Ecology of large felids and their prey in small reserves of the Yucatán Peninsula of Mexico.

Jaguars and pumas are top-predator species in the Neotropics that are threatened by habitat destruction, illegal poaching of their body parts and their favored prey, and by the human-wildlife conflicts that arise when predators attack livestock. Much of the remaining felid habitat in the Americas is in protected nature reserves that are too small and isolated to support local populations. Surrounding forests therefore play a vital role in felid conservation. Successful long-term conservation of these two felids requires evidence-based knowledge of their biological and ecological requirements. We studied population distributions of jaguars and pumas and their prey in and between two small, private reserves of the Northern Yucatán Peninsula, Mexico, with areas of 25 and 43 km2. During 2 years of camera trapping (2015 and 2016), we detected 21 jaguars, from which we estimated an average space requirement of 28-45 km2/individual. Dietary niche overlap exceeded random expectation. The most frequently occurring prey items in jaguar and puma diets were collared peccary and deer. Jaguar also favored nine-banded armadillos and white-nosed coati, while puma favored canids. Both felids avoided ocellated turkey. Overall, diet of jaguars was less species-rich, but similar in niche breadth, to that of pumas. A fluid use of space by both species, in 2015 tending toward mutual attraction and in 2016 toward partial exclusion of pumas by jaguars, combined with the high dietary overlap, is consistent with a dominance hierarchy facilitating coexistence. Jaguars and pumas favor the same prey as the people in local communities who hunt, which likely will intensify human-wildlife impacts when prey become scarce. We conclude that even small reserves play an important role in increasing the continuity of habitat for prey and large felids, whose generalist habits suppress interspecific competition for increasingly limiting prey that are largely shared between them and humans.

Los jaguares y pumas son las principales especies depredadoras del Neotrópico. Se encuentran amenazados por la destrucción de su hábitat, la caza furtiva de sus partes corporales, así como de sus presas favoritas, y por los impactos entre humanos y vida silvestre que surgen cuando estas especies atacan al ganado. Gran parte del hábitat protegido de los felinos restante en las Américas lo constituyen reservas naturales que son demasiado pequeñas y aisladas para por sí mismas sustentar las poblaciones locales de estas especies. Por lo tanto, los bosques circundantes juegan un papel vital para la conservación de estos felinos. La conservación exitosa a largo plazo de estas dos especies de felinos necesita conocimiento basado en evidencia de sus requerimientos biológicos y ecológicos. Estudiamos la distribución de poblaciones de jaguares y pumas, y sus presas, en dos pequeñas áreas protegidas privadas del norte de la península de Yucatán, México, con áreas de 25 y 43 km2, y en el área no protegida de 250 km2 que se encuentra entre ellas. Durante un estudio de foto-trampeo de dos años (2015 y 2016), detectamos 21 jaguares, a partir de los cuales estimamos requerimientos espaciales de 28­45 km2/individuo en promedio. La superposición entre nichos alimentarios superó las expectativas aleatorias. Las presas más frecuentes en las dietas del jaguar y el puma fueron el pecarí de collar y los venados. El jaguar también favoreció al armadillo de nueve bandas y coatí de nariz blanca, mientras que el puma favoreció a los cánidos. Ambos felinos evitaron al pavo ocelado. En general, la dieta de los jaguares presentó menor riqueza específica, pero similar amplitud de nicho a la de los pumas. Un uso fluido del espacio por parte de ambas especies hizo que en un año tendieran a tener atracción mutua y en otro a una exclusión parcial por parte de los jaguares a los pumas, lo cual, en combinación con la alta superposición alimentaria, es consistente con una jerarquía de dominancia que facilita la convivencia. Los jaguares y los pumas favorecieron las mismas presas que la gente que caza en las comunidades locales, lo que probablemente intensificará los impactos entre humanos y vida silvestre cuando las presas escaseen. Concluimos que incluso las reservas pequeñas desempeñan un papel importante en el aumento de la continuidad del hábitat para presas y grandes felinos, cuyos hábitos generalistas suprimen la competencia inter-específica por presas cada vez más limitadas que en gran parte comparten con los humanos.

