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.
Dumas, Jeannette V. 2000. Roseate Spoonbill (Plataleaajaja), 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
Another July has come and gone, but not all of the fireworks are over. The striking pink display of spotted knapweed, Centaurea stoebe ssp. micranthos, is still going strong in rangelands and old fields and along highways and railroad grades across the country. Native to Europe, spotted knapweed was introduced accidentally to North America in the late 19th century, and has since become a problematic invasive weed, especially in the west.
The pinkish-violet blossom of spotted knapweed.
I first noticed knapweed blooming on our wildlife sanctuary property in Pennsylvania about five years ago, at the same time that I started to seriously consider the possibilities for habitat management on the site. Knapweed control was one of my first projects on the property. Since I knew that mowing was counter-productive (causing the plants to flower at a lower height), I decided to pull the knapweed by hand. I’ve repeated the process for four years, and have eliminated spread of the plant while steadily reducing the seed bank at the main introduction site. Because spotted knapweed seedlings assume a low-growing rosette form during their first year and don’t bolt and bloom until their second year or later, I’ve been able to track my success by noting a significant reduction in rosettes (a few dozen this year compared to countless hundreds during the first year of two of treatment).
Unfortunately, Spotted Knapweed is a highly favored bee plant, used heavily by native bumblebee species. It’s always emotionally taxing for me to pull, bag and dispose of the knapweed with bumblebees crawling all over the blossoms as I work. This brings me to one of my take-home messages in invasive species control and restoration: in degraded habitats, native species often rely heavily on invasive plants because the diversity of native plants has been reduced. It is important to know what native insect and wildlife species rely on the invasive plant you are removing. Then, when planning a restoration, try to plant (or enhance habitat for) native plants that provide resources at the same time of year as the invasive. In my case, I’m working on restoring some meadows that will hopefully make up for (from a bee perspective) the eventual disappearance of my knapweed stand.
Spotted knapweed is an invasive plant, but is used extensively by native bumblebees
Since I’ve been working on this population for several years with a good deal of success, I thought I’d share a brief description of my spotted knapweed manual removal method.
Here are a few important points:
Get a good digging tool – I have tried various things – heavy clawhammers to grab and yank roots, various hand tiller/weeder/fork type things, etc. I’ve recently settled on a well-balanced, heavy-duty, and inexpensive digging tool (see the photo below) that I picked up at the friendly neighborhood home improvement warehouse.
Pull plants during their bloom period and before they’ve gone to seed. Be sure to bag and dispose of the plants in a landfill, to avoid dispersing seed or root fragments. A good rain just before (or even during) pulling makes the job much easier.
Be patient when pulling and learn to stop and dig more when you feel that the root is about to snap. Pieces of root left in the ground will sprout the following year.
Don’t dig right at the base of the plant – you risk cutting through the root, which often twists to one side or another a few inches down. Instead, loosen the soil about 5-6 inches from the base of the plant.
Here’s the process illustrated:
This is my tool of choice: a beveled, pointed blade on one end (used the most) and a straight blade on the other. The pointed blade sinks well into the shale soils where my infestation occurs.
Many stems usually radiate from a single root crown of older Spotted Knapweed plants. It's important to gather all the stems up to get a good grip on the plant for pulling.
Strike the ground about 5-6" from the base of the plant and loosen the soil, prying up with the tool while pulling straight up on the plant. Pulling at an angle makes it more likely that you'll break the root.
The root system should pull up cleanly if you loosen the soil enough and slowly pull upward on the plant.
The root crown can be quite broad on robust plants, or much smaller with fewer fibrous roots on stressed plants.
Please let me know if you have had success with other spotted knapweed control methods. I have considered trying Milestone, a selective herbicide that is supposedly quite effective on both knapweed and thistles. So far, I haven’t needed to resort to spraying though, since manual removal has been working well and at this point only takes me about a day each year to complete. Now if only I could eliminate my crown vetch, smooth brome, and reed-canary grass this easily!
Pinwheel Marasmius, Marasmius rotula, (c) Matthew Sarver 2009
“It’s marvelous though when we’re surprised by coincidences of light or sound in our presence – that’s one of the beautiful things about hunting mushrooms is that they’re, they grow up and they’re fresh at just a particular moment and our lives are actually characterized by moments, hmm?”
