Whooping Crane Conservation Association

The sixth aerial census of the 2010-11 whooping crane season was conducted March 1, 2011 in
a Cessna 210 piloted by Gary Ritchey of Air Transit Solutions, Castroville, Texas with USFWS
observers Tom Stehn and Brad Strobel. All portions of the crane range were covered in the 6-
hour census. Flight conditions were excellent, though late afternoon sun made it difficult to find
cranes when flying towards the sun.

Sighted on the flight were 216 adults and 41 juveniles = 257 total whooping cranes. The
expanded range of the cranes on upland areas and movements to fresh water made it harder to
find all the cranes. At least five additional family groups and pairs (14 cranes) and 7 subadults
were estimated to have been overlooked.

Observations on today’s flight confirmed the loss of two additional whooping cranes so that
winter mortality in 2010-11 has totaled 4 cranes (3 adults and 1 juvenile). No carcasses have
been found, and cause of the deaths is unknown. On today’s flight, one group of 1 adult with 1
chick was observed on the G1 prescribed burn on Matagorda Island with no other cranes around.
Also, for the third flight in a row, the East Spalding Lake juvenile was not found, with just the
adult pair seen on the territory. With this mortality, the current flock size is estimated at 279.
The peak size of the Aransas flock this winter was 283.

On March 1st, one whooping crane was confirmed present in a flock of > 10,000 sandhills cranes
near Pampa, (north of Abilene) in the Texas Panhandle. It’s likely that what might have been
the same crane seen in January and February in Texas near Electra and Anson never wintered
at Aransas, but instead elected to remain with sandhill cranes in north Texas and has started its
migration north with sandhills.

Crane habitat use observed on the census flight (n=257):
160 of the cranes observed were in salt marsh habitat
40 were in shallow open bay habitat
21 were on prescribed burns
20 were at fresh water sources
9 were on uplands areas
7 were at game feeders

The continuing moderate use of prescribed burns and heavy use of open bay habitat is notable,
although cranes are finding low numbers of blue crabs in the marsh. Low tides are continuing
with over 70% of San Jose Island consisting of dry mudflats. Cranes are continuing to seek out
freshwater to drink because of high marsh salinities.

The fourth aerial census of the 2010-11 whooping crane season was conducted February 11, 2011 in a Cessna
210 piloted by Gary Ritchey of Air Transit Solutions, Castroville, Texas with USFWS observers Tom Stehn and
Brad Strobel. Flight conditions and visibility were excellent throughout the 6-hour flight.

Sighted on the flight were 238 adults and 42 juveniles = 280 total whooping cranes. With the addition of a
confirmed report on February 8th of a single whooping crane in north Texas east of Dallas in Jones County, the
flock size is estimated at 281. This breaks the previous high of 270 reached in the fall, 2008. The flock of 281
consists of 236 white-plumaged and 45 juveniles = 281 total.

Cranes observed:

* All-time high for Welder Flats, breaking previous high of 32 set in December, 2010.
** Although only 42 chicks were observed, an estimated 3 others may not have been identified due to their
whiter plumage this time of the winter, or else were not picked out in large groups on prescribed burns.

Crane habitat use observed on the census flight (n=280):
111 of the cranes observed were in salt marsh habitat
71 were on prescribed burns
73 were in shallow open bay habitat
22 were on uplands areas
3 were at a game feeder
0 were at fresh water sources

The 73 whooping cranes in shallow bay habitat and the 65 cranes on prescribed burns were both notable.
The prescribed burns have changed the distribution of cranes on the winter range, with many cranes moving to
the 2 refuge burns from different parts of the wintering area. 

The low tides present on today’s flight contributed to the amount of open bay use observed. Much of San Jose
Island consisted of dry mudflats. This is normally a tougher time of the winter for whooping cranes to find
adequate food resources, and this winter is no exception as evidenced by increased use of uplands, burns, and
open bay habitat during the flight. However, observations continue of cranes catching a few blue crabs.

Tom Stehn, Aransas National Wildlife Refuge

The third aerial census of the 2010-11 whooping crane season was conducted January 19, 2011 in a Cessna 210 piloted by Gary Ritchey of Air Transit Solutions, Castroville, Texas with USFWS observer Tom Stehn.