Effects of different management strategies on long-term trends of Australian threatened and near-threatened mammals.

Monitoring is critical to assess management effectiveness, but broadscale systematic assessments of monitoring to evaluate and improve recovery efforts are lacking. We compiled 1808 time series from 71 threatened and near-threatened terrestrial and volant mammal species and subspecies in Australia (48% of all threatened mammal taxa) to compare relative trends of populations subject to different management strategies. We adapted the Living Planet Index to develop the Threatened Species Index for Australian Mammals and track aggregate trends for all sampled threatened mammal populations and for small (<35 g), medium (35-5500 g), and large mammals (>5500 g) from 2000 to 2017. Unmanaged populations (42 taxa) declined by 63% on average; unmanaged small mammals exhibited the greatest declines (96%). Populations of 17 taxa in havens (islands and fenced areas that excluded or eliminated introduced red foxes [Vulpes vulpes] and domestic cats [Felis catus]) increased by 680%. Outside havens, populations undergoing sustained predator baiting initially declined by 75% but subsequently increased to 47% of their abundance in 2000. At sites where predators were not excluded or baited but other actions (e.g., fire management, introduced herbivore control) occurred, populations of small and medium mammals declined faster, but large mammals declined more slowly, than unmanaged populations. Only 13% of taxa had data for both unmanaged and managed populations; index comparisons for this subset showed that taxa with populations increasing inside havens declined outside havens but taxa with populations subject to predator baiting outside havens declined more slowly than populations with no management and then increased, whereas unmanaged populations continued to decline. More comprehensive and improved monitoring (particularly encompassing poorly represented management actions and taxonomic groups like bats and small mammals) is required to understand whether and where management has worked. Improved implementation of management for threats other than predation is critical to recover Australia's threatened mammals.

Efectos de diferentes estrategias de manejo sobre las tendencias a largo plazo de los mamíferos amenazados y casi amenazados de Australia Resumen El monitoreo es fundamental para evaluar la efectividad del manejo, aunque faltan evaluaciones sistemáticas y a gran escala de este monitoreo para evaluar y mejorar los esfuerzos de recuperación. Compilamos 1,808 series temporales de 71 especies y subespecies de mamíferos terrestres y voladores amenazadas y casi amenazadas en Australia (48% de todos los taxones de mamíferos amenazados) para comparar las tendencias relativas de las poblaciones sujetas a diferentes estrategias de manejo. Adaptamos el Índice Planeta Vivo para desarrollar el Índice de Especies Amenazadas para los Mamíferos Australianos y así rastrear las tendencias agregadas de todas las poblaciones muestreadas de mamíferos amenazados y de los mamíferos pequeños (<35 g), medianos (35-5,500 g) y grandes (>5,500 g) entre 2000 y 2017. Las poblaciones sin manejo (42 taxones) declinaron en un 63% en promedio; los mamíferos pequeños sin manejo exhibieron las declinaciones más marcadas (96%). Las poblaciones de 17 taxones incrementaron 680% en los refugios (islas o áreas encercadas que excluían o eliminaban al zorro rojo [Vulpes vulpes] y al gato doméstico [Felis catus], especies introducidas) Afuera de los refugios, las poblaciones sometidas al cebado constante de los depredadores en un inicio declinaron en un 75% pero después incrementaron al 47% de su abundancia para el 2000. En los sitios en donde los depredadores no fueron excluidos o cebados sino sometidos a otras acciones (manejo del fuego, control de herbívoros introducidos), las poblaciones de los mamíferos pequeños y medianos declinaron más rápido, pero los mamíferos grandes declinaron de manera más lenta que las poblaciones sin manejo. Sólo el 13% de los taxones contaron con datos para sus poblaciones con y sin manejo; las comparaciones entre índices para este subconjunto mostraron que los taxones con poblaciones en incremento dentro de los refugios declinaron afuera de éstos, pero los taxones con poblaciones sujetas al cebado de depredadores afuera de los refugios declinaron más lentamente que las poblaciones sin manejo y después incrementaron, mientras que las poblaciones sin manejo continuaron su declinación. Se requiere un monitoreo más completo y mejorado (particularmente el que engloba las acciones de manejo mal representadas y los grupos taxonómicos como los murciélagos y los mamíferos pequeños) para entender si ha funcionado el manejo y en dónde. La implementación mejorada del manejo para las amenazas distintas a la depredación es fundamental para recuperar a los mamíferos amenazados de Australia.

