Drought, flood, and fire: an unexpected habitat recipe for at-risk bats

Mike Saxton is an ecologist restoration specialist at Shaw Nature Reserve, a 10 km2 mosaic of restored and reconstructed woodlands, prairies, wetlands, and riparian forest along the Meramec River in Gray Summit, Missouri.

For most land managers, there aren’t enough hours in the day. Between invasive species management, native seed collection and prescribed fire implementation, there are never enough boots on the ground. Add in equipment break downs, erratic weather and administrative tasks and it’s no surprise that with so many balls in the air, something gets dropped. Far too often, we drop the ball on science and monitoring, which are critically important for biodiversity-driven ecosystem management and restoration. Research and monitoring can, in some cases, be expensive; usually they take a certain amount of specialization, and they most certainly take time. For these reasons and many others, land managers build partnerships with universities, collaborate with outside agencies, and engage the public in community science to meet research and monitoring needs.

What follows is an example of a highly successful partnership between non-profit organizations, a private consulting group, and a federal agency to better understand and protect a federally endangered species.

A female Indiana bat, “Celeste”, captured during mist netting surveys at Shaw Nature Reserve in 2017 and 2019. Photo credit: Cassidy Moody.

In 2017, Shaw Nature Reserve hosted a Bioblitz partnering with the non-profit Academy of Science, St. Louis. For two days, participants combed the area looking for as many plant and animal species as they could find. A single federally endangered Indiana bat (Myotis sodalis) was captured during an evening mist netting session along a riparian corridor, marking the first time this species was documented at the Nature Reserve.

Wildheart Ecology, the local consulting firm which carried out the Bioblitz bat survey, returned in the summer of 2018 to deploy acoustic detectors to further document bat populations at the Nature Reserve. The data revealed the presence of nine different species, including the Indiana bat, the endangered gray bat (Myotis grisescens), and several other species of conservation concern.

The audio signature of an Indiana bat, captured by detectors at Shaw Nature Reserve. Courtesy: Wildheart Ecology.

After these surprising and impressive findings, scientists at the U.S. Fish and Wildlife Service carried out mist netting in summer 2019 at the Nature Reserve to gather more information about the federally endangered population of Indiana bats. Netted individuals were tagged and fitted with tiny transponders. Using telemetry, USFWS staff were able to locate a maternal roost colony tree in the Meramec River flood plain. After multiple emergence sampling events conducted at dusk, the population is estimated to be 150+ individuals, making it one of the largest recorded in Missouri.

Indiana bat roost site at Shaw Nature Reserve. Photo credit: Cassidy Moody.

So how did Shaw Nature Reserve end up with one of the state’s largest populations of at-risk bat species? The story begins in fall 2015, when a major flooding event on the Meramec River deposited large amounts of woody biomass and created logjams in the Nature Reserve’s floodplain. Another major flooding event in the spring 2017 compounded these conditions. In the fall of 2017, moderate drought gripped the region, drying leaf litter and woody fuels on the forest floor. In November of that year and on a low humidity day in drought conditions, we conducted a prescribed fire that thoroughly burned the floodplain forest, which normally does not carry fire. The flames crept into flood-debris logjams, causing a major conflagration. Dozens of floodplain forest trees died — mostly silver maple, elm and cottonwood— leaving an open patch of larger-diameter snags, or upright dead trees. It is in these snags where the federally-endangered Indiana bats have found a home. Turns out, the serendipitous convergence of flood, drought, and fire created just the ideal conditions. Couple that with high-quality foraging areas across a healthy, diverse, managed landscape and this population is thriving.

Indiana bat roost habitat along the Meramec River at Shaw Nature Reserve in Gray Summit, Missouri. Photo credit: Cassidy Moody.

Current status of Indiana Bats

Unfortunately, like many bat species, the Indiana bat has been in decline and imperiled by human disturbance and disease. According to the U.S. Fish and Wildlife Service, hibernating Indiana bats are especially vulnerable to disturbance, since they often congregate in large numbers – from 20,000 to 50,000 – to overwinter. A large number of deaths can occur if humans disturb these caves during hibernation. While other factors are also responsible for their decline, the devastating wildlife disease known as white-nose syndrome — discovered in 2006 — is a serious threat to the long-term survival of the species.

