I am a bird watcher, or a birder, if you like. Actually, truth be told, I am at heart a grassland birder. Grassland birds float my birding boat, big time. Much of this article is devoted to discussing grasslands at Manassas National Battlefield Park, hereafter MNBP or the Battlefield. MNBP is a unit of the National Park Service (NPS).
I wish to begin with this. My grassland concerns aside, I believe the NPS is doing a pretty good job at MNBP. In my opinion, the wildlife biologist assigned to MNBP is doing a good job too. A small area in the MNBP visitor center is devoted to telling the MNBP bird story. MNBP (and the NPS) publish a brochure entitled Grassland Conservation. These are nice touches; all the proof that I require to know that the Battlefield is trying to go in the right direction. MNBP's 2006 selection as an Audubon Important Bird Area earned the Battlefield an honorable mention in that year's NPS annual report. I am grateful for much of the good work being done at the Battlefield, and I agree that on balance MNBP is doing a good job of telling its natural resource story. But, from a grassland perspective, MNBP is an unfinished piece of work, and it would be helpful if all concerned would stop acting like the Battlefield is some kind of grassland showcase.
Much of the following criticism has nothing much to do with MNBP or the NPS. No, instead, my criticism is directed at a birding and conservation community that continues whistling in the wind while MNBP grassland fields are burning.
Grassland is a term that usually describes a treeless area comprised of herbaceous vegetation with no more than a minor shrub component (Heaton 2000). Grassland birds can be defined as species that are wholly or mostly dependent upon grasslands for their survival. (McCraken 2005).
It is not hard to find researchers who have commented on the deplorable state of North American grasslands and apparent declining grassland bird populations. Here is a mosaic of quotes that (taken together) paint a pretty grim picture of challenges ahead.
"Since the mid 1800s, it has been estimated that loss of grassland ecosystems in most areas North America has exceeded 80% (Brennan & Kuvlesky 2005). These authors cite Knoph (1994) and Noss et al. (1995).
Brennan & Kuvlesky (2005) insist that "there is no question that vast areas of the North American continent are suffering from a chronic ecological malaise," and that the "stabilization and increase of grassland bird populations will require healing sick landscapes." Paraphrasing Vickery & Heskert (1999), Brennan & Kuvlesky further write: "The loss of native grassland habitat has been so extensive over such a large area that restoration of grasslands throughout the United States probably is the most effective way of stabilizing grassland bird populations for many species."
"Native grassland habitats are the largest and most threatened habitats in North America" (McCraken 2005) McCracken cites Murphy (2003).
According to the Natural Resources Conservation Service (1999), "Many North American grassland species have experienced marked population declines in recent decades," resulting in "increased awareness for the need to preserve, manage, and restore grassland habitat in order to recover and maintain viable grassland nesting bird populations."
Grassland habitat is found throughout the United States. Eastern grasslands are found from Maine to Florida and westward to parts of Texas. This grassland habitat evolved over time mostly because of natural and early Native-American induced fires. With the passage of time, human activities, woody encroachment (think fire suppression), and afforestation resulted in the loss of significant eastern grassland habitat. Today, remaining eastern grassland habitat is often fragmented, isolated, and in some instances, terribly degraded. Western grassland habitats are in tough shape too.
Thanks to research that has already been done, the habitat requirements of many grassland species are well understood. And, a couple of decades of Breeding Bird Survey data points to some real problems with certain grassland bird populations. Problems that may well be unprecedented in scale.
Some of the newer grassland research is focused on learning more about the winter distribution and winter ecology of North American grassland birds, many of whom are short distance, temperate migrants. Others are moving away from plant ecology, thinking about the best way integrate grassland conservation with soil conservation, agricultural practices, and the role that wildlife plays in the maintenance of working grassland habitats. Today, the race is on to figure out the best way to create, restore, enhance, and monitor dysfunctional grassland habitats in something approaching a cost effective way. These are all tough tasks.
First, western and eastern grassland habitats face different challenges and will require varying types of prescriptive relief. In the public arena, we have to do a better job managing public land grassland habitats, and time is not on our side. With respect to private lands, we have to find the resources (money) to significantly expand programs like the Conservation Reserve Program. Ultimately, someone will have to figure out how to make modern farming and agricultural practices more grassland bird friendly. Understand! We are on a very slippery slope, and the climb ahead will be steep.