Responses of New Zealand forest birds to management of introduced mammals.

Over the past 1000 years New Zealand has lost 40-50% of its bird species, and over half of these extinctions are attributable to predation by introduced mammals. Populations of many extant forest bird species continue to be depredated by mammals, especially rats, possums, and mustelids. The management history of New Zealand's forests over the past 50 years presents a unique opportunity because a varied program of mammalian predator control has created a replicated management experiment. We conducted a meta-analysis of population-level responses of forest birds to different levels of mammal control recorded across New Zealand. We collected data from 32 uniquely treated sites and 20 extant bird species representing a total of 247 population responses to 3 intensities of invasive mammal control (zero, low, and high). The treatments varied from eradication of invasive mammals via ground-based techniques to periodic suppression of mammals via aerially sown toxin. We modeled population-level responses of birds according to key life history attributes to determine the biological processes that influence species' responses to management. Large endemic species, such as the Kaka (Nestor meridionalis) and New Zealand Pigeon (Hemiphaga novaeseelandiae), responded positively at the population level to mammal control in 61 of 77 cases for species ≥20 g compared with 31 positive responses from 78 cases for species <20 g. The Fantail (Rhipidura fuliginosa) and Grey Warbler (Gerygone igata), both shallow endemic species, and 4 nonendemic species (Blackbird [Turdus merula], Chaffinch [Fringilla coelebs], Dunnock [Prunella modularis], and Silvereye [Zosterops lateralis]) that arrived in New Zealand in the last 200 years tended to have slight negative or neutral responses to mammal control (59 of 77 cases). Our results suggest that large, deeply endemic forest birds, especially cavity nesters, are most at risk of further decline in the absence of mammal control and, conversely suggest that 6 species apparently tolerate the presence of invasive mammals and may be sensitive to competition from larger endemic birds.

Respuestas de Aves Habitantes de Bosques Neozelandeses al Manejo de Mamíferos Introducidos Resumen En los últimos 1000 años, Nueva Zelanda ha perdido entre el 40% y 50% de las especies de aves. De estas extinciones, más de la mitad se puede atribuir a la depredación por mamíferos introducidos. Las poblaciones existentes de aves de bosque todavía están siendo depredadas por mamíferos, principalmente ratas, zarigüeyas y mustélidos. La historia de manejo de los bosques en Nueva Zelanda durante los recientes 50 años representa una oportunidad única porque un programa variado de control de mamíferos depredadores ha creado un experimento de manejo replicado. Realizamos un metaanálisis de las respuestas a nivel poblacional de las aves de bosque ante diferentes niveles de control de mamíferos registrados en toda Nueva Zelanda. Recolectamos datos de 32 sitios tratados de manera única y de 20 especies existentes de aves que representan un total de 247 respuestas poblacionales a tres intensidades de control de mamíferos invasores (cero, bajo y alto). Los tratamientos variaron desde la erradicación de los mamíferos invasores por vía de técnicas terrestres hasta la eliminación periódica de los mamíferos por medio de toxinas dispersadas por vía aérea. Modelamos las respuestas a nivel poblacional de las aves de acuerdo con los atributos de historia de vida importantes para determinar los procesos biológicos que influyen sobre las respuestas de las especies al manejo. Las especies endémicas grandes, como la kaka (Nestor meridionalis) y la paloma de Nueva Zelanda (Hemiphaga novaeseelandiae), respondieron positivamente a nivel poblacional al control de mamíferos en 61 de los 77 casos para especies con un peso ≥20 g comparado con 31 respuestas positivas de 78 casos para especies con un peso <20 g. El ave cola de abanico (Rhipidura fuliginosa) y la curruca gris (Gerygone igata), ambas especies endémicas someras, junto con cuatro especies no endémicas (el mirlo [Turdus merula], el pinzón [Fringilla coelebs], el acentor [Prunella modularis] y el pájaro de anteojos [Zosterops lateralis]) que arribaron a Nueva Zelanda en los últimos 200 años presentaron una tendencia hacia las respuestas negativas o neutrales al control de mamíferos (59 de 77 casos). Nuestros resultados sugieren que las aves endémicas grandes y que habitan en las profundidades del bosque, especialmente aquellas que anidan en cavidades, tienen el mayor riesgo de vivir una declinación en el futuro si el control de mamíferos se ausenta. A la inversa, nuestros resultados también sugieren que seis especies aparentemente toleran la presencia de mamíferos invasores y podrían ser vulnerables a la competencia generada por aves endémicas de mayor tamaño.

