Abundance, richness and behaviour of Hong Kong butterflies in butterfly gardens

Abstract

Hong Kong, which is located within the tropics, has one of the highest proportions of country park area in Asia-Pacific region, and there are 260 species of butterflies found in this city. However, urbanization is expanding all over the world including Hong Kong, which would cause loss of habitats and vegetations needed for butterflies. Butterfly gardens help to conserve the butterflies by providing rich and stable nectar resources for butterflies. There are plenty of butterfly gardens scattered in Hong Kong. However, there has been no research about the butterfly diversity within the butterfly gardens in Hong Kong, and also their behaviour. In this study, butterfly diversity and behaviour were investigated in 10 butterfly gardens in Hong Kong. Also, the variables including nectar plants, host plants, proximity from habitat for conservation and from the urban developed area are statistically analysed to see if they would affect both butterfly diversity and behaviours in butterfly gardens. Results revealed that there are fair richness and abundance in the butterfly gardens. Most butterflies were showing flying behaviour in the butterflies gardens, followed by feeding behaviour. However, there was a scarce observation of oviposition behaviour. The increase of nectar flower abundance significantly increased both butterfly abundance and richness, including those which were feeding. A close proximity from habitat for conservation also significantly increased the general butterfly richness and both richness of abundance of butterflies that were feeding. The host plant richness only affected the butterfly richness positively. Interestingly, the close proximity from the main urban area resulted in an increase of butterfly abundance, and abundance of richness of butterflies that were feeding. Also, the decrease in the proportion of host plant cover increased both butterfly abundance and richness. It showed that both local and landscape variables of butterfly gardens affects butterfly diversity and their feeding behaviour. By studying the local and landscape variables effect in butterfly gardens diversity, measures to optimize the plantings and design of butterfly gardens, even some similar habitat types such as urban parks or other garden types, could be made accordingly and maximize the conservation effort of butterflies in this urbanized city.