The flight only covered 2/3’s of the crane area due to limited flight time.  Flight conditions and visibility were good throughout the 4-hour flight, although clouds made it a harder to find cranes during mid-portions of the census.  A follow-up flight the next day had to be cancelled due to fog and low ceilings.   

Sighted on the flight were 175 adults and 36 juveniles = 211 total whooping cranes.  The only recent confirmed report I have of whooping cranes not at Aransas was one white-plumaged whooping crane in north Texas near Electra on January 2nd.

Assuming numbers had remained the same from the previous flight in the areas not covered, the numbers represent an increase of 3 cranes above the previous record-tying count of 270.  However, although I fully expect flock size to be more than the 270 previously tallied, it will take several more flights before I can establish a better estimate of flock size.

Crane habitat use observed on the census flight (n=211):

              74 of the cranes observed were in salt marsh habitat

              82 were on prescribed burns

              21 were in shallow open bay habitat

              31 were on uplands areas

                3 were at fresh water sources

The 82 whooping cranes on prescribed burns was notably very high.

Burn Location     Unit Number        # of Cranes Observed

San Jose Island            –                                3

Matagorda Island         G1                            6

Aransas Refuge          C4/C5                       21

Aransas Refuge          C8/C9                       52

The prescribed burns have changed the distribution of cranes on the winter range, with many cranes moving to the two refuge burns from different parts of the wintering area.  For example, two of the radioed cranes have left Lamar and are staying on the refuge burns and adjacent salt marsh.  One adult female crane was captured on Lamar and radioed on January 8^th by biologists organized by The Crane Trust, Wood River, Nebraska.  They set out a snare attached to a long twine, and when the bird stepped in the snare, they yanked on a fishing pole and tightened the snare, ran out from blinds and grabbed the bird.

This is normally a tougher time for whooping cranes to find adequate food resources, and this winter is no exception as evidenced by increased use of uplands, burns, and open bay habitat during the flight.  A crab count conducted January 7th had found only 6 blue crabs in an hour of walking the marsh, but compared to some winters, this was not too bad.  No wolfberry fruits or flowers had been found, with the crop over for the year.

Salinities are currently 19 ppt in San Antonio bay just north of the refuge.  Several inches of rain that fell

January 15-16^th has provided additional drinking water for the cranes in various areas of standing water next to the salt marsh and eased access to drinking water for the cranes.

A severe hail storm that crossed the Texas coast in the early morning hours of January 9^th apparently killed over 1,000 birds in a narrow area on San Jose Island stretching over 15 miles.  Initially reported by a waterfowl hunter, a reconnaissance by Texas Parks and Wildlife Department estimated at least 1,000 birds had been killed.  Species found dead included sandhill crane, white pelican, roseate spoonbill, black skimmer, ducks, plovers, and terns.  Sixteen specimens were necropsied by the National Wildlife Health Center, but I do not yet have the results.  During the reconnaissance, TPWD had observed 8 whooping cranes that looked fine.  Additional searches in other parts of the crane range had not find any dead birds.  On today’s census flight, there was no evidence of hail-killed birds or missing whooping cranes on San Jose Island.  I think the whooping cranes dodged nature’s bullet, though we’ll probably never know for sure if a few whooping cranes perished.  Tornados and wind gusts > 60 mph associated with the storm had also damaged buildings in various locations in the Coastal Bend.

       Tom Stehn, Aransas National Wildlife Refuge

Aransas: December 9th, 2010

Tom Stehn, Aransas National Wildlife Refuge reports: “The second aerial census of the 2010-11 whooping crane season was conducted December 9, 2010 in a Cessna 210 piloted by Gary Ritchey of Air Transit Solutions, Castroville, Texas with USFWS observers Tom Stehn and Brad Strobel.”

Sighted on the flight were 223 adults and 45 juveniles = 268 total whooping cranes.