Trophic overlap of lionfish (Pterois volitans) and two native predators (Lutjanus apodus and Cephalopholis cruentata) in the western Caribbean / Traslape trófico del pez león (Pterois volitans) y dos depredadores nativos (Lutjanus apodus y Cephalopholis cruentata) en el Caribe occidental

Abstract Impact of invasive species on native biota may be due to predation, competition for space or food, or indirect effects. Lionfish (Pterois volitans), invasive in the western Atlantic, is a voracious generalist predator, so it is expected to have a significant trophic overlap with native fishes of comparable size and habits. The goal of this study was to determine the diets of potential competitors of the lionfish, in particular a grouper, Cephalopholis cruentata (Graysby), and a snapper, Lutjanus apodus (Schoolmaster), and to compare them to the diet of lionfish in Xcalak, southern Mexican Caribbean. Stomach contents were analyzed and electivity and diet overlap were estimated. The trophic overlap between the lionfish and the two putative competitors, especially the grouper, was high, including prey that was consumed by the predators in higher proportion than the relative abundance of the prey in the environment, and probably at the same time of day. Lionfish and grouper shared as important diet items Stegastes sp., Halichoeres sp., Brachyura, and Palaemonidae, and most full stomachs were found during the early morning. The hypothesis of competition between them for particular prey is supported, so we advise to continue the culling programs of lionfish and also to monitor the abundance of the possible native competitors.

Resumo El impacto de las especies invasoras sobre la biota nativa puede deberse a depredación, competencia por espacio o alimento, o efectos indirectos. El pez león (Pterois volitans), invasor en el Atlántico occidental, es un voraz depredador generalista, de modo que se espera que tenga un notable sobrelape trófico con peces nativos de tamaño y hábitos comparables. El objetivo de este estudio fue determinar las dietas de competidores potenciales del pez león, en particular un mero, Cephalopholis cruentata (payaso), y un pargo, Lutjanus apodus (canchix), y compararlas con la dieta del pez león en Xcalak, sur del Caribe mexicano. Se analizaron los contenidos estomacales y se estimó la selectividad y el traslape de dietas. El traslape trófico entre el pez león y los dos posibles competidores, sobre todo el mero, fue amplio, incluidas presas consumidas por los depredadores en proporción mayor a la abundancia relativa de éstas en el ambiente, y probablemente a la misma hora del día. El león y el mero compartieron como presas importantes Stegastes sp., Halichoeres sp., Brachyura, y Palaemonidae, y la mayoría de los estómagos llenos se encontraron en horas tempranas de la mañana. Se apoya entonces la hipótesis de competencia entre ellos por presas específicas, de modo que recomendamos continuar el programa de extracción de pez león y también el monitoreo de la abundancia de los posibles competidores nativos.

Planting gardens to support insect pollinators.