Chartered in 1940, MNBP memorializes the sites of the First and Second Battles of Manassas. By any definition, the Battlefield is a special place. The park is 5,073 acres in size, of which 1,500 acres are considered to be managed grasslands.
Here in Virginia, we sometimes adhere to a kind of Disneyland birding and conservation model, following the adage that is it better to print wishful thinking rather than actual fact. This is an annoying habit of mind. Looking good in print or on the web is a heck of lot more appealing to some than is reality. Why bother to fight certain battles when it is easier to declare victory and pose for the victory photo? And, with respect to the management of grassland habitat, this defective philosophy (in all its glory) is on display, in the bright light of daylight, at Manassas National Battlefield Park for all but the blind to see.
Buy, hey, if those little brown birds and other grassland birds are encountering some tough sledding at MBNP, well these birds are just going to have to work a little harder because everyone knows that MNBP, from an avian perspective, is in fine working order.
After all, MNBP has been declared an Audubon Important Bird Area (IBA). And, hey, how cool is this? The Battlefield actually features "quality" grasslands, including native grasslands that are "carefully sustained." To this end, "cutting regimes" have been "devised to fulfill the varied habitat requirements of important bird populations." And, of course, not surprisingly MNBP supports "healthy" populations of grassland birds, including state species of concern (NPS Grassland Conservation brochure).
But wait, there is more. At certain times of the year, species like Northern Bobwhite, Grasshopper Sparrow, and other grassland birds might be "common" at the MNBP. Wow! And, to this embarrassment of riches, why, Long-eared Owls might even be seen foraging over pastoral Battlefield fields in winter months. Could the news be any finer?
What a powerful and engaging story. Comforting to know that while the rest of North America is struggling to keep up with more grassland habitat and management challenges than can be imagined, much less counted and met, MNBP is standing tall. Seems to me that I ought to pack up my Battlefield concerns and call it a day. Maybe get my eyes checked too. Suspend my disbelief (Drinking some of the Battlefield and Audubon IBA Kool-Aide might be helpful here. Do you all drink this stuff straight or should this elixir be chilled and served with crushed ice?). On the other hand, since I actually know something about MNBP, perhaps I should try dismantling some of the Battlefield myths that others find so comforting, while trying to "light a candle in the darkness" (Neil Young rules).
Within the context of the following discussion, it is important to remember that MNBP is not simply protected open space or a National Wildlife Refuge, but is instead a Civil War Park. This means that there may be some barriers to managing this park's grassland component optimally, though by in large, these objectives are not as mutually exclusive as some would have others believe.
MNBP fields are mostly used for agricultural purposes. To preserve the park's historic character and to help manage the Battlefield's grassland component (think succession), MNBP devotes most of its grassland inventory to hay production.
MNBP features both warm and cool season grasses. In general, warm season grasses are native, while cool season grasses are non-native. (Supposedly, cool season grasses were introduced in much of the northeastern and eastern U.S. for some agricultural purpose.) Battlefield cool season grasses are heavily involved in hay production. These cool season grasses require fertilization, lime, and perhaps other chemical treatments that ultimately makes the maintenance of these grasses more labor intensive than their warm season counterparts. Because of budgetary constraints, including the costs associated with maintaining cool season grasses, MNBP uses agricultural leases with local farmers to maintain much of its grassland.
Warm season grasses comprise about 600 acres of the Battlefield's grassland inventory. Besides being native, warm season grasses require no fertilizer or lime, are drought resistant, and have a deep root system that helps with soil erosion, the filtration of nitrates, and provides a desirable riparian buffer.
[The optimal size for a truly functioning grassland habitat is difficult to know. Small, linear grassland habitats (less than 10 ha) appear to be of little help to grassland birds that are of conservation concern (McCaracken 2005), though other grassland species that are less area sensitive and are not necessarily species of conservation concern will use smaller grassland habitats (Heaton, 2000; Also, Herkert 1993). Vickery et al. (1994) suggest that grasslands should be at least 100 ha in size to support a diverse suite of grassland birds, while Heskert et al. (2003) suggest that optimal grassland size be something on the order of 1000 ha. Regardless, it is well understood that large monocultures that dominate some of today's grassland habitats are of little benefit to grassland birds (McCracken, 2005; Also, Best 1986). Nevertheless, by any definition, MNBP grassland acreage is indeed a candidate for active management.]