According to the U.S. Fish and Wildlife Service population status update, the states with largest net loss of Indiana Bats since 2007 (% decline since 2007) includes:

1. Indiana: -53,220 (-22%)
2. New York: -39,367 (-75%)
3. Missouri: -18,157 (-9%)
4. Kentucky: -15,220 (-21%)
5. West Virginia: -14,125 (-96%)
6. Tennessee -6,509 (-73%)
7. Ohio: -4,739 (-62%)
8. Pennsylvania: -1,027 (-99%)

What Can Be Done

With thoughtful management and strategic planning, conservation practitioners can conserve and restore bat habitat. Providing a continuous supply of roosting trees and maintaining a habitat structure to facilitate foraging are key aspects of restoration and management plans for bats. According to the Beneficial Forest Management Practices for White Nose Syndrome-affected Bats, below are some best-practice guidelines for achieving these goals:

  • Harvest timber during the hibernation period to eliminate or significantly reduces the likelihood of direct fatality or injury to tree-roosting bats.
  • Create large-diameter snags and canopy gaps, via girdling or chemical (e.g., “hack and squirt”) methods, to increase sun exposure to existing and potential roost trees.
  • Increasing midstory openness to facilitate travel corridors and foraging opportunities via increased mobility and insect prey detection.
  • Retain or create large-diameter snags during forest regeneration harvests or when managing stands affected by windthrow or disease/insect outbreaks.
  • Limit aerial or broadcast spraying near known hibernacula, maternity sites, and surface karst features, unless it can be demonstrated that it would have no adverse impact on bat populations or habitat.
  • Avoid disturbances near maternal roost sites or colonies when possible.
  • Fell hazard trees that appear to provide bat roosting habitat and do not pose an imminent danger to human safety or property during winter (hibernation period) and avoid removing them during June and July when non-flying bat pups may be present.
  • Avoid burning during cold periods since this can be detrimental to colonies of some species if individuals cannot escape smoke and heat from fires.
  • Apply low-intensity fires when possible since high-intensity fires are more likely to cause injury.
  • Account for caves, mines, important rock features, bridges, and other artificial structures when developing burn plans since these locations are often occupied by roosting or hibernating bats.
  • Remove hazard trees and construct fire-lines during winter, when possible, to reduce chances of removing occupied roost trees or disturbing maternity colonies.
  • Protect known maternity roost trees and exceptionally high-quality potential roost trees (e.g., large snags or large-diameter live trees with lots of exfoliating bark) from fire by removing fuels from around their base prior to ignition.
  • Limit management activities and disturbances near cave entrances.
  • Eradicate and control invasive plants to improve habitat quality for bats.

Green Again: Restoring rain forests in eastern Madagascar

Green Again Madagascar is a young non-profit aiming to reconnect rain forests in eastern Madagascar and collecting heaps of data in the process. Disclosure: Leighton Reid wrote this blog and is on Green Again’s board of directors.

Matt Hill is trying to restore a rainforest corridor across eastern Madagascar. His motivation is that Madagascar’s wet, eastern flank was once blanketed by a dark, rich forest festooned by bizarre plants and teeming with unique animals. No longer. Over the last 70 years humans cleared almost half of what was there in the 1950s – mostly for farming. Although the farming is often temporary, the forest rarely grows back. Weedy ferns and exotic trees find their way onto the abandoned farms and take hold – boxing out the Malagasy species.

Some tropical rain forests can recover swiftly on their own, but not these. Eastern Madagascar is a strong candidate for hands-on ecological restoration.

RevisedExpansionMap

Madagascar (left) and the region of eastern Madagascar where Green Again Madagascar operates (right). Dark green areas are intact rain forest. Colored ovals show the expanding project scope of Green Again over the past four years. Green Again hopes to one day reforest a longer corridor across the northeastern side of the island. Imagery is from Google Earth.

Melaleuca quinquenervia Analalava

In the landscape around Foulpointe, native forest was replaced by shifting agriculture, which was replaced by a forest of invasive Melaleuca quinquenervia, a tree native to Australia. Photo by L. Reid.

Matt is a middle-aged ex-pat and a self-described “quant”. His father was a math professor, and Matt followed in his footsteps, earning a degree in mathematics from the University of Chicago and subsequently a masters from UCLA. Before landing in Madagascar, Matt had a career on Wall Street analyzing large databases for Putnam. He retired early seeking a simpler and more natural lifestyle, which he found in abundance in rural northeastern Madagascar.

I first met Matt in 2015 at Parc Ivoloina – a zoo and forestry station near the port city of Toamasina. Clad in gym shorts and flip flops, Matt was buzzing between nursery beds shaded with bamboo slats and a laptop powered by a portable solar panel, where a local was entering data about tree survival and growth. Matt explained his tree planting system to me. At each stage, from seed to tree, he and his team measure plant performance – including survival, height, and diameter. Matt’s team uses these data to quickly adopt methods that work and discard methods that don’t.

