Plight of the Monarch

Written by Peter Pearsall/Photo by Peter Pearsall

We Americans consider very few insect species “iconic”—that is, cherished, beloved, recognized by millions across the country. We much prefer to lavish attention on furrier, floofier, more familiar creatures. But if any insect were to merit such status, that insect would surely be the monarch butterfly.

Measuring up to four inches from wing to wing, ostentatiously flitting about on warm sunny days, the monarch (Danaus plexippus plexippus) begs to be noticed. Its striking coloration—an aposematic palette of orange, black and white—signals to potential predators that it is toxic, owing to chemical compounds acquired from its only host plant, milkweed.

Monarch butterflies depend on milkweeds (Asclepias spp.) for survival—their larvae develop by eating the leaves and flowers of these plants and nothing else. Most monarch populations are migratory; in North America, the species is divided into two major groups: Eastern monarchs, which migrate from wintering grounds in Mexico to breed in states east of the Rocky Mountains; and Western monarchs, which breed west of the Rockies and winter in coastal California.

But across the country, monarchs are struggling. While both North American populations have been declining for decades, the Western monarch is now on the verge of disappearing altogether. Only 2,000 monarchs were counted on their California wintering grounds in November 2020—just last year, 30,000 were tallied there. Decades ago, there were millions.

Western monarchs utilize milkweeds in desert habitats, including those at Malheur Refuge. In 2014 the Refuge was identified as a priority Western monarch breeding area by the U.S. Fish and Wildlife Service (USFWS) Pacific Regional Office. Monarchs in the Harney Basin use showy milkweed (A. speciosa), a widespread and often abundant species, nectaring on its flowers and laying eggs on the plant itself. Surveys during that period turned up small numbers of monarchs using milkweed on the Refuge, but today there are likely even fewer to be found.

It is thought that habitat loss and heavy pesticide use are behind the widespread decline of monarchs, along with populations of many other native pollinators. Also implicated are the deleterious effects of climate change. Despite these dire circumstances, earlier this month the monarch butterfly was denied federal protection under the Endangered Species Act, a decision that came six years after USFWS was petitioned to list it. In the decision, USFWS acknowledged that the species warrants protection—but with conservation funding stretched thin, other, higher-priority species would take precedence.

Less than 1% of the entire Western population remains. If this iconic species can disappear from the American West in a matter of decades, what hope is there for the many other invertebrate species around that world that receive little to no conservation concern?

Gifts from Malheur

Submissions from James Pearsall, Teresa Wicks, and Dominic Bachman
Cover Photo by Teresa Wicks

James Pearson, Fisheries Biologist for Malheur NWR: Malheur National Wildlife Refuge gave me many gifts in 2020, but none compare to the gift of sharing the Refuge with my family. This summer my wife (Kelsey), our new baby girl, and I were able to live on the refuge during the field season. When the mosquitos were not too thick, we would go out in the evenings exploring. Experiencing the wildlife this summer from our front porch was an amazing experience, and sharing that experience with my family was a true gift!  


Teresa Wicks, Eastern Oregon Program Coordinator & Biologist for Portland Audubon: 2020 was a weird year for everyone. From physical distancing to not seeing our families, to canceled field seasons for many biologists, it felt like we were running up an escalator headed down. This made all of the moments working in the field, supporting conservation and science at Malheur feel even more precious and meaningful. Because of this, I’d say the gift that Malheur gave me is an endless cycle of dazzling sunrises, surprise Wilson’s phalarope and bobolink nest sightings, a glimpse at a recently hatched crane colt and a recently hatched American kestrel chick. In short, Malheur gifted me moments of awe/wonder, hope, and some quiet sanity in a year full of unpredictability and isolation from my family. 


Dominic Bachman, Aquatic Health Coordinator for High Desert Partnership: The lake and the refuge were good to us this year. We got a ton of field work and scientific data collected despite 2020 trying to derail us at every opportunity! This March was my first time on the lake during daylight and it was amazing, so much water and birds! We were able to remove 10K lbs of carp, get all the projects we started completed, and had a heck of a time doing it. The biggest gift the lake gave our crew this summer was focus…..we are working on improving the habitat the lake provides despite craziness going on in the rest of the world!


It is a wholesome and necessary thing for us to turn again to the earth and in the contemplation of her beauties to know the sense of wonder and humility.

Rachel Carson, The Exceeding Beauty of the Earth

What gifts have you received from Nature in 2020?

