Opossums on the Move
By: Cholla Nicoll, Borderlands Wildlife Preserve Lead Technician
A recent review paper in the journal Global Change Biology titled “Tropicalization of temperate ecosystems in North America: The northward range expansion of tropical organisms in response to warming winter temperatures” explains how tropical organisms are beginning to move northward in response to global climate change. One of the species on the move in our region is the Opossum.
The name "opossum" originates from the Algonquian word "apasum," meaning white animal. There are over 100 different opossum species found in the Americas. Yet, the Virginia Opossum and the common opossum are the only two species of opossum and only marsupials naturally occurring in the United States and Canada. (Just in case you are wondering, the correct term is "Opossum", "Possum" is the term used for a different marsupial family found in Australia.) As climate change increases average winter temperatures, the range for the opossum and other tropical species is also expanding into these recently warmer and less snow-covered areas.
The opossum has many superpowers. This fantastic creature enters the world about the same size as a honeybee and lives out its life span in the matter of one to two years. Opossums are gentle creatures. Although they have 50 sharp teeth when a bite does not deter a predator, their primary defense when threatened is to drool, appear unappetizing, and play dead. Playing dead is thought to be an involuntary response and, unfortunately, does not work on domestic dogs. Outside of this well-known unique behavior, opossums also build nests using their tail as a fifth appendage to gather materials. Opossums also seldom contract rabies due to a naturally low body temperature and are resistant to venomous snake bites. To top off their superpowers, opossums consume many pests, including snails, slugs, mice, and 95% of ticks that they meet by some estimates.
As we accept the reality of a changing climate, I would like to suggest keeping the famous quote from Fred Rodger's mother in mind “Look for the helpers. You will always find people who are helping.” Remember, people are not the only helpers. We also have many animals like the opossum who are on the move and ready to help.
Valuing helping animals like the opossum, which can help with pest mitigation, will be essential to our survival and maintaining a balanced ecosystem. If you encounter an opossum, the best thing to do is to leave them alone. They are rarely in any one area for more than a few days. Help opossums avoid humans and dogs by keeping a tidy outdoor space free of pet food, clutter, and trash. If you find an injured opossum contact your local animal control or wildlife rehabilitation center.
Our local wildlife rehabilitation center is the Tucson Wildlife Center.
For more information on how to live with opossums, please visit the Opossum Society of the United States.
Opossum trail camera video and pictures courtesy of the TNC Patagonia Sonoita Creek Preserve.
BWP wildlife monitoring during 2021- 2022 supported by the Wildlife Conservation Society Climate Adaptation Fund established by the Doris Duke Charitable Foundation to fund critical ecological restoration work along the path of the jaguar in southeast Arizona.
Read more about this project.
Restoration Along the Path of the Jaguar
By: Kurt Vaughn, BRN Executive Director
Borderlands Restoration Network is honored to have received a $245,000 grant from the Wildlife Conservation Society Climate Adaptation Fund, established by the Doris Duke Charitable Foundation, to fund critical ecological restoration work along the path of the jaguar in southeast Arizona. WCS's goal is to conserve the world's largest wild places in 14 priority regions, home to more than 50% of the world's biodiversity.
The Sky Islands region of southern Arizona and northern Mexico encompasses more than thirty mountain ranges and is recognized as a globally-significant biodiversity hotspot home to half the bird species in North America, and over 7000 species of plants and animals, including the last remaining jaguar in the United States.
Climate change is impacting habitat quality through increased aridification of the region, exacerbating drought intensity, and increasing extreme precipitation events. Increasing temperatures and declining annual precipitation have had severe consequences for many of the region's ecosystems, particularly riparian habitats.
This process of aridification combined with unsustainable groundwater use has caused a 96% reduction of surface flows in the historic rivers and streams in Arizona. Decreasing soil moisture availability and declining groundwater have left riparian habitats severely water-stressed. This regional aridification is further punctuated by seasonal and longer-term droughts. In the near future drought is projected to become more frequent, more intense, and more prolonged, resulting in water deficits in excess of those during the last 2000 years. Securing sufficient water availability to weather these extreme events is essential to the continued integrity of this migratory corridor.
During 2021 - 2022 BRN will perform restoration work in and around the Borderlands Wildlife Preserve, the critical wildlife corridor linking the Huachuca and Santa Rita mountains, complementing and expanding upon our work in the area. 250 erosion control structures will be installed including one-rock dams, media-lunas, trincheras, stick structures, and one log dams. Borderlands Earth Care Youth will build 26 of these structures as part of their programming.
