1
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Blanchet G, Bellinger MR, Kearns AM, Cortes-Rodriguez N, Masuda B, Campana MG, Rutz C, Fleischer RC, Sutton JT. Reduction of genetic diversity in 'Alalā (Hawaiian crow; Corvus hawaiiensis) between the late 1800s and the late 1900s. J Hered 2024; 115:32-44. [PMID: 37846510 DOI: 10.1093/jhered/esad063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 09/26/2023] [Accepted: 10/12/2023] [Indexed: 10/18/2023] Open
Abstract
Genetic and genomic data are increasingly used to aid conservation management of endangered species by providing insights into evolutionary histories, factors associated with extinction risks, and potential for future adaptation. For the 'Alalā, or Hawaiian crow (Corvus hawaiiensis), genetic concerns include negative correlations between inbreeding and hatching success. However, it is unclear if low genetic diversity and inbreeding depression are consequences of a historical population bottleneck, or if 'Alalā had historically low genetic diversity that predated human influence, perhaps as a result of earlier declines or founding events. In this study, we applied a hybridization-based sequence capture to generate a genome-wide single nucleotide polymorphism (SNP) dataset for comparing historical specimens collected in the 1890s, when 'Alalā were more numerous, to samples taken between 1973 and 1998, when 'Alalā population densities were near the lowest documented levels in the wild, prior to all individuals being collected for captive rearing. We found low genome-wide diversity in both sample groups, however, the modern sample group (1973 to 1998 cohort) exhibited relatively fewer polymorphic alleles, a lower proportion of polymorphic loci, and lower observed heterozygosity, consistent with a population decline and potential bottleneck effects. These results combined with a current low population size highlight the importance of continued efforts by conservation managers to mitigate inbreeding and maintain founder representation to preserve what genetic diversity remains.
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Affiliation(s)
- Geneviève Blanchet
- Department of Biology, University of Hawai'i at Hilo, 200 W Kāwili St, Hilo, Hawai'i 96720, United States
| | - M Renee Bellinger
- Department of Biology, University of Hawai'i at Hilo, 200 W Kāwili St, Hilo, Hawai'i 96720, United States
- U.S. Geological Survey, Pacific Island Ecosystems Research Center, PO Box 44, Hawai'i National Park, Hawai'i 96718, United States
| | - Anna M Kearns
- Center for Conservation Genomics, National Zoo and Conservation Biology Institute, Smithsonian Institution, Washington DC 20008, United States
| | - Nandadevi Cortes-Rodriguez
- Center for Conservation Genomics, National Zoo and Conservation Biology Institute, Smithsonian Institution, Washington DC 20008, United States
| | - Bryce Masuda
- San Diego Zoo Wildlife Alliance, P.O. Box 39, Volcano, HI 96785, United States
| | - Michael G Campana
- Center for Conservation Genomics, National Zoo and Conservation Biology Institute, Smithsonian Institution, Washington DC 20008, United States
| | - Christian Rutz
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, United Kingdom
| | - Robert C Fleischer
- Center for Conservation Genomics, National Zoo and Conservation Biology Institute, Smithsonian Institution, Washington DC 20008, United States
| | - Jolene T Sutton
- Department of Biology, University of Hawai'i at Hilo, 200 W Kāwili St, Hilo, Hawai'i 96720, United States
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Rehm EM, D'Antonio C, Yelenik S. Crossing the threshold: Invasive grasses inhibit forest restoration on Hawaiian islands. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2023; 33:e2841. [PMID: 36920234 DOI: 10.1002/eap.2841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 01/20/2023] [Accepted: 02/24/2023] [Indexed: 06/02/2023]
Abstract
Forest removal for livestock grazing is a striking example of human-caused state change leading to a stable, undesirable invasive grass system that is resistant to restoration efforts. Understanding which factors lead to resilience to the alternative grass state can greatly benefit managers when planning forest restoration. We address how thresholds of grass cover and seed rain might influence forest recovery in a restoration project on Hawai'i Island, USA. Since the 1980s, over 400,000 Acacia koa (koa) trees have been planted across degraded pasture, and invasive grasses still dominate the understory with no native woody-plant recruitment. Between this koa/grass matrix are remnant native Metrosideros polymorpha ('ōhi'a) trees beneath which native woody plants naturally recruit. We tested whether there were threshold levels of native woody understory that accelerate recruitment under both tree species by monitoring seed rain at 40 trees (20 koa and 'ōhi'a) with a range of native woody understory basal area (BA). We found a positive relationship between total seed rain (but not bird-dispersed seed rain) and native woody BA and a negative relationship between native woody BA and grass cover, with no indication of threshold dynamics. We also experimentally combined grass removal levels with seed rain density (six levels) of two common understory species in plots under koa (n = 9) and remnant 'ōhi'a (n = 9). Few seedlings emerged when no grass was removed despite adding seeds at densities two to 75 times higher than naturally occurring. However, seedling recruitment increased two to three times once at least 50% of grass was removed. Existing survey data of naturally occurring seedlings also supported a threshold of grass cover below which seedlings were able to establish. Thus, removal of all grasses is not necessary to achieve system responses: Even moderate reductions (~50%) can increase rates of native woody recruitment. The nonlinear thresholds found here highlight how incremental changes to an inhibitory factor lead to limited restoration success until a threshold is crossed. The resources needed to fully eradicate an invasive species may be unwarranted for state change, making understanding where thresholds lie of the utmost importance to prioritize resources.