Grassland conservation efforts should have a regional nexus, and local grassland sites should manage grassland habitat for targeted grassland species, instead of trying to manage local grassland habitats for a broader suite of grassland birds. Among other reasons, this is because grassland species in general have varied habitat requirements and different area-sensitivities. Regional soil differences and other factors figure into this equation too. I do not see any evidence that MNBP grassland is actually being managed for a targeted subset of grassland species.
For a variety of reasons, prescriptive grazing and burning management techniques are not likely to be employed at MNBP. However, the Battlefield claims to be following some kind of mowing regime, one that continues to confound me. This program has been explained to me a number of times over the years, and with apologies to no one, I still do not understand it. More importantly, I see a disconnect between the mowing program that is often discussed in print and elsewhere and actual conditions on the ground.
So far as I know, the central feature of MNBP's mowing program appears to be that grasses will not be cut during the breeding bird season. It is unclear (to me) if this policy applies to the cool season grasses used for MNBP hay production since it is well known that hay crops are often cut and harvested early to yield a higher quality crop, an agricultural trend that has developed in recent decades. I do believe that the MNBP mowing policy applies to warm season grasses.
Regardless, of how this policy is applied, over the years, I have, on more than one occasion, found scores of Battlefield fields clear-cut well inside the breeding bird season. And, I am hardly the only veteran birder to have made this observation.
A couple of years ago, I birded MNBP with a couple of Virginia Society of Ornithology (VSO) officials. For about two hours we walked Battlefield trails looking at hundreds of acres of contiguous, interior fields that had been clear-cut (cut-to-the-quick). After some discussion about the Battlefield's defective mowing practices, one of these VSO officials told me that the VSO would have no trouble straightening out this problem. (LOL! God bless the VSO. Too rich for words, really.)
Reaching further into the past, I remember the time that a veteran Virginia birder wrote Fairfax Audubon and a bevy of other veteran birders. He wanted to put together some folks who might be willing to discuss Battlefield mowing concerns with MNBP. Fairfax Audubon, as I recall, responded saying this crew was busy with other priorities. I never learned how many of the veteran birders that were contacted actually responded to this appeal. I know that I responded and that a couple of others did too. But, nothing came of this. Fast-forward to the present, and the list of local Virginia veteran birders who know something is wrong with MNBP's mowing regime is as long as ever.
Rotational mowing schemes are well understood, and all claims to the contrary, I do not see a lot of evidence that suggests MBNP grassland is actually being cut in an organized rotation schedule that makes sense to me.
Furthermore, I do not see the Battlefield doing much to actively manage the height of grasses. I see a lot of "clean edges" on perimeter Battlefield fields. Nor do I see much in the way of smaller (linear) grassland buffers (strips or subplots) being employed at MNBP. MNBP fields are not being mowed from the center out to allow birds to escape to edges. And, I have never seen a flushing bar used during MNBP grassland mowing operations. (Many grassland species are ground nesters and mowing from the center out and utilizing a flushing bar when mowing seems only fair, especially if you happen to be one of those little brown birds trying to breed in a MBNP hayfield, at a venue that claims to be actively managing its grassland inventory for grassland birds.)
Finally, I have a strong suspicion that MNBP has a big problem with grassland monoculture(s). I do not understand the cause(s) for this, but I have often wondered if this might not be related to the repeated application of chemicals in certain MBNP fields over a long period of time. I have been in these fields often enough over the years to know that it is difficult to beg, borrow, buy, or steal (much less see) a grassland bird in some of these fields. Recall that grassland birds do not have much use for monoculture.
My point being: While MNBP may feature some of the largest remaining grassland habitat in Northern Virginia, it is a little early to be describing this habitat as "quality" grasslands or grasslands that are actively managed, much less monitored, in some meaningful way.
And, no, the Battlefield's Virginia Birding & Wildlife Trail and IBA citations are incorrect. Northern Bobwhite and Grasshopper Sparrow are not "commonly" seen at any time of the year at MNBP. And, who knows what the meaning of the phrase "healthy" populations conveys. It is more accurate to say that the Battlefield supports a diverse assortment of grassland birds without commenting on the quality of the habitat, relative abundance, or the supposed health of MNBP grassland populations. (BTW, where is the list of unhealthy MNBP bird populations?)