As he explained his tree planting system to me, I was impressed by Matt’s attention to rigorous data collection – a preadaptation from his Wall Street career that serves him well in his new pursuit of tropical forest restoration.

MattQuant_Edit

Matt Hill (left) explains database management to a local community member.

Starting a forest restoration program in eastern Madagascar

Matt was introduced to forest restoration by accident when he was stranded for several days in Toamasina waiting for the wild, muddy road to Maroantsetra to become passable. He visited Parc Ivoloina on a whim and learned about a recent wildfire. A local man had been making charcoal when his fire got out of hand and burned his own farm and 20 acres of a nearby forest. The experience moved Matt to begin growing and planting native trees on the burned land. This effort congealed into an NGO called Green Again Madagascar.

From the start, Green Again has been a collaborative effort involving a team of local people. Jean François Solofo Niaina Fidy is the head forester at Parc Ivoloina and president of a nearby village association. He initially advised Matt on the project and helped build local support. Many community members joined the restoration effort – growing trees in the nursery and planting them in the burned area. It is a steep learning curve. Many local people have only a few years of school and may not have held a pencil for some time. Matt teaches them to use GPS units, record data on datasheets, and enter it into an Excel spreadsheet. When the data do not make sense, they return to the field to take repeated measurements.

The work is hard but good by local standards. Many locals make their living by breaking large boulders into gravel by hand, with a hammer. Others spend their days shoveling sand from the river into dugout canoes and paddling it to shore where it is picked up by road construction trucks. In contrast, locals who get involved in these forest restoration projects pick up transferable skills in horticulture, computing, and business management.

Coping with wildfire (and learning from it)

In early November 2016, Matt called me in a panic. There was a wildfire. His plantings had burnt to a crisp.

Fires are common in eastern Madagascar, but this was a tragedy. To make a bad situation worse, the plantings that burned were an experiment that Matt was doing for a master’s thesis at the University of Minnesota.

fire_03

A wildfire in 2016 that swept through a forest restoration site, destroying Matt’s master’s thesis experiment.

In the ashes of his ruined experiment, Matt found a few survivors. He discovered that some native trees are resistant to fire. These survivors may lose their leaves and stem to fire, but they can resprout from roots.

Importantly, Matt also learned that trees planted near the edge of plantings were more vulnerable to fire than trees planted in the center of a plantation. This is because the landscape outside of the tree plantations was more flammable than the trees inside the plantations. In particular, the thatch from a common fern (Dicranopteris linearis) would catch fire and burn for quite a long time.

Green Again’s recent projects have taken this new information on board. Now, new plantings are designed with the fire survivor species on the outside and the delicate species on the inside. Some new plantings are also more extensive, so that the edge-to-interior ratio is lower and less of the trees are placed in the riskiest spots.

For good measure, Matt’s team also includes some “vulnerable” tree plantings using the earlier techniques so that the next time a fire sweeps through one of the sites, Green Again will have tangible evidence about which strategy is the most fire-proof.

forest_06

A pristine rainforest in eastern Madagascar.

Green Again Madagascar has a small operating budget based on charitable donations and memberships. To learn more, visit the Green Again Madagascar website or write to Matt at GreenAgainMadagascar@gmail.com.

Photos: All photos are by Matt Hill unless otherwise noted.

 

Conservation and restoration in arid Australia – an uphill battle.

In their third report from arid Australia, James and Thibaud Aronson discuss some of the serious issues facing conservationists and restorationists.

Concerning the non-native animals in Australia, the general consensus today is that eradication is impossible: the only option that remains is control, in the form of fences or culling, or both. Yet, conflicts of opinion on the ethics of culling abound, even for the armies of feral cats that reportedly kill 75 million native animals every single night. Even fences have their pros and cons, in particular the interruption of the migration of thousands of emus.

Western Australia's State Barrier Fence, 1170 km long, meant to control dingoes, dogs, foxes and other feral animals, with more or less effectiveness….

Western Australia’s State Barrier Fence, 1170 km long, meant to control dingoes, dogs, foxes and other feral animals, with varying degrees of success.

Both feral cats and foxes are most lethal in areas with relatively little vegetation cover, that is, the massive dry interior of the continent. This is compounded by the monster fires that have plagued Australia since European settlement. A single such fire can burn down hundreds of thousands of hectares, leaving small mammals and other animals with nowhere to hide.

