21 research outputs found

    Gizzard contents of the Smooth-billed Ani Crotophaga ani in Santa Cruz, Galapagos Islands, Ecuador

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    The Smooth-billed Ani Crotophaga ani was introduced to the Galapagos archipelago in the 1960s, since when its population has grown significantly. We studied the dietary items in the gizzards of 56 anis sampled on the island of Santa Cruz. We confirmed that the diet of C. ani consists primarily of invertebrates and plant material, including native species and non-native invasives. The second most abundant seed in the anis’ diet was that of the highly invasive plant, Rubus niveus. Our findings suggest that C. ani poses a threat to the Galapagos ecosystem by dispersing seeds of non-native plants and by competing with other insectivorous species on the islands. Furthermore, the discovery of a Darwin’s Finch nestling in the gizzard of one C. ani establishes direct predation by this species on native birds

    Sharing land with giants: Habitat preferences of Galapagos tortoises on farms

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    One of the most pressing dilemmas of our time is determining how to satisfy the demands of a growing human population while still conserving biodiversity. Worldwide, land modification to accommodate human resource needs has caused significant declines in wildlife populations. To help minimize biodiversity loss, we must support wildlife on human-dominated land, such as farms and urban areas, but our knowledge of how to do so is lacking. Agriculture is a major driver of land modification; but also has the potential to play a role in conserving biodiversity. To support critically endangered ecosystem engineers that use farms, such as giant Galapagos tortoises, we need to understand the characteristics encouraging or hindering them. To quantify tortoise habitat preferences, we assessed the relationship between tortoise density, habitat structure, and land-use type, by recording tortoise density on farms on Santa Cruz Island, Galapagos, over two years. Tortoise density was lowest in abandoned farmland and highest in tourist areas and was most strongly positively correlated with abundant ground cover, short vegetation, and few shrubs. The habitat features favoured by tortoises could potentially be manipulated to help support tortoise conservation on farms. Measuring wildlife preferences in human-dominated areas is an important step towards balancing biodiversity conservation and human-enterprise

    ED011. Levantamiento de línea base de la diversidad de insectos en 40 fincas en Santa Cruz, Galápagos

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    Agricultural production in Galapagos began in the early 20th century on the 4 inhabited islands. Currently, very little is known about the number, abundance and distribution of insect and plant species in the agricultural area. Information on the presence of invasive species and their impacts on agricultural production is also limited. To ensure the sustainability of human life and the conservation of Galapagos species, it is essential to know the terrestrial biodiversity and the interactions with socio-ecological systems. To fill this information gap, a baseline of insects was established on 40 farms on Santa Cruz Island. Transects were set up to carry out foliage sweeps with entomological nets and manual collections of insects in the crops of each farm. A total of 16,533 individuals were collected and identified at different taxonomic levels, 10,331 were identified at the species level. 135 species of insects were identified, of which 18.7 % corresponded to endemic, 13.3 % to native, and 46.7 % to introduced species. The species: Bromeloecia wolverinei, Ceraeochrysa everes, Coproica bisphanta, Cosmosciara hartii, Dettopsomyia formosa, Pseudolycoriella cavatica, Psychoda alternata, Pullimosina heteroneura, Zagrammosoma lineaticeps are new records for Galapagos. This information is a useful tool to incorporate into sustainable agricultural practices. For this reason, it is recommended to strengthen the entomological survey system and technical support in the agricultural area of Santa Cruz.La producción agrícola en las Galápagos empezó a principios del siglo XX en las cuatro islas habitadas. Actualmente, se conoce muy poco acerca del número, abundancia y distribución de especies de insectos y plantas en el área agropecuaria. La información sobre la presencia de especies invasoras y sus impactos en la producción agrícola también es escasa. Para asegurar la sostenibilidad de la vida humana y la conservación de las especies de las Galápagos, es fundamental conocer esta biodiversidad terrestre y las interacciones con los sistemas socio-ecológicos. Con el propósito de llenar esta brecha de información, se levantó una línea base de insectos en 40 fincas de la Isla Santa Cruz. Para esto, se establecieron transectos en los que se realizaron barridos del follaje con redes entomológicas y colectas manuales de insectos en los cultivos de cada finca. Se colectaron e identificaron a diferentes niveles taxonómicos 16 533 individuos y de estos, 10 331 fueron identificados a nivel de especie. Se identificaron 135 especies de insectos, de estas el 18,7 % corresponde a insectos endémicos, el 13,3 % a nativos, y el 46,7 % a introducidos. Las especies: Bromeloecia wolverinei, Ceraeochrysa everes, Coproica bisphanta, Cosmosciara hartii, Dettopsomyia formosa, Pseudolycoriella cavatica, Psychoda alternata, Pullimosina heteroneura, Zagrammosoma lineaticeps son nuevos registros para Galápagos. Esta información constituye una herramienta útil a la hora de incorporar prácticas agrícolas sostenibles. Por esto, se recomienda reforzar el sistema de vigilancia entomológica y acompañamiento técnico en la zona agropecuaria de Santa Cruz

    Preventing Establishment: An Inventory of Introduced Plants in Puerto Villamil, Isabela Island, Galapagos

