Lincoln P. Brower Awards

Charlotte Hovland, MS student, University of Georgia, Odum School of Ecology

“Assessing Monarch Alternative Overwintering Sites in the Southeastern United States”

Abstract

In the face of observed declines in overwintering monarchs in Mexico, there is a pressing need to understand the role of alternative overwintering sites in the US coastal southeast. If migratory monarchs are able to successfully overwinter in these alternative sites, observations of the Mexican overwintering population may not provide a complete picture of the overall health and stability of the eastern North American migration. Building on volunteer science data, I propose field research to characterize overwintering habitats in coastal environments of the southeastern United States and to assess the health and other characteristics of the migrants that use these habitats. The proposed work will enhance our understanding of the drivers of coastal overwintering, the role coastal overwintering sites play in the larger eastern North American monarch migration, and the unique threats that the monarchs using these environments may face.

2024 Fall Update

Using Journey North winter sightings of adult butterflies in this region, Charlotte is looking for sites where butterflies may be overwintering in diapause, like their cousins in Mexico. To determine this, she eliminated reports that mentioned reproductive activity or were in proximity to sightings of juveniles. To date, she has identified a few locations in Georgia, Florida, and Texas that look promising for on-the-ground exploration.

Helen St. John, MS student, James Madison University, Department of Biology

“Migratory stage and the effect of Motus-compatible telemetry tags on monarch butterfly movement”

Abstract
 

Monarch butterfly declines across North America and advances in tracking technologies create a pivotal opportunity to address unanswered questions about habitat use and movement. Recent studies have used the international Motus telemetry tower network to track monarchs in response to environmental stressors. Such studies are integral to migratory species conservation, but a neglected first step is evaluating tag impacts. Preliminary results from data collected on breeding monarchs suggest that movement in heavier monarchs is compromised by tag weight. Physiological differences between breeding and migrating monarchs could compound negative effects of tags on movement in migrants. I will collect movement data on monarchs migrating through Cape May, NJ to determine if movement differs between tagged and untagged individuals. Tagging studies may become increasingly crucial for tracking threatened monarch populations during migration and overwintering periods, and this study will help minimize unintended negative consequences of a potentially promising conservation tool.

2024 Fall Update

Helen and her team collected on-the-ground flight path data from 124 migratory monarchs with and without radio telemetry tags in Cape May, NJ. Flight path recordings are still being transcribed but preliminary analyses suggest that Cellular Tracking Technologies’ 0.06-gram BlūMorpho tags have limited effects on monarch movement and behavior, while Lotek’s 0.13-gram NanoPin tags may inhibit movement, particularly in smaller individuals.

Nicole Yu, PhD student, Concordia University, Montreal, Canada, Department of Biology

“The Balcony Garden Project: using balconies to increase host plant and nectar resources in urban areas for monarch conservation”

Abstract

One of the priorities for monarch conservation is habitat restoration through milkweed planting all across their migratory route, including urban areas. Milkweed-growing in small urban green spaces such as backyards is known to support monarch butterflies through providing nectar and host-plant resources, but gaps in the urban landscape still remain where milkweed is sparse. The Balcony Garden project is a participatory science project that explores the role of balconies to increase urban nectar and milkweed resources for monarchs. We will establish a minimum of 36 balcony gardens in Montreal, Canada in areas of high monarch butterfly occurrence to test plant resources and environmental conditions needed for monarch oviposition success on balcony gardens. The findings from summer 2024 will inform new avenues in which the public engage in monarch conservation, and pave the way for research on using balcony gardens to increase urban milkweed patch connectivity.

2024 Fall Update

This summer, Nicole provided 34 participants with milkweed and nectar plants for their balconies and asked them to monitor for monarch eggs and caterpillars. Unfortunately, no monarch eggs or caterpillars were found on balconies (though aphids were abundant), and nearby neighborhood surveys revealed only two adult monarchs. In a separate test for plant survival and planting conditions, two monarch caterpillars were found on a potted milkweed plant placed on a balcony although the source of the eggs is uncertain. Though few monarchs were encountered during the project this summer, Nicole has demonstrated that common milkweed can grow well in pots when transplanted as short mature plants, and such milkweed can attract monarch oviposition.  