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Affiliation(s)
- Evan M Rehm
- Biology Department, Austin Peay State University, Clarksville, Tennessee, USA
| | - Carla D'Antonio
- Department of Ecology, Evolution and Marine Biology, University of California at Santa Barbara, Santa Barbara, California, USA
| | - Stephanie Yelenik
- U.S. Geological Survey, Pacific Island Ecosystems Research Center, Volcano, Hawaii, USA
- Rocky Mountain Research Station, US Forest Service, Reno, Nevada, USA
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3
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Ma R, Zheng W, Guo J, Hou R, Huang H, Xue F, Zhou Y, Wu W, Huang C, Gu J, Feng F, Yu X, Liu J, Li Z, Zhang L, Lan G, Chen C, Bi W, Dai Q, Owens JR, Yang H, Gu X, Yan QG, Qi D. Symbiotic microbiota and odor ensure mating in time for giant pandas. Front Microbiol 2022; 13:1015513. [PMID: 36466630 PMCID: PMC9712809 DOI: 10.3389/fmicb.2022.1015513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/27/2022] [Indexed: 06/29/2024] Open
Abstract
To achieve reproduction, male solitary mammals need to locate females using chemical communication with high levels of precision. In the case of giant pandas, the total estrus period of females was usually 15 days each year, however, successful mating activity is finished within 3 days from respective home range. The mating pattern of giant pandas, where multiple males compete for each female requires females employ efficient systems to communicate their estrus phases. To verifying whether the scent secretions of giant pandas changes by gender and estrus progression, the microbiota and compounds in 29 anogenital gland samples from 14 individuals during estrus were analyzed by 16S rRNA sequencing and GC-MS. We show that the microbiota communities covary by gender with 4 particular compounds of scent secretions. Among 597 genera, 34 were identified as biomarkers that could be used to distinguish between different estrus phases. By bacterial-compounds co-analysis, 3 fatty ester acids and squalene compounds covaried with the development of estrus in the bacterial communities of female giant pandas. This study helps clarify how a large, solitary mammal expresses accurate information to improve the likelihood of successful reproduction by changing the composition of microbiota and odor compounds of anogenital glands during estrus.
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Affiliation(s)
- Rui Ma
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | | | - Junliang Guo
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Rong Hou
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - He Huang
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Fei Xue
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Yanshan Zhou
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Wei Wu
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Chong Huang
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Jiang Gu
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Feifei Feng
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Xiang Yu
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Jiabin Liu
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Zusheng Li
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Long Zhang
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Guanwei Lan
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Chao Chen
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Wenlei Bi
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
| | - Qiang Dai
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Jacob R. Owens
- Los Angeles Zoo & Botanical Gardens, Los Angeles, CA, United States
| | - Hong Yang
- Daxiangling Nature Reserve, Yaan, China
| | - Xiaodong Gu
- Sichuan Forestry and Grassland Bureau, Chengdu, China
| | - Qi-gui Yan
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Dunwu Qi
- Sichuan Key Laboratory of Conservation Biology for Endangered Wildlife, Chengdu Research Base of Giant Panda Breeding, Chengdu, China
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4
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Vizentin-Bugoni J, Sperry JH, Kelley JP, Foster JT, Drake DR, Case SB, Gleditsch JM, Hruska AM, Wilcox RC, Tarwater CE. Mechanisms underlying interaction frequencies and robustness in a novel seed dispersal network: lessons for restoration. Proc Biol Sci 2022; 289:20221490. [PMID: 36100025 PMCID: PMC9470274 DOI: 10.1098/rspb.2022.1490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 08/15/2022] [Indexed: 12/25/2022] Open
Abstract
As human-caused extinctions and invasions accumulate across the planet, understanding the processes governing ecological functions mediated by species interactions, and anticipating the effect of species loss on such functions become increasingly urgent. In seed dispersal networks, the mechanisms that influence interaction frequencies may also influence the capacity of a species to switch to alternative partners (rewiring), influencing network robustness. Studying seed dispersal interactions in novel ecosystems on O'ahu island, Hawai'i, we test whether the same mechanisms defining interaction frequencies can regulate rewiring and increase network robustness to simulated species extinctions. We found that spatial and temporal overlaps were the primary mechanisms underlying interaction frequencies, and the loss of the more connected species affected networks to a greater extent. Further, rewiring increased network robustness, and morphological matching and spatial and temporal overlaps between partners were more influential on network robustness than species abundances. We argue that to achieve self-sustaining ecosystems, restoration initiatives can consider optimal morphological matching and spatial and temporal overlaps between consumers and resources to maximize chances of native plant dispersal. Specifically, restoration initiatives may benefit from replacing invasive species with native species possessing characteristics that promote frequent interactions and increase the probability of rewiring (such as long fruiting periods, small seeds and broad distributions).