I’m going to be afield for most of the upcoming week with limited internet time, so I thought I’d get one more short post up before I leave. First, I want to thank Jeff Gordon for his flattering introduction of me over on his blog. Thanks too, to the folks at Nature Blog Network, as well as many individual bloggers and blog readers who have taken the time to check out my site!
As I mentioned a few posts back, I recently spent a week in the Catskills enjoying a wonderful river valley. I’ll be sharing photos and nature tidbits from that trip in a series of posts.
The first really fun observation I would like to share is the experience of watching female Common Mergansers shepherding their large broods of chicks while the youngsters learned to fish. During our stay, the several local merganser broods would travel up or down the river, passing in front of our cabin only when we were inside, or around the back not paying attention! One female had a group of 14 chicks, while another nearby female herded only 6 or 7. (The largest known clutch is 19).
This quiet stretch of river was a favored spot for Common Merganser fishing lessons. The cabin is visible on the far side of the river among the trees. The rock in the foreground is now called Eagle Rock, since a Bald Eagle used it as a staging area for its bath on our list visit. Photo (c) 2009 Matthew Sarver
At first, I was disappointed that I did not have the opportunity to photograph the merganser broods (a task that surely would have required me to build a blind by the river’s edge). Later, though, I discovered that George Miksch Sutton had written this wonderful description of his encounters with merg broods on his trip down the Abitibi River with W.E. Clyde Todd in 1923:
The Abitibi was far more than a series of rapids, cataracts, and portage trails. There were beautiful quiet stretches down which, aided by the strong current, we must have made up to five knots or more. A notable feature of the birdlife were broods of half-grown common mergansers, each brood with its mother, all of them, mother and young alike, flightless, she in her late summer molt, they with their first major wing feathers only partly developed. The close-knit companies dived when they saw the distant canoe approaching; when hard-pressed, however, they did not dive but rushed off half-standing, churning the water furiously, bodies weaving from side to side, wings not flailing the air but folded in tightly, thus protecting the stubby blood quills. The noise of their sudden departure was startling, for it contrasted so sharply with the silence of the sequestered spots the birds so obviously enjoyed. One fact about this truly common species, which the guides called the sawbill, impressed me greatly: not a single adult drake did we see during our descent of that mighty wild river!
-G.M. Sutton 1980. Bird Student: an Autobiography (p 125)
The Abitibi River at Iroquois Falls in northeastern Ontario. Photo by P199 on Wikimedia Commons. Used under a Creative Commons License (Attribution Share-Alike 3.0 Unported).
Common Mergansers nest in tree cavities, often using old Pileated Woodpecker excavations, and also sometimes in crevices among rocks. The chicks leave the nest and follow their mother to the water. Since young chicks can’t fly until they are more than 2 months old, it’s a long summer for merganser moms.
Females frequently brood parasitize other females of the same species by laying their eggs into the nest of the other female. Another common, but poorly-studied phenomenon is the joining of several partly-grown broods under the care of a single female, knows as brood amalgamation. While this happens frequently, it is unknown whether more aggressive females tend to “take over” other broods, or if the adoption of these chicks is simply the result of confusion on the part of the youngsters.
Because of these complications, it is impossible to know exactly how many chicks are actually the offspring of their apparent mother. None of this is the male’s problem, however, since as Sutton observed, they are nowhere to be seen during this period. The pair bond apparently ends at incubation, but where do the males spend their time during mid-summer? Do they hang out in trees, enjoying the cool mountain shade?
According to A.C. Bent’s Life Histories:
The drakes desert the ducks and usually disappear from the breeding grounds entirely as soon as the eggs are laid, leaving the females to perform the duties of incubation and care for the young alone. In Newfoundland we saw only females on the lakes, where they were busy with family cares, but we saw plenty of males on the swift water rivers, playing in the rapids and fishing in the pools. Several observers in Maine have said that the males are not seen during the summer, but this may be due to the fact that the males are in eclipse plumage at this time and are very shy and retiring.
Can anyone out there shed some more light on the mystery of the missing merg males?
