are not really approaching and receding from one another in space.  What is actually going on is more a race than a dance.

Jupiter, Venus and Moon, Dec 1, 2008. Image from Starry Night Pro Software

Picture a circular track with the sun in the center.  The innermost lane is occupied by the planet Mercury, whizzing around the track like Jimmie Johnson at Dover Downs, and completing its circuit in a mere 88 days.  Venus is in lane 2, making its journey in a zippy 243 days – not exactly NASCAR, but at least a turbo-charged Mustang.  Earth orbits in lane 3, getting once around in a respectable 365 days – the Mustang minus the turbocharger. By the time we get to lane 6, way out beyond Mars and the asteroids, it’s taking 12 years to complete one circuit.  That’s Jupiter – a Yugo driven by your grandmother.

So, what we have been observing over the last couple of weeks is a nightly snapshot of speedy Venus overtaking plodding Jupiter, from the perspective of lane 3.

Another effect of where we all are in space (or on that track) is the sometimes peculiar look of Venus through a telescope.  Right now it appears to be a tiny half-moon!  Indeed, like the moon, Venus (and Mercury) has phases, and for the same reason:  since it is inward toward the sun from our perspective on Earth (lane 2 as seen from lane 3), the planet will at times be only partially lit, appearing as full,  half, or crescent as it approaches and overtakes the Earth.

Now, how do you follow an act like a planetary conjunction?  WIth a meteor shower!  The Geminids, so named because they appear to radiate from the constellation Gemini, peak on the night/morning of Dec. 13 – 14.  These are bright, medium-fast meteors that can be colorful: In addition to the usual white, I have seen distinctly yellow and green ones, and they can also be blue or even red.  You can start looking a little north of east any time after 8:00 pm.  Gemini will have just cleared the horizon by then, so the best time to observe is realy after midnight, when Gemini is high in the sky.  There is one major problem with this year’s shower, however – we will be just one night removed from the largest, closest, brightest full moon of 2008, which will blot out all but the brightest meteors.  Ah, the moon – beloved of poets and romantics, bane of astronomers…

No matter which category you fit into, if it’s clear, brave the cold anyway – at it’s height,  this shower can produce a meteor a minute!

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By John Harrod, Backyard Habitat Coordinator

Yesterday Delaware Nature Society staff went to the Wilmington Riverfront for our annual Christmas field trip to see two construction projects – one completed and one in progress.

Our first destination was at the Barclays building to see a green building technique – a newly installed green roof. On this cold, gray winter-like day, the landscape on the roof looked pretty desolate. It was reminiscent of the arctic tundra containing only inches-high sedum plants growing on a bed of gravel. Thought the plants are still filling in, I imagine what it would look in the summer with a lush carpet covering the roof with greens, yellows, and oranges. Even now in its duller winter shades it is still more beautiful than a traditional roof.

So why grow a bunch of plants on the roof of an office building…for lunch time respite maybe? While that is an added benefit, it was actually built to help alleviate storm water problems caused by rain water running across impervious surfaces like roofs and pavement instead of infiltrating (soaking) into the ground. When it rains, this roof collects and holds the water that would otherwise run off the roof and pick up pollutants, carrying them to the nearest stream or river…in this case, the Christina River.

After viewing the green roof we walked along the riverfront, viewing beds of native plants along the way including one of my favorites, the scarlet rose mallow (Hibiscus coccineus). Our destination was beyond the Shipyard Shops where the sidewalk ends. Located there is the Peterson Urban Wildlife Refuge and within it the soon to be completed DuPont Environment Education Center. DNS will operate the center once it is completed in 2009. The center will offer fantastic views of the marsh, river and city, as well as exhibits and activities year-round on a variety of urban environmental issues.  Look for future announcements about the completion of this new center in 2009.

DuPont Environmental Education Center now

DuPont Environmental Education Center upon completion

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By Jim White, Associate Director, Land and Biodiversity

Later winter and spring is the time that most amphibians begin to make their way from winter hibernation sites (often called brumation sites for cold-blooded animals) to nearby wetlands to breed.  However, under the cover of darkness one kind of salamander usually gets a head-start by breeding in late November and December.  In anticipation of this early amphibian activity, Nate Nazdrowicz and I headed to southern Delaware on Thanksgiving eve in search of breeding Eastern Tiger Salamanders.  Our mission was to collect life history data on this rare species for the Delaware Natural Heritage Program.  As we drove south, we hoped that the relatively small amount of rain that had fallen lately would be enough to begin to fill the vernal pools in which the salamanders breed.

We arrived in Sussex County after dark and were excited to find shallow water in the first pool; however, after thorough searching, we found no sign of salamanders.  A little discouraged, we visited a second, much smaller pool and were immediately rewarded with the sight of several egg masses that were laid by female Tiger Salamanders.  The clear, gelatinous egg masses each contained up to a hundred eggs.  We could tell from the condition of the eggs that they were laid recently, possibly within the last few days.  Unfortunately, we couldn’t find any adult salamanders, so after counting the egg masses and measuring water depth and temperature, we headed to another pool.

