On July 6, 2025, EUC Professor Sheila R. Colla — activist, author, ecologist, educator, mentor, researcher, and scientist — passed away after almost two years of battle with Mesothelioma (cancer caused by asbestos exposure). She is well-remembered as a brilliant conservation scientist and a fierce advocate for saving bumblebees.
Since her appointment in 2015 at the then Faculty of Environmental Studies (now Faculty of Environmental and Urban Change), Professor Colla studied wild bumblebees in Canada and the U.S. As an Executive Committee member of the Centre for Bee Ecology, Evolution & Conservation (BEEc) at York University, she was a driving force guiding the research group to foster interdisciplinary, innovative, collaborative, and cutting-edge research for the advancement of knowledge and the implementation of policy changes to help sustain pollinators globally.
A recipient of nearly $3.5 million in external and internal research grants and awards throughout her career, she mentored and trained students and colleagues in the field of conservation biology, while creating opportunities for community participation and conservation outreach. In her NSERC Discovery Grant that investigated the differential success of native pollinators subject to multiple environmental stressors, her team examined behavioural ecology, population dynamics and inter-species interactions to understand why some species remain common while others are deemed at-risk of extinction.
Professor Colla is respected for her work on wild bee conservation, being one of the first scientists in North America to quantitatively document declines in certain wild bees, including the now federally protected Rusty-Patched bumble bee. She has co-authored numerous research articles with colleagues and students that have shaped our understanding of wild bee declines and conservation tools. Her research papers have been cited more than 5,500 times. She produced key studies on the status of and threats to wild pollinators, which have since become part of a large and growing field of insect conservation, including for species to receive provincial and federal protection. As an interdisciplinary conservation scientist, her articles have spanned research fields and topics across the natural and social sciences.
She became a leading voice in the development of policy, citizen science programing, and science communication on pollinators, mobilizing scientific research on their conservation across a variety of jurisdictions including in the United States, Canada, Ontario, and Toronto. She gave more than 100 educational talks about pollinator conservation to communities, reaching more than 11,000 adults and 3,000 youth. Additionally, she gave countless media interviews with journalists reaching over one million people. She helped produce several resources to educate and encourage action to promote pollinators, including helping create the free Bees of Toronto guide, a downloadable poster about the bumble bee species of Southern Ontario, and an accessible guide to planting a flower patch for the rusty-patched bumble bee.
Professor Colla also co-authored books and book chapters about wild bees and their conservation. The Field Guide to the Bumblebees of North America (Princeton University Press, 2014), a comprehensive guide to the taxonomy and identification of North American bumble bees, won the American Library Association Outstanding Reference Source Award and has sold more than 20,000 copies – making it one of the most widely used wildlife identification guidebooks in North America. More recently, she co-published a national bestseller, A Garden for the Rusty-Patched Bumblebee: Creating Habitat for Native Pollinators: Ontario and Great Lakes Edition (Douglas & McIntyre, 2022). The fully-illustrated guide helps gardeners and nature lovers discover the crucial connections between native plants and native pollinators and learn how to cultivate patches of pollinator paradise. The following year, A Northern Gardener’s Guide to Native Plants and Pollinators: Creating Habitat in the Northeast, Great Lakes, and Upper Midwest (Island Press, 2023) was published for habitat gardeners south of the border.
Professor Colla was appointed York Research Chair Tier II in Interdisciplinary Conservation Science from 2020-2025. In this capacity, she combined ecology, citizen science, policy analysis and biocultural understanding to better address pollinator conservation and management challenges. Recognizing the multi-faceted and complex nature of pollinator declines, and the various stakeholders involved in their conservation and management, Professor Colla aimed to produce research that reflected the interconnected nature of ecosystems and the essential contributions and plight of native pollinators. Her interdisciplinary research was highly regarded in the field of pollinator conservation and her research continues to inform conservation recommendations and recovery strategies for at-risk and declining bumblebee species as well as other wild pollinators. She applied interdisciplinary frameworks and methodologies incorporating and co-producing different types of knowledge and understanding in her research and subsequent outputs, ensuring pollinator conservation was inclusive, accessible, and grounded in evidence-based approaches.
