Motus captures migration in motion

Post by Jen Berlinghof

The back-to-school season in early fall brings restlessness and routine to my house. I’m struck by how it parallels the flurry of fall migration across the natural world: a return to the patterns of movement ingrained over generations.

At Ryerson Conservation Area in Riverwoods—part of the Lake County Forest Preserves in northern Illinois—I observe ruby-throated hummingbirds (Archilochus colubris) tucking their heads quickly in and out of crimson cardinal flower (Lobelia cardinalis) blooms, fueling up for long flights across the Gulf of Mexico.

Green darner (Anax junius) dragonflies skim the skies by the dozens along the lakefront at Fort Sheridan in Lake Forest, their wings glittering. Fields of bee balm (Monarda didyma) along the 31.4-mile Des Plaines River Trail quiver with monarch butterflies (Danaus plexippus) nectaring to gear up for their epic journey. And, sporting less vibrant feathers than in the spring, migratory birds take flight in muted autumnal tones, heading south. As the sun sets in September and the harvest moon rises, this silent surge of fall migration commences.

A female ruby-throated hummingbird (Archilochus colubris) rests on a twig. This species migrates south to wintering grounds in Mexico, Central America and along the Gulf Coast. Photo © Phil Hauck.
A female ruby-throated hummingbird (Archilochus colubris) rests on a twig. This species migrates south to wintering grounds in Mexico, Central America and along the Gulf Coast. Photo © Phil Hauck.
Green darner dragonflies (Anax junius) undertake long migrations, discussed in this post from our archive. Stock photo.
Green darner dragonflies (Anax junius) undertake long migrations, as discussed in this post from our archive. Stock photo.
Monarch butterflies (Danaus plexippus) east of the Rocky Mountains undertake long journeys to overwinter in oyamel fir (Abies religiosa) trees in Mexico. Stock photo.
Monarch butterflies (Danaus plexippus) east of the Rocky Mountains undertake long journeys to overwinter in oyamel fir (Abies religiosa) trees in Mexico. Stock photo.

Migration is an extraordinary phenomenon of great scientific inquiry and mystery. A new, groundbreaking effort to study animal migrations and connect researchers, scientists and students to real-time migratory data across the globe is underway. Lake County, Illinois is one of the newest links in the chain.

The Motus Wildlife Tracking System (Motus) uses automated radio telemetry to study the movements of birds, bats and large insects. Tiny, digitally encoded tags are safely attached to an animal and detected by receiving stations on the landscape. Stations come in many configurations, but at their basic level consist of a radio receiver, one or more antennas and a power supply. Chain o’ Lakes State Park and Illinois Beach State Park currently host stations. The newest local site is under construction this fall at Ryerson Conservation Area. The Motus station at Ryerson Conservation Area is funded by a grant from the Margot Merrick Fund and an Annual Fund grant from the Preservation Foundation of the Lake County Forest Preserves. We are grateful for the support of these donors!

An infographic outlining how the Motus system works. Graphic © Motus Wildlife Tracking System, Bird Studies Canada.
An infographic outlining how the Motus system works. Graphic © Motus Wildlife Tracking System, Bird Studies Canada.

Previous efforts to track migration have faced many challenges. Bird banding and GPS tags require recapturing animals, which has proven somewhat unreliable. Large movements of groups of birds can be detected on radar, such as with Birdcast. This is valuable and fascinating to watch in real time, but it can’t distinguish between individuals or species. Passive Integrated Transponders (PIT tags), like those we use in our Blanding’s Turtle Recovery Program, can only operate in close proximity to a receiver and are impractical for aerial species.

While all these methods provide important information, none are able to accurately track very small birds and insects. Motus has solved this by using solar-powered nanotags weighing as little as 0.15 grams and measuring smaller than a paperclip. They can be used on bees, butterflies, dragonflies and diminutive bird species.

Recent assessments report that one-third of North America’s bird populations are at risk, and pollinators, such as native bees and monarch butterflies, are in decline. Almost 200 species of avian adventurers, though, have been tagged for Motus tracking, crisscrossing continents on their annual trips and potentially passing 800 receiving stations installed across the Americas.

What’s gained are invaluable, real-time migration mapping data that provide ecological insights into the animals’ journeys, which can be used collaboratively in scientific research, conservation efforts and education. Motus is the ultimate hands-on community science project with real-world impacts both globally and locally here in Lake County.

Learn more about fall bird migration in the fall 2021 issue of our Horizons quarterly magazine. Want to spot birds following their migration routes? Attend one of our FREE Birdwatching Hot Spots programs on October 8 at Hastings Lake in Lake Villa and November 12 at Rollins Savanna in Grayslake. All ages. Adult supervision required. No registration required.

Milkweed. It’s not just for the monarchs.

Post by Jen Berlinghof

Being home more these past months has allowed my family copious time to observe the common milkweed (Asclepias syriaca) in our garden go through its life cycle day by day. We’ve witnessed the transformation from wily little sprouts in early summer to blooming beasts, with pompoms of eraser-pink flowers wafting perfume across the yard—even threatening to take over the footpath—by Fourth of July. Now in the sweet days of September, our milkweed is laden with swelling seed pods, ready to burst with floating seeds like so many little white parachutes scattered in the autumnal sky. The situation is similar in many of the Lake County Forest Preserves in northern Illinois.

The beautiful flowerhead of common milkweed (Asclepias syriaca). Photo © Lake County Forest Preserves.
The beautiful flowerhead of common milkweed (Asclepias syriaca). Photo © Lake County Forest Preserves.
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