TY - JOUR TI - Beyond biomass: measuring the effects of community‐level nitrogen enrichment on floral traits, pollinator visitation and plant reproduction AU - Burkle, Laura A. AU - Irwin, Rebecca E. T2 - Journal of Ecology AB - Summary 1. Nitrogen (N) limits primary productivity in many systems and can have dramatic effects on plant–herbivore interactions, but its effects on mutualistic interactions at the community level are not well‐understood. The reproduction of many plants depends on both soil N and pollination, and N may affect floral traits, such as flower number or size, which are important for pollinator attraction to plant individuals and communities. 2. Thus, N may influence plant biomass and reproduction directly as well as indirectly via changes in pollination. The degree to which the effects of N enrichment scale from plant individuals to assemblages through emerging community‐level changes in species interactions, like pollination, is relatively unknown. 3. For 4 years, we tested how N addition to subalpine plant assemblages in Colorado, USA, affected primary productivity and species diversity, floral traits and plant–pollinator interactions, and components of female and male plant reproduction. 4. At the community level, we found that high‐N addition favoured the biomass and seed production of grasses, whereas low‐N addition promoted forb growth, flower production and pollinator visitation. However, using a pollen supplementation experiment, we found no evidence that N addition altered patterns of pollen limitation of seed production. Pollinators distributed themselves evenly across floral resources such that per‐flower visitation rate did not differ among N treatments. Thus, individual plants did not incur any extra benefit or cost from community‐level changes in plant–pollinator interactions that resulted from N enrichment, and the effects of N on forb reproduction were direct. 5. Synthesis . Understanding how mutualistic and antagonistic species interactions influence individual and community responses to abiotic resources may provide insight to the dominant forces structuring communities and is especially important in the context of predicting the effects of environmental change. In this case, the direct effects of N addition on plants were stronger than the indirect effects mediated through plant–pollinator interactions, thus supporting the concept of bottom‐up resource limitation controlling plant response. DA - 2010/4/20/ PY - 2010/4/20/ DO - 10.1111/j.1365-2745.2010.01648.x VL - 98 IS - 3 SP - 705-717 J2 - Journal of Ecology LA - en OP - SN - 0022-0477 1365-2745 UR - http://dx.doi.org/10.1111/j.1365-2745.2010.01648.x DB - Crossref ER - TY - JOUR TI - Nectar Robbing: Ecological and Evolutionary Perspectives AU - Irwin, Rebecca E. AU - Bronstein, Judith L. AU - Manson, Jessamyn S. AU - Richardson, Leif T2 - Annual Review of Ecology, Evolution, and Systematics AB - Not all floral visitors attracted to flowers are pollinators. Instead, some visitors circumvent the floral opening, usually removing nectar without contacting the anthers and/or stigma. Here we review the evolutionary ecology of nectar robbing from both the plant and animal perspective. Effects of robbing on female and male components of plant reproduction range from negative to positive. Their underlying mechanisms are diverse, including direct effects and indirect effects mediated through changes in pollination. We detail how plants may be able to deter robbers through morphological and chemical traits. For the evolutionary ecology of robbing to move beyond a phytocentric perspective, studies must also address the causes of robbing and the consequences for both robbers and pollinators. We use an energetics approach to evaluate these causes and consequences. Finally, we highlight unanswered questions in need of further research. DA - 2010/12/1/ PY - 2010/12/1/ DO - 10.1146/annurev.ecolsys.110308.120330 VL - 41 IS - 1 SP - 271-292 J2 - Annu. Rev. Ecol. Evol. Syst. LA - en OP - SN - 1543-592X 1545-2069 UR - http://dx.doi.org/10.1146/annurev.ecolsys.110308.120330 DB - Crossref ER - TY - JOUR TI - Diet of age-0 tarpon (Megalops atlanticus) in anthropogenically-modified and natural nursery habitats along the Indian River Lagoon, Florida AU - Jud, Zachary R. AU - Layman, Craig A. AU - Shenker, Jonathan M. T2 - Environmental Biology of Fishes DA - 2010/11/3/ PY - 2010/11/3/ DO - 10.1007/s10641-010-9734-6 VL - 90 IS - 3 SP - 223-233 J2 - Environ Biol Fish LA - en OP - SN - 0378-1909 1573-5133 UR - http://dx.doi.org/10.1007/s10641-010-9734-6 DB - Crossref KW - Dietary plasticity KW - Habitat fragmentation KW - Mosquito control impoundments KW - Optimal foraging KW - Predator-prey interactions KW - Mangrove marsh restoration ER - TY - JOUR TI - Simple ecological trade-offs give rise to emergent cross-ecosystem distributions of a coral reef fish AU - Grol, Monique G. G. AU - Nagelkerken, Ivan AU - Rypel, Andrew L. AU - Layman, Craig A. T2 - Oecologia AB - Ecosystems are intricately linked by the flow of organisms across their boundaries, and such connectivity can be essential to the structure and function of the linked ecosystems. For example, many coral reef fish populations are maintained by the movement of individuals from spatially segregated juvenile habitats (i.e., nurseries, such as mangroves and seagrass beds) to areas preferred by adults. It is presumed that nursery habitats provide for faster growth (higher food availability) and/or low predation risk for juveniles, but empirical data supporting this hypothesis is surprisingly lacking for coral reef fishes. Here, we investigate potential mechanisms (growth, predation risk, and reproductive investment) that give rise to the distribution patterns of a common Caribbean reef fish species, Haemulon flavolineatum (French grunt). Adults were primarily found on coral reefs, whereas juvenile fish only occurred in non-reef habitats. Contrary to our initial expectations, analysis of length-at-age revealed that growth rates were highest on coral reefs and not within nursery habitats. Survival rates in tethering trials were 0% for small juvenile fish transplanted to coral reefs and 24-47% in the nurseries. As fish grew, survival rates on coral reefs approached those in non-reef habitats (56 vs. 77-100%, respectively). As such, predation seems to be the primary factor driving across-ecosystem distributions of this fish, and thus the primary reason why mangrove and seagrass habitats function as nursery habitat. Identifying the mechanisms that lead to such distributions is critical to develop appropriate conservation initiatives, identify essential fish habitat, and predict impacts associated with environmental change. DA - 2010/11/12/ PY - 2010/11/12/ DO - 10.1007/s00442-010-1833-8 VL - 165 IS - 1 SP - 79-88 J2 - Oecologia LA - en OP - SN - 0029-8549 1432-1939 UR - http://dx.doi.org/10.1007/s00442-010-1833-8 DB - Crossref KW - Connectivity KW - Life history traits KW - Predator-prey dynamics KW - Nursery KW - Ontogenetic niche shifts ER - TY - JOUR TI - Variation in the phenology and abundance of flowering by native and exotic plants in subalpine meadows AU - Wilke, Brook J. AU - Irwin, Rebecca E. T2 - Biological Invasions DA - 2010/// PY - 2010/// DO - 10.1007/s10530-009-9649-3 VL - 12 IS - 7 SP - 2363–2372 SN - 1387-3547 1573-1464 UR - http://dx.doi.org/10.1007/s10530-009-9649-3 ER - TY - JOUR TI - Evolutionary Ecology: When Pollinators Are Also Herbivores AU - Irwin, Rebecca E. T2 - Current Biology AB - Plants often face a dilemma in attracting mutualists versus deterring antagonists. This dilemma may be exceptionally challenging when the mutualist and antagonist are the same visitor. It has now been demonstrated how plants can resolve this conflict through a novel change in flowering traits. DA - 2010/2// PY - 2010/2// DO - 10.1016/j.cub.2009.12.005 VL - 20 IS - 3 SP - R100-R101 J2 - Current Biology LA - en OP - SN - 0960-9822 UR - http://dx.doi.org/10.1016/j.cub.2009.12.005 DB - Crossref ER - TY - JOUR TI - Restoration of genetic connectivity among Northern Rockies wolf populations AU - Hebblewhite, Mark AU - Musiani, Marco AU - Mills, L. Scott T2 - MOLECULAR ECOLOGY AB - Probably no conservation genetics issue is currently more controversial than the question of whether grey wolves (Canis lupus) in the Northern Rockies have recovered to genetically effective levels. Following the dispersal-based recolonization of Northwestern Montana from Canada, and reintroductions to Yellowstone and Central Idaho, wolves have vastly exceeded population recovery goals of 300 wolves distributed in at least 10 breeding pairs in each of Wyoming, Idaho and Montana. With >1700 wolves currently, efforts to delist wolves from endangered status have become mired in legal battles over the distinct population segment (DPS) clause of the Endangered Species Act (ESA), and whether subpopulations within the DPS were genetically isolated. An earlier study by vonHoldt et al. (2008) suggested Yellowstone National Park wolves were indeed isolated and was used against delisting in 2008. Since then, wolves were temporarily delisted, and a first controversial hunting season occurred in fall of 2009. Yet, concerns over the genetic recovery of wolves in the Northern Rockies remain, and upcoming District court rulings in the summer of 2010 will probably include consideration of gene flow between subpopulations. In this issue of Molecular Ecology, vonHoldt