In 2021, with support from the Weston Family Foundation, Professor Colla co-developed a wild pollinator conservation strategy for Canada, along with a national pollinator framework. The study served as a needs assessment for science-based policy solutions for wild pollinator conservation in Canada. General themes included improving the Canadian government’s approach in assessing pesticide risk to pollinators, curbing pathogen spillover between managed and wild pollinators, and improving research and monitoring efforts of pollinators and their threats in Canada, among other areas.
Professor Colla co-founded Bumble Bee Watch, a collaborative community science project that enables anyone with a camera to help document and monitor North America’s bumble bees – filling a large data gap on bumble bee distributions across Canada. With citizen science growing as a field of research, she co-published an article that reviewed citizen science programs for conservation focusing on the best practices to make them successful. More recently, Professor Colla co-published an article titled Bumble Bee Watch (BBW) community science program increases scientific understanding of an important pollinator group across Canada and the USA comparing the BBW data to the scientific Bumble Bees of North America (BBNA) database to understand the contribution of citizen scientists to the state of the knowledge about native bumble bees.
With EUC Professor Lisa Myers, through the SSHRC New Frontiers in Research Fund, she studied the intersections of art, ecology and education in the Finding Flowers project that considered relations between the conservation of native plants and pollinators, along with care for Indigenous artistic practices, cultures and languages. Inspired by the garden work of the late Mi’kmaw artist Mike MacDonald, Finding Flowers focuses on Indigenous gardens as artworks, as ecological refuge, as spaces for contemplation, and as sites for learning about sustenance and medicine. The project produced the Sounds like Land podcast, broadcasting seeds of Indigenous languages and diving into the deep relationships between Indigenous languages and ecological knowledge by telling stories of how Indigenous communities sustain forms of cultural stewardship that assert their sovereignty over their lands.
Professor Colla received numerous honours and awards attesting to her significant contributions to research, her expertise and leadership in her field, her innovative and impactful work, and her commitment and dedication to science communication and outreach. Aside from the York Research Chair in 2020, these include the Entomological Society of Canada’s C. Gordon Hewitt Award (2021), the EUC Dean’s Research Award (2023/2024), the Ontario Nature Education Award (2023/2024), the NSERC Science Promotion Award (2024), the YorkU President’s Research Impact Award (2024) and the King Charles Coronation Medal (2025).
Professor Colla was a beloved mother, wife, daughter, sister, friend, teacher, supervisor, author, activist, scientist, and community member. In addition to her vast impacts in the world of conservation, she also stood up against injustices everywhere – from supporting women and persons of colour in science and research, to co-organizing a community group to stand up against racism, and much more. Her legacy teaches us the importance of working together to create compassionate and welcoming spaces where all can thrive. Indeed, Professor Colla has left a remarkable legacy that will continue to live on and inspire the next generation of conservation science leaders and advocates for equity, justice, and kindness.
Acknowledgements: Many thanks to Briann Dorin, Dean Alice Hovorka, Carrie Klassen, Victoria MacPhail, EUC Associate Dean Research Carlota McAllister and Rhoda Reyes for their insights and contributions to writing this article.
Read more tributes to Professor Sheila R. Colla
Expression of Condolence for Sheila Colla – by Toronto City Council
Remembering Sheila Colla – by the Wildlife Preservation Canada
Passings: Sheila R. Colla – by Alex Huls, YFile
Sheila R. Colla – EUC Professor (b.1982 – d.2025) – by the Faculty of Environmental and Urban Change
Sheila Colla, advocate for bees, died on July 6th, 2025, aged 43 – by Rhett Ayers Butler