Scientific studies show ECS can increase surface water availability, extend seasonal flows and increase in-stream volume, decrease water stress in plants, increase vegetation cover and increase soil carbon sequestration. ECS are constructed of parallel rows of self-reinforcing rocks incorporated into eroding ephemeral stream channels. These structures, often only one-rock high in profile but several rows wide, rest at right angles to the direction of water flow and remain passive to overtop flows. This arrangement allows ECS to trap organic-rich sediment upstream while extending the hydro-period for plant establishment and increasing water infiltration.
In conjunction with erosion control efforts, we will actively revegetate the site with hardy, locally-adapted plants grown from hand-collected seed at our Borderlands Restoration Nursery & Seed native plant nursery to return degraded ecosystems, further stabilize soil, and provide habitat for fauna. Plant material will be selected based on resiliency to increased environmental stressors. Over 4000 seedlings and saplings will be planted with monsoonal rains on grazing-excluded sites, as grazing in conjunction with climate change has been determined to be one of the largest threats to sapling success. Plantings will be co-located with ECS to increase the likelihood of survival.
To address the 0ver 40 acres of bare soil surfaces across the project area, BRN will distribute native mulch and grass seed pellets. Mulch promotes soil moisture retention and revegetation of bare ground, further stabilizing the soil surface. It will also act as a seed refugia for hand-scattered seed pellets, further promoting vegetative recovery. Additionally, we will monitor wildlife camera data to better understand impacts on wildlife communities in the Borderlands Wildlife Preserve.
We are grateful to the Wildlife Conservation Society’s Climate Adaptation Fund, established by the Doris Duke Charitable Foundation, for the opportunity to advance this corridor toward a trajectory of recovery and enhance the resilience of this landscape to current and future climate impacts.
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By: Jeremiah Leibowitz, CLO Executive Director & Jose Manuel Perez, BRN Senior Fellow & CLO Director of Operations
Cuenca Los Ojos’ (CLO) founder, Valer Clark, has always believed that restoring CLO’s ecosystems would bring back wildlife and improve the biodiversity making our lands more resilient to climate changes. Our mission from the beginning has been to restore the biodiversity balance of CLO’s lands.
While inspecting CLO’s pastures last year, we ran into one of our neighbors and told him that 2020 was a very dry year and that it was the third bad year for us, to which he replied that it was not three bad years, but 18 very dry years. He was right, these changes have been in process for a long time. We then started evaluating our management practices to ensure we were preparing for continued climate changes. One of those strategies is our use of a high-intensity, rotational grazing program to restore grasslands.
Last year while touring a group of producers from Chihuahua throughout CLO, we inspected the Animas Valley pastures in the northeast corner of Sonora. These pastures represent grasslands that have been over rested. The group made several observations about the grassland’s health. First, the pastures were dying from the inside out and losing biodiversity. Second, the stem to leaf ratio showed a greater stem percentage. Third, the pastures were transitioning from permanent perennial species to annual and herbaceous species. Fourth, the distance between plants was increasing, which exposed more bare ground.
To combat this type of grassland degeneration, CLO, as part of our grassland restoration strategy, employs a high-intensity rotational grazing system. The purpose is to knock down undesirable and non-native grass and plant species, stimulate growth of native grass species, disturb the earth, apply manure and urine as fertilizer, and then give the land adequate rest time (18 to 20 months) so it can regenerate. We use electric fences and an aggressive rotation schedule moving the herd 3 to 4 times a day depending on pasture conditions. Each pasture is different and requires daily management so as not to overgraze the land.
Thus far, in areas where we have implemented this strategy, we are seeing the return of perennial plants, denser plant concentration, less bare soil, and greater organic matter distributed on the soil. These improved pasture conditions aid with water retention and infiltration when it does rain. We are also evaluating how these improved grasslands can work as a carbon sink for atmospheric carbon.
Another benefit of improved grassland health in this northeast region of Sonora has been an increase in wildlife populations. The increase in perennial pastures has expanded the diversity of different species, especially grassland birds, which use these pastures during their migration to feed and reproduce. In addition to birds, native and endangered animals live and migrate throughout these grasslands. As we observe drier climate conditions throughout the desert Southwest, we are encouraged that the proper employment of livestock as a grassland management tool has thus far improved soil quality and increased biodiversity improving the ecosystems’ resiliency to mitigate the challenges of a changing climate.
