Africa witnessing decline in butterfly population

ECC Champion

Biodiversity loss is one of the most pressing issues facing the planet. Insects are a vital component of biodiversity because they comprise over half of the world’s terrestrial species, excluding eubacteria, archaea, and viruses.

An observational analysis by EnviroPress reviewed that butterfly population in the country is declining and very few people are taking notice.

The causes of the decline of butterflies are thought to be similar in most countries, mainly habitat loss, degradation and chemical pollution. Climate change is allowing many species to spread northward while bringing new threats to susceptible species.

Butterflies play important roles in the functioning of ecosystems: for example, as pollinators or food for other animals.

In recent years, evidence has grown about the decline of terrestrial insects across the world and the possibility of ecosystem collapse.

The factors causing the decline of butterflies fall into three main categories: habitat loss/degradation, chemical pollution, and climate change (the latter having both positive and negative effects, depending on the species and region).

Without doubt, the most serious cause of butterfly decline has been habitat loss and degradation.

A major driving force behind these losses has been the expansion of intensive agriculture, which has led to plowing of grasslands for arable crops, and the reseeding and/or fertilization of pastures and other habitats.

One consequence of widespread habitat loss and degradation is that remaining habitats tend to be relatively small and isolated.

Populations breeding in such areas are more likely to become extinct, either through normal stochastic processes or by inbreeding depression.

Habitat fragmentation is now a serious concern for many butterflies, especially sedentary habitat specialists.

Chemical pollution covers a wide variety of substances that adversely influence butterflies and their habitats. The most obvious are insecticides, which are routinely sprayed on arable crops to reduce damage by insects and other organisms.

According to National Geographic, 450 butterfly species are rapidly declining due to warmer weather.

There are an estimated 660 species of butterflies in South Africa, with 52% endemic to the region. The Southern African Lepidoptera Conservation Assessment’s latest report says this means extinctions in the butterfly taxonomy in the country often mean a global extinction of that species.

A four-year study by the Southern African Butterfly Conservation Assessment found that three of the country’s butterflies were now extinct, and a further 60 species and subspecies were threatened with extinction.

Thirteen butterfly species became more threatened in the period between 2013 and 2018, according to the South African National Biodiversity Institute.

This report was made possible through support from WAN-IFRA Media Freedom’s Strengthening African Media Programme: Climate Change and Environmental Reporting. Views expressed here do not belong to WAN-IFRA