Global insect pollinator declines have prompted habitat restoration efforts, including pollinator-friendly gardening. Gardens can provide nectar and pollen for adult insects and offer reproductive resources, such as nesting sites and caterpillar host plants. We conducted a review and meta-analysis to examine how decisions made by gardeners on plant selection and garden maintenance influence pollinator survival, abundance, and diversity. We also considered characteristics of surrounding landscapes and the impacts of pollinator natural enemies. Our results indicated that pollinators responded positively to high plant species diversity, woody vegetation, garden size, and sun exposure and negatively to the separation of garden habitats from natural sites. Within-garden features more strongly influenced pollinators than surrounding landscape factors. Growing interest in gardening for pollinators highlights the need to better understand how gardens contribute to pollinator conservation and how some garden characteristics can enhance the attractiveness and usefulness of gardens to pollinators. Further studies examining pollinator reproduction, resource acquisition, and natural enemies in gardens and comparing gardens with other restoration efforts and to natural habitats are needed to increase the value of human-made habitats for pollinators.

Siembra jardines para dar soporte a los insectos polinizadores Resumen La declinación mundial de insectos polinizadores ha dado pie a esfuerzos de restauración, incluyendo la jardinería amigable con los polinizadores. Los jardines pueden proporcionar néctar y polen para los insectos adultos y también pueden ofrecer recursos reproductivos, como sitios de anidación y plantas hospederas para las orugas. Realizamos una revisión y un meta-análisis para examinar cómo las decisiones que toman los jardineros relacionadas a la selección de plantas y el mantenimiento del jardín influyen se la supervivencia, abundancia y diversidad de los polinizadores. También consideramos las características de los paisajes vecinos y los impactos de los enemigos naturales de los polinizadores. Nuestros resultados indicaron que los polinizadores respondieron positivamente a la alta diversidad de especies de plantas, la vegetación leñosa, el tamaño del jardín y la exposición al sol, mientras que respondieron negativamente a la separación entre los jardines y los sitios naturales. Las características intrínsecas de los jardines tuvieron una mayor influencia sobre los polinizadores que los factores del paisaje vecino. El creciente interés por la jardinería para polinizadores resalta la necesidad de entender como los jardines contribuyen a la conservación y como algunas características de los jardines pueden incrementar lo útil y atractivo de los jardines para los polinizadores. Se requieren estudios más profundos que examinen la reproducción de los polinizadores, la adquisición de recursos y los enemigos naturales en los jardines, y también que comparen a los jardines con otros esfuerzos de restauración y con los hábitats naturales para incrementar el valor de los hábitats para polinizadores creados por humanos.

Review: Knowledge status of predators of the freshwater prawn Cryphiops caementarius (Decapoda: Palaemonidae) in river systems along the North Western Andean region from Perú and Chile

Introduction: Cryphiops caementarius, is an endemic prawn from river ecosystems in Southern Perú and Northern Chile. In these watersheds, natural populations are threatened by multiple anthropic interventions such as mining activities and fishing pressure, but also, by increasing impacts of invasive exotic predators. Information related with predation on C. caementarius is scarce representing a major knowledge gap to ensure suitable management and conservation practices. Accordingly, the further deepening in relevant aspects such as the estimation of populations losses due to predators has been indicated as critical by relevant agencies as FAO. Objective: To conduct a complete registry and classification of C. caementarius predators, updating the knowledge for the Andean region. Methods: A thorough bibliographic review on existing information on C. caementarius' predators from Perú and Chile was carried out calculating percentage of occurrence, relative frequency of species, zoogeographic origin, trophic structure, phenotypic attributes, river zone that inhabits and life stage of incidence. The registry was complemented using semi-structured interviews from prawn´s fishers in central-Northern Chile. Results: C. caementarius is predated along the entire fluvial network (estuary, potamon and rhithron) by 21 species of opportunists, carnivores, omnivores and herbivores, mostly aquatic vertebrates. In turn, these belong to 15 families and six guilds of native, exotic and cosmopolitan species. Approximately 86 % predate on adult prawns, whilst, 71 % on juveniles and 24 % on larvae. More than 40 % of the predation pressure seems to be exerted by native waterfowls and 24 % by exotic fish. Conclusions: The results emphasize the relevance for conservation of native species of predators in the Andean region and the need of control measures on exotic species in a latitudinal basis. Accordingly, this review may serve as an initial decision-making tool for future conservation efforts both on prawns and native biota, but also supporting restocking actions, fisheries management plans and risk assessment for C. caementarius populations across the Andean region.