As we observe drier climate conditions throughout the desert Southwest, we are encouraged that the proper employment of livestock as a grassland management tool has thus far improved soil quality and increased biodiversity improving the ecosystems’ resiliency to mitigate the challenges of a changing climate.
Looking ahead, one of CLO’s long-term objectives is to use our rotational grazing grassland restoration practice as one model to bring desert pastures in northern Mexico, the southwestern United States, and other arid regions of the globe back to life.
Carbon Credits for the Southwest
By: Dr. Richard Pritzlaff, BRN Senior Fellow & Biophilia Foundation Board Member
Carbon is constantly cycling between our atmosphere and other places like soil, oceans and rock, where it is stored for varying lengths of time. While these carbon pools have naturally fluctuated over the history of our planet, humans have been rapidly moving carbon from many of its more inert storage pools into the atmosphere.
Atmospheric carbon is a powerful greenhouse gas which means it impedes the release of solar heat back into space resulting in a warming planet. While most of this is due to the burning of fossil fuels, in our part of the world erosion caused by disturbances such as unsustainable timber harvest, over pumping of surface and groundwater, overgrazing, development, and extirpation of beaver have also released huge amounts of carbon.
Fortunately, drawing upon ancient traditional practices, a generous spirit, and a deep passion for the earth, Valer Clark the founder of Cuenca Los Ojos and inspiration for Borderlands’ efforts has been restoring degraded washes for almost forty years. The earliest of these she installed at her home, Rancho El Coronado, located in the Chiricahua Mountains.
These interventions help replicate the functions of healthy riparian ecosystems, where tree roots and vegetative debris help stabilize soil, slowing the speed and energy of water moving downstream, thereby reducing the water’s ability to transport sediments. This sedimentation reverses past erosion of waterways and captures carbon both in the soils and in the plants that then revegetate the restored riparian floodplain. Additionally, construction of these structures can be iterative and adaptive, responding to conditions as needed raising the streambed further and essentially reattaching the streambed to its former floodplain.
Soils store most of the Earth’s terrestrial carbon—far more than the terrestrial biosphere and atmosphere combined. In fact, arid soils are thought to hold the largest carbon stocks of any biome making them an important part of the global carbon cycle.
Once carbon is stored within a soil, assessing its stability over long time periods is vital to global atmospheric carbon sequestration efforts. Because of Valer Clark’s pioneering work, as well as those of BRN and others, we have several long-term restoration sites to learn from. The most detailed study of carbon sequestration in our region assessed the ability of different rock structures to capture carbon after a wildfire. The findings of this study have inspired our efforts to assess the possibility of developing financing mechanisms including developing a carbon credit market that who help increase the scale of our watershed restoration efforts.
The Biophilia Foundation, a founding partner of BRN, has brought together a working group of scientists, practitioners, finance, and third-party carbon market experts to identify best practices for developing this potential financing mechanism. Examples of market-based solutions from other places with similar environmental characteristics, including Mexico, show that there is significant opportunity to create and sell carbon credits to finance the regional scaling of riparian restoration projects in the arid lands of the American Southwest.
We are excited about the prospects of expanding our efforts and exploring multiple paths for getting carbon out of the atmosphere and back in our borderlands soils.
By: Alberto Mellado, Erica Barnett, Laura Monti and Gary Paul Nabhan
On a breezy winter day along the Sonoran coast of the Sea of Cortés in Mexico, six of us went wading into fragmented stands of mangroves in backwater lagoons. Our binational, multicultural team had come out to count the number of red mangrove seedlings surviving in our restoration plots along the shores of coastal lagoons, and assess the quantity of seeds developing in eelgrass mats thrown upon onto the beaches during the last windstorm.
For us, these humble little plants were not the only things that Comcaac (Seri Indian) teams of 10 young men and women had sown two months before that windy day in mid-February. They had also sown hope: hope that the plants might survive treacherous currents, hurricane fringe storms, predation by herbivores, and drought; that they could endure ocean level rising to buffer their nursing grounds for shellfish and finfish from invasion and erosion; and that they could sequester enough “blue carbon” to reduce if not reverse the march of climate change.
The coastal communities and fisheries of the Sea of Cortés--- known to many Americans as the Gulf of California—are facing several threats associated with climate change. These may include higher sea levels; greater salinity in coastal groundwater where aquifers have already been overpumped; acidification of the seawaters where fishes breed; huge shifts in the volumes of harvestable lobsters and abalones; and delayed or disrupted migrations and reproduction of already threatened sea turtles and whales.
