Butterfly Biodiversity at Iracambi – A preliminary study

Lizzie Coleman

INTRODUCTION

• In order to effectively conserve its forests, it is necessary for any conservation organization to acquire a deeper understanding of the biodiversity of species living within the rainforest, and how these species interact.
• The Atlantic Rainforest is home to 2124 species of butterfly, two thirds of Brazil's butterflies and one eighth of the world's butterfly fauna.
• Like all insects, butterflies are essential members of the forest community. They play an important role in the pollination of flowers and both butterflies and caterpillars are vital food sources for animals such as birds. Butterflies are also highly sensitive creatures and are an important indicator species.

OBJECTIVES

1. To investigate the biodiversity of butterflies at Iracambi during the summer, building on a biodiversity study that was conducted in 2001 during the winter months of June and July. At that time approximately 100 butterfly species were either collected and identified or observed. Butterflies are more active during the summer (November-February) when peak breeding occurs so a biodiversity study at this time is also necessary.
2. To map the distribution of species at Iracambi.
3. To collect caterpillars with host plants and observe pupation and development into a butterfly, taking photos at each stage, thus establishing a link between host plant, caterpillar and butterfly.
4. Create a ´butterfly fact file´ with pictures and text to aid subsequent research.

METHODOLOGY

The trails that cover the Iracambi estate were used as the basis for the study area. Butterflies were caught using a net constructed from mosquito netting and bamboo. The specimens were then transferred into a jar and euthanised using cotton balls soaked in formaldehyde. The upper side and the underside of the butterflies were then photographed and two measurements were taken, the wingspan and the wing width. The pictures were then used to identify the family genus and species.

Several caterpillars were also caught and stored in a jar covered with cheesecloth. The host plant (or the plant that the caterpillar was found on) was collected with the caterpillar and placed in the jar; fresh host plants were added to the jars every day.

RESULTS

Twenty-seven different species of butterfly were identified at Iracambi during this study.

Species representing all five families of butterfly were identified with the Nymphalids being the most abundant followed by the Pierids, the Hispierids, the Lycaenids and then the Papilionids.

DISCUSSION

The diversity of species captured was less than that caught during the winter months and was considerably lower than expected. However this may have been due to the relatively short period that this study was conducted over and the fact that many species of butterfly were extremely difficult to catch, than to any actual biological phenomenon.

The species of butterfly at Iracambi caught during November also differed greatly from the species of butterfly captured during June and July. Only 7 of the 27 species recorded are present at both times of year. Further study is necessary in order to eliminate experimental design as a causal factor for this trend.

Research has shown that many of the butterflies identified and observed require specific habitat types. A significant number of the butterflies (13 of the 27 species) were caught on a path that traverses several different habitat types indicating the importance of preserving habitat diversity at Iracambi.

RECOMMENDATIONS

More extensive studies on the biodiversity of butterflies at Iracambi are needed to complete the species list. A comparative study is also necessary to draw any conclusions regarding the biodiversity level at Iracambi. Further investigation into the role of butterflies as pollinators of crops specific to the Iracambi area, such as coffee, is also required. Recent studies have shown that crops grown near to forested areas where there is an abundance of pollinator species results in higher yields and higher quality crops. Developing methods to increase the abundance of specific butterfly pollinators could serve the dual role of benefiting the local farmers and increasing local butterfly populations.