Page 2 This Year's Monarch Population at Lowest Recorded Once every winter, all of the colonies in Mexico are measured. This is done in December, because during the coldest time of year the butterflies are clustered together most tightly. Like a snapshot in time, these annual winter measurements give scientists a chance to estimate the size of the entire over-wintering population. Last month Mexican biologists announced the results for Winter 2000/2001. Here are this winter's measurements, along with data from past years for comparison. The data show the surface area each colony covered, in hectares: Size of Over-Wintering Monarch Population (Monarch Coverage in Hectares) Sanctuary 1994/95 95/96 96/97 97/98 98/99 99/00 00/01 Sierra Chincua 3.48 4.16 7.09 0.73 1.96 0.92 0.77 El Rosario 3.58 4.35 7.61 2.12 2.00 3.78 1.27 Other 3 Sanctuaries* 0.75 4.00 3.17 0.33 1.25 1.27 0.25 TOTAL 7.81 12.51 17.87 3.18 5.21 5.97 2.29 *Note: The "Other 3 Sanctuaries" are Chivati, Cerro Pelon and Altamirano. So that the ears can be compared, we have excluded data from some of the smaller colonies (such as San Andrés, Piedra Herrada, San Fco. Oxtotilpan and Palomas) for which data was not consistently collected every year. Page 1, 2, 3