Sara Reports: Finding Nests! April 25, 2008
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As you read Sara's report this week . . .

1. What information can the birds' radio signals give about nesting?

2. When Sara didn't pick up a radio signal from one of the pairs she saw, what did she conclude? Why?

3. How many pairs in the new flock are nesting so far this spring ?

Meet Sara

Dear Journey North,

April 23 was a beautiful day and the perfect day for the nest survey flight I had scheduled with Windway pilot Mike Frakes. The purpose was to check on known nests that aren’t visible from the ground as well as check on other pairs of birds suspected to be nesting. When Richard Urbanek flew on 14 April he found and confirmed 6 active nests on the Necedah NWR. Since then two other pairs were suspected to have started nesting.

Signals Help
Even when the birds aren’t visible we learn a lot based on the strength of the signal from their radio transmitter. If a transmitter is functioning normally, the signal is usually pretty strong. If all of the sudden the signal is coming from the same area but is sometimes weak we begin to suspect that the weak signal is due to that bird sitting on a nest and incubating. In a sitting position the antenna is covered and the range of the signal is reduced.

Nest Check: Four Known Plus Three New
We quickly checked the 4 nests on the southern half of the refuge (211 and 217; 213 and 218; 313 and 318; and 309 and 403). We observed one member of each pair sitting on the nest, incubating. After checking those 4 nests, we headed north to check the pairs who were suspected to be nesting. Our tracking team had done an excellent job interpreting the behavior and the signals of the birds, as we discovered both suspected pairs (11 & 12-03 and 1-04 & 8-05) were indeed incubating! Within the first 45 minutes of our flight we had seen 6 nests, 2 of which hadn’t been confirmed prior to our seeing them. We checked the other pairs known to be nesting on the north half of the refuge. Then tracked down our final pair, 408 and 519. They had been seen together on Tuesday afternoon (Apr. 22), which meant they weren’t on a nest — but when we found them, one of them was incubating! It sometimes amazes me how quickly these birds seem to go from appearing to do nothing (in regards to reproductive behavior) to building a nest, laying eggs, and beginning incubation. Our total was now 9 active nests.

Missing Pair Found! TEN Nests Now!
Our next task was to look for missing pair #212 and 419. The transmitters on both these birds are non-functional so they can’t be tracked. We first searched their main use area on a state wildlife area north of Necedah but found no Whooping Cranes. On the way to the private property they use in the fall, I saw two white birds on a large, remote marsh east of us. Pilot Mike turned the plane and we went for a closer look. We descended and circled over the birds; they were Whooping Cranes — and a nest! I scanned through all the radio signals and didn’t pick up a single beep. It had to be our missing pair: 212 and 419. The count was now TEN nests. An excellent day!! (See chart >>)

What’s Next?
So far the birds are doing great. We hope that will continue. Some pairs (like #211 and 217) have already been incubating for over two weeks. Others (like 408 and 519) just started yesterday. That means more monitoring and keeping fingers crossed in hopes that all these pairs will successfully hatch their eggs! Stay tuned.

Sara Zimorski, Aviculturalist

April 23 Nest Survey
Click photos to enlarge.
Photos Sara Zimorski

From the air: nest of #212 and #409.

See the little box? It's the nest of 408 and 519! This
brand new nest probably just began April 22. I’ve drawn a square around the nest since it’s hard to pick out otherwise.

This is #309's FIRST nest! Her new mate is $403.