A Man In Uniform
It’s hard to ignore the proclamation of spring from the returning Red-wing Blackbirds. MLIVE shares, “One of spring migration’s first arrivals; when their trilling calls once again fill Michigan’s thawing wetlands, you know winter is on the wane.” Their unmistakable call of “konk-aree!” brighten the sometimes gloomy gray days as winter reluctantly gives way to spring. 
One of the most abundant birds across North America, and one of the most boldly colored, the Red-winged Blackbird is a familiar sight atop cattails, along soggy roadsides, and on telephone wires.
Photos by Bob Vuxinic
The males are glossy-black with shoulder patches of scarlet and yellow called epaulets, which they are able to puff up or hide according to their level of confidence. Displaying the bold red epaulets can signal aggression, so keeping the red under cover helps avoid unnecessary confrontations in “social situations,” such as visiting neighborhood bird feeders after a long migration north.
Red-winged Blackbird males secure breeding territories in the early spring, before females return from their southern wintering grounds. Their immediate goal is to secure a breeding territory, for virtually all of the mating is accomplished by males with territories. Males must be calculating and judicious, for although a bigger territory can support more females, the effort needed to defend a territory increases with its size.

A male's second goal is to court females to nest in his territory. The number of females within a male's territory varies from one to fifteen. However, each bird has a finite amount of energy and both territorial defense and courting require energy, so a male must find a balance of defense and acquisition of mates. 
Males spend much of their time during the breeding season patrolling territorial boundaries and fending off intruders by performing their song spread displays (photo by Jeff Mitton) that highlight bright red shoulder patches. The song spread is critically important in defense of a territory, and the song is also evaluated by females as a facet of courting. Immature males return earlier than mature males to vie for territory, but the experience of the established males is a proven advantage, and immature males often lose out to their “elders.” However, playing the long game is smart for the young males and returning to the same breeding grounds to wait out the mature males often pays off.
When the females return, they choose their mate partly on the quality of his territory, making sure that it has an abundant food supply of small arthropods, water for drinking and bathing, and tall grass for safe nesting sites.

Because the top males can defend territories that safely support multiple nests, you will often find multiple females nesting within high-ranking male territories, making Red-winged Blackbirds one of the most recognizable examples of resource-defense polygyny in birds. Some populations see 90% of territorial males with more than one female blackbird nesting in their territory.
However, females may also have multiple partners, and one-quarter of the nestlings may be fathered by different males. This means that females exhibit polyandrous mating system.
Photo of female red-winged blackbird by Jim Simek.

Red-winged blackbirds are notorious for defending their genetic investments. Adults are very aggressive in nesting territory, attacking larger birds that approach, and loudly protesting human intruders.  
During the breeding season, males fiercely defend their territories, spending over a quarter of the hours of daylight in this task. They chase other males out of their territory and attack nest predators, including much larger animals, such as horses and people! Keep an eye out for potential nest sites now to head off "aerial maneuvers" during the nesting season.
Save the Date!

Please consider supporting the EIC's mission of community outreach and education on March 16,
Did You Know?
Living in the Great Lakes State, we should all be aware that we are sitting on the 20% of the world’s available fresh water. Two dates have been set aside in recognition of the global importance of available, clean water. World Wetlands Day, celebrated on February 2 since 1997. The theme for 2022 is Wetlands Action for People and Nature. The public campaign is an appeal to invest financial, human and political capital to save the world’s wetlands from disappearing and to restore those that have been degraded.  

Coming up is World Water Day on March 22. This year's theme is:
Groundwater is invisible, but its impact is visible everywhere.
Out of sight, under our feet, groundwater is a hidden treasure that enriches our lives. Almost all of the liquid freshwater in the world is groundwater.
As climate change gets worse, groundwater will become more and more critical. We need to work together to sustainably manage this precious resource.

Let's raise a glass in celebration. Cheers!
Tales from the Trails
"Mink on the Move."
Although sightings of American Mink (Mustela vison) in the Environmental Study Area (ESA) have not been reported over the last several months, the recent ground cover of snow revealed that they are still active and making their usual rounds. I followed one individual mink’s trail of paw prints in the snow for a while, and it took me on a tour of around 10 acres of the ESA. I discontinued my tracking effort when the trail set out onto the snow-covered ice of Fair Lane Lake.

Reflecting the mink’s slender form and loping movements, their trails are easy to distinguish from most other mammals in the ESA. Tracking a mink will likely take you through different habitats, as they hunt on both land and in and around water. Carnivorous, their diet includes birds, insects, fish, frogs, squirrels, small rodents, muskrats, and pretty much any other animal they can subdue.

Mink are known as active cruisers in their habitats. According to information on mink behavior in Rollin H. Baker’s classic Michigan Mammals, the trail of a single male mink in southern Michigan was tracked in circular fashion for about 5 miles, within a 1,300 acre space. Female mink occupy smaller spaces, up to about 50 acres. This has to do with how male mink occupy larger areas that overlap with more than one female.

Mink mating season is currently underway. Breeding takes place in February and March. The single annual litter of mink pups is usually born in April or May. Females are the sole caregivers of the young. In the ESA, sightings of an adult mink with several pups have been a highlight of some of the nature walks for school groups. These memorable encounters were the first of their kind to be experienced by most, if not all of the school children present. Yet another instance of how EIC programs “keep it real” through direct observation and education about local biodiversity.
-Rick Simek

Check out an earlier sighting of a mink in the Environmental Study Area below.

Venturing outdoors and encountering nature is good for your physical and mental health! Our trails are accessible, so please visit our Environmental Study Area. Check out our Remote Learning Activities & Resources page for ideas to create a “Neighborhood Nature Journal” and “Family Nature Walk” activities!
Please stay safe, stay tuned, and stay engaged in learning activities while we eagerly wait for the opportunities to share experiences together. In the meantime, watch for our new online activities to satisfy your curiosity about the natural world.