Many ecological communities in Pennsylvania (including native grasslands, oak-hickory forests, and serpentine barrens) depend on periodic fires to maintain their plant community composition and structure. In an even wider range of habitats, fire can be a tool to help combat invasion by non-native plant species. But conducting prescribed burns on private land has been a challenge in the state because of liability concerns. While other regions of the country have embraced the modern use of prescribed fire in managing habitats, Pennsylvania has long been stuck in the Smokey the Bear fire suppression mentality, with only a few organizations conducting regular prescribed burns on private land.
A prescribed burn in progress on a conservation property in New Jersey. Photo (c) 2009 Matthew Sarver
All that changed on July 14th 2009, when Pennsylvania Governor Ed Rendell signed House Bill 262, establishing the Prescribed Burning Practices Act. Introduced by Rep. Gary Haluska, the new law authorizes the state Department of Conservation and Natural Resources to establish standards for the conduct of prescribed burns in the state. The state will begin regulating burning practices by certifying burn managers and requiring state approval for burn plans. In exchange, the law limits the criminal and civil liability of landowners and burn managers, so long as the regulatory process is followed:
No owner of property who contracts with or authorizes a prescribed burn manager to conduct or permit a prescribed burn on the property pursuant to the requirements of this act shall be subject to civil or criminal penalty for damage or injury caused by the fire or resulting smoke, unless negligence is proven.
– PA House Bill 262
The passage of this law is a major step forward in facilitating the use of prescribed fire as a management tool on private conservation lands in the state. I hope to be able to use fire to manage the grasslands at my own wildlife sanctuary property in southwestern Pennsylvania at some point in the future.
Another exciting step forward is the establishment of The Pennsylvania Prescribed Fire Council, an organization created “to promote the exchange of information, techniques, and experiences of the Pennsylvania prescribed fire community, and to promote public understanding of the importance and benefits of prescribed fire.”
PPFC has named Matt Boss of The Nature Conservancy as the Council’s first Training Coordinator. You can join the effort to promote prescribed burning in Pennsylvania by becoming a member of PPFC.
It’s been more than four years since I left Arkansas, Ivory-billed Woodpecker T-shirt in hand, just days after the news of the rediscovery of the species broke in the national media. During five months in the swamps over the winter and spring of 2004-2005, I had really gotten to know the Big Woods. Lately I’ve been longing to get back to the bayous of the Natural State and enjoy a peaceful paddle through the cypresses.
Members of the search team paddle Bayou DeView in winter of 2004. (Photo L Morgens)
Even though the controversy over the existence of the Ivory-bill has quieted down a bit by now, I still get questions about the project all the time. People want to know if the bird was really there! What began as a fascinating biological adventure has turned into an extended window into the nature of hope, cynicism, and public opinion of science.
This past season’s systematic search activity by Cornell’s mobile search team was the final effort after five years of field work, according to a recent article in the Cornell Chronicle. The recent search yielded no Ivory-bills, but lots of ecological data on difficult-to-access natural communities in south Florida.
The House Sparrow (Passer domesticus) is one of those critters that birders love to hate. The species makes a habit of usurping the nest sites of native species, especially bluebirds, and is therefore reviled by many a birder.
Initially released on this continent in the early 1850s in New York City and parts of New England, followed by many more releases across the U.S. and Canada during subsequent decades, the Old World sparrow rapidly established outposts on New World soils. By the 1880s, the species was well-established in many cities, and its impacts on native avifauna were becoming obvious. The bird that had once captivated the countless Americans who aided in its rapid spread had already worn out its welcome.
When watching these birds, it’s not difficult to see why they have persisted for the past century. Their ability to thrive in urban settings, scavenging discarded french fries and other bits of refuse, is notorious. Anyone who has watched House Sparrows making themselves at home inside warehouse stores or building sloppy nests of dry grass in every conceivable type of lamppost can attest to their adaptability. I have to admit that I’m ambivalent about the species. The scientist in me dislikes the impact of the House Sparrow on native birds, but the humanist in me loves the plucky spirit of these little tank-like city-dwellers.