et al. (2010) conduct the largest analysis of gene flow and population structure of the Northern Rockies wolves to date. Using an impressive sampling design and novel analytic methods, vonHoldt et al. (2010) show substantial levels of gene flow between three identified subpopulations of wolves within the Northern Rockies, clarifying previous analyses and convincingly showing genetic recovery. DA - 2010/10// PY - 2010/10// DO - 10.1111/j.1365-294x.2010.04770.x VL - 19 IS - 20 SP - 4383-4385 SN - 1365-294X KW - conservation genetics KW - dispersal KW - Endangered Species Act KW - gene flow KW - Northwestern United States KW - wolf re-introduction ER - TY - JOUR TI - Ranking Mahalanobis Distance Models for Predictions of Occupancy From Presence-Only Data AU - Griffin, Suzanne C. AU - Taper, Mark L. AU - Hoffman, Roger AU - Mills, L. Scott T2 - JOURNAL OF WILDLIFE MANAGEMENT AB - ABSTRACT The Mahalanobis distance statistic (D 2 ) has emerged as an effective tool to identify suitable habitat from presence data alone, but there has been no mechanism to select among potential habitat covariates. We propose that the best combination of explanatory variables for a D 2 model can be identified by ranking potential models based on the proportion of the entire study area that is classified as potentially suitable habitat given that a predetermined proportion of occupied locations are correctly classified. In effect, our approach seeks to minimize errors of commission, or maximize specificity, while holding the omission error rate constant. We used this approach to identify potentially suitable habitat for the Olympic marmot ( Marmota olympus ), a declining species endemic to Olympic National Park, Washington, USA. We compared models built with all combinations of 11 habitat variables. A 7‐variable model identified 21,143 ha within the park as potentially suitable for marmots, correctly classifying 80% of occupied locations. Additional refinements to the 7‐variable model (e.g., eliminating small patches) further reduced the predicted area to 18,579 ha with little reduction in predictive power. Although we sought a model that would allow field workers to find 80% of Olympic marmot locations, in fact, <3% of 376 occupied locations and <9% of abandoned locations were >100 m from habitat predicted by the final model, suggesting that >90% of occupied marmot habitat could be found by observant workers surveying predicted habitat. The model comparison procedure allowed us to identify the suite of covariates that maximized specificity of our model and, thus, limited the amount of less favorable habitat included in the final prediction area. We expect that by maximizing specificity of models built from presence‐only data, our model comparison procedure will be useful to conservation practitioners planning reintroductions, searching for rare species, or identifying habitat for protection. DA - 2010/7// PY - 2010/7// DO - 10.2193/2009-002 VL - 74 IS - 5 SP - 1112-1121 SN - 0022-541X KW - habitat model KW - Mahalanobis distance KW - Marmota olympus KW - Olympic marmot KW - Olympic National Park KW - presenceonly data ER - TY - BOOK TI - Procedures for implementing small mammal inventories in Bhutan AU - Foresman, K. R. AU - Mills, L.S. AU - Phurba DA - 2010/// PY - 2010/// PB - Bhutan: Ugyen Wangchuck Institute for Conservation and the Environment ER - TY - JOUR TI - Population-specific vital rate contributions influence management of an endangered ungulate AU - Johnson, Heather E. AU - Mills, L. Scott AU - Stephenson, Thomas R. AU - Wehausen, John D. T2 - ECOLOGICAL APPLICATIONS AB - To develop effective management strategies for the recovery of threatened and endangered species, it is critical to identify those vital rates (survival and reproductive parameters) responsible for poor population performance and those whose increase will most efficiently change a population's trajectory. In actual application, however, approaches identifying key vital rates are often limited by inadequate demographic data, by unrealistic assumptions of asymptotic population dynamics, and of equal, infinitesimal changes in mean vital rates. We evaluated the consequences of these limitations in an analysis of vital rates most important in the dynamics of federally endangered Sierra Nevada bighorn sheep ( Ovis canadensis sierrae ). Based on data collected from 1980 to 2007, we estimated vital rates in three isolated populations, accounting for sampling error, variance, and covariance. We used analytical sensitivity analysis, life‐stage simulation analysis, and a novel non‐asymptotic simulation approach to (1) identify vital rates that should be targeted for subspecies recovery; (2) assess vital rate patterns of endangered