Matthew Sarver » Delaware

Out of Hibernation!

Matthew Sarver — Mon, 01 Feb 2010 19:03:14 +0000

Stretch…. Yawn…. Is spring here yet? Just in time for groundhog day, I’m coming out of my recent cyber-hibernation on The Modern Naturalist blog. What have I been up to during the past couple of months? I’ve been busy traveling, spending time with family, and working on some writing projects. December included an amazing birding trip to Colombia that will be the subject of some photo-laden posts in the very near future! I also managed to spend some more time in the South Carolina Lowcountry, and even squeezed in a brief run for some prime Snail Kite viewing in the Everglades. January has been full of reorganization, adapting to my new Mac computing world (yes, I finally took the plunge), and getting to work on several new projects.

Today I want to share with you a fascinating story from Science Daily on how the invasive reed Phragmites australis manages to suppress other wetland plants by taking advantage of the biochemical activities of native plant roots and native microbes in the soil. Apparently, “Phrag”, as it is known to those of us who are all too familiar with it, releases larger-than-usual amounts of compounds called gallotannins, which are initially harmless. BUT, when enzymes produced by microbes in the root zone of the soil (as well as by the roots of some native wetland plants) get hold of the gallotannins, they convert them to toxic gallic acid. The gallic acid actually destroys the structural integrity of plant roots by breaking down the tubulin protein that helps keep the roots rigid.

Unlike many other examples of allelopathy, the chemicals secreted by the invasive Phragmites don’t do the damage themselves, but take advantage of enzyme activity already present in the soil of native plant communities! How fortuitous for the invader! What isn’t known yet is how the invasive strains of Phragmites are themselves able to resist damage from gallic acid present in the soil. Research like this is revealing that complex underground warfare between plants is much more common (and more fascinating) than we once thought!

The research, conducted by investigators at the University of Delaware, was published in the December 2009 issue of the journal Plant Physiology. You can download the full PDF here.

For more information on Phragmites, the threats it poses to wetland ecosystems, and its identification and control, check out the Plant Conservation Alliance’s Phrag page or download a free copy of my publication, Mistaken Identity? Invasive Plants and their Native Look-alikes: an Identification Guide for the Mid-Atlantic.

Spoonbill Mania

Matthew Sarver — Fri, 14 Aug 2009 05:07:15 +0000

The rash of unexpected Roseate Spoonbill sightings this summer has been a treat for birders up and down the east coast. While northward movement of juveniles during post-breeding dispersal is known for the species, the numbers of birds involved and the extent of the northward movement this season is impressive.

According to the Birds of North America species account, spoonbills, “especially immatures, occasionally disperse great distances, but seasonal patterns of movement are poorly understood” (Dumas 2000). In past years, the occasional individual has appeared as far north as Pennsylvania, Ohio, Wisconsin, and Nebraska. Spoonbills regularly disperse in small numbers along the gulf coast in the states of Alabama and Mississippi, and north along the Atlantic coast to Georgia. In 1972, a large movement of immatures occurred as far inland as Tennessee. This summer, spoonbills have appeared in many eastern states, including Virginia, Delaware, and New Jersey. In fact, I saw the bird that appeared at Thousand Acre Marsh in Delaware last month.

I’ve been fortunate to be in the Low Country of South Carolina for a couple of weeks, which is where I took the photo below. These birds were part of a larger flock that contained at least 47 individuals. The peak number of Spoonbills observed at this site this summer was 63 a few weeks ago.

I’m sitting in a john boat, taking this photo with a point-and-shoot camera, which gives an idea of how close I am to these birds. They don’t seem too bothered, do they? I keep wondering what drives these irruptions, and whether climate change is a contributing factor. Spoonbill foraging is dependent on fluctuating water depths, so water level changes at foraging habitat in Florida might trigger large-scale movements. Hopefully this year’s irruption (and its documentation by birders) will help us better understand the movements of this fascinating species.

Citation:

Dumas, Jeannette V. 2000. Roseate Spoonbill (Platalea ajaja), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/490

Test Post

Matthew Sarver — Mon, 18 May 2009 17:09:18 +0000

Hello friends. I’ve decided to try my hand at the world of blogging. The site is currently under development while I wrap my brain around using Wordpress and setting everything up. I’ll be back soon with some actual posts. In the meantime, here is a photo of a recent bird walk I attended at White Clay Creek State Park in Delaware, led by Jeff Gordon.