Yesterday I witnessed an event that made me smile. As I was about to get out of my car, I noticed a female House Sparrow that had flown to the ground nearby with something shiny and green in her bill. I froze in the driver’s seat, window down, and watched. Not ten feet away, the bird lit on some reddish landscaping gravel. At this range I could tell what the mysterious object was: not one, but two Japanese Beetles! The unfortunate beetles were attached to each other for the purposes of mating (a position referred to by entomologists as in copulo) and had no hope of disuniting in time for either to escape! The sparrow settled down to lunch and quickly munched most of the first beetle of the pair, while the beetle’s mate could only wriggle in vain, still attached to the little that remained of its mate. After briefly dropping the remaining beetle into the stones, the House Sparrow deftly picked up a piece of gravel, dropped it aside, and reclaimed its prey.
Two Japanese Beetles down, millions more to go. One introduced pest species feasting on another. Unfortunately, the energy-rich beetle innards, recycled, no doubt, from some gardener’s prized roses, were going to help produce more House Sparrows.
Such is the way of the urban jungle. At least now I feel a little better about my guilty admiration for Passer domesticus.
House Sparrow (Passer domesticus) by J. Garg. Distributed under the terms of a Creative Commons Attribution ShareAlike 3.0 License (http://creativecommons.org/licenses/by-sa/3.0/)
All of these buzzwords make us feel good about our progress toward mainstreaming alternative energy sources. We need to power an increasingly energy-hungry world in the face of global climate change, and we all know that fossil fuels are not the solution.
What often gets lost in the excitement surrounding “green” energy, though, is that these technologies are not free from collateral damage to biodiversity and wildlife habitats. Wind turbines atop Appalachian ridges, for instance, may impact unique mountain-top habitats, and they are known to kill birds and large numbers of migrating bats. As pressure has been building on wind farm operators to address this problem, basic steps are being taken to help reduce the impact. Common sense solutions like shutting down the turbines on relatively calm nights are apparently effective at reducing bat kills, for example.
Biofuels are not without their problems, either, but the problems have largely gone unrecognized, and the solutions are not as straightforward. From a climate change perspective, one major issue is the increase in emissions caused by land use changes associated with biofuel production. This is the focus of a current campaign by the Union of Concerned Scientists. At the “Take Action” section of their site, you can personalize and send a letter to the EPA, urging the agency to consider land use changes when calculating life-cycle analyses of biofuels for the agency’s Renewable Fuels Standard (RFS).
What the UCS letter doesn’t directly address is the impact of those same land use changes on other ecosystem services, wildlife habitat, and biodiversity. European studies have shown that production of biofuel crops such as corn in the amounts necessary to meet EU targets is generating significant negative impacts on biodiversity.
The production of so-called second-generation biofuels from grasses is somewhat less detrimental, but still far from ideal. As cellulosic biofuel production becomes more cost-effective and energy efficient, switchgrass, a high-yield, perennial grass, is poised to become an important commodity here in the U.S.
Switchgrass (left) is poised to surpass Corn (right) as the commodity of choice for production of ethanol for biofuel. Photo by USDA ARS Photo Unit, USDA Agricultural Research Service, Bugwood.org (used under a Creative Commons 3.0 Attribution License)
Switchgrass (Panicum virgatum) is a tall, native warm-season grass that was once widespread throughout the American tallgrass prairie. Today, many cultivars are available, and the species is used for conservation plantings and wildlife habitat, providing valuable food and cover for birds and other wildlife. So what’s the problem? When grown in a monoculture, as required for harvesting for biofuels, switchgrass is only marginally better wildlife habitat than corn, or any other crop.
Native prairies were historically very diverse plant communities, with species composition maintained by periodic fires. Structurally, native grasslands varied in density and height based on fire history, soils, and other factors. Many grassland birds of conservation concern require patchy bunchgrasses with some bare ground in between plants. Native bees require a diversity of wildflowers that bloom at different times throughout the year, as well as access to bare soils for nesting. Butterflies all require different species of hostplants on which their caterpillars can grow. In short, grassland biodiversity depends on both structural and species diversity of the plant community. Monocultures just don’t cut it.
