Monarch Conservation Science Partnership

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The Monarch Conservation Science Partnership is a USGS led group of scientists, managers, and conservation organizations who perform science related to the conservation of monarch butterflies. We come from federal agencies, non profits, and academia and from the three countries where monarchs range (Mexico, Canada, and the United States). To date meetings of the MCSP have been hosted by the USGS John Wesley Powell Center for Analysis and Synthesis in Ft. Collins, CO. PIs include Darius Semmens and Jay Diffendorfer (GECSC) and Wayne Thogmartin (UMESC).

Are we witnessing the end of the migration of monarchs in the eastern U.S.?
What is the issue?

The Eastern, migratory population of monarch butterflies has declined by ~80% over the last decade, despite efforts in Mexico to end illegal logging in the fir forests used by overwintering monarchs. These declines are coincident with the rapid adoption of glyphosate-resistant crops on agricultural lands of the north central U.S.

What are the challenges?

The monarch’s multi-generational migration between overwintering grounds in central Mexico and summer breeding grounds in northern U.S. and southern Canada creates shared management responsibilities across North America.

No national-level monitoring and insufficient basic ecological research (e.g., few habitat-specific estimates of milkweed density) lead to key gaps in our understanding of monarch life history and ecology.

Threats are numerous, including herbicide and pesticide application, loss of natural and conserved areas, and disruption from climate change and consequences of extreme weather, leading to ‘death by a thousand cuts’.

Strategies for mitigating threats are weakly defined.

The Partnership is engaged in considerable research to address information gaps associated with the ecology and conservation of monarch butterflies. Among these efforts include analyses of extinction risk, continental-scale full-annual-cycle demography, threats assessment, overwinter density estimation, milkweed target estimation, and storylines for conservation recovery. Strategies for sampling monarchs and the milkweed that sustains them are being developed. In addition, geospatial tools, both desktop and online, for aiding in conservation planning have been completed.

Decline in the eastern migratory monarch butterfly population as surveyed by the World Wildlife Fund-Mexico

Decline in the eastern migratory monarch butterfly population as surveyed by the World Wildlife Fund-Mexico.Populations in the high-elevation Oyamel fir forests where eastern monarchs overwinter are indexed by the area over which they occur.Semmens et al. (2016) provided an adjusted measurement of population size which corrects for observation error.(Public domain.)

National Valuation of Monarch Butterflies Indicates an Untapped Potential for Incentive-Based Conservation

The annual migration of monarch butterflies (Danaus plexippus) has high cultural value and recent surveys indicate monarch populations are declining. Protecting migratory species is complex because they cross international borders and depend on multiple regions. Understanding how much, and where, humans place value on migratory species can facilitate market-based conservation approaches. We performed a contingent valuation study of monarchs to understand the potential for such approaches to fund monarch conservation. The survey asked U.S. respondents about the money they would spend, or have spent, growing monarch-friendly plants, and the amount they would donate to monarch conservation organizations. Combining planting payments and donations, the survey indicated U.S. households valued monarchs as a total one-time payment of $4.78–$6.64 billion, levels similar to many endangered vertebrate species. The financial contribution of even a small percentage of households through purchases or donations could generate new funding for monarch conservation through market-based approaches.

Local and cross-seasonal effects of climate and land-use on breeding abundances of a migratory species.

​Saunders, S. P., L. Ries, K. S. Oberhauser, W. E. Thogmartin, and E. F. Zipkin. 2018. Local and cross-seasonal effects of climate and land-use on breeding abundances of a migratory species. Ecography

​DOI: ​10.1111/ecog.02719 

Quantifying how climate and land use factors drive population dynamics at regional scales is complex because it depends on the extent of spatial and temporal synchrony among local populations, and the integration of population processes throughout a species’ annual cycle. We modeled weekly, site-specific summer abundance (1994–2013) of monarch butterflies Danaus plexippus at sites across Illinois, USA to assess relative associations of monarch abundance with climate and land use variables during the winter, spring, and summer stages of their annual cycle. We developed negative binomial regression models to estimate monarch abundance during recruitment in Illinois as a function of local climate, site-specific crop cover, and county-level herbicide (glyphosate) application. We also incorporated cross-seasonal covariates, including annual abundance of wintering monarchs in Mexico and climate conditions during spring migration and breeding in Texas, USA. We provide the first empirical evidence of a negative association between county-level glyphosate application and local abundance of adult monarchs, particularly in areas of concentrated agriculture. However, this association was only evident during the initial years of the adoption of herbicide-resistant crops (1994–2003). We also found that wetter and, to a lesser degree, cooler springs in Texas were associated with higher summer abundances in Illinois, as were relatively cool local summer temperatures in Illinois. Site-specific abundance of monarchs averaged approximately one fewer per site from 2004–2013 than during the previous decade, suggesting a recent decline in local abundance of monarch butterflies on their summer breeding grounds in Illinois. Our results demonstrate that seasonal climate and land use are associated with trends in adult monarch abundance, and our approach highlights the value of considering fine-resolution temporal fluctuations in population-level responses to environmental conditions when inferring the dynamics of migratory species.

Monarch Conservation Science Partnership

(Public domain.)