April 01, 1999

TO: Division of Endangered Species, USFWS, Albuquerque, NM

FROM: Whooping Crane Coordinator, Aransas NWR, Austwell, Texas

SUBJECT:  Whooping Crane Census at Aransas

An aerial census of the Aransas NWR and surrounding areas made 4/01/99 revealed the presence of 122 adults and 15 young = 137 whooping cranes.  The flight was made in charter aircraft with Tom Stehn as observer and Tom Taylor, pilot.  Peak population this winter was 165+18=183.

Recap of cranes observed: (137)

  Refuge   Lamar   San Jose   Matagorda  Welder  Other      Total
   43+3     2+1      24+3       40+4      13+4          122+15=137

Remarks:   Visibility was good in the morning but deteriorated by afternoon.  Since the previous flight on March 25, an estimated 25+2=27 cranes have started the migration, including two family groups, six adult pairs, and nine subadults.  This spring, an estimated 3 out of 18 families (17%), 12 of 33 adult pairs (36%), and 13 of 63 subadults (21%) have migrated, a total of 46 of 183 cranes (25%).

In the past week, cranes started the migration from the following wintering areas; Refuge (4), Lamar (0), San Jose (10), Matagorda (13), and Welder (0).  This was a different pattern from the March 25 flight when zero cranes had departed from San Jose or Matagorda.

Interesting locations included the following;

Many of the cranes were in saltmarsh vegetation on relatively dry substrate.  This same pattern was first observed last week.  The Big Tree family was far from their territory in saltmarsh at the northeast end of Copano Bay north of Holiday Beach.  The previous two flights, they were located in marshes south of Holiday Beach, indicating a continued pattern of wandering from their usual territory.  This pattern has been documented in late winter for the past few years.  Adult female RwR-YbY was still again closely associated with two other birds.