Introducción: Cryphiops caementarius es un camarón endémico de los ecosistemas fluviales del sur de Perú y norte de Chile. En estas cuencas hidrográficas, las poblaciones naturales están amenazadas por múltiples intervenciones antrópicas, como la actividad minera y presión pesquera, pero también por el creciente impacto de depredadores exóticos invasores. Información relacionada con la depredación sobre C. caementarius es escasa, representando una brecha de conocimiento importante para asegurar apropiadas prácticas de manejo y conservación. En consecuencia, la profundización en aspectos relevantes como la estimación de las pérdidas de población debido a los depredadores, ha sido indicada como crítica por agencias relevantes como FAO. Objetivo: Realizar un registro completo y clasificación de los depredadores de C. caementarius, actualizando el conocimiento para la región Andina. Métodos: Se realizó una revisión bibliográfica exhaustiva de la información existente sobre los depredadores de C. caementarius de Perú y Chile, calculando el porcentaje de frecuencia de ocurrencia y frecuencia relativa para cada especie, además de su respectivo origen zoogeográfico, estructura trófica, atributo fenotípico, zona fluvial que habita y etapa de la vida de incidencia del camarón. El registro se complementó con entrevistas semi-estructuradas a pescadores de camarones del centro-norte de Chile. Resultados: C. caementarius es depredado en diferentes zonas de la red fluvial (estuario, potamon y ritron) por 21 carnívoros, omnívoros y herbívoros, oportunistas y selectivos, en su mayoría vertebrados acuáticos. A su vez, estos se distribuyen en 15 familias y seis gremios, pertenecientes a tres categorías de origen zoogeográfico (nativo, exótico y cosmopolita). Aproximadamente el 86 % de estas especies depreda sobre la fracción adulta, mientras que el 71 % lo hace sobre juveniles y el 24 % sobre estadios larvales. Las aves acuáticas nativas ejercen más del 40 % de la presión depredadora, seguido por peces exóticos con un 24 %. Conclusiones: Los resultados enfatizan sobre relevancia que tiene la conservación de depredadores nativos en la región Andina y la necesidad de medidas de control sobre especies exóticas. En consecuencia, esta revisión puede servir como una herramienta inicial de toma de decisiones para futuros esfuerzos de conservación tanto de camarones como de la biota nativa, pero también apoyando acciones de gestión pesquera y evaluación de riesgos para C. caementarius en toda la región Andina.

Cómo perciben los niños el jaguar, Panthera onca (Carnivora: Felidae) en Jalisco, México