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Affiliation(s)
- Jeferson Vizentin-Bugoni
- Departamento de Ecologia, Universidade Federal do Rio Grande do Sul, Avenue Bento Gonçalves 9500, Porto Alegre, Rio Grande do Sul 91501-970, Brazil
- US Army Corps of Engineers, Engineer Research Development Center, 2902 Newmark Dr, Champaign, IL 61826, USA
- Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, 1102 South Goodwin Avenue, Urbana, IL 61801, USA
- Department of Zoology and Physiology, University of Wyoming, 1000 East University Avenue, Laramie, WY 82071, USA
| | - Jinelle H. Sperry
- US Army Corps of Engineers, Engineer Research Development Center, 2902 Newmark Dr, Champaign, IL 61826, USA
- Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, 1102 South Goodwin Avenue, Urbana, IL 61801, USA
| | - J. Patrick Kelley
- Department of Zoology and Physiology, University of Wyoming, 1000 East University Avenue, Laramie, WY 82071, USA
| | - Jeffrey T. Foster
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Donald R. Drake
- School of Life Sciences, University of Hawai‘i at Mānoa, Honolulu, HI 96822, USA
| | - Samuel B. Case
- Department of Zoology and Physiology, University of Wyoming, 1000 East University Avenue, Laramie, WY 82071, USA
| | - Jason M. Gleditsch
- Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, 1102 South Goodwin Avenue, Urbana, IL 61801, USA
- Integrative Ecology Laboratory, Center for Biodiversity, Temple University, Philadelphia, PA 19122, USA
| | - Amy M. Hruska
- Department of Botany, University of Hawai‘i at Mānoa, Honolulu, HI 96822, USA
- Smithsonian Environmental Research Center, Edgewater, MD 21037, USA
| | - Rebecca C. Wilcox
- Department of Zoology and Physiology, University of Wyoming, 1000 East University Avenue, Laramie, WY 82071, USA
| | - Corey E. Tarwater
- Department of Zoology and Physiology, University of Wyoming, 1000 East University Avenue, Laramie, WY 82071, USA
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Andrews CE, Anderson SH, van der Walt K, Thorogood R, Ewen JG. Evaluating the success of functional restoration after reintroduction of a lost avian pollinator. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2022; 36:e13892. [PMID: 35171538 PMCID: PMC9545379 DOI: 10.1111/cobi.13892] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 11/19/2021] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
Conservation translocation is a common method for species recovery, for which one increasingly frequent objective is restoring lost ecological functions to promote ecosystem recovery. However, few conservation translocation programs explicitly state or monitor function as an objective, limiting the ability to test assumptions, learn from past efforts, and improve management. We evaluated whether translocations of hihi (Notiomystis cincta), a threatened New Zealand passerine, achieved their implicit objective of restoring lost pollination function. Through a pollinator-exclusion experiment, we quantified, with log response ratios (lnR), the effects of birds on fruit set and seed quality in hangehange (Geniostoma ligustrifolium), a native flowering shrub. We isolated the contributions of hihi by making comparisons across sites with and without hihi. Birds improved fruit set more at sites without hihi (lnR = 1.27) than sites with hihi (lnR = 0.50), suggesting other avian pollinators compensated for and even exceeded hihi contributions to fruit set. Although birds improved seed germination only at hihi sites (lnR = 0.22-0.41), plants at sites without hihi had germination rates similar to hihi sites because they produced 26% more filled seeds, regardless of pollination condition. Therefore, although our results showed hihi improved seed quality, they also highlighted the complexity of ecological functions. When an important species is lost, ecosystems may be able to achieve similar function through different means. Our results underscore the importance of stating and monitoring the ecological benefits of conservation translocations when functional restoration is a motivation to ensure these programs are achieving their objectives.
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Affiliation(s)
- Caitlin E. Andrews
- Department of ZoologyUniversity of CambridgeCambridgeUK
- Institute of ZoologyZoological Society of LondonLondonUK
| | | | - Karin van der Walt
- Ōtari Native Botanic Garden and Wilton's Bush ReserveWellingtonNew Zealand
| | - Rose Thorogood
- Department of ZoologyUniversity of CambridgeCambridgeUK
- Helsinki Institute of Life Science (HiLIFE)University of HelsinkiHelsinkiFinland
- Research Program in Organismal and Evolutionary Biology, Faculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
| | - John G. Ewen
- Institute of ZoologyZoological Society of LondonLondonUK
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6
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Case SB, Postelli K, Drake DR, Vizentin-Bugoni J, Foster JT, Sperry JH, Kelley JP, Tarwater CE. Introduced galliforms as seed predators and dispersers in Hawaiian forests. Biol Invasions 2022. [DOI: 10.1007/s10530-022-02830-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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7
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Yelenik S, Rose E, Paxton EH. Trophic interactions and feedbacks maintain intact and degraded states of Hawaiian tropical forests. Ecosphere 2022. [DOI: 10.1002/ecs2.3884] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Stephanie Yelenik
- U.S. Geological Survey Pacific Island Ecosystems Research Center Hawaiʻi National Park Hilo Hawaiʻi USA
| | - Eli Rose
- U.S. Geological Survey Pacific Island Ecosystems Research Center Hawaiʻi National Park Hilo Hawaiʻi USA
| | - Eben H. Paxton
- U.S. Geological Survey Pacific Island Ecosystems Research Center Hawaiʻi National Park Hilo Hawaiʻi USA
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8
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Testing the maintenance of natural responses to survival-relevant calls in the conservation breeding population of a critically endangered corvid (Corvus hawaiiensis). Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03130-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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9
