Pollinator diversity for woodland ephemerals; a citizen science investigation
draft proposal

Details - focal plants, sites, scope - will be revised, depending on the interests of collaborators.

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Ann Arbor, Michigan is an urban area increasingly surrounded by development and habitat fragmentation. Yet it retains large blocks of protected land that host diverse native flora. This study will evaluate a subset of flowering species in four woodland preserves to determine the species composition and relative abundance of pollinators for the focal plants. Results will inform land managers about local ecology of key native plants; suggest follow-up research with a broader scope; and foster excitement about the charismatic taxa upon which plants rely.

Initial target Plants (or, see alternative based on all plants for target date)   

The choice of target plants is somewhat arbitrary, but the three suggested here might best fit several criteria. One, they are each abundant and widely distributed, likely to co-occur in most local woodland preserves. Two, the plants bloom in early-to-mid-spring, and likely share generalist pollinators. Three, early season flowers are of special interest, given that climate change may be driving a mis-match in plant/pollinator synchrony. Finally, each plant has at least one specialized pollinator species that may be key to reproduction.

Phenology, iNaturalist data for Washtenaw County over several years

Spring beauty
Spring beauty, claytonia virginica
Specialist pollinator: Andrena erigeniae. Click to magnify and view the pollen.
Beefly, Bombyliius major, generalist pollinator

Trout lily
Yellow trout lily, Erythronium americanum
Specialist pollinator: Andrena erythronii 
Beefly, Bombyliius major, generalist pollinator

Wild geranium
Wild Geranium, Geranium maculatum
Specialist pollinator: Andrena distans. How do you ID this species? Diagnosis.
Bufflehead mason bee, Osmia bucephala, generalist pollinator

Sites

Washtenaw County sites will include Greenview/Pioneer, Marshall Park, and County Farm Park in Ann Arbor, and Iron Creek Preserve in Manchester.

Data collection, specimen processing

In mid-April and mid-May, we will patrol at least 3 target plants at each site for 30-60 min, net all visiting insects, and freeze them for later pinning and ID. The plant list will be increased or modified based on site manager interests, and available volunteer hours.

All previously frozen specimens will be identified to species, or morphospecies* This could be accomplished by David Cappaert; however it would be preferable to share this work with participants, so that ownership and taxonomic knowledge might be shared with collaborating organizations. David could train anyone interested to ID to the genus level, or morphospecies.

More 2025 observations on spring beauty
Nomad bee. These are parasitic in the nests of other bees.
One of the several dozen species of tiny sweat bees in the subgenus Dialictus. ID depends on microscopic details.
Chrysidid wasp, another parasitic species.
Beefly, also a bee parasite.

Data analysis

The primary metric will be species distribution and abundance, for plants and across sites. From preliminary 2025 sampling, pollinators would include bees in genera including Andrena, Halictus, Lasioglossum, Osmia, Ceratina, and Nomada. The list would include species not yet recorded in iNaturalist, because they can’t be ID’d from photos. Data might be summarized like this (example with made-up data).

Specimens will be photographed in the field, and detailed focus-stacked images will illustrate details that inform identification.

Summary of benefits

Feb 27, an alternative approach: collect from all plants at intervals through the spring.

A simple protocol: collect from all plants in bloom in each sampling period (mid June, mid May), 60 minutes/species.
  • Doesn’t require that each site has the same set of target plants;
  • Captures info on unique sites. E.g., squill at Scio Woods;
  • Simple protocol: for each plant in bloom, do e.g., 60 min of opportunistic netting.
  • Would work well for a larger team on a site, more like bioblitz;
  • More likely to catch unique taxa, or potential plant/pollinator relationships worth follow-up in 2027;

For example, April flowers at Johnson Preserve

  • Virginia strawberry
  • Spring beauty;
  • Wild geranium;
  • Cut-leaved Toothwort
  • Jack-in-the-Pulpit;
  • Virginia Springbeauty;
  • Common Blue Violet;
  • Wood Anemone;
  • Wintercresses;
  • Black cherry
  • Trout lily;
A bit daunting, but sample time would be only 9 hours at Johnson Preserve.
Hypothetical species abundance count at one site for 3 plant species.
Simplified network diagram. How are plants and pollinators connected?

What would you need to do this?

* morphospecies are morphologically unique specimens that count towards diversity, but can’t be ID’d precisely. E.g., bees in the genus Nomada are often impossible to key out, because there is no reliable key.

**The need for specimen collecting as a part of a conservation strategy:

Volunteer Information

ZOOM 14 Apr 7:00pm EDT - registration Pollination Networks of Spring Ephemerals A citizen science project for Washtenaw County —David Cappaert, Quamash EcoResearch Land conservancy groups in southeast Michigan have a granular understanding of the plants that are the basis of a healthy ecosystem. We know much less about the pollinators on which the plants depend. So we’ve begun an investigation of plant-insect relationships of early woodland wildflowers. Our study design leverages the concept of a pollinator network, a technique for illustrating how many plants interact with many pollinators. Our approach is essential citizen science: use volunteers to collect, identify, analyze, and present results to the collaborating organizations.

Team Captain Training: Community Pollinator Survey

If you are near Ann Arbor, there are a couple of ways to volunteer. The first will include stakeholders for the parks/preserves involved. The second is for just the sampling days:

Date: Thursday, April 9th 2-4pm
Location: County Farm Park, Field Operations Building
Team Captains are invited to a project kickoff meeting to learn more about a new project to study the pollinators of spring wildflowers. David Cappaert will introduce the goals, discuss the scope, and give an overview of the field methodology. Your feedback and ideas are essential to creating a project that achieves goals tailored to your interests and curiosities! A zoom link will be provided for those who can’t attend in person and a recording will be available after the session.

Call for Volunteers: Community Pollinator Survey

Join Naturalist Shawn Severance and entomologist David Cappaert in investigating the abundance and diversity of wild pollinators in our local natural areas. You will learn how to identify flowers and the bees, flies, and beetles on which these plants depend. Everyone is welcome, those who are already familiar with pollinators and those looking to learn more about them. We will visit spring ephemerals during bloom time to observe flower visitation. These data will be used to map pollinator networks and answer questions important to local conservation organizations. Surveys will happen between April 11th and May 31st during good bee weather. Please note: It is hard to predict in advance when the bees will be flying but we will generally be able to give a 3-4 day advance notice of field times and locations. Interested in volunteering? Sign up here to be on the contact list. Questions about this project? Email Shawn Severance at severances@washtenaw.org.

Update April 6, 2026
David Cappaert, Quamash EcoResearch, cappaert@comcast.net

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