New Toilets at Malheur Refuge

Written by Peter Pearsall/Photo by Ed Moulton, Refuge Maintenance Supervisor

The unsung heroes at Malheur Refuge are its maintenance staff. These hardworking Refuge employees ensure that roads are kept in good shape; signs, gates, kiosks and other structures are functioning properly; Refuge water levels are controlled to enhance habitat for wildlife—and much, much more. Another of these duties is the maintenance of public-use infrastructure such as toilets.

Thanks to maintenance staff, new vault toilets were recently installed at Malheur Refuge, replacing ones that were more than 20 years old. According to Ed Moulton, Maintenance Supervisor at Malheur Refuge, these new toilets are a prefabricated one piece concrete vault. The new toilets are more ADA friendly, have a larger tank capacity, and require much less annual maintenance.

The toilets cost just over $17,000 each, including delivery and installation. The contractor for this project used a four-person ground crew to excavate the pits and install the toilets. The contractor also brought in a crane and an operator to lift the buildings off the trailer and set them in the holes. The operator used a mini-excavator to excavate and grade the area. 

All four of the vault toilets outside of Refuge Headquarters were replaced: one at Buena Vista Overlook, two at Krumbo Reservoir and one at P-Ranch. The toilets are maintained/stocked twice a week, depending on visitation.

Senescence

Written by Peter Pearsall/Photo by Peter Pearsall

The verdant meadows, marshes and upland areas of Malheur Refuge, so vibrant in spring and summer, change swiftly to a palette of umber, straw and gray-green in fall. This is the harbinger of winter: sun giving way to clouds, greens giving way to browns, and the nights waxing long, dark and cold. It is an inexorable shift; as the planet turns, so the leaves.

Our northerly latitude provides us with discrete transitions from season to season, where marked differences in day length and temperature dictate the cadence of life. The move from fall to winter represents the declension of daylight—a time when plants and animals must adapt to changes wrought by the sun’s ebbing rays. Nowhere is this change more apparent than in the foliage of our deciduous trees.

Like all green plants, trees are predominately autotrophic, meaning that they make, or “synthesize” food for themselves via photosynthesis. Inside the cells of every leaf are disk-shaped structures called chloroplasts, which contain the pigments necessary to turn solar energy into chemical energy. Photosynthesis—the process by which plants convert sunlight and carbon dioxide to sugars within their chloroplasts—relies almost entirely on chlorophyll, the green, light-absorbing pigment that gives most leaves their color. During a tree’s growing season chlorophyll is the dominant pigment, working literally all day to capture sunlight while the getting’s good.

But chlorophyll is a frangible compound, inclined to close up shop and dissolve when there’s little light. After the autumnal equinox, the photoperiod—or length of day—shortens by almost two minutes per diem until December 22 or so, when night reigns for nearly 14 hours at its peak. More influential than extremes of temperature or precipitation, this decrease in daylight is the tree’s signal to power down its chloroplasts and hole up for winter. Cells begin producing sugars and amino acids in lieu of chlorophyll, to act as antifreeze agents. Nutrients are drawn from the leaves down into the branches and roots for storage. The tree is undergoing “plant senescence”, a gradual paring down of its metabolic processes in preparation for months of cold, dark dormancy.

First and foremost is the matter of the leaves. Deciduous trees carry leaves that are fair-weather fans: thinly clad, built for maximum light absorption and therefore extremely useful in sunny months. Come autumn, however, the leaves become a liability, siphoning precious fluids through their veins and finding less and less photosynthetic work to do. Frail and unarmored, they are at the mercy of the wind and cold. Chlorophyll breaks down completely by this point, exposing the gaudy carotenoid, anthocyanin, and xanthophyll pigments hidden beneath. (These compounds, responsible for the reds, yellows, purples, and oranges so fancied in fall foliage, act as a sort of sub-dermal sunscreen for the leaf during periods of growth, protecting it from harmful solar rays.) Seeking to cut its losses, the tree forms a layer of cells at the petiole, or base, of each leaf, clogging its veins. Soft parenchymal cells adhere to the leaf side of each stem, while waxy, impermeable suberized cells stick to the tree side. This cellular cork, called the abscission layer, is built upon until the desiccated leaf hangs by a mere wisp of tissue, poised to tear free and drift down on the breeze.

Thus denuded, the tree bides its time through the too-short days and frigid nights, living sparingly on its sugar stores until spring. We marvel at the variegated exuberance of fall—the brilliant reds and lambent yellows of a globe-girdling conflagration—but it is simply a wardrobe change between seasons, as the raiment of the sun is cast off and the spartan coat of winter shrugged on in its stead.

