A well-timed birding weekend with my nephew (turns out the heat dome settled over Michigan the day after I got home) brought lots of memorable sightings. Two were extra special in that one species is on the endangered list and one was delisted in 2019 after almost 50 years of conservation work — the Piping Plover and Kirtland’s Warbler, respectively. I’m fortunate in that both nest in Michigan, a few hours away from home base in the Detroit suburbs.
Piping Plover nesting site at 1. Kirtland’s Warbler at 2.
Piping Plover
I’ll start with the impossibly cute Piping Plover. These tiny rotund birds
hide in plain sight on sandy ocean and lake shores, blending right in with their sandy gray backs. It's not until they scurry down the sand on their orange legs that you're likely to spot these big-eyed shorebirds with a sharp black collar and an orange bill. They nest in soft sand away from the water's edge along the Atlantic Coast, Great Plains, and Great Lakes. They are endangered due to habitat loss, disturbance, and predation. All About Birds
Sorry west coasters, but their range and sightings are strictly east of the Rockies.
Piping Plover nesting habitat — Lake Huron beach at Tawas Point State Park
Piping Plovers are on the U.S. endangered species list, so if you see one don't get too close. If one starts frantically calling or feigning injury, back away carefully as there may be an almost invisible nest nearby. All About Birds
Zoomed and cropped from the previous photo.
The Endangered Species Coalition explains how Piping Plovers were first hunted for their feathers, and why their nesting sites are so perilous.
Piping plovers were common along coasts until the late 19th century, when the birds’ downy, sand-colored feathers were sought after for the hat-making trade. Because of excessive hunting of plovers and other birds, the United States passed the Migratory Bird Act of 1918. This law served to bolster the piping plover population until mid-century when the birds’ welfare was once again at risk, this time through the increased development and recreational use of beaches.
Piping plovers are especially susceptible to human disturbances because they are ground nesting birds that make their home on open, sandy shorelines—the same beaches people value for residential and commercial development. Not only is there habitat loss, but breeding and rearing success is threatened by vehicular and foot traffic, increased predator populations attracted to human refuse, and unmonitored pets. Changes to coastal ecologies also impact the birds’ prey populations (insects and small aquatic invertebrates) and modifications to shoreline topographies may make nests more vulnerable to tidewaters, storms, and winds.
Piping plovers are monogamous and share incubation and most rearing duties; however, the egg-laying process itself is long and treacherous for the unhatched offspring. About four eggs are laid over the course of 6-7 days but the nest is not usually incubated during this week-long process. The unmonitored eggs are well-camouflaged which offers some protection, but with increasing traffic nests are often crushed unknowingly or abandoned by the plover parents if overly disturbed.
Both times I’ve been to Tawas State Park, dedicated volunteers were busy monitoring the plovers. They are part of the Great Lakes Piping Plovers Conservation Team,
a partner group of federal and state agencies, Great Lakes tribes, universities, non-governmental organizations and interested private citizens [that] works for recovery of this unique shorebird of the Great Lakes beaches.
This link to the Team’s home page has a photo gallery and a four minute video from the U.S. Fish & Wildlife Service. The statistic that had my jaw dropping is that the population went from 800 Great Lakes nesting pairs to 13 in 1986. The good news is that in 2023, that had grown to 80 pairs.
Warning sign at Piping Plover nesting site.
I was there a little earlier in the season last year, when volunteers were building nest enclosures, called exclosures. A volunteer explained that they watched the birds’ behavior for signs that they had selected a nesting site. This year, two exclosures were already on the beach, with signs and caution tape in place. One of the volunteers expected chicks to hatch any day in one of the nests.
From the Conservation Team’s monitoring and protection page:
Summer monitors first hike the shorelines looking for territorial plovers. Then spend hours searching for nests and helping USFWS to protect them with wire "exclosures" that keep the eggs safe. They then check on the birds daily (or nearly so) at most beaches allowing us to monitor the status of their nesting attempts, try to resolve any issues that arise, and to react quickly to certain situations (a new nest that needs an exclosure or an abandoned nest with eggs that can be rescued and taken to the captive rearing center).
Nest exclosures have dramatically increased the breeding success of Piping Plovers. These wire "cages" that are put over plover nests reduce the egg predation rate significantly. The spacing of the wires is large enough for an adult plover to run through but small enough that a crow, a gull, or another predator can't reach the eggs.
Nest exclosure with female on the nest. Bigger.
A little out of focus, but here’s the female on the nest.
Two frames later, the female is off the nest. Notice the Common Grackle in the background for size comparison.