Photograph by Vickie Henderson

This was an increase of 31 cranes since the previous flight conducted December 1st.  Flight conditions and visibility were excellent throughout the flight.  A low pressure system that had brought howling north winds on December 8th had moved off the coast, followed by clear skies and moderate southeast winds.  With nearly complete flight coverage of the crane area, the 268 cranes counted represents an accurate estimate of the number of cranes present.

One additional whooping crane is known present near Cherokee in northern Oklahoma.  Thus, flock size is at least 269.  Although there have been no additional recent migration reports, as many as 15-20 more whooping cranes are hoped to still be in migration.  Recent reports of whooping cranes at Aransas possibly not located on today’s flight include a group of 9 seen flying over the refuge’s back gate road on December 7, and a single that was observed roosting at Heron Flats Marsh on December 1 and 6 and followed sandhills to forage on pasture land and/or farm fields north of the refuge.

To date, 45 of the 46 juveniles found in mid-August on the nesting grounds have made it safely to Aransas.  The 45 chicks at Aransas include five sets of “twin” chicks, (adult pairs that have brought two chicks each). Five pairs with two chicks each had been sighted in Canada in August. This is the second highest total of “twin” families at Aransas, exceeded only by the 7 sets of “twins” present at Aransas in the 2006 winter.  The two new twin families found on today’s flight were located on Matagorda Island and Welder Flats.

Crane habitat use observed on the census flight:       

• 209 of the 268 cranes observed were in salt marsh habitat.
• 10 were in shallow open bay habitat.
• 8 were on uplands in areas rooted up by feral hogs on Matagorda Island.
• 26 were on uplands with no sign of hog rooting.
• 4 were at a game feeder at Welder Flats.
• 11 were at fresh water sources.

Habitat use by the whooping cranes has changed some over the past week.  A total of 78.0% of the cranes were in salt marsh, whereas the previous week it had been 89.0%.  Upland use observed totaled 34 cranes compared to eight last week, and freshwater use is starting to occur (11 cranes compared to zero last week).  The salinity at a gauge in San Antonio Bay north of Mustang Lake is currently 14.5 parts per thousand (ppt).  Refuge salinities measured on December 6 ranged from 17 to 20 ppt, levels where crane use of fresh water sources starts to be observed.  Blue crabs are still readily available, with 101 crabs counted on a 1,000 meter transect on December 6.  However, the wolfberry crop is nearing an end with only 7 berries and no flowers observed on transects run on December 6.  Tides were also considerably lower this week with exposed mud flats observed on San Jose.  A string of about 100 commercial blue crab traps were noted in the bay edge off of Matagorda Island between Twin lakes and Power Lake.

Tom Stehn, Aransas National Wildlife Refuge

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The first aerial census of the 2010-11 whooping crane season was conducted December 1, 2010 in a Cessna 210 piloted by Gary Ritchey of Air Transit Solutions, Castroville, Texas with USFWS observers Tom Stehn and Brad Strobel. Sighted on the flight were 199 adults and 38 juveniles = 237 total whooping cranes.

December 1 – Recap of whooping cranes (237) found at Aransas:

Flight conditions and visibility were excellent throughout the flight as a low pressure system that had brought howling north winds on November 30 had moved off the coast, followed by clear skies and light southeast winds. With nearly complete coverage of the crane area during the flight, the 237 cranes counted represent an accurate estimate of the number of cranes present.

To date, 38 of the 46 juveniles found in mid-August on the nesting grounds have made it safely to Aransas. The 38 chicks include three sets of “twin” chicks, (adult pairs that have brought two chicks each). Five pairs with two chicks each had been sighted in Canada in August. The third set of “twin” chicks to make it to Aransas had spent 21 days (October 29 – November 18) in Brown County, South Dakota observed nearly daily by Jay Peterson, USFWS District Manager of the Sand Lake Wetland Management District. Jay writes:

“What a treat it was for me to see the birds each time, but it was more rewarding for me to be associated with the folks I took with or gave directions to, who did not have whoopers on their life bird list.”

The last 3 of the 10 radioed whooping cranes completed the migration on November 26th, missing their Thanksgiving feast of blue crabs by one day. All 10 radioed cranes are now at Aransas. With no recent sightings reported north of Oklahoma (as of November 29th), it appears the migration is nearing completion. I have my fingers crossed that 50 more whooping cranes will still arrive since I’m hoping for a peak count greater than 285 this winter.

