From: Tom Stehn
Subject: Aransas migration report - April 4
Date: Fri, 5 Apr 2002 08:27:56 -0600

An aerial census of the Aransas NWR and surrounding areas made 04 April, 2002 estimated the number of whooping cranes present at 137 adults + 12 chicks = 149. The size of the Aransas-Wood Buffalo whooping crane population in spring, 2002 is estimated at 174, with a maximum of 25 cranes having started the migration. An estimated 16 cranes have migrated since the last flight on March 28.

Recap of cranes observed: (147 )

Refuge Lamar San Jose Matagorda Welder Flats Indianola Total

38+5     4+0       23+1       48+5            20+1          2+0      135 + 12 = 147

                               change from March 28 flight

   0         -3          -9            -6                 0                0       151 + 14 = 165

Remarks: Census conditions were a high overcast throughout the day which made it somewhat difficult to find all the cranes. All areas were covered except for northern parts of St. Charles Bay and Heron Flats Marsh.

It is estimated that 16 cranes (2 families, 3 pairs, and 4 subadults) have started the migration since the last flight on March 28. Nine of the 16 departed from San Jose Island.  Extremely strong south winds blew March 30 with a peak gust of 54 mph recorded in Corpus Christi which presumably some of the cranes used to initiate migration. A low pressure system brought north winds to the Texas coast March 31. The Big Tree family group on the Lamar is believed to have migrated approximately April 1 or 2. A total of 25 suabadults were found on today’s flight compared to 31 last week, with six fewer found on the south end of Matagorda Island. Visibility was such that I presumably overlooked at least two of these subadults, thus estimating 149+ cranes were present even though I only tallied 147. On San Jose Island, the crane with an injured left wing was located in a widely separated trio. A single whooping crane confirmed March 20 on the Platte River in Nebraska is believed to still be there.

Unusual Locations: The two "Indianola" cranes were again located in salt marsh on the Alcoa property next to the Myrtle Foster Whitmire Unit of the Aransas NWR west of the town of Indianola. The South Dunham Point pair was on the Big Tree Marsh for the second straight week. Two subadult cranes were located on DA 128, a marsh created with dredged material in 1995 by the Army Corps of Engineers. These two cranes had a dingy grey appearance indicating an ongoing molt of body feathers.

Habitat: Tides have risen with oyster reefs in the bays partially covered and somewhat more than half of the mud flats on San Jose covered with water. South Texas is in a drought, with January-March the 6th driest ever recorded for the area. Current total rainfall for 2002 in Corpus Christi is 0.68 inches, a deficit of 4.74 inches from the norm. Aransas has received a little more rainfall in 2002 than Corpus Christi.