Of all these challenges to human and wildlife communities, perhaps the rising of ocean levels and the concomitant loss of coastal habitats seems most daunting, if not intractable. For the Pacific Coast of southwestern North America in general, the rapid loss of ice sheets on Antarctica could drive rates of sea-level rise above 50 mm/year (2 inches/year) by the end of the century. Under the most extreme scenarios, that could potentially lead to a potential sea-level rise exceeding 10 feet by 2200. This accelerated rate of sea-level rise would be about 30-40 times faster than the sea-level rise experienced over the last century.
At the same time, the vertical rise in ocean levels would have exacerbated “horizontal” effects along significant portions of the Gulf’s coastlines of Sonora and Baja California. The northern end of this inland Sea or “Upper Gulf” already experiences a 32-foot tidal range, the third largest in North America and two-thirds of that suffered in the Bay of Fundy, suggesting that the rising sea level would eat far further into the coastlands than in most places along the Pacific coast of Mexico and the U.S.
This would be particularly devastating to barrier islands and peninsulas like those of Estero Sargento and Estero de la Cruz (near Kino Bay) that protect both the Sonoran coast and the hypersaline lagoons behind them from tropical storms and hurricanes. These backwater mangrove lagoons and adjacent beds or “pastures” of eelgrass are essential to the reproduction and survival of both shellfish and finfish that provide the economic basis for most costal fishing communities. And because virtually every other stretch of offshore waters along the Sonora and Baja California coasts has been repeatedly dredged and trawled over the last five decades, the undredged lagoon and shoals of the Comcaac indigenous nation may be considered “blue carbon’s last stand” in the midriff of the Gulf of California.
The annual economic median value of these fisheries is at minimum valued above US $37,500 per hectare of mangrove fringe. That value –estimated a decade ago-- falls at the higher end of values previously calculated values worldwide for all mangrove ecosystem services together.
It is also many times higher than that for other nursery grounds for fish and shellfish remaining in the Sea of Cortés. That is because coastal development, dredging, chemical pollution and other human activities have diminished the size and density of these nursery grounds everywhere else in the Gulf, leaving just four mangrove stands within Comcaac territory as the northernmost and last of any of significant size on the Sonoran coast.
As we waded along, counting the number of still-surviving red transplants of red mangroves in the shallow waters of two lagoons along the shores of the Comcaac homeland, we were heartened to find that the vast majority of these seedlings had survived several months of rough weather. We were hopeful that if such survival rates persisted as time went on, the patches of red mangroves we transplanted could “stitch together” the edges of mangrove buffer zones that protect the Comcaac coast from inclement weather and further habitat fragmentation. With as many of five rows of transplants rooting in the shallow intertidal waters and holding sediments in place, the transplants were forming a living bandage over storm-wounded areas that had served as nick points for erosion and loss of vegetative cover.
We had to be extremely strategic in determining where to place our investment in these living, breathing bandages of blue carbon. Both Sonora and Baja California are projected to receive an increase in total annual precipitation as climate change advances, but much of that rain will come with hurricane fringe storms that cause flashfloods in the many intermittent and ephemeral streams that flow into the Gulf. During such tropical storms, two to eight inches of rain may drop in the matter of two days, literally reworking the routes to the sea taken by streams overflowing their banks. At least twice in the last decade, the indigenous Comcaac communities have suffered flooding of their villages from inland rains. One of these catastrophic events sent floodwaters three feet deep through Desemboque del Sur, damaging the walls, floors and appliances in virtually every house in the village. These floods also destroy bridges and elevated roads leading into these remote coastal villages, such that both villages have gone as many as eight days in the aftermath of a storm without the arrival of medical care, food or water from inland sources.
Fortunately, dozens of Comcaac community members have begun to engage in beneficial actions which will not only serve to protect their villages from storm surges and flashfloods, but ones which may ultimately slow or reverse sea level rises if combined with similar actions around the world. The transplanting of thousands red mangrove seedlings to shore up and restore vegetation to vulnerable “nick points” along barrier islands and in bays adjacent to villages will serve as buffers to protect these natural refuges. Farther out into the bays and swale-like channels of the Canal del Infiernillo, the transplanting of eelgrass to form more extensive pastures for sea turtles, blue-eating crabs and finfish will serve as an additional buffer from storms.