Crane habitat use observed on the census flight:

211 of the 237 cranes observed were in salt marsh habitat.

18 were in shallow open bay habitat.

5 were on uplands in areas rooted up by feral hogs on Matagorda Island.

3 were on grazed pasture oak savannah uplands at Welder Flats.

The cranes are feeding heavily on blue crabs and wolfberries this fall with both of those food items abundant in November. It is possible that the 18 whooping cranes observed in open bay habitat could also have been foraging on blue crab. The largest group size observed during the census was nine birds seen on refuge salt flats just north of the Pipeline. No cranes were observed at freshwater sources since salinities in San Antonio Bay are 14 parts per thousand, low enough for the cranes to drink water directly from the marsh. However, salinities have been rising (they were 9 ppt one week ago) and the area could use rain. Tides were high on today’s flight with all the tidal flats covered with water on San Jose Island. No commercial blue crab traps were found in the crane marshes or within 100 yards of shore. Only a few abandoned traps were seen in the crane marshes that will be targeted for removal during the annual crab trap pickup in February.

The observed proliferation of black mangrove in the crane marshes on Matagorda Island and at Welder Flats is very disturbing. The mangrove completely replaces the former salt marsh vegetation and excludes forage items used by the whooping cranes including Carolina wolfberry and fiddler crab populations. Many acres of marsh have become completely covered with this native species that is moving north as climate change reduces the number of hard freezes. In the past, hard freezes over multiple days limited the northward spread of mangrove since mangrove can only tolerate short spells of freezing temperatures. The last extended extremely hard freeze at Aransas occurred in 1989.

Happy Holidays

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All books ordered through this link to Amazon will result in a small commission being paid to the Whooping Crane Conservation Association and any money received will be used to help pay for operation of this web page.

Thank you for your support.

This web site is maintained by Business Cornerstone Services

Tim Dellinger checked one of our Florida whooping crane families from the air today (they are not visible from the ground) and discovered they have 2 chicks instead of 1 (as seen on the previous flight). Raising 2 chicks to 15 days of age is a record for this flock. Until now a pair had only raised both of their chicks up to 12 days of age before losing one. This is this pair’s first nest attempt. They will turn 7 years of age next month.
–Marty Folk

The third aerial census of the 2009-10 whooping crane season was conducted December 10, 2009 in a Cessna 210 piloted by Gary Ritchey of Air Transit Solutions of Castroville, Texas with USFWS observer Tom Stehn. Sighted on the flight were 211 adults and 19 juveniles = 230 total. This was an increase of 20 cranes since the previous flight conducted December 2nd. With 230 at Aransas and 8 known to still be in migration, currently 238 whooping cranes can be accounted for. I am expecting up to 22 juveniles based on August fledging surveys done on the nesting grounds by CWS. With that number of juvenile produced, the flock may experience a break-even year with a flock total around 247 expected.

December 10th – Recap of whooping cranes (230) found at Aransas on the aerial:
[TABLE=2]
*Since 6 family groups were present on Matagorda Island on the December 2nd flight, it is possible that one family group was overlooked on today’s flight. However, it is also possible a Matagorda Island family group from N. Power Lake had moved over to N. Shoalwater Bay where there was an additional family on today’s flight.

Migration Update: Cold fronts that reached Aransas on December 4th and 9th helped 20 additional cranes complete their 2,400-mile long migration. Additional cranes are known to still be in migration. Four were present at Quivira NWR on December 7th even though the marshes were about 90% frozen. Four were recently sighted west of Mad Island Preserve in Matagorda County Texas about 40 miles northeast of Aransas. Two cranes that have been staying east of Tivoli about 15 miles north of Aransas were located on today’s flight in the Hynes Bay Unit of the Guadalupe Delta Wildlife Management Area operated by Texas Parks and Wildlife.

Crane Identities: We are not sure if the Lobstick pair has returned this fall. However, 2 cranes that may have been the Lobsticks were sighted on the Lobstick territory on December 9 and 10. If present, the Lobstick male is 31 years old.