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Heleno RH, Mendes F, Coelho AP, Ramos JA, Palmeirim JM, Rainho A, de Lima RF. The upsizing of the São Tomé seed dispersal network by introduced animals. OIKOS 2021. [DOI: 10.1111/oik.08279] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Ruben H. Heleno
- Centre for Functional Ecology (CFE‐UC), Dept of Life Sciences, Univ. of Coimbra, Calçada Martim de Freitas Coimbra Portugal
| | - Filipa Mendes
- Centre for Functional Ecology (CFE‐UC), Dept of Life Sciences, Univ. of Coimbra, Calçada Martim de Freitas Coimbra Portugal
| | - Ana P. Coelho
- Centre for Ecology, Evolution and Environmental Changes (cE3c) and Dept of Animal Biology, Faculty of Sciences, Univ. of Lisbon Lisboa Portugal
- Dept of Biology and CESAM, Univ. of Aveiro, Campus de Santiago Aveiro Portugal
| | - Jaime A. Ramos
- Centre for Ecology, Evolution and Environmental Changes (cE3c) and Dept of Animal Biology, Faculty of Sciences, Univ. of Lisbon Lisboa Portugal
| | - Jorge M. Palmeirim
- Marine and Environmental Sciences Centre (MARE), Dept of Life Sciences, Univ. of Coimbra Coimbra Portugal
| | - Ana Rainho
- Centre for Ecology, Evolution and Environmental Changes (cE3c) and Dept of Animal Biology, Faculty of Sciences, Univ. of Lisbon Lisboa Portugal
| | - Ricardo F. de Lima
- Centre for Ecology, Evolution and Environmental Changes (cE3c) and Dept of Animal Biology, Faculty of Sciences, Univ. of Lisbon Lisboa Portugal
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Lee HN, Greggor AL, Masuda B, Swaisgood RR. Anti-Predator Vigilance as an Indicator of the Costs and Benefits of Supplemental Feeding in Newly Released ‘Alalā (Corvus hawaiiensis). FRONTIERS IN CONSERVATION SCIENCE 2021. [DOI: 10.3389/fcosc.2021.701490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Although supplemental feeding is commonly used as a conservation strategy during animal translocations, it comes with a number of pros and cons which can be hard to quantify. Providing additional food resources may lead to improved physical health, survivorship, and reproduction. However, offering predictable food sources could make individuals more conspicuous to predators and less aware of their surroundings, disrupting their natural predator-prey dynamic. Decisions such as release cohort size and supplemental feeder design could influence the balance of these costs and benefits, depending on how animals behave in the face of predation risk and static food sources. Additionally, animals released to the wild from long term human care must balance foraging and predation risk while adjusting to a novel environment. To help conservation managers make informed decisions in light of these potential costs, we studied the behavior of a cohort of 11 conservation-bred ‘alalā (Corvus hawaiiensis) at supplemental feeding stations after release into the wild. Vigilance, foraging behavior and social group size was quantified via 1,320 trail camera videos of ‘alalā over the span of 12 months. We found that vigilance increased over time since release, suggesting that ‘alalā learn and adjust to their novel surroundings. Both vigilance and eating decreased with group size, indicating that although conspecifics may share the burden of scanning for threats, they also increase competition for food. We also found that the design of the feeder may have limited birds' abilities to express anti-predator behavior since less vigilance was observed in individuals that manipulated the feeder. Yet, birds may have been able to offset these costs since they increasingly scrounged for food scraps next to the feeder as time progressed. We discuss how changes to behavior over time, social interactions, and feeder design should all be considered when planning supplemental feeding as part of wildlife translocations.
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Pre-release training, predator interactions and evidence for persistence of anti-predator behavior in reintroduced `alalā, Hawaiian crow. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01658] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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12
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Li Y, Chen Z, Peng C, Huang G, Niu H, Zhang H. Assessment of habitat change on bird diversity and bird-habitat network of a Coral Island, South China Sea. BMC Ecol Evol 2021; 21:137. [PMID: 34229631 PMCID: PMC8259361 DOI: 10.1186/s12862-021-01865-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/21/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Understanding how island ecosystems change across habitats is a major challenge in ecological conservation under the conditions of habitat degradation. According to a 2-year investigation on Dong Island of the Paracel Islands, South China Sea, we assessed the roles of different habitats at the species level and community level of birds using topological and network analysis. RESULTS In addition to the thousands of Sula sula (a large-sized arboreal seabird) inhabiting the forests, there were 56 other bird species were recorded, representing 23 families and 12 orders, ranging in habitats of wetlands, forests, shrublands, grasslands, and/or beaches. The bird-habitat network had high nestedness, and bird species showed obvious clustering distribution. Integrated topological and network analysis showed that wetlands had a high contribution to species diversity and network structure, and it was a cluster center of migrant birds. Forests and grasslands were species hub and connector respectively, and forests were also the key habitat for residents. Beaches and shrublands were peripherals. The loss of wetlands and forests will result in a sharp reduction of species richness, and even make the S. sula, and most of the resident birds, become locally extinct. CONCLUSIONS These results suggest that the wetland and forest habitats on the focal island are key important for migrant birds and resident birds respectively, and therefore much more attention should be paid to conservation of the focal island ecosystems.
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Affiliation(s)
- Yingcan Li
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Zhiwen Chen
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Chao Peng
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Guangchuan Huang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Hongyu Niu
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China
| | - Hongmao Zhang
- Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, Hubei, China.