Let me set the table. North American has an unfolding grassland crisis. Grassland species appear to be declining on a continental scale. MNBP has 1,500 acres of grassland habitat that it wishes to actively manage. More than 700,000 people from all over the United States (perhaps the world) visit the Battlefield annually. MNBP has a powerful grassland story waiting to be told, and here in Virginia, I cannot think of a better place to begin telling this story to a wider audience.
Conservation partnerships are all the rage. I look at the Virginia Important Bird Area web site, and I see that the Virginia Society of Ornithology, Virginia Department of Game & Inland Fisheries, and the Center for Conservation Biology have partnered with Virginia's Important Bird Area program. Good to know!
But, I have a question. It is my understanding that the purpose of an Important Bird Area (IBA) program is not just to recognize important bird areas, but to begin mobilizing the resources that will be required to protect these areas. I hear a lot of chatter regarding the supposed protected status that IBA designations confer, but, truthfully, I do not get the whole IBA protected status thing. It is not clear to me that IBA status actually conveys some kind of protected legal status. I do, however, understand the whole resource mobilization thing.
So, my question is this. MNBP was recognized as an Audubon IBA in 2006. It is now 2010, so I am wondering what resources Audubon and others have mobilized to help protect MNBP? Surely, with a grassland crisis that is already in full bloom, Audubon, the Virginia Society of Ornithology, and others can gin up the enthusiasm to get more involved at MNBP, especially since the Battlefield is an IBA. Or, are we back to the whole Disneyland birding and conservation thing again?
If I were in charge of this charade, the following would happen:
MNBP would establish a Battlefield grassland demonstration area, complete with interpretive signing. (What is wrong with sending 700,000 people (or as many of these people as is possible) home to community's around the United States with a better understanding of grassland habitat and grassland birds?) MNBP conservation partners would underwrite the expense associated with this signing. This can be accomplished without compromising the Battlefield's primary mission. Recall that grassland management and MNBP's primary mission are not mutually exclusive objectives.
I would sit down with MNBP and figure out which grassland species the Battlefield wants to manage for.
I would take a long, hard, and honest look at MNBP's mowing regime. Among other things, I would figure out a way to make sure that large tracts of contiguous fields (especially interior fields) are cut in rotation to each other. Fields would be cut from the center outward. Night time mowing would be prohibited since roosting and breeding birds are less likely to flush at night. Flushing bars would be the order of the day. Here is a surprise: Grassland birds are actually grassland specialists. (Who knew?) They require appropriate grassland habitat year-round, not just during the breeding season. Based on the total number of grassland acres under management, the amended MNBP mowing regime would ensure that some percentage of appropriate grassland habitat is available to grassland birds year-round. I would publish MNBP's amended mowing schedule.
I would be scheduling grassland bird walks at the Battlefield, both for local birders and the benefit of MNBP visitors. (Of course, some MNBP visitors will take advantage of this opportunity.)
Hey, I probably ought to put the glue away because MNBP is not going to do any these things. Absolutely. I can prattle on from now until doomsday (which for grassland birds is on the horizon), and MNBP is not going to do anything more than yawn before getting back to the serious work of mowing down grassland habitat with near reckless abandon.
However, supposedly, MNBP has conservation partners. These are the folks who can make a real difference at MNBP. 1,500 acres, 700,000 visitors, and a great story waiting to be told. If Audubon, the VSO, and others will make the right pitch to MNBP, I have no doubt that the Battlefield will respond affirmatively. But, hey, what do I know?
Winding Up:
Based on their understanding of some historical perspective of a North American wildlife management model, Brennan & Kuvlesky (2005) predict that great progress with grassland birds can be achieved after this current generation of resource managers retires. (LOL!) (ROFL!) I bet North American grassland birds are just giddy at this news.
Frankly, I do not share this optimism. To begin with, the costs associated with restoring grassland habitat on a continental scale will likely be staggering, perhaps even prohibitive. For instance, think about the long-term costs associated with simply preventing woody encroachment in restored grassland habitat, especially eastern grasslands. (Today, MNBP cannot even afford to maintain its own grassland.) Furthermore, it is unlikely that the large-scale changes required to make modern farming and agricultural practices more grassland bird friendly will ever be achieved, notwithstanding initiatives like the Conservation Reserve Program. And, the truth of this matter, so far as I am concerned, is that we have simply run out of time to heal sick landscapes on some grand scale. Our best hope is that the Breeding Bird Survey data that today reflects decades long declines in grassland bird populations will somehow turn out to be wrong.
