This is a repository copy of Temporal variation in abundance and diversity of butterflies in Bornean rain forests: opposite impacts of logging recorded in different seasons. White Rose Research Online URL for this paper: https://eprints.whiterose.ac.uk/2522/ Article: Hamer, K C, Hill, J K orcid.org/0000-0003-1871-7715, Mustaffa, N et al. (4 more authors) (2005) Temporal variation in abundance and diversity of butterflies in Bornean rain forests: opposite impacts of logging recorded in different seasons. Journal of Tropical Ecology. pp. 417-425. ISSN 1469-7831 https://doi.org/10.1017/S026646705002361 Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ Journal of Tropical Ecology (2005) 21:417–425. Copyright © 2005 Cambridge University Press doi:10.1017/S0266467405002361 Printed in the United Kingdom Temporal variation in abundance and diversity of butterflies in Bornean rain forests: opposite impacts of logging recorded in different seasons K. C. Hamer∗,1, J. K. Hill†, N. Mustaffa†,‡, S. Benedick†,‡, T. N. Sherratt§, V. K. Chey# and M. Maryati‡ ∗ Earth Biosphere Institute, University of Leeds, UK † Department of Biology, University of York, UK ‡ Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia § Department of Biology, Carleton University, Ottawa, Canada # Forest Research Centre, Sandakan, Sabah, Malaysia (Accepted 3 December 2004) Abstract: We used traps baited with fruit to examine how the temporal variation of butterflies within primary forest in Sabah, Borneo differed between species. In addition, we compared patterns of temporal variation in primary and selectively logged forest, and we tested the hypothesis that selective logging has different recorded impacts on species diversity of adults during the wet monsoon period and the drier remaining half of the year. Species of Satyrinae and Morphinae had significantly less-restricted flight periods than did species of Nymphalinae and Charaxinae, which were sampled mainly during the drier season, especially in primary forest. Species diversity of adults was significantly higher during the drier season in primary forest, but did not differ between seasons in logged forest. As a consequence, logging had opposite recorded impacts on diversity during wetter and drier seasons: primary forest had significantly higher diversity than logged forest during the drier season but significantly lower diversity than logged forest during the wetter monsoon season. The results of this study have important implications for the assessment of biodiversity in tropical rain forests, particularly in relation to habitat disturbance: short-term assessments that do not take account of seasonal variation in abundance are likely to produce misleading results, even in regions where the seasonal variation in rainfall is not that great. Key Words: biodiversity, fruit feeding, Lepidoptera, Nymphalidae, seasonality, selective logging INTRODUCTION the abundance of new foliage (Fensham 1994, Novotny & Basset 1998, Shapiro 1975). In regions with no Herbivorous insects in temperate regions display marked distinct dry season, adult abundance and activity are temporal variation in abundance and activity, mainly generally less variable (Hebert 1980, Wolda & Galindo in response to changes in temperature and photoperiod 1981), although some species still show clear temporal (Speight et al. 1999, Wolda 1988). Such variation also fluctuations in relation to more subtle variations in occurs in the tropics but is more complex and less well rainfall and host-plant dynamics (see Didham & Springate understood, although it is clear that rainfall rather than 2003 and Wolda 1988 for reviews, Hill et al. 2003). temperature or photoperiod is more important (Fensham Inadditiontobeingrelatedtoecologicalcharacteristics, 1994, Louton et al. 1996). In tropical regions with distinct the degree of temporal variation displayed by species wetanddryseasons,manyinsectspeciesattainmaximum is also likely to be constrained by phylogeny. Within adult abundance during the wet season, probably in the family Nymphalidae, the subfamilies Satyrinae and response to changes in plant physiology and growth Morphinae are regarded as being very closely related, (Didham & Springate 2003, Wolda 1989), in particular forming a single clade, with the subfamilies Nymphalinae and Charaxinae forming a separate grouping along with the mainly neotropical Heliconiinae and Calinaginae 1Corresponding