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Automated telemetry reveals post-reintroduction exploratory behavior and movement patterns of an endangered corvid, ʻAlalā (Corvus hawaiiensis) in Hawaiʻi, USA. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01522] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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14
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Fruit and seed traits of native and invasive plant species in Hawai‘i: implications for seed dispersal by non-native birds. Biol Invasions 2021. [DOI: 10.1007/s10530-021-02473-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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15
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Case SB, Tarwater CE. Functional traits of avian frugivores have shifted following species extinction and introduction in the Hawaiian Islands. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13670] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Samuel B. Case
- Department of Zoology and Physiology and Program in Ecology University of Wyoming Laramie WY USA
| | - Corey E. Tarwater
- Department of Zoology and Physiology and Program in Ecology University of Wyoming Laramie WY USA
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16
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Jiguet F. The Fox and the Crow. A need to update pest control strategies. BIOLOGICAL CONSERVATION 2020; 248:108693. [PMID: 32834058 PMCID: PMC7342009 DOI: 10.1016/j.biocon.2020.108693] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/19/2020] [Accepted: 06/26/2020] [Indexed: 06/11/2023]
Abstract
The recent discovery that cats and mustelids can be infected by SARS-CoV-2 may raise the question of monitoring domestic, feral and wild populations of such animals, as an adjunct to the elimination of COVID-19 in humans. Emergency solutions might consider large scale control of these animals in the wild. However, looking at science recently published on native vertebrate pest control reveals first that usual controls do not succeed in reducing animal numbers and associated damages, second that controlling can be counter-productive in increasing the infectious risks for humans and livestock. The examples of red fox and corvids are detailed in a European context, illustrating the urgent need for an ethical evaluation of ecological and economic costs and benefits of pest control strategies. A complete scientific evaluation process must be implemented and up-dated regularly, to be organized in four major steps, once the aim of the control strategy has been defined: (1) evaluating damages/risks caused by the animals, to be balanced with the ecosystem services they may provide, also in terms of economic costs; (2) unravelling spatial and temporal population dynamics of target animals to identify, if any, optimal control scenarios - which could be done within an adaptive management framework; (3) estimating the economic costs of implementing those optimal control scenarios, to be compared to the economic costs of damages/diseases; (4) finally evaluating how the control strategy reached its aims. A modern fable of the Fox and the Crow should deliver a timely moral for an ethical, ecological and economical appraisal of pest control strategies in Europe.
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Affiliation(s)
- Frédéric Jiguet
- UMR7204 Centre d'Ecologie et des Sciences de la Conservation, MNHN-CNRS-SU, CP135, 43 Rue Buffon, 75005 Paris, France
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MacDonald SE, Ward MP, Sperry JH. Manipulating social information to promote frugivory by birds on a Hawaiian Island. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2019; 29:e01963. [PMID: 31247121 DOI: 10.1002/eap.1963] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 05/04/2019] [Accepted: 05/28/2019] [Indexed: 06/09/2023]
Abstract
Animals across a range of taxa use social information when foraging. Fruit-eating vertebrates are no exception and use social information to find fruit, which may ultimately affect plant populations via seed dispersal. In many systems, mutualistic relationships between fruiting plants and frugivores are critical to maintain ecosystem functioning, especially in the tropics. On the island of O'ahu, Hawaii, USA, all native, fruit-eating birds are extinct and several plant species are experiencing reduced recruitment likely due to a lack of seed dispersal. Over the years, numerous bird species, many of which are frugivorous, have been introduced to the island. Yet, introduced birds may not recognize native fruits as a resource and social information may be needed for introduced frugivores to target and feed on native fruits. We investigated whether social information, in the form of broadcasted bird vocalizations, of introduced birds could increase visitations and more importantly frugivory on focal fruiting plants. We also tested whether the visitation rates of introduced bird species to focal plants were influenced by conspecific and/or heterospecific vocalizations. We conducted 80 playback experiments at native and introduced fruiting plants, and compared responses to silent control periods. Four times as many frugivores were detected and 10 times more frugivory events were recorded at plants with broadcasted vocalizations compared to control periods. The Japanese White-eye (Zosterops japonicus) exhibited the strongest response to both conspecific and heterospecific playbacks. White-eyes also consumed the most fruit from the widest array of plant species during trials. Introduced birds that use social information and readily identify novel resources may more effectively colonize new areas. We suggest that the White-eye's use of social information may help to support their robust population on O'ahu. Ecosystems throughout the world are affected by the loss of mutualistic relationships, many of which provide valuable ecological services. As humans continue to modify environments, novel conservation approaches may be required to maintain important ecological functions. The use of social information to facilitate frugivory may not only be important in Hawaii, but in other tropical systems where key frugivorous species are lost or abundances have been reduced.
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Affiliation(s)
- S E MacDonald
- Department of Natural Resources and Environmental Science, University of Illinois at Urbana-Champaign, 1102 S. Goodwin Avenue, Urbana, Illinois, 61801, USA
| | - M P Ward
- Department of Natural Resources and Environmental Science, University of Illinois at Urbana-Champaign, 1102 S. Goodwin Avenue, Urbana, Illinois, 61801, USA
| | - J H Sperry
- Department of Natural Resources and Environmental Science, University of Illinois at Urbana-Champaign, 1102 S. Goodwin Avenue, Urbana, Illinois, 61801, USA
- Engineer Research and Development Center, P.O. Box 9005, Champaign, Illinois, 61826, USA
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18
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Vizentin-Bugoni J, Tarwater CE, Foster JT, Drake DR, Gleditsch JM, Hruska AM, Kelley JP, Sperry JH. Structure, spatial dynamics, and stability of novel seed dispersal mutualistic networks in Hawaiʻi. Science 2019; 364:78-82. [DOI: 10.1126/science.aau8751] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 11/29/2018] [Accepted: 03/05/2019] [Indexed: 11/02/2022]
Abstract
Increasing rates of human-caused species invasions and extinctions may reshape communities and modify the structure, dynamics, and stability of species interactions. To investigate how such changes affect communities, we performed multiscale analyses of seed dispersal networks on Oʻahu, Hawaiʻi. Networks consisted exclusively of novel interactions, were largely dominated by introduced species, and exhibited specialized and modular structure at local and regional scales, despite high interaction dissimilarity across communities. Furthermore, the structure and stability of the novel networks were similar to native-dominated communities worldwide. Our findings suggest that shared evolutionary history is not a necessary process for the emergence of complex network structure, and interaction patterns may be highly conserved, regardless of species identity and environment. Introduced species can quickly become well integrated into novel networks, making restoration of native ecosystems more challenging than previously thought.