bighorn sheep relative to other ungulate populations; (3) evaluate the performance of asymptotic vs. non‐asymptotic models for meeting short‐term management objectives; and (4) simulate management scenarios for boosting bighorn sheep population growth rates. We found wide spatial and temporal variation in bighorn sheep vital rates, causing rates to vary in their importance to different populations. As a result, Sierra Nevada bighorn sheep exhibited population‐specific dynamics that did not follow theoretical expectations or those observed in other ungulates. Our study suggests that vital rate inferences from large, increasing, or healthy populations may not be applicable to those that are small, declining, or endangered. We also found that, while asymptotic approaches were generally applicable to bighorn sheep conservation planning, our non‐asymptotic population models yielded unexpected results of importance to managers. Finally, extreme differences in the dynamics of individual bighorn sheep populations imply that effective management strategies for endangered species recovery may often need to be population‐specific. DA - 2010/9// PY - 2010/9// DO - 10.1890/09-1107.1 VL - 20 IS - 6 SP - 1753-1765 SN - 1939-5582 KW - endangered species KW - management KW - Ovis canadensis sierrae KW - population models KW - recovery KW - Sierra Nevada bighorn sheep KW - ungulate KW - vital rates ER - TY - JOUR TI - Foraging patterns of cavity-nesting birds in fire-suppressed and prescribe-burned ponderosa pine forests in Montana AU - Pierson, J. C. AU - Mills, L. S. AU - Christian, D. P T2 - Open Environmental Sciences AB - Fuel-reduction/forest restoration treatments that consist of thinning followed by prescribed burning are becoming increasingly important land management actions that likely affect various wildlife species. To assess potential effects on bark-gleaning birds, we compared the foraging patterns of five cavity-nesting species in thinned and burned ponderosa pine (Pinus ponderosa) forest sites and control sites. We recorded foraging behavior, location on forage tree, and tree characteristics that may be important in the selection of foraging substrates. Foraging surveys were conducted on three replicate 20-ha thinned/burned plots located within larger treatments that ranged from 60 - 250 ha, paired with three replicate control plots. Red-breasted Nuthatches (Sitta canadensis) foraged more often in control sites. Mountain Chickadees (Poecile gambeli) foraged at similar rates on both treatment types. Black-backed Woodpeckers (Picoides arcticus), Hairy Woodpeckers (P. villosus) and White-breasted Nuthatches (Sitta carolinensis) foraged almost exclusively in thinned/burned sites. Overall, all species selectively foraged on larger diameter trees. In control sites, Red-breasted Nuthatches selected larger ponderosa pine trees and Mountain Chickadees selected larger, live trees. In thinned/burned sites, Red-breasted Nuthatches selected larger, live trees, Mountain Chickadees selected larger trees with more canopy connections, Black-backed Woodpeckers selected trees with beetle evidence present and Hairy Woodpeckers selected recently dead trees. These results suggest fuel reduction/forest restoration treatments in dry ponderosa pine forests may be compatible with providing foraging substrates for cavity-nesting species often present in post-fire habitats. DA - 2010/// PY - 2010/// DO - 10.2174/1876325101004010041 VL - 41 SP - 41-52 ER - TY - JOUR TI - Combining ground count, telemetry, and mark-resight data to infer population dynamics in an endangered species AU - Johnson, Heather E. AU - Mills, L. Scott AU - Wehausen, John D. AU - Stephenson, Thomas R. T2 - JOURNAL OF APPLIED ECOLOGY AB - Summary 1. To successfully manipulate populations for management and conservation purposes, managers must be able to track changes in demographic rates and determine the factors driving spatial and temporal variation in those rates. For populations of management concern, however, data deficiencies frequently limit the use of traditional statistical methods for such analyses. Long‐term demographic data are often piecemeal, having small sample sizes, inconsistent methodologies, intermittent data, and information on only a subset of important parameters and covariates. 2. We evaluated the effectiveness of Bayesian state‐space models for meeting these data limitations in elucidating dynamics of federally endangered Sierra Nevada bighorn sheep Ovis canadensis sierrae . We combined ground count, telemetry, and mark–resight data to: (1) estimate demographic parameters in three populations (including stage‐specific abundances and vital rates); and (2) determine whether density, summer precipitation, or winter severity were driving variation in key demographic rates. 