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    As part of an island-wide project to identify and eradicate potentially invasive plant species before they become established, a program of inventories is being carried out in the urban and agricultural zones of the four inhabited islands in Galapagos. This study reports the results of the inventory from Puerto Villamil, a coastal village representing the urban zone of Isabela Island. We visited all 1193 village properties to record the presence of the introduced plants. In addition, information was collected from half of the properties to determine evidence for potential invasiveness of the plant species. We recorded 261 vascular taxa, 13 of which were new records for Galapagos. Most of the species were intentionally grown (cultivated) (73.3%) and used principally as ornamentals. The most frequent taxa we encountered were Cocos nucifera (coconut tree) (22.1%) as a cultivated plant and Paspalum vaginatum (salt water couch) (13.2%) as a non cultivated plant. In addition 39 taxa were naturalized. On the basis of the invasiveness study, we recommend five species for eradication (Abutilon dianthum, Datura inoxia, Datura metel, Senna alata and Solanum capsicoides), one species for hybridization studies (Opuntia ficus-indica) and three species for control (Furcraea hexapetala, Leucaena leucocephala and Paspalum vaginatum)

    An Extensive Alien Plant Inventory from the Inhabited Areas of Galapagos

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    Anne Guézou et al...Background Plant invasions are causing habitat degradation in Galapagos. Problems are concentrated on the four inhabited islands. Plants introduced to rural areas in the humid highlands and urban areas on the arid coast act as foci for invasion of the surrounding Galapagos National Park. Methodology/Principal Findings Here we present results of the most comprehensive inventory to date of alien vascular plants in the inhabited areas of Galapagos. The survey was conducted between 2002 and 2007, in 6031 properties (97% of the total) on Floreana, Isabela, San Cristobal and Santa Cruz Islands. In total 754 alien vascular plant taxa were recorded, representing 468 genera in 123 families. Dicotyledons represented 554 taxa, monocotyledons 183, there were 7 gymnosperms and 10 pteridophytes. Almost half (363) of the taxa were herbaceous. The most represented families were Fabaceae (sensu lato), Asteraceae and Poaceae. The three most recorded species in the humid rural areas were Psidium guajava, Passiflora edulis and Bryophyllum pinnatum, and in the dry urban areas, Aloe vera, Portulaca oleracea and Carica papaya. In total, 264 (35%) taxa were recorded as naturalized. The most common use for taxa was ornamental (52%). Conclusions/Significance This extensive survey has increased the known alien vascular flora of Galapagos by 257 species, giving a ratio of alien to native taxa of 1.57:1. It provides a crucial baseline for plant invasion management in the archipelago and contributes data for meta analyses of invasion processes worldwide. A repeat of the survey in the future would act as an effective early detection tool to help avoid further invasion of the Galapagos National Park.This work was accomplished with the support of Project ECU/00/G31 “Control of Invasive Species in the Galapagos Archipelago”, a donation from the Global Environment Facility (GEF) to the Ecuadorian Government, represented by the Ministry of Environment. The Project was implemented by the United Nations Development Programme (UNDP) and was executed by the Galapagos National Park Service (GNPS), Charles Darwin Foundation (CDF), National Institute for Galapagos (INGALA) and Ecuadorian Service for Agriculture and Livestock Sanitation - Galapagos (SESA-Galapagos). Additional financial support was provided by TAME Airlines, Galapagos Conservation Trust and Galapagos Conservancy. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. SWCA is included in the article because it relates to Christopher Buddenhagen's current place of employment, but SWCA did not fund any of the work and does not have any relation with the submitted article. C. Buddenhagen was employed by the Charles Darwin Foundation at the time of the inventory, and any subsequent work in relation with the submitted article was done on his own personal time.Peer reviewe

    Total number of introduced plant taxa in each neighbourhood in Puerto Villamil.

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    <p>Numbers above the bar indicate the number of properties surveyed in each neigbourhood. The neighbourhoods are organized by time since establishment with oldest neighborhoods on the left.</p

    Complete list of the introduced plant taxa encountered in Puerto Villamil.

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    <p><u>Legend</u> : Growth form: t) tree; sh) shrub; ssh) subshrub; h) herb; v) vine. Introduction status in Galapagos: Na) Native (not endemic); NaQ) Doubtfully native, possibly introduced; Cu) Cultivated (introduced for culture, not naturalized); Es) Escaped (introduced for culture, naturalized); Ac) Accidental (introduced unintentionnally, naturalized); AcQ) Doubtfully accidental (introduced, naturalized but it is not known if introduction was casual or intentional). Naturalization assessment: cu) cultivated; notcu) not cultivated; sex1) sexual regeneration from a non cultivated plant; sex2) sexual regeneration from a cultivated plant; asex1) asexual regeneration from a non cultivated plant; asex2) asexual regeneration from a cultivated plant; fl) presence of flowers; fr) presence of fruits; ▸fully naturalized taxon in Puerto Villamil.</p>1<p>indicates a new record for Galapagos,</p>2<p>indicates a new record for Isabela Island</p

    of Puerto Villamil with administrative divisions (2005) Source: Municipality of Isabela, Galápagos.

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    <p>of Puerto Villamil with administrative divisions (2005) Source: Municipality of Isabela, Galápagos.</p
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