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19
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González-Castro A, Pérez-Pérez D, Romero J, Nogales M. Unraveling the Seed Dispersal System of an Insular “Ghost” Dragon Tree (Dracaena draco) in the Wild. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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20
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Gómez JM, Schupp EW, Jordano P. Synzoochory: the ecological and evolutionary relevance of a dual interaction. Biol Rev Camb Philos Soc 2018; 94:874-902. [PMID: 30467946 DOI: 10.1111/brv.12481] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/22/2018] [Accepted: 10/24/2018] [Indexed: 12/31/2022]
Affiliation(s)
- José María Gómez
- Departamento de Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas (EEZA-CSIC), Ctra Sacramento s/n, La Cañada de San Urbano, E-04120 Almería, Spain
| | - Eugene W Schupp
- Department of Wildland Resources and Ecology Center, S. J. and Jesse E. Quinney College of Natural Resources, 5230 Old Main Hill, Utah State University, Logan, UT 84322-5230,, U.S.A
| | - Pedro Jordano
- Departamento de Ecología Integrativa, Integrative Ecology Group, Estación Biológica de Doñana (EBD-CSIC), Avda. Americo Vespucio S/N, E-41092 Sevilla, Spain
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21
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Sutton JT, Helmkampf M, Steiner CC, Bellinger MR, Korlach J, Hall R, Baybayan P, Muehling J, Gu J, Kingan S, Masuda BM, Ryder OA. A High-Quality, Long-Read De Novo Genome Assembly to Aid Conservation of Hawaii's Last Remaining Crow Species. Genes (Basel) 2018; 9:genes9080393. [PMID: 30071683 PMCID: PMC6115840 DOI: 10.3390/genes9080393] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 07/23/2018] [Accepted: 07/27/2018] [Indexed: 11/16/2022] Open
Abstract
Genome-level data can provide researchers with unprecedented precision to examine the causes and genetic consequences of population declines, which can inform conservation management. Here, we present a high-quality, long-read, de novo genome assembly for one of the world’s most endangered bird species, the ʻAlalā (Corvus hawaiiensis; Hawaiian crow). As the only remaining native crow species in Hawaiʻi, the ʻAlalā survived solely in a captive-breeding program from 2002 until 2016, at which point a long-term reintroduction program was initiated. The high-quality genome assembly was generated to lay the foundation for both comparative genomics studies and the development of population-level genomic tools that will aid conservation and recovery efforts. We illustrate how the quality of this assembly places it amongst the very best avian genomes assembled to date, comparable to intensively studied model systems. We describe the genome architecture in terms of repetitive elements and runs of homozygosity, and we show that compared with more outbred species, the ʻAlalā genome is substantially more homozygous. We also provide annotations for a subset of immunity genes that are likely to be important in conservation management, and we discuss how this genome is currently being used as a roadmap for downstream conservation applications.
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Affiliation(s)
- Jolene T Sutton
- Department of Biology, University of Hawaii at Hilo, Hilo, HI 96720, USA.
| | - Martin Helmkampf
- Department of Biology, University of Hawaii at Hilo, Hilo, HI 96720, USA.
| | - Cynthia C Steiner
- Institute for Conservation Research, San Diego Zoo, Escondido, CA 92027, USA.
| | - M Renee Bellinger
- Department of Biology, University of Hawaii at Hilo, Hilo, HI 96720, USA.
| | | | | | | | | | - Jenny Gu
- Pacific Biosciences, Menlo Park, CA 94025, USA.
| | | | - Bryce M Masuda
- Institute for Conservation Research, San Diego Zoo Global, Volcano, HI 96785, USA.
| | - Oliver A Ryder
- Institute for Conservation Research, San Diego Zoo, Escondido, CA 92027, USA.
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22
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Pesendorfer MB, Sillett TS, Morrison SA. Spatially biased dispersal of acorns by a scatter-hoarding corvid may accelerate passive restoration of oak habitat on California's largest island. Curr Zool 2018; 63:363-367. [PMID: 29491996 PMCID: PMC5804183 DOI: 10.1093/cz/zow075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 10/27/2015] [Accepted: 06/21/2016] [Indexed: 11/12/2022] Open
Abstract
Scatter hoarding by corvids (crows, jays, magpies, and nutcrackers) provides seed dispersal for many large-seeded plants, including oaks and pines. When hoarding seeds, corvids often choose nonrandom locations throughout the landscape, resulting in differential survival of seeds. In the context of habitat restoration, such disproportional storing of seeds in areas suitable for germination and establishment can accelerate expansion and recovery of large-seeded tree populations and their associated ecosystems. Here, we investigate the spatial preferences of island scrub jays Aphelocoma insularis during scatter hoarding of acorns (Quercus spp.) on Santa Cruz Island. We use a large behavioral data set on the birds’ behavior in combination with seedling surveys and spatial analysis to determine whether 1) island scrub jays disproportionally cache seeds in specific habitat types, and 2) whether the preferred habitat type is suitable for oak regeneration. Our results show that the jays nonrandomly cache acorns across the landscape; they use chaparral and coastal sage scrub disproportionally while avoiding open and grassy areas. The areas used most often for caching were also the areas with the highest oak seedling densities. We discuss the potential role of these findings for the recovery of Santa Cruz Island’s oak habitat since the 1980s.