Grasshopper Sparrow (Ammodramus savannarum) and other grassland birds are at risk from high biofuel commodity prices. Photo (c) Jeffrey A. Gordon
So what’s at stake? The concern of many conservationists (myself included) is the potential conversion of privately-owned land that is currently enrolled in federal conservation programs to switchgrass monocultures for biofuel production over the next couple of decades. Over 33.5 millions acres are currently enrolled in the USDA program called CRP (Conservation Reserve Program), which pays farmers an annual rental rate for retiring land from crop production and planting it to wildlife cover. CRP contracts typically tie up the land for 10 to 15 years.
Currently, CRP land management is governed by contract stipulations that prohibit disturbance during the breeding season, and encourage wildlife use of the acreage. Many studies have shown that CRP land is vital to sustaining grassland bird populations. Pollinating insects, reptiles and amphibians, and other fauna benefit from these habitats as well.
According to USDA figures, almost 60% of the current active acreage in CRP will see contracts expire by the end of 2013. With the signing of the 2008 Food Conservation and Energy Act (aka the Farm Bill) the CRP cap (maximum acreage to be enrolled in CRP) was already reduced from 39.2 million acres to 32 million acres beginning in 2010. Thus a mandated net loss of over 4% of current active CRP acreage is already slated to occur in the near future.
While some of the expiring contracts will be renewed under the new acreage cap, if prices for biofuel commodities rise high enough, a large amount of CRP land may be lost when owners decide not renew, but to seek “greener pastures” in switchgrass or corn production for biofuel. A mass exodus of from the CRP program would be a disaster for conservation of grassland species in North America. In addition, there is the possibility that the USDA could change the rules for CRP contracts at some point in the future to allow switchgrass production on CRP lands.
Over at the Biofuels and Bio-based Carbon Mitigation Blog of the School of Natural Resources and Environment at the University of Michigan, Kristen Johnson wrote a great post discussing the potential magnitude of the conversion of CRP lands to switchgrass production for cellulosic biofuel. She states that acres currently in corn are unlikely to be converted to switchgrass, since EPA guidelines call for a continued increase in corn-based ethanol production in the near future.
As long as the prices of other commodities like soybeans are high, that leaves only pastureland, hay production land, and CRP land as prime targets for conversion to biofuels. Compared to cropland, these land uses are all of much higher value to wildlife.
The take-home message here is this: if you value grassland habitats and the wildlife that depends on them, keep an eye on this issue. While the Union of Concerned Scientists letter doesn’t specifically address habitat loss, it does shed light on the emissions consequences of biofuel production, and is a step toward helping our public agencies recognize that biofuels are not free of collateral damage. You can view the letter at the Union of Concerned Scientists “Take Action” site.
I recently returned from spending several days hard at work on my “farm”. Why the quotation marks? Well, the 116-acre property, which has been in my family since the early 1900s, doesn’t grow crops or livestock these days, but does produce both Grasshopper Sparrows and Henslow’s Sparrows on 80+ acres of reclaimed strip mine.
Situated on the western slope of Chestnut Ridge, the property climbs over 400 feet in a little over half a mile. The walk from the stream bank of Laurel Run to the top of a high, grassy knoll on the eastern end of the property tests the aerobic fitness of most visitors, myself included.
Once atop the hill, a panoramic view to the west awaits. Sunsets here are magnificent, and on clear days the towers of the Pittsburgh skyline some 35 miles distant are clearly visible. Because our parcel is only part of a 200+ acre reclaimed strip mine, the property has hosted area-sensitive grassland birds for many years. Recently, however, Black Locust, Tree-of-heaven, Autumn Olive, and other woody vegetation have been gradually shrinking the available habitat for these grassland specialists.
To combat the loss of grassland habitat to succession, fight invasive species, and plant natives, we enrolled in the USDA Natural Resources Conservation Service Wildlife Habitat Incentive Program (WHIP). The cost-share assistance provided by this program has allowed us to begin restoring habitat on the property. We’re in the fourth year of our WHIP contract, and the restoration work is steadily progressing. I’ve added a new page, titled Sanctuary, to the main site, with a PayPal button so you can contribute to our efforts if you’d like to help us out!
Look for more on the restoration progress and the biota of the property in upcoming posts!