Tiger Salamander Egg Case by Jim White

The third pool, like the first, was relatively large and contained water that was approximately 10 inches deep.  Wading into the clear water, it wasn’t long before we saw several adult Tiger Salamanders swimming lazily along the bottom.  So as not to disturb possible egg masses, we moved carefully through the pond, capturing the adults with dip nets as we went.  After catching 13 males and 3 females we quickly measured each individual (they measure between 7 and 9 inches), took a few photos, and then immediately released them back into the pool. 

Jim with Tiger Salamanders

The fact that we found no egg masses in the third pool led us to believe that the adult salamanders we had seen had very recently entered the pool and had not yet mated.  However, we knew that mating and egg-laying would take place soon and the cycle of Tiger Salamander life would continue.  In February or March, the eggs will hatch into aquatic larvae, and the larval salamanders will metamorphose into subadults in July or early August, at which time they will crawl out of the pool to live in the surrounding woodlands.  We knew that by this time next year, some of the eggs that are being laid here this fall will have developed into adults that may return to this very same pool to breed, and thus continue the cycle.

Tiger Salamander in the water by Jim White

After leaving the pools that night, the long drive home was made much easier by the fact that we had just successfully witnessed the beginning of the breeding season of one of the rarest animals in Delaware–the Eastern Tiger Salamander.

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By Jason Beale, Abbott’s Mill Nature Center Manager

The chilly morning air was mediated by a beautiful clear blue sky and abundant sun.  The honking of Snow Geese greeting us as a flock of a few hundred passed over.  Throughout the morning, four flocks of similar size worked their way from east to west, presumably from Prime Hook NWR.  This Delmarva spectacle is unpredictable around Abbott’s Mill, with daily sightings for a week or so, followed by weeks without any and seems to depend on where the winter wheat is up and where local hunting pressure is. 

Abbott’s Pond held a Belted Kingfisher perched on a stump and an adult Bald Eagle was perched in the “Eagle Tree”, a prominent loblolly pine on the southwest pond edge.  In discussions with local residents, it seems we have at least four separate adults and few juveniles in the area.  Otherwise, birding was quiet, but we did encounter a few Winter Wren, Hermit Thrush, Golden-crowned Kinglet, and Cedar Waxwing throughout the morning.

The recent rain and frost heaves have left the soil in great condition to record the calling cards of many animals, including free-roaming House Cats (Top) and Red Fox (Bottom).  Last night, I read in Whitaker and Hamilton’s Mammals of the Eastern United States that these species tend to have a limiting effect on Long-tailed Weasels, a species that local residents used to see from time to time, especially around chicken houses.  As Coyote populations increase, they in turn limit the Red Fox and Feral Cats.  Will we begin to see more Weasels as we see more Coyotes?

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By Joe Sebastiani, Members Program Team Leader

Today started off comfortable and warm at the Bucktoe Creek Preserve near Kennett Square, PA.  The walk ended with a chilly wind.  Birding was a little slow, as many songbirds stayed hidden and would not come out for a good look.  Highlights of the walk included good looks at a male American Kestrel, Sharp-shinned Hawk, Cooper’s Hawk, Red-tailed Hawk, and even a fly-by Merlin.  We got really good looks at an adult male Yellow-bellied Sapsucker (photo below) and a female or first year male Purple Finch eating Ash tree seeds.   We had a Winter Wren sing at one point.  Any of you that were concerned about us birding opening day of hunting season in PA, rest assured.  We made it back safe and sound.

The bird feeding station at the parking area is drawing in lots of birds, but unfortunately, the House Sparrows have found us.  Anyone know any good eradication methods??  Below is a photo of “coffee time” before the walk with a few of us checking out the new bird feeding station.

Here is a list of what we saw for the day:

Canada Goose     500
Black Vulture     8
Turkey Vulture     10
Sharp-shinned Hawk     1
Cooper’s Hawk     1
Red-tailed Hawk     2
American Kestrel     1
Merlin     1
Ring-billed Gull     12
Mourning Dove     25
Belted Kingfisher     1
Red-bellied Woodpecker     12
Yellow-bellied Sapsucker     2
Downy Woodpecker     4
Hairy Woodpecker     2
Northern Flicker     6
Blue Jay     20
American Crow     10
Carolina Chickadee     8
Tufted Titmouse     6
White-breasted Nuthatch     5
Carolina Wren     5
Winter Wren     1
Eastern Bluebird     20
American Robin     60
European Starling     20
Cedar Waxwing     20
Song Sparrow     15
White-throated Sparrow     4
Dark-eyed Junco     40
Northern Cardinal     4
Red-winged Blackbird     20
Common Grackle     1
Brown-headed Cowbird     4
Purple Finch     1
House Finch     10
American Goldfinch     31
House Sparrow     15

This report was generated automatically by eBird v2(http://ebird.org)

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