Whooping Crane Conservation Association

Brian Johns, Wildlife Biologist, Canadian Wildlife Service reports that, “Lea Craig-Moore and Kathy St. Laurent have completed the whooping crane breeding pair surveys in Wood Buffalo National Park and surrounding area. Habitat conditions were good, with water levels being higher than normal. The spring was slightly later than average and the northern portions of the nesting area still had a number of snow banks and some frozen wetlands.

In total 61 nests were discovered, only 5 fewer than the all time high of 66 in 2008. Another 22 pairs of cranes were observed, half of which have likely bred in previous years and the remainder were subadult pairs. Lea, Tom Stehn and Jim Bredy will be conducting the hatching success surveys in a couple of weeks and I will send an update after those are completed.”

Tom Stehn, Whooping Crane Coordinator reports that, “ Four whooping cranes were seen by experienced staff this afternoon (May 28, 09) at Aransas NWR along the Intracoastal Canal that runs through the Aransas National Wildlife Refuge. The cranes were grouped as a duo, and then about 5 miles away were two singles separated by 100+ yards. I presume all 4 are subadults.”

Tom adds that, “I have not done a census flight since April 21st , and probably will not do so until July to see if these 4 decide to spend the summer and whether any others are still around. These 4 cranes could still migrate, but they also could spend the summer at Aransas.”

Marty Folk, Florida Fish and Wildlife Conservation Commission reports that, “The two active whooping crane nests described in my 5th Update have failed. One nest failed on Saturday and one Sunday. Visits to the abandoned nests revealed no eggs or remains. Water levels had declined such that it would have been possible for mammalian predators to approach the nests without getting their feet wet. Normally the birds abandon at this point so the nest failures were predictable. The Polk County nest was in a large lake that was not immune to the drying effects of this drought. We still could see a nesting (our latest laying date is 27 May) but not likely from the 2 pairs that just failed. The chick in Osceola County is now 60 days old.”

Marty explained that, “The South Florida Water Management District recently reported that the
period from November 2008 through April 2009 ranked as the driest
six-month period in South Florida history based on records dating back
to 1932. The trouble is, we began this drought back in 2006 and had
already accumulated a large deficit prior to November last year.
However, this week a stalled front is bringing rain to Florida! We’ve
had 3.2 inches of rain at my house this week (it seems like the Great
Flood), and some areas have gotten more. It is “too little too late” for
this breeding season, but is a start for rehydrating the thirsty
landscape.”

Spring 2009 Newsletter

Great news!
Marty Folk,Florida Fish and Wildlife Conservation Commission issued his second update report for the day (5-5 09). Marty notified us that, “The minute I sent out my update #3 on Florida’s non-migratory flock of whooping cranes (see below) we discovered another nesting (actually a re-nest). The pair who had the 2nd nest (in Lake County, see report below), have re-nested and currently have 1 egg, just laid since yesterday’s check of the pair. We moved our video surveillance equipment and began recording their behavior.”

WCCA is thrilled to send you Marty Folk’s” report. Hopefully, this nest will be another success. We will keep you posted.

Marty Folk, Florida Fish and Wildlife Conservation Commission biologist reports that: “Earlier I reported on a whooping crane chick in ‘nest #1’.The chick from nest #1 still survives and is 46 days of age today (May 5, 2009). The eggs that we collected from ‘nest #2′ showed no sign of embryos. The pair at nest #2 produced fertile eggs during their previous 3 nest attempts and we suspect that winter rainfall was insufficient to stimulate copulation or some aspect of egg or sperm production. We now have a new nest by a pair in Polk County. They are nesting in a lake because all marshes in the area are dry.”

Marty advised,”We continue intensive daily monitoring in order to document survival and movements of the whooping cranes. Also, as you may know, we have identified that male whooping cranes aren’t living as long as females, and that male whooping cranes are more vulnerable to collisions with power lines than females. We suspect this may be associated with the males’ propensity to lead the flocks and be the defenders of the flocks. We are also collecting behavioral data to help us learn more about this. We also continue to gather data on whooping crane feather molt. Every other year, on average, adult whoopers molt all their flight feathers and are grounded for an average of 44 days while the new feathers grow.”

Marty stated that in the area of Florida’s non-migratory whooping crane habitat there is no sign of relief here from the drought. The long days with high temperatures at 90 degrees really bake the landscape.

Brian Johns, Wildlife Biologist, Canadian Wildlife Service sends a brief report on the most recent events concerning the Aransas-Wood Buffalo whooping crane flock, the Wisconsin-Florida migratory experimental flock and the Florida non-migratory experimental flock.