Los estudios sobre percepción humana hacia depredadores, generalmente se realizan con adultos. Sin embargo, es importante entender las percepciones de los niños, para diseñar estrategias de conservación y educación ambiental efectivas a largo plazo, ya que muchos de ellos serán los futuros manejadores de los recursos naturales. Analizamos las percepciones sobre el jaguar en niños de 8-12 años (n = 89) en comunidades dentro de la Reserva de la Biosfera Sierra de Manantlán (RBSM) y en su zona de influencia (ZI). Para conocer la percepción del jaguar, organizamos talleres con los niños, guiándolos con preguntas abiertas que respondieron con dibujos: ¿Qué animales viven en el monte/bosque? ¿Qué animales peligrosos viven en el monte/bosque? ¿Cómo es el jaguar y qué come? En todas las preguntas se especificó que nos referíamos a los animales presentes en los alrededores de su comunidad. Aparentemente el miedo colectivo hacia los animales influye en que animales se perciben en el entorno, ya que casi nadie dibujó al jaguar como parte del paisaje, pero si como animal peligroso. Las serpientes fueron las que más se relacionan como parte del entorno, y a la vez fueron las que más se mencionaron como animales peligrosos en ambas zonas. En el dibujo de animales peligrosos, hubo 72 menciones de animales no nativos. En ambas áreas, poco más de la mitad de los niños reconoce la forma básica del jaguar. Sobre todo, en la RBSM, la mayoría dibujó ganado vacuno en la dieta del jaguar, representando uno de los conflictos jaguar-humanos. Casi la mitad de los niños dibujó a los venados como parte de la dieta del jaguar en la RBSM y un tercio en la ZI. Un número considerable de niños incluyeron humanos en la dieta en ambas zonas. Concluimos que con el fin de mejorar la percepción es deseable desarrollar estrategias para cambiar las percepciones negativas del jaguar. Por ende, es importante generar material educativo y llevar a cabo campañas de educación ambiental resaltando la importancia ecológica del jaguar, enfatizando que el buen manejo del ganado reduce la depredación y que los humanos no son elementos de la dieta del jaguar. En resumen, es importante generar mayor empatía con el jaguar, y aclarar creencias erradas que puedan afectar la supervivencia del jaguar a largo plazo en estas áreas.

Predator perception studies generally only regard adults. However, it is necessary to also understand children perceptions in order to achieve more effective long term conservation and environmental educational strategies, since many of them will be the future resource managers. We analyze perceptions of the jaguar amongst children (n = 89) between 8 and 12 years old, in the Sierra de Manantlán Biosphere Reserve (SMBR) and its influence zone (ZI). To understand their perceptions, we organized workshops, using open-ended questions, to be answered with drawings: What animals live in the forest? Which dangerous animals live in the forest? What do jaguars look like and what do they eat? In all questions, we specified that we referred to animals close to their community. Apparently collective apprehension influences, which animals are perceived as part of the environment. Our results suggest that the jaguar is not conceived as part of the (direct) environment, but is conceived as dangerous animal in the area. Snakes are most mentioned as part of the environment; at the same time, they are perceived as the most dangerous. In the dangerous animal drawings, there were 72 mentions of no native animals. In all cases, more than half of the children knew the basic shape of a jaguar. Overall in the SMBR, most children drew cattle as the main food staple for the jaguar, representing one of the human-jaguar conflicts. Half of children drew deer as jaguar diet in the SMBR and one third in the ZI. A considerable number of children included humans in the jaguar diet in both zones. We conclude that it is necessary to develop strategies to change the negative perceptions of the jaguar. As such, it is important to generate educational material and carry out educational campaigns that highlight the ecological importance of the jaguar, and emphasizing those livestock management actions to reduce predation and the disappearance of false beliefs; which include jaguar as a people eater. In summary, is important to generate greater empathy with the jaguar, and clarify misconceptions that may affect the long-term survival of the jaguar in these areas.

A possible role of decorations in spiderwebs as protection devices that distract predators

Several functions have been proposed for silk decorations (i.e., stabilimenta) in spiderwebs. One hypothesis is that web decorations protect spiders from predators, either by concealing the spiders, physically shielding them, or by deflecting predatory attacks. This study uses data gathered in opportunistic manner when studying the behavior of Stenolemus giraffa, an assassin bug that preys almost exclusively on web-building spiders. Stenolemus giraffa approach orb spiders on foot, and usually capture the spiders at the hub region of the web. When pursuing spiders, S. giraffa routinely tap the web with their antennae, and also tap the spiders prior to attacking them. The observations available from this study suggest that S. giraffa got "distracted" momentarily by the decorations in the webs of Purumitra sp. (Uloboridae) and Argiope katherina (Araneidae). In some instances, the assassin bugs tapped these structures for several seconds or minutes instead of tapping the adjacent spiders. In interactions with A. katherina, S. giraffa was more successful at capturing the spiders when the webs lacked decorations; however, sample sizes are small (this could not be tested for Purumitra sp. because only one web lacked decorations). Finally, some of the spiders detected S. giraffa tapping the decorations or that had begun tapping the spiders and that had interrupted this behavior to tap the decorations. The data available suggest that, for S. giraffa, the decorations in these webs interfered with the process of locating the spiders. If further experiments corroborate this idea, this information would be in accord with Hingston's (1927) hypothesis that web decorations can confuse spider predators.