My own outlook for grassland birds hardly means that we should concede this grassland fight. Yes, as usual, we come to this fight late, without either the resources or the best science to tell us how create, restore, and/or enhance grassland habitats, much less manage and monitor them on anything approaching a cost effective basis. Is it any surprise then that we find ourselves in such a precarious position with respect to the quantity and quality of native North American grassland habitat, much less struggling to understand what is actually going on with certain grassland bird populations? This grassland fight has begun in earnest, and we should leave no stone unturned in this fight, beginning with some understanding of how difficult, long-suffering, and challenging this grassland struggle will be.
As for MNBP, it would be helpful if we shelved the conservation rhetoric, parked the parade floats, and rescheduled the grassland habitat and grassland bird victory march. I can think of some organizations that should be more involved at MNBP, beginning with the Virginia Society of Ornithology (which - in my opinion- is often busy, doing not much of anything) and Audubon.
Straightening out MNBP's mowing regime and telling the right Battlefield grassland story to a wider audience are things worth doing. This in no way conflicts with MNBP's primary mission. The proof of this is as obvious as daylight, but for the slow afoot, here is one last Battlefield story.
MNBP visitors can see a short film about the Civil War battles fought there. Every frame of this film shows Battlefield grasslands in a condition that is entirely consistent good grassland management practices. This film was produced at MNBP. Prior to filming, MNBP did two things.
First, the Battlefield built a small demonstration house to be used as a prop in its film in an interior park field. Second, MNBP waited for the grass to grow before doing any filming. Obviously, MNBP wanted its film to be realistic because clearly The First and Second Battles of Manassas were not fought on tightly manicured, chemically enhanced, and aggressively mowed landscapes.
Look closely at MNBP's grassland brochure, and one can easily see that this same pattern is repeated. Photographs used in this publication were carefully selected to show Battlefield fields in a herbaceous condition. This is no accident.
MNBP makes a big deal about wanting to maintain Battlefield landscapes in some historical context, but the disconnect between this goal and some of the Battlefield's actual grassland management techniques (aggressive mowing) along the Route 29 and 234 corridors (and interior fields) could not be any more striking.
The lesson here. Grasslands that look so good in the MNBP demonstration film and grassland brochure work for grassland birds too; proof (so far as I am concerned) that there are no real conflicts between effective grassland management and the historical character of MNBP grassland fields.
References:
Brennan and Kuvlesky. "North American Grassland Birds: An Unfolding Conservation Crisis,"Journal of Wildlife Management, 69(1): 1-13, 2005.
Knopf. "Avian Assemblages on Altered Grasslands," Studies in Avian Biology, 15:247-257.
Noss, et al.. "Endangered Ecosystems of the United States: A Preliminary Assessment of Loss and Degradation." Report No 0611-R-01, National Biological Service, 1995.
Heaton. "Conserving Local Grassland Habitat for Declining Grassland Birds," Bird Conservation Network, 2000.
McCraken. "Where the Bobolinks Roam: The Plight of North America's Grassland Birds," Biodiversity, 6(3): 20-29.
Vickery & Heskert. "Ecology and Conservation of Grassland Birds of the Western Hemisphere,"Studies in Avian Biology No 19, Cooper Ornithological Society.
Murphy. "Avian Population Trends Within The Evolving Agricultural Landscape of Eastern and Central United States," Auk, 120:20-34, 2003.
"Grassland Birds." Natural Resources Conservation Service, No 8: 1-12, 1999
Askins. "Restoring North American Birds. Lessons From Landscape Ecology," Yale University Press, 2000.
Vickery, Hestert, et al. "Grassland Birds: An Overview of Threats & Recommended Management Techniques,"
Vickery & Hestert. "Recent Advances in Grassland Bird Research: Where Do We Go From Here? Auk, 118(1), 2001
"Grassland Management: Your Land, Your Legacy. A Management Guide For Landowners,"Williston Conservation Trust, date unknown.
"Grasslands Conservation." National Park Service and the National Capital Region Inventory and Urban Ecology Research Learning Alliance, date unknown.
"Conservation Tilleage; Ecological Traps for Nesting Birds?" Wildlife Society Bulletin, 14:308-317.
Heskert et al. "Habitat Establishment, Enhancement, and Management for Forest and Grassland Birds in Illinois." Technical Publication #1, Division of Natural Heritage, Illinois Department of Conservation, 1993.