Extreme close up of the nest area from the prior photo. I think I can barely see an egg.
Once the chicks hatch, the exclosure is no longer useful. The chicks are precocial, which means that within a few hours of hatching, they are running around feeding themselves. The plover family leaves the nest and never returns, though they usually stay nearby. Once they leave the exclosure we are much less able to protect the chicks from predation. We continue to watch over them until they can fly in order to do what we can to protect this vulnerable time of their lives.
The female (her forehead strip is not nearly as prominent as the male’s) came out of out of the exclsoure and began foraging.
The male took his turn in the exclosure.
He easily slips through the wire mesh.
Monitoring doesn't end when Piping Plovers leave the Great Lakes for their winter territories. Other dedicated observers keep an eye on them and report their locations and activities during the 9 months that they spend in the south each year.
Male Piping Plover foraging along Lake Huron. Zoomed
Kirtland’s Warbler
About an hour-and-a-half drive west is the Kirtland Warbler nesting site we visited. Mr. C and I were introduced to the site last year as part of a Michigan Audubon Society field trip. I wrote a Daily Bucket about it so I won’t repeat all that detail here.
The current nesting site is along Camp Road in the Huron-Manistee National Forest, outside of Roscommon, Michigan.
The TLDR version for the Kirtland’s fast decline is habitat loss and Brown-headed Cowbirds.
Kirtland’s are ground nesters and nest solely in young Jack Pine forests. The young trees have branches that go all the way to the ground, forming a dense protective screen. Once the trees reach a certain age, the lower branches break off and that protection disappears. Jack Pine pinecones require substantial heat to open and distribute seeds, hence the need for fire. While the Warblers used one site, periodic natural fires cleared the way for new forests to grow.
Young Jack Pine forest in the Huron-Manistee National Forest
The problem was humans, of course, and the belief that all forest fires are bad. Fire suppression left the older Jack Pine forests intact and no way for the natural fire/regrowth cycle to continue. Thankfully, the State of Michigan, along with many partners, began to rethink forest fire management. Jack Pine forests began to be managed in stages to ensure appropriate new habitat is available nearby.
As a condition for the warbler’s delisting [from the Endangered Species List], the USFWS, U.S. Forest Service, and the Michigan Department of Natural Resources signed a memorandum of understanding that the agencies will continue habitat management at sufficient levels to ensure a continued stable Kirtland’s Warbler population. All About Birds News
Michigan DNR has committed to planting
1.8 million jack pine seedlings per year going forward to help maintain the 38,000 acres of suitable jack-pine habitat needed to keep the warbler population above the 1,000-breeding-pair threshold for recovered status. AAB
Our first view was of a male in the distance and way up in a snag.
Brood parasitism by Brown-headed Cowbirds has been the second factor in the decline. Surprise surprise — humans again were the initial source of the problem. From a 2019 National Audubon Society article:
The [Cowbird] species—which moved into Kirtland’s breeding territory in the early 20th century after logging and land-clearing created new habitat—lays eggs in warbler nests and lets the endangered birds do the energy-draining work of raising cowbird chicks, which often outcompete their smaller nestmates and diminish overall reproductive success. To give the warblers a fighting chance, the FWS began trapping and euthanizing cowbirds in 1972. Emerging research suggests that the cowbird control may no longer be needed—perhaps because their own habitat has been dwindling in Michigan—but for now that work continues.
The males were establishing territories, so patience paid off. We first heard the Kirtland’s singing far in the distance. Then spotted the one singing closer in the previous photo, but still a ways away. This male’s territory straddled Camp Road, so he would periodically stop to sing close to the road.
In July, the Journal of Wildlife Management published research by [Nathan Cooper, a postdoctoral fellow at the Smithsonian Migratory Bird Center] that showed cowbirds parasitized less than 1% of Kirtland’s Warbler nests after cowbird traps had been recently removed. It seems the Kirtland’s Warbler population is strong enough now to tolerate cowbirds. “We’re still working out what parasitism rates the Kirtland’s population can withstand,” Cooper says, “but it’s safe to say 1 to 2% is fine.” All About Birds
Kirtland’s Warbler singing to establish territory at Huron-Manistee National Forest.
Although great strides have been made in restoring and maintaining nesting habitat, the Kirtland’s Warbler still faces uncertainty in its wintering grounds in the Bahamas from the prolonged and intensifying hurricane season. So even though they are off the ESA, they’re still not out of the woods just yet.
Kirtland’s Warbler female from last year. Zoom
Kirtland’s Warbler male, also from last year. Zoom
Now it’s your turn. What’s up in your birdy world?
