Species Spotlight: Kirtland’s Warbler

By Ally Brown, MNA Intern

In some instances, the occurrence of a wildfire can mean devastation for species with restricted ranges and population; however, for one of Michigan’s rarest warblers, fires are crucial for building its niche habitat and sustaining the population. The Kirtland’s warbler is a member of the Parulidae or New World warbler family which measures about six inches in length and is distinguishable by the striking yellow plumage on its throat and breast and split white eye rings. As is the case with many of Michigan’s bird species, the Kirtland’s warbler nests in parts of the Upper and Lower Peninsulas during the summer months and makes the long journey to the south for the winter months – in this case a 1400 mile trip to the Bahamas. While it may seem as though this long-distance flight would be the toughest part of life as a Kirtland’s warbler, the largest challenge this population faces comes from its time up north.

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Photo: Ron Austing

Although not immediately obvious by the forested landscapes known today, Michigan’s history is one of expansive barrens and frequent fires. Many grassland and barren species adapted to this cycle of burnings, one of which is the fire dependent jack pine tree. Heat is necessary to the lifecycle of the jack pine, as it promotes the tree’s cones to fully open and successfully germinate. With the suppression of fire, young stands of jack pine become less and less common and old stands grow dense and tall, losing their lower branches due to lack of sunlight. The degradation and succession of the jack pine ecosystem reasonably follows this lack of fire, but what was not suspected was the subsequent decline in the Kirtland warbler population.

According to the DNR, Kirtland’s warblers nest in young jack pines on branches that essentially touch the ground, where they can hide their nests among dense thickets of pine and grasses. In order for these conditions to occur, the pines must be young and small so that sunlight can reach the ground and keep the lower branches of the trees alive. This also requires the occurrence of frequent fires to remove older trees in exchange for the germination of their cones. Without these fires, the selective female warblers will refuse to nest and, according to the Cornell Lab of Ornithology, only single male warblers will continue to live in the old, successional stands. Another major benefit of hiding nests in the lower branches of young jack pines is protection from the parasitic brown headed cowbird, which will remove warbler eggs from the nest and replace them with eggs of its own.

Today, with the importance of fire and the jack pine to Kirtland’s warbler populations known, effort is being placed to conserve this habitat and the warbler population. Several of MNA’s sanctuaries house populations of jack pine, including Redwyn’s Dunes Nature Sanctuary, and today birders can view this rare bird through tours given by the Kirtland’s Warbler Recovery Team. According to the DNR, the best way to support this endangered species is to educate yourself and those around you through research or attending birding tours, as well as to donate to local organizations, like the Michigan Nature Association, dedicated to protecting and rebuilding the warbler population.

Piping plovers, Kirtland’s warblers, and the Great Lakes: this week in environmental news

Each week, MNA gathers news stories from around the state and country related to conservation and the environment. Here is what happened this week in environmental news:

Credit: Don Freiday/USFWS

Piping plovers make comeback in the Great Lakes (Great Lakes Echo): The piping plover, a shorebird once nearly extinct, is on the rebound. There were once only 12 pairs left in the Great Lakes region, but thanks to conservation efforts. scientists are seeing an upswing in the population. The plovers should arrive on the shores of the Great Lakes in the next couple of weeks.

Judges skeptical of challenge to proposed EPA rule on climate change (The New York Times);  Lawyers for coal companies, two dozen states, and the Environmental Protection Agency argued before the U.S. Court of Appeals over a rule proposed by President Obama to curb carbon pollution from coal-fired power plants. The rule would require all states to draft plans to restructure their electricity sectors and transition from coal power to cleaner forms of energy. The plaintiffs say the rule is wreaking economic havoc and that the EPA lacks the authority to issue the regulation. They have petitioned the court to block it from finalizing the rule.

New mapping of Great Lakes’ wetlands released (The Swamp School): A new and comprehensive map of the Great Lakes region’s coastal wetlands was recently released by the Michigan Tech Research Institute. The map is the first of its kind, with fluorescent bands of color outlining the Great Lakes. It displays both Canadian and U.S. wetlands along more than 10,000 miles of shoreline. The new coastal map is the result of years of work expanding on previous maps from the Michigan Tech Research Institute.

Endangered Wisconsin Kirtland’s warbler found in the Bahamas (Milwaukee Journal Sentinel): For the first time, scientists have found a Kirtland’s warbler from Wisconsin in the forests of the Bahamas. The bird was one of six warblers banded last summer in central Wisconsin. The state has a total population of fewer than 25 Kirtland’s warblers. It is estimated that there are about 4,000 total Kirtland’s warblers scattered in Wisconsin, Michigan and Ontario. The field crew in the Bahamas has found about two dozen total Kirtland’s warblers since mid-March.