Aransas/Wood Buffalo flock:
Brian reports that, “Some whoopers that departed their Aransas, Texas wintering habitat have migrated to Canada while others continue on their way. The cranes are in the process of completing their migration to Wood Buffalo. There have been fewer sightings in Canada this spring compared to other years, which may mean that the birds have had good migration conditions and have moved on through or that there are still a few birds to come. Habitat conditions on the breeding grounds appear to be near normal and Lea Craig-Moore will begin nesting surveys in about 10 days.”

Wisconsin/Florida:
Brian advised that, “Twelve nests were initiated this spring in Wisconsin and as of May 3 all nests had failed.”

Florida:
Biologist Johns wrote that, “Three nests were initiated by whoopers in Florida’s non-migratory flock. One nest failed, one is being incubated and one has a 46 day old chick.”

The eleventh aerial census of the 2008-09 crane season at Aransas was conducted April 21, 2009 with USFWS observer Tom Stehn in a Cessna 210 piloted by Gary Ritchey of Air Transit Solutions of Castroville, Texas. Viewing conditions were ideal with clear skies and moderate winds. Nearly all parts of the crane range were flown.

Migration
Today’s flight tallied 20 adults plus 1 juvenile = 21 total. BLACKJACK! Thirteen of the cranes were located on the BLACKJACK Peninsula (Aransas NWR), 6 were on Matagorda Island, and 2 at Welder Flats. Thus, 91.5% of the flock has started the migration (226 birds out of 247), including all known adult pairs. Eighty-eight cranes have started the migration since the last flight on April 7th when 109 cranes were estimated present. Whooping cranes in migration have recently been reported as far north as Saskatchewan. Some cranes not tallied above presumably headed north today since conditions were very good for migration with sunny skies and mostly southwest and south winds after several days of unfavorable migration weather.

Eight of the 21 cranes located on today’s flight were singles. The one juvenile present was closely associated in a group with 3 white-plumaged cranes, the largest group observed on today’s flight. The juvenile’s parents have presumably started the migration and left “junior” behind. This juvenile crane will be fine and has the knowledge to make the return migration to Wood Buffalo National Park on its own or with other subadult cranes.

Whooping Crane Numbers
With estimated losses that have occurred at Aransas this winter, the current flock size is estimated at 225 adults + 22 juveniles = 247. The estimated peak winter flock size was 232 adults + 38 juveniles = 270 total.

Habitat use
For the first time all winter, all the whooping cranes on today’s flight were found in salt marsh. The cranes are believed to be feeding on fiddler crabs since blue crabs in the marsh ponds are still scarce due to the continuing drought. A blue crab count done on April 1st found zero crabs in the marsh. The refuge has discontinued its program of supplemental feeding with corn since most of the cranes have migrated.

A lightning-caused wildfire that started April 18th on Matagorda Island burned approximately 10,000+ acres of upland prairie lands. The fire, located between Pringle Lake and Power Lake, was contained on April 20th and allowed to burn out. The burn will benefit the prairie habitat by recycling nutrients and controlling brush.
– By Tom Stehn – Aransas National Wildlife Refuge

Marty Folk, Florida Fish and Wildlife Conservation Commission reports that “One whooping crane chick hatched from the nest described in my first update. Today the chick is 24 days old. A second nest was initiated in Lake County on 4 March. This 2nd nest was incubated longer than necessary (something that never happens in Wisconsin!) and on Friday we collected 2 non-viable eggs for necropsy. We video-taped both nests this year with surveillance equipment that recorded the activity at the nest during all daylight hours. We will be analyzing this pool of video, along with other footage previously recorded through the years, to determine if incubation behavior by the birds may have been associated with nest success.”

Marty advises, “We’ve not witnessed any other nesting activity this spring. Because of drought, there is little suitable habitat available.Beginning in March we began intensively monitoring the flock in order to collect more data to help us understand what happens to the birds when they go missing. In March, 3 field people drove 9660 miles, flew 28.6 hours, and spent long days monitoring the flock. So far we’ve recovered no dead birds (we need birds to die so we can find them and necropsy them). What we have documented is substantial movements by much of the flock. Some birds have dispersed beyond where we could find them (beyond the central FL peninsula), only to return later. Several are still missing. Dispersal is a suspected reason why birds have “disappeared” in the past. So even if we don’t document mortality with our intensive monitoring, we are documenting this extreme rate of movements/dispersal. We suspect the birds are moving in response to drought, perhaps looking for wetter/greener pastures.”

