1996 was not the year that Red Admirals caught the attention of counters. Unlike 2001 (see last issue's column about the biggest Red Admiral boom in the count program), 1996 had the lowest percentage of Red Admiral presence on counts north of Mexico (40%), since records like this started being kept in 1982. By contrast, in 2001, 78% of counts recorded Red Admiral.

     This map shows the relative abundance of Red Admirals on 1996 counts, which were held from January 3 to November 27, as individuals per party-hour per count. (Party-hours = total hours of observation summed for all parties, or groups, of counters on a count.) These "observation rates" of Red Admirals per hour of counting make it possible to compare relative abundance among counts. For example, two counts might report 10 Red Admirals. But if one count had 5 party-hours and the other had 50 party-hours, then Red Admirals were relatively more abundant in the places counted in the first count circle (2 per party-hour) than in the second (0.2 per party-hour).

     1996 was also significant for the relatively contracted geographic scope of Red Admirals over the continent. They were recorded in Canada in southern Ontario and southern British Columbia, but not in Alberta, Saskatchewan, or Nova Scotia. In 2001 (see map in previous column, also posted on the NABA website: www.naba.org), Red Admirals were recorded on even the northernmost counts in all those provinces. Likewise, in 1996, Red Admirals occurred no further south in Texas than the northern tier of counts. In 2001, Red Admirals extended down the coast to northern Mexico. To put this1996 bust into perspective, the next column will show a "typical" year-1998 (61% presence of Red Admirals on counts).

     The experience on a given count could be quite different from prevailing regional and continental patterns, because of habitat, timing of count date relative to timing of the Red Admiral life cycle, and local variation in butterfly abundance. The more counts in the program, the better the continental picture the count program can portray!

Copyright © 2002 by the North American Butterfly Association, Inc. All rights reserved.