Undergraduate student Fernanda Naomi Shimizu Romero from the Faculty of Higher Studies Zaragoza of the National Autonomous University of México (UNAM) for project titled “Soil Properties in Ecological Restoration Zones Within the MBBR”

Fernanda Naomi Shimizu Romero worked on a project to understand soil property changes resulting from restoration efforts. After illegal logging occurred in 2016 in the core zone of Sierra Chincua in the MBBR, an ecological restoration project to rehabilitate 10 deforested areas was established. Naomi examined litterfall from various restored and conserved areas to see if the specific composition of litterfall (leaves, branches, bark, flowers, and fruits) modified the chemical properties of the soil as they decomposed. Although there were differences in the soils between restored areas and conserved areas, no nutrient deficiencies or significant alterations in the nutrient cycle affecting plant development were identified. Naomi’s work adds to our understanding of forest restoration processes.

Graduate student Grace Thomas from the University of Nebraska at Omaha for project titled “The Effects of Bison and Cattle Grazing on Milkweeds and Monarch Butterflies”

Grace Thomas spent the summer visiting habitat throughout Missouri, Kansas, Nebraska, and Iowa looking for monarch eggs on milkweed in fields grazed by bison and cattle, as well as on ungrazed lands. Her research seeks to determine whether bison-grazing is less harmful than cattle-grazing. In March, 2024 Grace presented her final report which confirmed her hypotheses that ungrazed fields contained more milkweeds and juvenile monarchs than grazed fields. Bison and cattle both grazed milkweed stems but Bison fields did tend to have more milkweed stems per square meter than cattle fields, though this did not lead to an increased number of juvenile monarchs.

Graduate student Darene Assadia, from the University of Michigan for project titled “Quantifying Monarch butterfly perceptual range when locating nectar sources: role of olfactory and visual systems"

Darene Assadia is trying to understand the role of visual and olfactory perception, individually and in combination, between fall and summer monarchs when locating nectar sources. With a behavioral assay that uses potted Lantana Camara plants, she has been able to demonstrate that monarchs overwhelmingly choose the plant versus empty control. Preliminary results indicate that visual cues are sufficient and more important than olfactory cues for this choice. Results of this research helps conservation efforts by helping to make predictions about the effects of anthropogenic sensory pollutants on foraging monarchs. This work will be an excellent follow-up to the work conducted by past Brower awardee Libesha Anparasan.

Graduate student Salvador Huitrón, from the Autonomous University of the State of Mexico for project titled "Identification of Optimal Overwintering Sites for the Monarch Butterfly (Danaus plexippus) within the "Monarch Butterfly Complex"

Salvador has almost completed his research analyzing the biophysical, social and economic variables that influence the monarch butterfly’s overwintering habitat. His results indicate that 77.11% of the area with medium to high potential for the establishment of overwintering sites are found within a Natural Protected Area, with 44.96% of the areas located in the MBBR. This represents 23.76% of the total surface of the Reserve. An important finding is that 15.27% of the potential sites were in the Nevado de Toluca. which speaks to the relevance of the assisted migration research being conducted. MBF is happy to contribute to this effort to further improve our understanding of the monarch butterfly’s winter habitat.

PhD student Ana Merlo Reyes, from the Institut des Géosciences de l’Environnement – Université Grenoble Alpes in France for project titled "Mobility of Agrochemicals and Environmental Risk in Microwatersheds of the Monarch Butterfly Biosphere Reserve"

Ana is researching the environmental risk of pesticides used in the avocado and corn plantations of Monarch Butterfly Biosphere Reserve and its influence zone. As a result of interviews with campesinos, she found that the most frequently used pesticide in the entire sample population is glyphosate, which is a herbicide used by a third of the interviewees on their corn plantations. This herbicide was followed by the fungicide benomyl, the insecticide imidacloprid, and the herbicide paraquat, mainly used in avocado plantations in the municipality of Zitácuaro. Imidacloprid is an insecticide used in all the properties to control red spiders, a pest that attacks corn and avocado. Ana concluded that workshops about the proper use of pesticides, their risks and using appropriate agricultural practices are necessary. Communities need more information on how to prevent human health problems and the contamination of the ecosystems around the MBBR.