Since the beginning of the year one pair has been bouncing between 4 points in north and central Florida (see attached figure). The minimum distance traveled by the whoopers this past quarter was 470 miles. This much traveling of course increases the odds of travel-related mortality such as collisions with power lines, etc.

Marty stated, “We continue to monitor 4 migratory whoopers in Polk County and the 1 on Paynes Prairie near Gainesville. We will keep you posted.”

The tenth aerial census of the 2008-09 crane season at Aransas was conducted April 7, 2009 with USFWS observer Tom Stehn in a Cessna 210 piloted by Gary Ritchey of Air Transit Solutions of Castroville, Texas. Viewing conditions were ideal with clear skies and light winds, although turbulence made the ride uncomfortable most of the time. Nearly all parts of the crane range were flown.

Migraton
Today’s flight tallied 103 adults + 6 juveniles = 109 total. Thus, 56% of the flock has started the migration. Whooping cranes have been confirmed on April 2nd as far north as Nebraska. I expect a considerable number of cranes will start the migration in the next week. Conditions should be ideal for departure with very strong southeast winds forecast for Aransas April 8-9.

Whooping Crane Numbers
With estimated losses that have occurred at Aransas this winter, the current flock size is estimated at 225 adults + 22 juveniles = 247. The estimated peak winter flock size was 232 adults + 38 juveniles = 270 total.

Mortality
Today’s flight provided evidence of 2 additional mortalities, with total winter mortality now estimated for the winter at 7 adults and 16 chicks totaling 23 whooping cranes, a loss of 8.5% of the flock that was a record 270 in the fall. In the last 20 years, the current winter ranks as the worst in terms of mortality, ahead of 1990 when 7.5% of the whooping cranes (11 out of 146) died at Aransas. The 3rd worst winter in 1993 showed a 4.9% loss at Aransas (7 out of 143). Mortality in the 2008-09 winter (23 birds) can be added to the 34 whooping cranes that left Aransas in the spring of 2008 and failed to return in the fall. Thus, 57 whooping cranes have died in the last 12 months, or 21.4% of the flock of 266 present at Aransas in the spring, 2008.

The 2 additional mortalities confirmed on today’s flight that had been reported earlier by volunteers and staff are as follows:

Tour Boat Naturalist Ray Kirkwood had seen March 19-29 the Rattlesnake Island juvenile with a very bad limp, using its wings when it moved to try to reduce the weight put on its injured leg. The bird retained flight ability but was lethargic and may have stopped eating. The chick was not observed on April 1st when I looked for it from a boat and had presumably died. The pair believed to be its parents was observed on their territory on today’s flight with no sign of the juvenile.

The second mortality involved a grouping of 1 adult with 1 chick observed twice about 4 hours apart on April 1st in the marsh west of the airstrip on the south end of Matagorda Island. This same grouping of 1+1 was observed on their East Bray territory on today’s flight, providing confirmation that one adult has died.

Sightings near Aransas
Three whooping crane subadults that used the farm fields south of Austwell for much of the winter were last reported present on March 14th. They have either returned to the salt marsh or have started the migration.

Habitat use
For the first time all winter, nearly all the whooping cranes were found in the salt marsh on today’s flight. The cranes are believed to be feeding on fiddler crabs since blue crabs in the marsh ponds are still scarce due to the continuing drought. A blue crab count done on April 1st found zero crabs in the marsh.

Whooping crane locations on the flight included 2 observed at man-made fresh water sources, 2 at a game feeder, and 9 in open bay habitat. No cranes were on burned or unburned uplands. Tides were low caused by a very strong “norther” that had brought northwest winds on April 6th. Salinities remain high, measured recently at 29 ppt in the refuge boat canal and 39 in the adjacent marsh. One monitoring station in San Antonio Bay has a salinity of 25 ppt. The drought rated as “exceptional” shows no sign of ending in central and south Texas. Many counties have imposed prescribed burn bans due to the fire danger. Corpus Christi, Texas is 4.5 inches below normal rainfall starting January 1st.

Overall, these continue to be some of the worst conditions I have ever observed for the cranes at Aransas, with some birds looking thin and with disheveled plumage. The refuge is continuing its program of supplemental feeding with corn. A moderate response by the whooping cranes has continued. The cranes are getting somewhat of an energy boost by catching fiddler crabs just prior to migration.
– By Tom Stehn – Aransas National Wildlife Refuge