Habitat Use: Tides measured at the refuge boat ramp were high (2.7 feet). Salinities currently at 8 parts per thousand in San Antonio Bay have dropped noticeably in November and December so that the cranes are drinking directly from the marsh and have stopped making flights to fresh water dugouts. An extremely heavy rain event on November 20th with some coastal areas getting up to 16 inches has filled refuge dugouts and swales and flooded portions of the uplands on San Jose Island and Welder Flats. Conditions are very wet. Since that rain event, some blue crabs seem to have moved into the marshes, and some cranes have recently been observed catching blue crabs 2-3 inches in size. However, 65 cranes on today’s flight were sighted on uplands. These cranes were mostly foraging on patches of bare ground, some flooded and some dry. This behavior is indicative of a less than optimal food situation for the cranes. Although some wolfberry flowers are still present in the marshes, few berries are present and have stopped making up a significant part of the crane diet. An additional 5 cranes on today’s flight were on a shell road in the uplands. No cranes were at game feeders or in open bay habitat, and there are currently no prescribed burns in the crane area. The largest group size observed was 8 birds seen on the uplands on San Jose accompanied by sandhill cranes. More black mangrove was noted on Ayes and Roddy islands.

Flight Conditions: Visibility was good for most of the flight, but darker overcast at times made for somewhat challenging viewing conditions. Due to limited flight hours, the aircraft was usually kept at 140 knots making it a lively task to find all the cranes. Total flight time was 4.6 hours and we felt a very good count was achieved despite some crane movements that had to be sorted out as cranes moved to and from the uplands.

– Tom Stehn, Aransas National Wildlife Refuge

Tom Stehn, Whooping Crane Coordinator,U.S. Fish and Wildlife Service has prepared a lengthy, detailed report concerning the 2008 – 2009 whooping crane population. The following summary of the report provides much new information. To read the entire report, you may download it by clicking here. The download is a PDF file.

The Aransas-Wood Buffalo population (AWBP) of whooping cranes reached a record population of 270 at Aransas in December, 2008. The number would have been substantially higher but for the loss of 34 birds that left Aransas in the spring, 2008 and failed to return in the fall. Faced with food shortages from an “exceptional” drought that hammered Texas, record high mortality during the 2008-09 winter of 23 cranes (8.5% of the flock) left the AWBP at 247 in the spring, 2009. Total flock mortality for the 12 months following April, 2008 equaled 57 birds (21.4% of the flock). The refuge provided supplemental feed during the 2008-09 winter to provide some cranes with additional calories. Two whooping cranes failed to migrate north, but survived the hot and dry 2009 Aransas summer.

A below-average 2009 production year in Canada with 22 fledged chicks from 62 nests was half the production of the previous summer and is expected to result in a break-even year for the AWBP. Threats to the flock including land and water development in Texas, the spread of black mangrove on the wintering grounds, and wind farm construction in the migration corridor all remained unabated in 2009.

The Cooperative Whooping Crane Tracking Project documented 79 confirmed sightings of whooping cranes in the U.S. Central Flyway during fall, 2008 and 38 sightings in spring, 2009.

The captive flocks had a very good production season in 2009. Twenty-nine chicks were reintroduced into the eastern migratory population, bringing that flock to 106 total birds. Three chicks of high genetic value were held back for the captive flocks.

Production in the wild from reintroduced flocks in 2009 was disappointing. In Florida because of the continuing drought, only 4 of 11 pairs nested and fledged 1 chick. In Wisconsin, all 12 nesting pairs abandoned their nests. Five or 6 pairs re-nested hatching 2 chicks, but neither chick survived. The major hurdle of nest abandonment in Wisconsin must be overcome for that reintroduction to have a chance of success. Although efforts to clear this hurdle should continue, the Recovery Team recommended starting reintroductions in different areas, both looking for other release sites in Wisconsin for the migratory whooping cranes, and starting a nonmigratory flock in Louisiana.

In 2009, total production could not quite keep up with mortality, with the total population of wild and captive birds dropping from 538 to 534 during a12-month period. The drop was primarily due to the high mortality experienced by the AWBP.