3. Models combining all existing data types increased the precision and accuracy in parameter estimates and fit covariates to vital rates driving population performance. They also provided estimates for all years of interest (including years in which field data were not collected) and standardized the error structure across data types. 4. Demographic rates indicated that recovery efforts should focus on increasing adult and yearling survival in the smallest bighorn sheep population. In evaluating covariates we found evidence of negative density dependence in the larger herds, but a trend of positive density dependence in the smallest herd suggesting that an augmentation may be needed to boost performance. We also found that vital rates in all populations were positively associated with summer precipitation, but that winter severity only had a negative effect on the smallest herd, the herd most strongly impacted by environmental stochasticity. 5. Synthesis and applications . For populations with piecemeal data, a problem common to both endangered and harvested species, obtaining precise demographic parameter estimates is one of the greatest challenges in detecting population trends, diagnosing the causes of decline, and directing management. Data on Sierra Nevada bighorn sheep provide an example of the application of Bayesian state‐space models for combining all existing data to meet these objectives and better inform important management and conservation decisions. DA - 2010/10// PY - 2010/10// DO - 10.1111/j.1365-2664.2010.01846.x VL - 47 IS - 5 SP - 1083-1093 SN - 0021-8901 KW - Bayesian state-space models KW - demographic parameter estimation KW - fecundity KW - ground count KW - mark-resight KW - Ovis canadensis sierrae KW - Sierra Nevada bighorn sheep KW - survival KW - telemetry ER - TY - JOUR TI - Natural, not urban, barriers define population structure for a coastal endemic butterfly AU - Leidner, Allison K. AU - Haddad, Nick M. T2 - CONSERVATION GENETICS DA - 2010/12// PY - 2010/12// DO - 10.1007/s10592-010-0117-5 VL - 11 IS - 6 SP - 2311-2320 SN - 1572-9737 KW - Population genetics KW - Habitat fragmentation KW - Urbanization KW - Conservation KW - Atrytonopsis KW - Population structure ER - TY - JOUR TI - Ecological Connectivity for a Changing Climate AU - Krosby, Meade AU - Tewksbury, Joshua AU - Haddad, Nick M. AU - Hoekstra, Jonathan T2 - CONSERVATION BIOLOGY AB - Conservation BiologyVolume 24, Issue 6 p. 1686-1689 Diversity Ecological Connectivity for a Changing Climate MEADE KROSBY, Corresponding Author MEADE KROSBY Department of Biology, University of Washington, Box 351800, Seattle, WA 98195-1800, U.S.A.email [email protected]Search for more papers by this authorJOSHUA TEWKSBURY, JOSHUA TEWKSBURY Department of Biology, University of Washington, Box 351800, Seattle, WA 98195-1800, U.S.A.Search for more papers by this authorNICK M. HADDAD, NICK M. HADDAD Department of Zoology, North Carolina State University, Raleigh, NC 27695-7617, U.S.A.Search for more papers by this authorJONATHAN HOEKSTRA, JONATHAN HOEKSTRA The Nature Conservancy, Seattle, WA 98101, U.S.A.Search for more papers by this author MEADE KROSBY, Corresponding Author MEADE KROSBY Department of Biology, University of Washington, Box 351800, Seattle, WA 98195-1800, U.S.A.email [email protected]Search for more papers by this authorJOSHUA TEWKSBURY, JOSHUA TEWKSBURY Department of Biology, University of Washington, Box 351800, Seattle, WA 98195-1800, U.S.A.Search for more papers by this authorNICK M. HADDAD, NICK M. HADDAD Department of Zoology, North Carolina State University, Raleigh, NC 27695-7617, U.S.A.Search for more papers by this authorJONATHAN HOEKSTRA, JONATHAN HOEKSTRA The Nature Conservancy, Seattle, WA 98101, U.S.A.Search for more papers by this author First published: 21 October 2010 https://doi.org/10.1111/j.1523-1739.2010.01585.xCitations: 143Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Literature Cited Bennett, G. 2004. 