The Comcaac community members of both villages recognize the “promise of blue carbon” as a potential future source of funds to stabilize their now-vulnerable economy in the face of daunting climatic challenges. But in the meantime, the restoration of mangroves and eelgrass for the food, income and protective buffers they provide are sufficient to justify their community engagement.
Special thank you to 11th Hour Racing, a program of The Schmidt Family Foundation for support of this project.
By: Doug Smith, BRN Board President & Ann Gosline, BRN Board Member
Climate change mitigation and adaptation are the defining issues of our time. While the public discourse on planetary warming tends to focus on carbon emissions from fossil fuel burning, it is equally important to develop strategies to store carbon in plants and soils. The programs of the partner organizations that make up our network--Borderlands Restoration Network itself, Cuenca Los Ojos, Deep Dirt Farm, Wildlife Corridors, and Borderlands Restoration L3C—work squarely in that dimension, stressing habitat rehabilitation, watershed health, regenerative range and grassland management, permaculture, and native plant propagation. The word “climate” may not appear front and center here, but the climate implications of all that work are always close. In fact, the climate emergency backgrounds (and sometimes foregrounds) pretty much everything we do.
We work every day on projects to slow climate change and to make our ecosystems and communities more resilient to the hotter and drier borderlands we are likely to see in the years to come. Riparian and riverine restoration features centrally in the work of CLO, BRN, and DDF. BRN’s and WC’s native habitat enhancement work supports the diversity and viability of regional food webs. A BRN-DDF collaboration is stewarding production and distribution of wild foods, including native perennials, for a more self-sufficient local food system. BRN’s bats and agave work, including the Bats and Bacanora project that aims to buttress ecological relationships between agaves, pollinators, and mezcal culture in Sonora, looks to restore the abundance of an historically important arid lands plant, and one that may well figure significantly in a livable arid lands future.
BRN’s “blue carbon” project extends our carbon storage efforts into the mangroves of the Sonoran coast. All of these endeavors require scientific monitoring and evaluation. To that end, we are also working on appropriate methodologies to gauge the effectiveness of our sequestration efforts. We could go on. We leave it to the authors to describe some of our projects in more details in other blogs in this special Earth Day series of blogs.
All organizations in the BRN family see their work as part of a necessary paradigm shift toward a restorative economy. We are part of a global effort to create synergies between human economic activity and natural systems in order to build more prosperous, stable, and socially just local economies. Whether or not we achieve such a sea change will in large part determine the qualities of the human future in relationship to the rest of the biosphere. And in the face of too-little progress up to now, time is very much of the essence. That is, the transition toward restorative economies is already underway all over the planet, but we need to speed things up. Our objective is to provide inspiration and leadership in our corner of the world, and we are presently doing so in at least three ways.
First, our organizations themselves are part of this economy, providing training and livelihoods in restorative economy jobs. Those jobs involve growing and distributing native plants, restoring stream systems, and conducting research to support this work. For example, in Patagonia, BRN is one of the most significant local employers. Cuenca Los Ojos and its sister organization in Mexico employ dozens of people in watershed restoration and conservation ranching.
Second, our education programs inspire and train youth and others to do the work now and lead others to do it in the future. One of those programs, Borderlands Earth Care Youth, has directly prepared young people in our region to attend college in conservation-related sciences. BRN and CLO support college and post-grad interns on both sides of the border who then proceed to other remarkable restorative economy projects. Deep Dirt Farm has trained hundreds of kids and adults in permaculture principles and skills.
Third, we are beginning to flesh out collaboratives across our organizational network and with community leaders to think and work in restorative economy terms. This has become the lodestar of our mission. To inaugurate it, we have formed a coalition of nonprofits and business organizations to commission a comprehensive study of nature-based economic opportunities in Santa Cruz County.
We hope you enjoy our Earth Day series of blogs, digging deeper into the work of BRN and our network. Make sure to sign-up for our monthly enewsletters and follow us on our social channels to keep in touch and informed about our work.
As it becomes safer in the future, we invite you to also join us for hands on volunteer work. Now is a great time to get on our list and be notified when future volunteer opportunities arise.
And, lastly, our work is only possible through the generous support of donors. We have a wide variety of giving options from monthly, to special giving societies and major and planned gifts.
Learn more about supporting our work at this link, together we can rebuild, restore, and reconnect the borderlands!
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