Vast lake is very still. Large box made of poles and canvas is constructed in the middle of the lake. A biologist stands next to it in knee deep water.

Carp Suppression & Collaborative Lake Restoration

Written by James Pearson/Photo by James Pearson

The Common Carp (Cyprinus carpio) is the eighth most prevalent nonnative invader in the world, often reaching high levels of abundance (>1000 kg/ha) due to their ability to tolerate a range of aquatic conditions. Once a population of Common carp (hereafter “carp”) becomes established, their mode of feeding can degrade aquatic ecosystems. For instance, carp use a benthic foraging technique that uproots aquatic vegetation while simultaneously increasing turbidity in the water column, which diminishes light penetration. In turn, this can further inhibit growth of aquatic vegetation. The bioturbation of the aquatic environment by carp has been hypothesized to be one of the major drivers that has led to the currently degraded (turbid) state in Malheur Lake.  

Control of carp can be extremely difficult, however, due to their high capacity for population growth and expansion, survival in habitat refugia, and ability to modify their environment to their own advantage. Carp populations exhibit compensatory density dependence, in which demographic rates (i.e. mortality and recruitment) shift in response to variations in the population’s overall density. Thus, even if carp are removed in large numbers, the species can rebound quickly.  

In the past, biologists with the MNWR have undertaken large-scale carp rotenone (pisicide) treatments, removing a total of 2.5 million carp. Effectiveness monitoring conducted in the years following the rotenone treatments determined that submergent vegetation and waterfowl production rebounded, however this apparent success was short lived, with the aquatic ecosystem of Malheur Lake quickly returning to the turbid state. While rotenone treatments have been successful at quickly reducing the carp population and promoting short term improvements in the aquatic health of Malheur Lake (e.g., increases in submergent vegetation and waterfowl production), rotenone treatments have failed to suppress carp over the long term, and recovery of carp is hypothesized to be the reason for the quick rebound in the turbid state. For this reason, researchers at MNWR have been working to better understand how to suppress the carp population long-term, such that the benefits of carp control can be maintained in perpetuity.  

Large die offs were the result of rotenone treatment for mass removal of common carp from the Blitzen Valley and Malheur Lake system. MNWR Archival Photograph

In an effort to better understand carp management, a carp population model (CarpMOD) was constructed for Malheur Lake, and simulations suggest that removal strategies that target multiple life stages (Adult and Juvenile) may be able to reduce the carp biomass below the desired threshold if the cumulative mortality is maintained at approximately 40%. Furthermore, the modeling also demonstrated that lake area fluctuations (function of annual snow pack) strongly controls the carp population dynamics due to increased density dependent natural mortality and decreased juvenile recruitment. Therefore, these model results suggest that future management actions can be more effective if plans are implemented to more strongly compound the mortality already imposed by the environment via lake fluctuations.  

This summer, the MNWR collaborated with our partners at the High Desert Partnership and the US Forest Service to conduct a large scale carp removal effort, targeting carp in the lower Blitzen River in September (hypothesized refugia habitat). After 7 days of collaborative removal efforts targeting the lower Blitzen River via boat electroshocking, we were able to remove roughly 9,004 lbs. (1,722 individuals) of carp. While the collaborative carp removal was very successful, we also operated the Sodhouse fish trap on the Blitzen River throughout the summer, and we were able to remove 1,225 lbs (545 individuals) of carp. Therefore, our overall carp removal total for the 2020 field season was 10,229 lbs. (2,267 individuals) of carp.  

While collectively the MNWR aquatic health program had a very successful 2020, we are only at the beginning of a long term journey to restore the currently degraded state of Malheur Lake. On the ground research and modeling efforts have helped us understand that the current turbid state of Malheur Lake is being maintained by strong positive reinforcing feedback loops (i.e. bioturbation via carp and wind sediment resuspension), which are pulling the lake towards the turbid state. In order to shift Malheur Lake back to the historically clear state, a transformative effort is necessary, incorporating a combination of carp and wind-wave suppression, and restoration of emergent/submergent vegetation. To better understand the major mechanisms driving and maintaining the current turbid state, the MNWR has initiated three major collaborative research projects (emergent vegetation expansion and transplantation, mesocosm water quality enhancement, and carp radio telemetry), over the next two field seasons (2021-2022). Finally, it is our hope that the outputs from these collaborative research projects will help us identify the combination of restoration actions necessary to not only flip Malheur Lake, but also maintain the clear state in perpetuity for the ecological benefit of fish and wildlife species that utilize the MWNR.