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Affiliation(s)
- Mario B Pesendorfer
- School of Biological Sciences, University of Nebraska - Lincoln, 348 Manter Hall, Lincoln, NE 68588-0118, USA.,Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, MRC 5503, Washington, D.C. 20013-7012, USA.,Cornell Lab of Ornithology, 159 Sapsucker Woods Rd, Ithaca, NY 14850, USA
| | - T Scott Sillett
- Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, MRC 5503, Washington, D.C. 20013-7012, USA
| | - Scott A Morrison
- The Nature Conservancy, 4th Floor, 201 Mission Street, San Francisco, CA 94105, USA
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23
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Kaushik M, Pejchar L, Crampton LH. Potential disruption of seed dispersal in the absence of a native Kauai thrush. PLoS One 2018; 13:e0191992. [PMID: 29381764 PMCID: PMC5790251 DOI: 10.1371/journal.pone.0191992] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 01/15/2018] [Indexed: 11/18/2022] Open
Abstract
Hawaii has experienced a catastrophic decline in frugivorous native birds coupled with the introduction of non-native species. Puaiohi (Myadestes palmeri), a critically endangered thrush, is the sole extant native songbird capable of dispersing fleshy fruited plants in the rainforest of Kauai island, Hawaii. As this species has declined to occupy a small proportion of its original range, a suite of largely omnivorous non-native birds have been introduced to this region, including the common and widespread Japanese White-eye (Zosterops japonicus). This reshuffling of the bird community could have long-term implications for plant community composition if introduced birds incompletely replace the ecological role of native species. The objective of this study was to evaluate the potential consequences of the local extirpation of Puaiohi for seed dispersal. Specifically, we compared the diet of Puaiohi and Japanese White-eye, vegetation characteristics, and seed rain at sites with and without Puaiohi in the Na Pali-Kona Forest Reserve on the island of Kauai. We found high overlap in the composition of seeds consumed by the two bird species, but differences in the characteristics of seeds consumed; Japanese White-eye appeared more likely to consume smaller seeded species compared with Puaiohi. Sites with Puaiohi received substantially higher seed rain during the study period, despite no significant differences in overall fruit abundance. Our results suggest that non-native birds are unlikely to completely replace the seed dispersal services provided by Puaiohi. If Puaohi continue to be rare and range restricted, we predict a shift in plant community composition through an increase in non-native and small-seeded plants, and possible dispersal failure of other native species. Our findings lend further support to efforts to conserve Puaiohi across its current and former range, and to consider introductions to other suitable areas to ensure the persistence not only of the species and but also its functional role in Hawaii's montane ecosystems.
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Affiliation(s)
- Monica Kaushik
- Wildlife Institute of India, Chandrabani, Dehardun, India
| | - Liba Pejchar
- Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, CO, United States of America
| | - Lisa H Crampton
- Hawaii Department of Land and Natural Resources and University of Hawaii Manoa, Kaua'i Forest Bird Recovery Project, Hanapepe, HI, United States of America
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24
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Zwolak R. How intraspecific variation in seed-dispersing animals matters for plants. Biol Rev Camb Philos Soc 2017; 93:897-913. [DOI: 10.1111/brv.12377] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 09/13/2017] [Accepted: 09/18/2017] [Indexed: 12/13/2022]
Affiliation(s)
- Rafał Zwolak
- Department of Systematic Zoology, Faculty of Biology; Adam Mickiewicz University, Umultowska 89; 61-614 Poznań Poland
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25
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Gleditsch JM, Hruska AM, Foster JT. Connecting Resource Tracking by Frugivores to Temporal Variation in Seed Dispersal Networks. Front Ecol Evol 2017. [DOI: 10.3389/fevo.2017.00098] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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26
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Nogales M, González-Castro A, Rumeu B, Traveset A, Vargas P, Jaramillo P, Olesen JM, Heleno RH. Contribution by vertebrates to seed dispersal effectiveness in the Galápagos Islands: a community-wide approach. Ecology 2017; 98:2049-2058. [DOI: 10.1002/ecy.1816] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 02/26/2017] [Accepted: 03/06/2017] [Indexed: 11/08/2022]
Affiliation(s)
- M. Nogales
- Island Ecology and Evolution Research Group (IPNA-CSIC); Canary Islands Spain
| | - A. González-Castro
- Island Ecology and Evolution Research Group (IPNA-CSIC); Canary Islands Spain
| | - B. Rumeu
- Centre for Functional Ecology; Department of Life Sciences; University of Coimbra; Coimbra Portugal
| | - A. Traveset
- Institut Mediterrani d'Estudis Avançats (UIB-CSIC); Balearic Islands Spain
| | - P. Vargas
- Real Jardín Botánico (RJB-CSIC); Madrid Spain
| | - P. Jaramillo
- Charles Darwin Foundation; Puerto Ayora, Santa Cruz, Galápagos Ecuador
| | - J. M. Olesen
- Department of Bioscience; Aarhus University; Aarhus C Denmark
| | - R. H. Heleno
- Centre for Functional Ecology; Department of Life Sciences; University of Coimbra; Coimbra Portugal
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27
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Shiels AB, Medeiros AC, von Allmen EI. Shifts in an invasive rodent community favoring Black rats (Rattus rattus
) following restoration of native forest. Restor Ecol 2017. [DOI: 10.1111/rec.12494] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Aaron B. Shiels
- USDA, APHIS, WS, National Wildlife Research Center, 4101 LaPorte Avenue; Fort Collins CO 80521 U.S.A
| | - Arthur C. Medeiros
- Pacific Cooperative Studies Unit; University of Hawai'i, 3190 Maile Way; Honolulu HI 96822 U.S.A
- U.S. Geological Survey, Pacific Island Ecosystems Research Center, PO Box 369; Makawao HI 96768 U.S.A
| | - Erica I. von Allmen
- Pacific Cooperative Studies Unit; University of Hawai'i, 3190 Maile Way; Honolulu HI 96822 U.S.A
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28