Even this rather small fire, which spared the trees, has almost entirely eliminated all low vegetation, thereby exposing small animals to predation by cats and foxes. West MacDonnell National Park, Northern Territory.

Even this rather small fire, which spared the trees (their dead appearance is deceptive; these trees will resprout), has almost entirely eliminated all low vegetation, leaving small animals vulnerable to cats and foxes. West MacDonnell National Park, Northern Territory.

What’s more, as mentioned in our previous blogpost, most land managers continue to burn on an annual basis without sufficient attention to the impact on animals and indeed many plants. Things are changing though.

In the seasonally dry, tropical Kimberley region, in the northwest, the Australian Wildlife Conservancy, or AWC, is testing new methods, focusing on patchy prescribed burning in the early dry season, and controlling cattle grazing. They are having good results with this approach in preserving more plant cover for small native animals and thereby reducing the lethal impact of feral cats. The AWC has also shown that their fire management techniques are not only beneficial for native animals, but also for pasture quality, and would therefore benefit pastoralists, whom Australians call graziers. Since most landowners in the area are graziers, let’s hope they will follow suit and try new fire management regimes. It is in this region, by the way, that occurs the endemic baobab of Australia, known here as Boab. To our surprise there are thousands of them, in a wide range of habitats. Some are estimated to be well over 1000 years old. Survival of this tree, at least, is clearly not threatened by fire or foxes, even if other problems – such as climate change – do exist. Let’s hope they go on thriving for another 1000 years.

A typical landscape of the Kimberley, dominated by the majestic boabs (Adansonia gregorii). King Leopold Ranges Conservation Park.

A typical landscape of the Kimberley, dominated by the majestic boabs (Adansonia gregorii). King Leopold Ranges Conservation Park.

Another reason invoked for the proliferation of cats and foxes in Australia is the virtual absence of top predators to control them. This phenomenon, called meso-predator release, is also found in North America, where coyotes have greatly expanded following the extirpation of wolves throughout large portions of the continent. Therefore, some have suggested that allowing dingoes to maintain higher population numbers would have a significant effect on controlling cats and foxes. However, dingoes are still considered pests by pastoralists, and large amounts of money go into controlling them.

And that’s not the last of it. In the last 200 years, people have also introduced many exotic plant species, some of which have become terrible weeds, such as buffel grass (Cenchrus ciliaris) (see our previous blog post), but also Tamarix, Kutch (aka Bermuda grass, Cynodon dactylon), Karroo thorn (Acacia horrida) and others. By 2009, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) estimated that introduced invasive plants were costing the country 4 billion Australian dollars a year in weed control and lost agricultural production, and causing “serious damage to the environment”. With climate change, it seems possible that numerous “lurking” or “sleeper” weeds such as the White weeping broom, Retama raetam, may increase their ranges and their negative impacts.

Buffel grass presents a particularly severe problem – and like the cats, and dingoes, it is controversial. It was one of dozens of African grasses intentionally introduced by Australian agricultural researchers to “improve” pasture for cattle. Indeed cattle do like it, but the problem is that the grass spreads with amazing tenacity and crowds out native grasses, and all other groundstory plants where it invades, and, it carries fire like few other plants. Control is possible, but it is tedious and expensive and is never 100% effective at a large-scale. Furthermore, the ranchers prefer it to the native grasses, and their ideas on when and how to burn are very different from those concerned with conservation. Indeed, only few of the people we met envision stopping prescribed fire altogether.

For example, Peter Latz,  a native of the Red Centre,  plant ecologist, and author we met in Alice Springs, has been conducting manual removal of buffel and Kutch on his own land. But his main focus has been on excluding fire altogether, and achieving thereby pretty impressive results.

 

Peter Latz in his garden, next to the hemi-parasitic quandong tree (Santalum acuminatum). Alice Springs.

Peter Latz in his garden, next to the hemi-parasitic quandong tree (Santalum acuminatum). Alice Springs.

For more on Peter Latz’s views and lifetime of experience in central Australia, see The Flaming Desert: Arid Australia – a Fire Shaped Landscape.

In our next blog post, we’ll talk about some of the other people and groups in arid and SW Australia undertaking serious steps towards restoration, while fully aware of the obstacles and the complexity of the challenge.

Tale of two Highlands Part I: Horton Plains, Sri Lanka

This post is contributed by Dr. James Aronson, a restoration ecologist at MBG’s Center for Conservation and Sustainable Development, and his son Thibaud Aronson. James is also a researcher with the CNRS (National Center for Scientific Research) in Montpellier, France.

