Will the Whooping Crane Partners Opt for Black Fly Suppression?

By 2005, four individual birds in Wisconsin’s growing flock of whooping cranes had formed pairs and made a first attempt at nesting. No one was surprised when the two nests that resulted were unsuccessful – these were still young and inexperienced birds. When one of the pairs succeeded in 2006 in welcoming the first wild whooping crane hatched in Wisconsin in more than a century, the wildlife community was jubilant. And optimistic that more such successes would naturally be following in succeeding years.

Parent and chick: Wisconsin is yearning for more of these – in the wild. (Photo courtesy of ICF)

But three very long years would pass before even a single wild chick would once again hatch in Wisconsin, and four years before another one hatched and survived. Instead of chicks hatching, what was happening during this time were mounting numbers of “nest abandonment.” Over time it was observed that many pairs, after forming and building a nest together, were suddenly leaving that nest and not returning.

WCEP Studies Nest Abandonments

By 2009 this problem was being actively studied and various hypotheses were put forward by officials of the Whooping Crane Eastern Partnership – the actual folks responsible for bringing the whooping crane back to eastern North America, and Wisconsin, in particular. These included theories that maybe the cranes were too inexperienced in the wild, or were undernourished, or too stressed by predators, or harassed by biting black flies, or something else.

I don’t think it took long for the biologists involved in closely monitoring the nesting whooping cranes to notice large numbers of black flies on some of the incubating cranes. But it has taken a while for this, and the various other hypotheses to be tested – science, after all, takes its time, and the scientists, understandably, want to get it right.

Are More Bti Treatments the Answer?

However, the citizen scientists and fans of progress for the whooping cranes in Wisconsin – myself among them – who were tuned into the Wisconsin DNR’s Ask The Experts online chat last week, seemed to be expressing a lot of eagerness for a continuation of Bti treatments to reduce the Black fly population. Bti is Bacillus thuringiensis israelensis, a naturally occurring soil bacterium – considered a good alternative to chemicals used to suppress insects. It was applied in certain areas of Necedah National Wildlife Refuge in 2011 and 2012, to see if fewer black flies would result in fewer nest abandonments by whooping cranes.

It seems like it did, in fact, help. Here is a page all about it at the WCEP website. I once saw a picture of a nesting whooping crane covered with nasty looking black flies, and hoped to find and link to it for this post; while my quest for it was unsuccessful, I urge you to look closely at the eggs in the photo on the WCEP page – they are covered with the flies, and seem to tell the story!

At the Ask the Experts event, Davin Lopez, the DNR whooping crane coordinator could only say that the matter is still being studied. But he seemed to promise that a decision will be forthcoming in winter, 2014. The decision will be made by the WCEP partners, but for now Davin offered the opportunity to contact him directly, Davin.Lopez@wisconsin.gov , for those with more question or comments.

Ask the Experts – The Whooping Crane Edition

The Wisconsin Department of Natural Resources held an online chat about whooping crane migration and other related issues last week. It took place at noon, October 31st.

It was one of the DNR’s series of Ask The Experts online events, where various DNR staff take part in discussions and answer questions about their topic of expertise. There have been sessions on walleye fishing, deer hunting, well water testing, beach monitoring, and so many other topics.

For the Whooping Crane version of Ask The Experts, Davin Lopez – the DNR’s whooping crane coordinator, was joined by 2 other partners in the whooping crane reintroduction efforts in Wisconsin. Joan Garland, outreach coordinator for the International Crane Foundation, and Heather Ray, associate director of development for Operation Migration, joined Davin in typing back answers to the questions almost as fast as we online chatterers submitted them.

Midway through the chat we learned that there were approximately 100 who were participating! As a participant you have no idea that you are part of such a large virtual audience.

Among the many dozens of questions that were asked, the topic that attracted the most attention – at least 12 questions and comments – was concerned with treatments to reduce the Black fly population (which seems to contribute to the cranes abandoning nests at breeding time) at Necedah NWR. I’ll add a separate post about that, but first, here is a list of some of the topics touched on:

– Although the ultralight-led migration began for this year’s crop of new cranes on October 2nd, there have been no reports of “on migration” sightings of any of the 100-plus adult whooping cranes in Wisconsin. Heather Ray said that generally they don’t begin migration before November.

– She also said that the ultralight migration flights begin with short flights of 5 to 20 miles in distance and gradually expand to 50 and 60 mile flights, as the birds gain experience and stamina.

Efforts to train whooping cranes to migrate with ultralights begins when the colts are very young.

– The goal of the whooping crane re-introduction campaign in Wisconsin (technically the campaign is for the entire Eastern half of North America, but Wisconsin is key, as the northern terminus of the flyway that is being established) is 100 individual birds (that goal is within reach) and 25 successful breeding pairs (not even close); actually, Davin Lopez called this “a very rough goal . . . what we need is a self sustaining, growing population.”

– Ray reported that there were 20 breeding pair in Wisconsin in 2013. Unfortunately only 3 chicks hatched from these nests, and only one has survived to fledge. (The survivor is designated #W3-13 – the 3rd chick hatched in the wild in 2013 – and will be migrating south with its parents: #9 from 2003, and #3 from 2004).

– Except for 3 surviving wild chicks (the 2013 survivor, and #w1-06, and #w3-10) all of Wisconsin’s wild whooping cranes were hatched from eggs produced each year by the captive populations at ICF and Patuxent Wildlife Research Center in Maryland. Ray said that there are generally 30 and 40 eggs available each year from these sources, and they are split 50/50 between Wisconsin and the new <strong>Louisiana Non-migrating flock; efforts to establish this were launched in 2011.

– One participant commented about a Sandhill Crane hunt, which has been rumored for Wisconsin. He suggested that it would be hard for hunters to distinguish between young whooping crane colts and Sandhills. Joan Garland referred him to a fact sheet at the International Crane Foundation website that addresses the hunting proposal.

– As the chat closed, another guest added this personal note: “Thanks to a school presentation by Joan, my son is hooked on the whooping crane and he wants to be a biologist when he grows up!”

How lucky, that courtesy of the International Crane foundation, I just happen to have a picture of Joan making such a presentation! And here it is:

International Crane Foundation’s Joan Garland gives a school presentation.

[Photo credits: Whooping Crane Eastern Partnership, and the International Crane Foundation.]