Lipids Mass of Monarch Butterflies*
(in milligrams)
Month

Butterflies
in Clusters

Butterflies
at Flowers

Nov

138

 

Dec

128

53

Jan

101

23

Feb

73

21

Mar

58

21

Apr

26

 

* Based on butterflies collected at the Mexican overwintering sites by many researchers over serveral years at different times during the overwintering months. Exception: April data, in red above, were butterflies collected in the southern United States after successfully migrating from Mexico.

From: Alonso-Mejia, A., E Rendon-Salinas, Brower, L.P. 1997. Use of lipid reserves by monarch butterflies overwintering in Mexico: Implications for conservation. Ecological Applications, 7(3), 1997, pp 934-947.