In Sinhalese Sri Lanka means “Resplendent Isle”, a fine name indeed for this tear-shaped island off the coast of southeastern India, just north of the equator. Last month I travelled with my son on a self-guided Natural History + Ecological Restoration visit, we are finding and photographing cloud forests and birds galore, like the endangered endemic Sri Lanka whistling thrush, Myophonus blighi, and the Kashmir flycatcher, Ficedula subrubra, which over-winters exclusively in the Sri Lanka highlands, from its very restricted breeding grounds in Kashmir, northern India.

We were also looking at the mosaic of grasslands, cloud forests, and lowland forests we find here from a restoration ecology perspective.  That means we’re trying to “read” the landscapes we see in terms of known transformations carried out during the British colonial era (1815 and 1948, when Sri Lanka was known as Ceylon), and since independence. The remarkable Horton Plains National Park is a mosaic of montane grassland (ca. 35%) and cloud forest (ca. 65%), encompassing the headwaters of three major rivers. It was declared a sanctuary in 1969 and elevated to national park status in 1988; it became part of a large UNESCO World Heritage site in 2010. In the central highlands of Madagascar, grasslands appear to occupy about 99% and most people assume they are anthropogenic…. This month, I’m travelling with Leighton Reid in the Central Highlands of Madagascar, and we will be blogging about this soon.

But, the history of preservation in the highlands here goes back a lot further, to the days when the Isle was part of the British empire, along with all of India. According to information we gathered at the extraordinary, and poorly known Hakgala Botanic Gardens, the great English botanist and explorer Joseph Dalton Hooker had advised the British government to leave all montane forests above 5000 ft. (ca. 1300 m) above sea level “undisturbed” and after 1873 the administration prohibited clearing and felling of forests throughout the central highlands. What a great idea that was! It is too bad there were not enlightened laws on hunting of wild animals as well. One Scottish officer in colonial service in Sri Lanka bragged he had shot and killed over 1400 elephants in Horton Plains and nearby. Today, there are none left there and, so far as we could determine, no plans to reintroduce them from the other remarkable parks, including Yalla and Uda Walawe….

So, what is the significance of the absence of elephants in this park? And, what else can we learn from past regimes and historic periods in Sri Lanka? For starters, we discover that conservation, and respect for other organisms goes back much further than the 19th century. Consider the sign at the entrance to Udawattakele Forest Reserve, near Kandy, one of the historic capitals from the long period of successive kingdoms the island had known prior to the European colonial chapter in Sri Lanka’s history:

O Great King, the birds of the air and the beasts have an equal right to live and move about in any part of this land as thou. The land belongs to the peoples and the other beings and thou are only the guardian of it.”

-Arahath Mahinda (a son of the emperor Asoka the Great, who brought Buddhism to Sri Lanka)

How would it be if we could revive that approach to the Web of Life in our own day and age?

So, what has Horton Plains National Park, with its grassland-forest mosaic, its tourists, and its absent elephants got to do with the Central highlands of Madagascar? For one thing, we can see that fire is a big ecological driver in both areas. The abundant arborescent Rhododendrons in Horton Plains tell a vivid tale in this regard.

Rhododendron arboreum subsp. zeylanicum at Horton Plains National Park. It appears to be fire-resistant and is the only tree species present in large areas of grasslands subject to fire.

Rhododendron arboreum subsp. zeylanicum at Horton Plains National Park. It appears to be fire-resistant and is the only tree species present in large areas of grasslands subject to fire.

On the grand scale of things, Sri Lanka’s Central highlands also resemble those of Madagascar’s since both are the crowns of a poor, emerging tropical island with small and very similar human population size (21 million vs. 24 million), despite being much nearly ten times smaller, and with over 30,000 years of human history, as compared to merely two millennia for Madagascar.

Horton Plains also has remarkable conservation value both for its biodiversity and the ecosystem services it provides to people. Also, as I said, it’s a mosaic of grasslands and cloud forest, that in the past was certainly much affected by both elephants and fire.

Finally, both Sri Lanka (along with the Western Ghats of southern India) and Madagascar count among the world’s biodiversity hotspots, easily visible in their fauna and flora, which is one of the main reasons why MBG researchers, and many others travel and work in Madagascar.

Now, let’s turn back to fires. A big fire hit Horton Plains in 1998, and there are serious invasions of two noxious, cosmopolitan weeds, namely Gorse and Bracken fern. Some control work is underway on the Gorse, but the Bracken fern is apparently not seen as being a problem. Rainbow trout were introduced in the 19th c. and apparently have displaced all native fish, and are taking a toll on native shrimp and no doubt other fauna.