Summer Butterflies


Beauty at its Peak
A wide diversity of butterfly species abound during the warm summer months. It may seem as though we are seeing the same butterflies over and over in our east bay parks, but the reality is more complicated and interesting. Most adult butterflies live two to three weeks at most. With common small species, the first females to emerge in spring or early summer lay eggs that will soon hatch. The caterpillars grow rapidly and pupate, and another batch of adults appear. This means there may be three or more generations in these warm summer months.

Climate Impacts
There has been a decline in butterfly populations, particularly at lower elevations. Some Bay Area species have already gone extinct while others are threatened. The reasons for their decline are complex. Shorter summers often mean fewer generations of butterflies.

Helping From Home
While planting native milkweeds can be extremely beneficial to monarch butterflies, planting non-native milkweeds may do more harm than good. Non-native milkweed species may act as a physiological trap for monarchs during the fall and spring migrations. Choosing to grow plants native to your region will encourage normal monarch migration patterns and contribute to their natural life cycles. Visit to discover which milkweed species are native.

Activities to Attract Wildlife 

• Create a bat box
• Make a bee or butterfly ‘bath’ by putting rocks and water in a shallow dish
• Grow native plant species
• Use pesticide alternatives like diluted soaps and natural plant oils, like cedar oil, to deter pests

Jen Vanya, Public Information Specialist