author. Earth Biosphere Institute, School of Biology, (Ackery 1984, Parsons 1999). Species of Satyrinae and University of Leeds, Leeds LS2 9JT, UK. Email: [email protected] Morphinae have narrower geographical distributions on 418 K. C. HAMER ET AL. average than species of Nymphalinae and Charaxinae light in primary forest could be used to predict responses (Hamer et al. 2003) and also differ in their host plants to selective logging and thus explain changes in species (Robinson et al. 2001). They may additionally differ in diversity within rain forest in relation to habitat their patterns of temporal variation, for instance as a disturbance. However it was not known how temporal result of phylogenetic variation in host-plant dynamics variation in abundance differed between species, or (Didham & Springate 2003) but this has not previously whether responses of species to selective logging differed been examined. between seasons. Differences among species in the pattern of tempo- In this paper we examine the temporal variation in ral variation in abundance could have important impli- adult abundance of butterfly species, we compare patterns cations for comparisons of the diversity and faunal of temporal variation in primary and selectively logged composition of species assemblages between natural and forest, and we test the hypothesis that selective logging disturbed habitats in different seasons. This may be a has different impacts on species diversity during different particular problem if habitat disturbance affects patterns seasons of the year. of temporal variation, for instance due to changes in host-plant dynamics or species composition (Didham & Springate 2003). Such problems are likely to be espe- METHODS cially important in tropical regions, where very high species diversity coupled with practical and financial Study site and butterfly sampling constraints on biodiversity sampling have resulted in increasing emphasis on short-term rapid surveys (e.g. Fieldwork took place within the Danum Valley Jones & Eggleton 2000, Kitching et al. 2001). For in- Conservation Area (DVCA) and the Ulu Segama Forest stance,tropicalbutterflieshavebeenshowntobesensitive Reserve, Sabah (5◦N, 117◦50′ E; details of sites in Marsh to seasonal changes in rainfall (Braby 1995, Hill et al. & Greer 1992). The DVCA covers approximately 428 km2 2003) but there have been few quantitative descriptions of unlogged lowland evergreen rain forest and is of community-wide patterns of butterfly seasonality in surrounded by extensive areas of production forest, tropical rain forests (DeVries et al. 1999, Owen & Chanter most of which have been selectively logged. During the 1972) and it is not known whether disturbance has 1980s, logging methods in the study area followed a different impacts on butterfly assemblages in different modified uniform system (Whitmore 1984) in which all seasons. commercial stems > 0.6 m diameter were removed using Within South-East Asia, the greatest impact of habitat high lead cable and tractor extraction methods. Tempe- disturbance is on forests in the Malay Archipelago, rature at the study area (annual mean = 26.7 ◦C) is including the island of Borneo. In the Malaysian state typical of the moist tropics (Walsh & Newbery 1999). of Sabah (northern Borneo), most remaining forest Rainfall is usually > 100 mm every month (as is typical is reserved as production forest and designated to of evergreen rain forest; Whitmore 1991) but there is be selectively logged at regular intervals of 30–60 y nonetheless regular seasonal variation, with significantly (Whitmore 1991). By the end of 2010, all remaining higher rainfall occurring during the northerly monsoon forest that is not within conservation areas is likely to period (October–January, in some years extending into have been selectively logged at least once, and there is September and February; mean = 255.1 mm mo−1,SD± increasing pressure on remaining areas of forest as timber 40.5, n = 6 mo), than during the remaining half of the resources run out. year (March–August; mean = 189.7 mm mo−1,SD± Butterfly assemblages on Borneo are diverse (c. 1000 38.0, n = 6 mo; t-test using equal variance estimate; t10 = species; Otsuka 1988) with many endemic species depen- 2.88, P = 0.02; data are monthly means for the period dent on closed-canopy forest (Beck & Schulze 2000, 1985 to 1998, from Table 2 in Walsh & Newbery 1999). Collins