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Citing Literature Volume24, Issue6December 2010Pages 1686-1689 ReferencesRelatedInformation DA - 2010/12// PY - 2010/12// DO - 10.1111/j.1523-1739.2010.01585.x VL - 24 IS - 6 SP - 1686-1689 SN - 1523-1739 ER - TY - JOUR TI - The conflicting role of matrix habitats as conduits and barriers for dispersal AU - Kuefler, D. AU - Hudgens, B. AU - Haddad, N. M. AU - Morris, W. F. AU - Thurgate, N. T2 - Ecology (Brooklyn, New York, N.Y.) AB - Determining connectivity within complex landscapes is difficult if habitats that facilitate dispersal differ from habitats where animals normally are found or enter. We addressed the question of how landscape features affect dispersal by quantifying two critical aspects of animal movement behavior that determine dispersal rates across complex landscapes: conductivity of major habitat types and behavior at boundaries between habitat types. Our tests consisted of behavioral experiments and observational surveys of a wetland butterfly, Satyrodes appalachia . Displacement rates varied among habitats, with the longest moves and straightest paths leading to greater displacement rate in open habitat and shortest moves and most sinuous paths causing the slowest displacement rate in riparian forest habitat. We found a strong negative relationship between the probability of entering a habitat and the speed of moving through it. Recognizing this central conflict between entering and moving through habitat is important for assessing the connectivity of complex landscapes. DA - 2010/// PY - 2010/// DO - 10.1890/09-0614.1 VL - 91 IS - 4 SP - 944-950 ER - TY - JOUR TI - Ecosystem engineers maintain a rare species of butterfly and increase plant diversity AU - Bartel, Rebecca A. AU - Haddad, Nick M. AU - Wright, Justin P. T2 - OIKOS AB - We evaluated whether ecosystem engineers can accomplish two conservation goals simultaneously: (1) indirectly maintain populations of an endangered animal through habitat modification and (2) increase riparian plant diversity. We tested for effects of a prominent ecosystem engineer, the beaver Castor canadensis, on populations of St. Francis' satyr butterfly Neonympha mitchellii francisci and plant species richness and composition. We performed our test by surveying riparian vegetation communities in all stages of beaver-influenced wetland succession. We found that beavers created wetland habitats that supported plant species not found elsewhere in riparian zones and increased plant species diversity across the landscape by creating a novel combination of patch types. Our results confirmed what others have found about engineering effects on plant diversity, but these results further demonstrated a case where ecosystem engineers indirectly maintain populations of rare animals by modifying the composition and diversity of plant communities within wetlands. Our research demonstrates how an ecosystem engineer can influence habitat availability and composition of plant communities important for an endangered insect, and maintain overall plant species diversity by increasing habitat heterogeneity. DA - 2010/5// PY - 2010/5// DO - 10.1111/j.1600-0706.2009.18080.x VL - 119 IS - 5 SP - 883-890 SN - 1600-0706 ER - TY - JOUR TI - Does Tropical Forest Fragmentation Increase Long-Term Variability of Butterfly Communities? AU - Leidner, Allison K. AU - Haddad, Nick M. AU - Lovejoy, Thomas E. T2 - PLOS ONE AB - Habitat fragmentation is a major driver of biodiversity loss. Yet, the overall effects of fragmentation on biodiversity may be obscured by differences in responses among species. These opposing responses to fragmentation may be manifest in higher variability in species richness and abundance (termed hyperdynamism), and in predictable changes in community composition. We tested whether forest fragmentation causes long-term hyperdynamism in butterfly communities, a taxon that naturally displays large variations in species richness and community composition. Using a dataset from an experimentally fragmented landscape in the central Amazon that spanned 11 years, we evaluated the effect of fragmentation on changes in species richness and community composition through time. Overall, adjusted species richness (adjusted for survey duration) did not differ between fragmented forest and intact forest. However, spatial and temporal variation of adjusted species richness was significantly higher in fragmented forests relative to intact forest. This variation was associated with changes in butterfly community composition, specifically lower proportions of understory shade species and higher proportions of edge species in fragmented forest. Analysis of rarefied species richness, estimated using indices of butterfly abundance, showed no differences between fragmented and intact forest plots in spatial or temporal variation. These results do not contradict the results from adjusted species richness, but rather suggest that higher variability in butterfly adjusted species richness may be explained by changes in butterfly abundance. Combined, these results indicate that butterfly communities in fragmented tropical forests are more variable than in intact forest, and that the natural variability of butterflies was not a buffer against the effects of fragmentation on community dynamics. DA - 2010/3/10/ PY - 2010/3/10/ DO - 10.1371/journal.pone.0009534 VL - 5 IS - 3 SP - SN - 1932-6203 ER -