DNR to celebrate 40 years of Endangered Species Act with week of events

Photo courtesy of the DNR.

Photo courtesy of the DNR.

By Kary Askew Garcia, MNA Intern

The state of Michigan has hit a major milestone and the Department of Natural Resources, or DNR, has decided to honor it in an extraordinary way: by hosting a week in honor of the Endangered Species Act, or ESA, from Aug. 4-10.

The ESA was signed into law on July 11, 1974 and came into effect on Sept. 1 of that year. The DNR invites Michiganders to join them at the nearest state park for an insightful lecture on what the ESA is and what it means for an animal to be classified as endangered or threatened.

Click here to find the schedule of events.

According to the DNR, one success that the ESA is the recovery of the rare Kirtland’s warbler. This bird has garnered attention from far and wide. In a release from the DNR, Specialist Dan Kenneday said “Michigan’s ESA has been pivotal in the recovery of the Kirtland’s warbler.”

A Kirtland's warbler in an MNA sanctuary. Photo by Cindy Mead.

A Kirtland’s warbler in an MNA sanctuary. Photo by Cindy Mead.

The ESA plays a large role in maintaining balance in Michigan’s wondrous natural habitats and ecosystems. Without laws protecting animals, habitat decline, pollution and other issues will continue to cause harm to animals and their homes throughout the state, which may compromise the health of Michigan’s invaluable natural scenery.

When a species is classified as endangered, it means that it is in danger of becoming extinct. There are also many other species listed as threatened and may be on the verge of being listed as endangered. The ESA is one step in finding methods to solve the problem of extinction and has already found success in the restoration of the Kirtland’s warbler.

MNA supports the efforts of the ESA and the DNR and congratulates them on the 40th anniversary of the act. Don’t miss a chance to celebrate the ESA! For more information about the Michigan Department of Natural Resources, click here.

 

Bird migration: Why does it happen?

By Sally Zimmerman, MNA Intern

The Kirtland's warbler migrates from Michigan to the Bahamas. Photo by Cindy Mead.

The Kirtland’s warbler migrates from Michigan to the Bahamas. Photo by Cindy Mead.

Many people know that birds migrate south when it starts to get cold and that they can be seen flying in a V-shape as they leave, but not much more than that. The large-scale movement of birds as the weather changes is imperative to their survival and is stamped into their genetic makeup.

The migration of birds happens because there is a difference between their breeding home and nonbreeding home. Their breeding home is where they spend the summer months building nests and laying their eggs. The nonbreeding home is where they spend the winter months. The two main resources birds look for when they migrate are food and nesting locations. They typically move from areas of decreasing resources to areas of increasing resources.

In the northern hemisphere, birds migrate north in the spring. They thrive on insect populations and budding plants. There are also plentiful nesting locations for the birds to build their homes. When it starts to get cold, the insect populations decrease and the plants are no longer budding, so the birds migrate south.

Birds can cover a span of thousands of miles in their migration. They often travel the same route with little deviation from year to year. Researchers believe birds use a variety of techniques to navigate, including navigation by the stars, changes in the earth’s magnetic field and smell. Birds have important stopover locations in their migration pathways that provide food supplies.

Raptors such as hawks, eagles, vultures and falcons use landmasses such as the Keweenaw Peninsula as a stopover point in their migration. This shortens their flying time over Lake Superior and the updrafts carry the birds so they exert minimal energy.

The Kirtland’s warbler is another bird species that uses Michigan as one of its homes. The bird arrives in Michigan anywhere from late April to early May and constructs its nest between mid-May and early June. Egg-laying occurs from late May to mid-July. Incubation takes about 15 days with fledging occurring nine days afterward. The bird migrates from northern Michigan where it nests exclusively in young jack-pine forests to the Bahamas in the winter, where they nest in pine woods, broad-leafed scrub and Australian pipe. The Kirtland’s warbler makes the journey to the Bahamas sometime between August and October without any stops, following a narrow band that crosses Ohio, West Virginia, Virginia, North Carolina and South Carolina.

Recently, there have been increasing migration hazards for birds as more communication towers and tall buildings are being constructed. The lights of tall buildings attract birds and are accountable for millions of collision deaths each year. Food supplies, weather and exposure to predators can also affect the journey. Organizations like MNA have been working to protect these important flyway areas for migratory birds. You can read about MNA’s efforts to discourage the building of a cell phone tower on Brockway Mountain in the Fall 2013 issue of Michigan Nature magazine

Scientists use banding and satellite tracking to study migration, with the hope of locating important stopover and winter spots. The goal is to make steps toward protecting and saving these important locations.