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Rutz C, Klump BC, Komarczyk L, Leighton R, Kramer J, Wischnewski S, Sugasawa S, Morrissey MB, James R, St Clair JJH, Switzer RA, Masuda BM. Discovery of species-wide tool use in the Hawaiian crow. Nature 2016; 537:403-7. [DOI: 10.1038/nature19103] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 07/12/2016] [Indexed: 11/09/2022]
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29
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Pejchar L. Introduced birds incompletely replace seed dispersal by a native frugivore. AOB PLANTS 2015; 7:plv072. [PMID: 26139183 PMCID: PMC4526755 DOI: 10.1093/aobpla/plv072] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 06/01/2015] [Indexed: 05/28/2023]
Abstract
The widespread loss of native species and the introduction of non-native species has important consequences for island ecosystems. Non-native species may or may not functionally replace the role of native species in ecological processes such as seed dispersal. Although the majority of Hawaii's native plants require bird-mediated seed dispersal, only one native frugivore, Omao (Myadestes obscurus), persists in sufficient numbers to fill this functional role. Omao are restricted to less than half their original range, but two introduced frugivores are abundant throughout Hawaii. Given large-scale extinctions on islands, it is important to understand whether introduced birds serve as functional replacements or whether the absence of native frugivores alters plant communities. To assess seed dispersal by native and introduced birds, seed rain, vegetation characteristics, bird diet, density and habitat use were measured at three sites with Omao and three sites without Omao on Hawaii Island. The diet of native and introduced birds overlapped substantially, but Omao dispersed a variety of native species (n = 6) relatively evenly. In contrast, introduced birds dispersed an invasive species and fewer native species (n = 4), and >90 % of seeds dispersed by introduced birds were from two ubiquitous small-seeded species. Seed rain was significantly greater and more species rich at sites with Omao. These findings suggest that patterns of seed dispersal are altered following the local extinction of a native island frugivore. To more directly evaluate the relative roles of native and introduced frugivores in ecological processes, future studies could include reintroducing Omao to a suitable habitat within its historic range, or novel introductions to nearby islands where closely related species are now extinct. In an era of widespread extinction and invasion of island ecosystems, understanding the consequences of novel animal assemblages for processes like seed dispersal will be critical for maintaining diverse and self-regenerating plant communities.
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Affiliation(s)
- Liba Pejchar
- Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, CO 80523, USA
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30
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Shiels AB, Drake DR. Barriers to seed and seedling survival of once-common Hawaiian palms: the role of invasive rats and ungulates. AOB PLANTS 2015; 7:plv057. [PMID: 26019231 PMCID: PMC4497476 DOI: 10.1093/aobpla/plv057] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/12/2015] [Indexed: 05/28/2023]
Abstract
Mammalian herbivores can limit plant recruitment and affect forest composition. Loulu palms (Pritchardia spp.) once dominated many lowland ecosystems in Hawai'i, and non-native rats (Rattus spp.), ungulates (e.g. pigs Sus scrofa, goats Capra hircus) and humans have been proposed as major causes of their decline. In lowland wet forest, we experimentally determined the vulnerability of seeds and seedlings of two species of Pritchardia, P. maideniana and P. hillebrandii, by measuring their removal by introduced vertebrates; we also used motion-sensing cameras to identify the animals responsible for Pritchardia removal. We assessed potential seed dispersal of P. maideniana by spool-and-line tracking, and conducted captive-feeding trials with R. rattus and seeds and seedlings of both Pritchardia species. Seed removal from the forest floor occurred rapidly for both species: >50 % of Pritchardia seeds were removed from the vertebrate-accessible stations within 6 days and >80 % were removed within 22 days. Although rats and pigs were both common to the study area, motion-sensing cameras detected only rats (probably R. rattus) removing Pritchardia seeds from the forest floor. Captive-feeding trials and spool-and-line tracking revealed that vertebrate seed dispersal is rare; rats moved seeds up to 8 m upon collection and subsequently destroyed them (100 % mortality in 24-48 h in captivity). Surprisingly, seedlings did not suffer vertebrate damage in field trials, and although rats damaged seedlings in captivity, they rarely consumed them. Our findings are consistent with the hypothesis generated from palaeoecological studies, indicating that introduced rats may have assisted in the demise of native insular palm forests. These findings also imply that the seed stage of species in this Pacific genus is particularly vulnerable to rats; therefore, future conservation efforts involving Pritchardia should prioritize the reduction of rat predation on the plant recruitment stages preceding seedling establishment.
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Affiliation(s)
- Aaron B Shiels
- USDA, National Wildlife Research Center, Hawai'i Field Station, Hilo, HI 96721, USA
| | - Donald R Drake
- Department of Botany, University of Hawai'i, 3190 Maile Way, Honolulu, HI 96822, USA
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32
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Wu JX, Delparte DM, Hart PJ. Movement Patterns of a Native and Non-native Frugivore in Hawaii and Implications for Seed Dispersal. Biotropica 2014. [DOI: 10.1111/btp.12087] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Joanna X. Wu
- Tropical Conservation Biology and Environmental Sciences; University of Hawaii at Hilo; 200 W. Kawili St Hilo HI 96720 U.S.A
| | - Donna M. Delparte
- Department of Geosciences; Idaho State University; 921 S. 8th Ave Stop 8072 Pocatello ID 83209 U.S.A
| | - Patrick J. Hart
- Tropical Conservation Biology and Environmental Sciences; University of Hawaii at Hilo; 200 W. Kawili St Hilo HI 96720 U.S.A
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