What Are the Reasons That the Checkerspot Butterfly Population Is Declining?

With an ever increasing human population, the critical grassland environments of many butterfly species are being destroyed throughout the western United States. These environments contain the various plant material required for checkerspot survival and while the species are somewhat adaptable, they can only alter their diet so much. Industrialization and commercial crop production lead to an increase in nitrogen rich soil, potentially introducing non-native species.

Invasive and non-native species can be detrimental to native populations. Not only do they have the potential to wipe out native plants, the plants checkerspot butterflies have evolved to feed on, but they may also be damaging or poisonous to the butterflies themselves. Over time, these invasive species have the capability to overhaul the ecosystem in which they invade (ie. change soil quality, air quality and temperature).

Commercial crops supply humans with the vast majority of food products and any loss can be quite costly. However, insecticides and chemicals used have their own cost when it comes to surrounding natural butterfly populations. Checkerspot butterflies are negatively affected by these chemicals and may have trouble reproducing or surviving. This is of particular importance as these butterflies only mate annually, following plant growth cycles to ensure greater survival.

Unfortunately, as this decline continues, it is less likely the checkerspot butterflies will be able to recover without intervention. Populations are too small and too distant to expect natural migration and mating between populations. Assisted migration or translocation may be necessary to introduce new individuals and greater biodiversity to each population with the hopes of greater survival in these altered conditions.