Officially – on the calendar anyway – it’s still summer for another two weeks, even though most of Summer 2014 is now in our memories, lots of it probably fading fast. In the spirit of capturing some of the season’s best, I’m going to record some memories from my Natural Resources Foundation field trip back at the beginning of summer – Memorial Day weekend.
Usually that’s a good time to head for the Door Peninsula – northeastern Wisconsin’s best known natural resource. But this year I got in my car on Friday of the holiday weekend and drove west – the opposite direction – to join an NRF Field Trip featuring both whooping cranes and Kirtland’s warblers. Experts who work with these two endangered birds here in Wisconsin were leading an expedition of birders & other enthusiasts into the habitats where these rare creatures can be found.
Driving west across Wisconsin’s early summer landscape – it was a green, sunny day, and warm – I was full of happy anticipation. I could hardly wait to see some of the whooping cranes that live in the wild in Wisconsin.
Field Trips to Wisconsin’s Natural Resources
Every spring, summer, and fall, the NRF offers over 100 expert-guided field trips, to natural places in every region of the state. They are of varying activities, and activity levels, – there must be something for everyone. Hence, these trips have become very popular, and many are booked to capacity long before they occur.
I had been on a waiting list for the Warblers and Whooping Cranes trip, which added to my sense of good fortune that day. But I should confess the obvious right here – I was on the trip, first and foremost, to see the whooping cranes; I knew next to nothing about the Kirtland’s warblers, and had little interest. But that was about to change.
I should also add that the sightings we enjoyed of whooping cranes were few, and very, very far away. Even though that was not what I was hoping for as I drove west, it turned out not to matter so much.
The Saturday morning tour of the Kirtland’s warbler breeding territory in Adams County, and the sighting of a single, singing Kirtland high above us, followed by the afternoon guided tour of Necedah National Wildlife Refuge, combined with the pleasure of touring with some of the experts of the Whooping Crane Eastern Partnership – all those things added up to a wonderful experience.
Learning About Kirtland’s Warblers . . .
The two-day field trip began at a Wisconsin Rapids hotel with a Friday night program that was packed with information about the ongoing, intensive efforts to save these two endangered species. I quickly learned from the presentation of Kim Grveles, Avian Ecologist with the Wisconsin DNR, and an expert on the warblers, that it would be impossible to learn about the Kirtland’s big conservation story and not develop an interest in this pretty little bird. With charts, maps and photos, Kim showed the growing success for the species as the birds’ limited breeding ground in northern lower Michigan spread – beginning in 1995 – into the state’s Upper Peninsula, and then, since 2007, into Wisconsin, as well as Ontario.
Then Kim told us about the parasitic cowbirds, and their role in suppressing the Kirtland’s warblers. I don’t think many there knew much about the cowbirds, and certainly not that they are considered parasites to the nests of the smaller warblers. (More explanation to come.)
. . . and Whooping Cranes
The International Crane Foundation’s Director of Field Ecology, Jeb Barzen, (Jeb works with cranes in Southeast Asia and China, as well as here in the midwest,) then reviewed the history of efforts to save the whooping crane species – noting that efforts to help an endangered species can just kind of “bump along” for a lengthy period of time before they finally seem to “just take off.” The Kirtland’s warbler species was now enjoying a period of “really taking off” Jeb said, adding hopeful assurance that the whooping crane species may see that day, too.
Jeb reminded us that when the International Whooping Crane Recovery Team began to put together a plan for the species “they were quick to realize the need for two populations,” to improve its’ chances. Then he enumerated various efforts at establishing the hoped-for second population, and the things learned from those attempts. These included (in the mid-1970s to mid-80s) a Rocky Mountain population which relied on sandhill cranes to raise and teach the migration route to whooping cranes, with the result of whoopers imprinting so thoroughly on the sandhills they never paired and never reproduced with other whooping cranes.
And in the 90s, an attempt to establish a non-migrating flock in Florida, met with unacceptable levels of adult mortality. To date, Jeb said, the Eastern Migratory Population (the Wisconsin cranes) has been the most successful – they learn the migration route well and almost all return back here every spring, they show good survival rates in adulthood, and they pair up well with each other. And yet, their very-low rate of raising chicks to fledging has all the whooping crane professionals still trying to puzzle out a lasting solution for this group.
The above is the briefest of summaries of what we were learning Friday night. The information continued to flow all day Saturday. I hope to capture some Saturday highlights in the photos below.
Very early the next morning – most of us toting coffee, light jackets, and binoculars – we divided into four groups and boarded the vans driven by NRF staff and headed out to a pine tree plantation that included a significant growth of jack pines – prime Kirtland’s warbler habitat.
The pine tree habitat we visited (in the photo below), was a mixture of red pine, and the jack pine which is critical for the Kirtland’s warbler. Kim Grveles pointed out the difference: the jack pine are the “scrubbier” trees in the foreground. Behind them and to the left are the fuller, bushy red pines.
Look closely, and you will see a screened enclosure amid the pine trees (in the top photo, right) and a closer picture of some of the cowbirds, within the enclosure, (below). This is a temporary home for the cowbirds during the most critical weeks of the Kirtland’s warblers’ breeding season. The cowbirds, when a Kirtland’s mother is temporarily out of the nest, will lay Cowbird eggs in it, and the warbler mother, unable to recognize the bigger eggs as different from her own, will raise the bigger chicks that hatch, to the detriment of her own smaller warbler chicks. The cowbird chicks will thrive and the warblers will not, and thus the Kirtland’s warbler population has declined as a result.
Because of this “nest parasitism” practiced by cowbirds, every effort is made to trap them – in enclosures like this. These social birds can easily fly in from the top, attracted by the birds already there, but once in, it’s very difficult for them to fly back out.
It was a fascinating morning in the field with DNR and USFWS staff on the warbler territory – and yes, one tiny, bright yellow and gray Kirtland’s warbler was found singing in an Oak tree high above the pine habitat. This was classic male singing behavior by a bird in search of a mate. After hearing the stories, and seeing the pictures of warblers up on a big screen the night before, to see the actual bird, through one of the scopes that were trained on him, was a real thrill – so surprisingly better than the virtual one – and everyone felt it.
After lunch in the welcoming new visitor center at Necedah NWR, we walked the trails (like the one pictured above), that spread out from the center . The prairies, meadows, and wetlands seem to go on indefinitely.
At one point, Jeb Barzen (in the photo below, right), demonstrated the use of tracking equipment that would have picked up the signal from a banded whooping crane if one had been anywhere near us. But that antenna, held by Jane Easterly, a field trip participant, remained silent throughout.
We all boarded our vans again, but before it was time to head back to the hotel, we spent another hour driving through the back roads of the refuge. Our drivers, from both the NRF and the International Crane Foundation, kept in touch with each other via walkie talkies, and the drivers and passengers both seemed to take turns spotting birds of interest.
Alas, it was never the great white whooping crane, but maybe it was a yellow-throated vireo, or another time a rose-breasted grosbeak, a Baltimore oriole, or a red-headed woodpecker, that caused the four vans to pull over, and all of us to spill out with our binoculars, encouraging each other with directions: “Over there, the third tree on the left, two-thirds of the way up,” and other suggestions for finding the bird. We were four vans full of happy birders. That was contagious, and seeing so much of Necedah – it’s wetlands and woodlands, seemed to go on forever – that was a wonderful way to start a summer.