Her study is published in Science of the Total Environment.

Graduate student Libesha Anparasan, from the University of Western Ontario, Canada for project titled "Identifying critical nectaring sites for migrating monarch butterflies: New promise from stable isotopes and fatty acids"

Libesha’s research project is titled “Identifying critical nectaring sites for migrating monarch butterflies: New promise from stable isotopes and fatty acids” and is focused on developing new ways to identify critical stopover nectaring sites for Monarch Butterflies. The Fall migration of the Monarch Butterfly requires frequent stopovers where they rest and refuel. At overwintering sites, individuals must have enough stored lipids to last through the winter and fuel part of the return and reproduction. Libesha completed her research in 2022 and her results support the growing hypothesis that monarch butterflies do not generate large fat reserves for their fall migration and thus may be highly dependent on en route nectaring until getting closer to their overwintering grounds where more lipid accumulation has been seen. Additionally, she observed that during its actual migration in the wild, monarchs must use gliding flight and make frequent stopovers to be able to hold onto their lipid reserves for future reproduction.

Graduate student Natalie Melkonoff, from the Desert Botanical Garden in Phoenix, Arizona for project titled “Plant trait analysis and environmental niche modeling to determine the future demography of native milkweeds and their capacity to support monarch butterfly populations in Arizona and the arid West"

Natalie’s research project is titled “Plant trait analysis and environmental niche modeling to determine the future demography of native milkweeds and their capacity to support monarch butterfly populations in Arizona and the arid West”. As monarch butterfly (Danaus plexippus) populations decline at an alarming rate, the need for advanced conservation and monitoring becomes clearer. With visits from both the eastern and western migratory populations, Arizona is uniquely poised to impact monarch conservation in the arid West. In May, 2022 Natalie reported she had successfully gathered critical information on Arizona milkweed and carried out species distribution and future climate scenario modeling. This initial funding from MBF has allowed her to seek more complex and extensive funding proposals to expand many aspects of the project. Among these she secured funding to construct an experimental heating array onsite in order to measure physiological responses of these plants under warming conditions that will mimic episodic heat waves. She also received funding to perform trial restoration techniques with these native milkweed taxa as very little is known about milkweed restoration in the desert southwest. Natalie’s research will lay the foundation for carrying out and evaluating habitat restoration projects in Arizona and the arid West.

Entomology MSc Student, Anna Skye Harnsberger from the Wisconsin Energy Institute for project titled "Monarch butterfly landscape ecology: optimizing habitat restoration spatial configuration"

Anna’s research is focused on understanding the effects of milkweed patch size and surrounding landscape on monarch presence and survival in the Upper Midwest United States. Anna will survey habitat characteristics and monarchs at 60 sites in Wisconsin that vary in patch size and the landscape context within which the patches exist. This will help her explore how monarch presence, density, and survivorship vary across sites to understand the effect of habitat size and isolation on monarch presence and survival. She has presented a poster with her preliminary results. Anna statistically analyzed the data collected in 2018 and 2019 and will eventually publish her results so that Anna can disseminate this research which will contribute to the improvement of breeding habitat restoration for monarch butterflies. In 2022, Ana published an article on this topic in the journal Landsc Ecology.

BS/MS student Cody Prouty from the University of Georgia for project titled "Sub-Lethal Effects of Neonicotinoids on Butterfly Behavior and Physiology"

Cody concluded his experiments to determine how exposure to neonicotinoids affects monarch behavior and population size. Three studies examined how monarch caterpillars and adults respond to increasing doses of two different neonicotinoid insecticides. Cody concluded that monarchs are more susceptible when exposed to neonicotinoids as larvae than adults, and the milkweed species they were reared on can also affect their response to the insecticides. Monarchs exposed as adults will have lethal and sub-lethal effects at concentrations much higher than what could be found in wild nectar. Cody’s study will provide an understanding of the impacts of neonicotinoids on monarch behavior and physiology, including potential consequences for the long-distance migration of this iconic butterfly. On November, 2019 Cody presented a summary of his research so far and presented his final report. In 2023, Cody published an article on this topic in the journal Ecological Entomology.l