Butterfly diversity, habitat and vegetation usage in Hong Kong urban parks

Abstract

The conservation value of urban parks for butterfly communities remains poorly understood, particularly for tropical butterflies in Asia. We conducted point count and route transect butterfly surveys, and used them to sample four habitats located within 13 urban parks across Hong Kong. We found 1054 individuals and 58 species of butterflies recorded in 60 survey hours over 6 months. This represents approximately one quarter of the entire known Hong Kong butterfly species list. Over 30 % of the individuals counted were Catospilia sp. but six of the species identified are classified locally as rare or very rare. Tree-covered habitats and grasslands showed higher butterfly diversity than open areas. The most common butterfly behavior was Bdirected flight,^which we also found to be habitat-dependent and most common in ponds and open areas. We additionally observed the use of vegetation in urban parks, which included 40 species of nectar plant and four records of butterfly oviposition. The high butterfly diversity, presence of rare species and usage of vegetation (especially as a nectar resource) we documented in this study suggests that urban parks have some conservation value for Hong Kong. However, the use of pesticides and heavy vegetation clearing may limit significant butterfly reproduction and population growth. Altogether these results emphasize the diversity of uses of urban parks for butterflies in Hong Kong while also providing possible directions for improvement in habitat and vegetation management that could increase urban park value for biodiversity.

Can butterflies cope with city life? Butterfly diversity in a young megacity in southern China

“…Our study is consistent with others in suggesting that to promote urban butterfly diversity it is necessary to make urban parks as large as possible and to set aside area of parks as "unmanaged" or with limited human management (Giuliano et al 2004). In those areas where management is necessary, planting native butterfly host and nectar plants is the optimal management strategy (Tam and Bonebrake 2015).…”

“…Three quarter of these species (74%) were classified as common. This is similar to the findings from Guangzhou where 70% of the species sampled in urban green spaces were common (Li et al 2009), and Hong Kong where 79% of the species recorded in urban parks were common (Tam and Bonebrake 2015). In contrast, in Kuala Lumpur, Malaysia, 97% of the butterfly species sampled in urban parks were considered common species with good dispersal abilities (Sing et al 2016).…”

“…Li and colleagues (2009) sampled 73 species during an intensive study (May 2005-December 2006 across four different sites with various degrees of human disturbance in Guangzhou (approximately 100 km from Shenzhen), but only 43 species were collected in the urban center. Tam and Bonebrake (2015) reported 58 species (June-November 2013) across 13 urban parks in Hong Kong (approximately 27 km from Shenzhen).…”

“…Unmanaged areas, often with a high diversity and quality of (often native) early-successional plants, provide suitable foraging habitat for butterflies (Swanson et al 2011;Chong et al 2014). Alternatively, intensively managed sites, such as those frequently mowed, are reported to sustain low populations and abundance of butterflies due to destruction of potential host plants and foraging patches (Stock et al 2003;Tam and Bonebrake 2015). Our study is consistent with others in suggesting that to promote urban butterfly diversity it is necessary to make urban parks as large as possible and to set aside area of parks as "unmanaged" or with limited human management (Giuliano et al 2004).…”

Does Nature Need Cities? Pollinators Reveal a Role for Cities in Wildlife Conservation

“…Indeed, populations of many species are reappearing in force across urban spaces-from fishers (LaPoint et al, 2015) and coyotes (Morey et al, 2007) to bullfinches (Audet et al, 2016) and peregrines (Caballero et al, 2016). Other urban wildlife dwellers include migratory species of birds, dragonflies and butterflies that rely on habitat patches in cities to move through landscapes dominated by large-scale agriculture (Seewagen et al, 2011;Goertzen and Suhling, 2013;Tam and Bonebrake, 2016). Significantly, several American cities support a higher diversity of native bee species-including the endangered rusty patched bumble bee (Bombus affinis)-than do adjacent rural areas (Hall et al, 2017;U.S.…”