Researchers in a press conference, in Mexico City on Friday, said that the Monarch Butterfly covered nearly 4 hectares of forest this last december, a more than 3 fold improvement from the 1.13 hectares covered the previous december.

The Monarch Butterfly were recorded at a record low while in their winter grounds in Central Mexico in 2013-1014. Their numbers are measured in Hectares as they clump together so densely in would be impossible to count individuals, and when they were at their lowest they only spanned 0.67 Hectares. Down significantly from when they consistently covered at least 8 hectares in the 80’s and 90’s, peaking at about 18 hectares 20 years ago.

The Monarch populations began their steady decline during the introduction of herbicide resistant crops. The herbicides that then werebeginning to be used killed off the Milkweed plant which the butterflies not only feed on, but exclusively lay their eggs on.

Efforts by the US to reintroduce Milkweed within the next 5 years, planting nearly 100,000 hectares already, and designate pesticide free areas has helped the populations begin to recover. But a recent surge of illegal logging within the Monarch’s winter grounds in Central Mexico has posed a new threat by reducing the canopy coverage they need to shelter from the elements.