Muchas arañas agregan a sus telas estructuras de seda, detritos, u otros, que son conocidas como "estabilimentos" o "decoraciones". Varias funciones han sido propuestas para estas estructuras. Una de las hipótesis plantea que las decoraciones protegen a las arañas de los depredadores, ya sea porque ocultan a las arañas, o porque funcionan como una barrera física que separa al depredador de la araña, o porque desvían los ataques de los depredadores. En este estudio, se utilizan datos que fueron tomados de manera oportunista mientras se estudiaba el comportamiento del chinche asesino Stenolemus giraffa, un insecto que se alimenta casi exclusivamente de arañas que hacen tela. Stenolemus giraffa ataca a las arañas en el meollo de la tela, y se acerca hasta estas caminando. Stenolemus giraffa usualmente "toquetea" a las arañas con sus antenas (comúnmente sin hacer contacto con la araña) antes de atacarlas. Las observaciones de este estudio sugieren que S. giraffa se distrajo de forma momentánea con las decoraciones en las telas de Purumitra sp. (Uloboridae) y Argiope katherina (Araneidae). En algunas ocasiones, los chinches toquetearon con sus antenas estas estructuras por algunos segundos o incluso minutos, en vez de toquetear a las arañas que estaban adyacentes a estas. En interacciones con A. katherina, S. giraffa capturó en mayor proporción a las arañas que se encontraban en telas sin decoraciones; sin embargo, el tamaño de la muestra es pequeño. No se pudo realizar una comparación similar para Purumitra sp., ya que todas las telas, excepto una, tenían decoraciones. Algunas de las arañas detectaron a los chinches cuando estos estaban toqueteando las decoraciones, o después de que hubieran toqueteado a las arañas e interrumpieran este comportamiento para toquetear las decoraciones. Dichas observaciones sugieren que las decoraciones en estas telas interfirieron con el proceso de S. giraffa de localizar a las arañas. Si esto se corrobora mediante futuros experimentos, esta información apoyaría la idea de Hingston (1927) de que las decoraciones en las telas funcionan para confundir a los depredadores de arañas.

Diversidad de las comunidades de peces en dos áreas marinas protegidas del Caribe y su relación con el pez león / Diversity of native reef fish communities in two protected areas in the Caribbean Sea and its relationship to the invasive lionfish

Resumen El pez león (Pterois volitans) invadió la región del Caribe y tiene el potencial de alterar la composición y estructura de las comunidades de peces en los arrecifes coralinos. El objetivo de este estudio fue analizar los índices de diversidad en las comunidades de peces nativos en sitios invadidos por el pez león en dos áreas marinas protegidas (AMP) del Caribe y compararlos con datos previos a la invasión. En ambas AMP, Parque Nacional Guanahacabibes (PNG) en el occidente de Cuba y Parque Nacional Arrecifes de Xcalak (PNAX) en el S de Quintana Roo, se realizaron censos visuales de las especies de peces en hábitats durante las épocas de seca y lluvia del 2013-2015. Se evaluaron nueve sitios, mediante conteos estacionarios. Se registró mayor riqueza de especies en el PNG (43.47±5.14) que en el PNAX (40.22±4.96). No se observaron diferencias entre épocas en ninguna de las AMP. El pez león se ubicó entre las especies más abundantes del PNG. La abundancia media en el PNG (0.76 ± 1.25) fue mayor a la registrada en el PNAX (0.19±0.46). La diversidad disminuyó después de la llegada del pez león en un solo sitio del PNG y en dos sitios del PNAX, pero al parecer estos resultados están más asociados al efecto de la pesca que a la presencia del pez león. A partir de los resultados y asumiendo que los cambios en las comunidades de peces por el pez león podrían no detectarse aún, recomendamos seguir los monitoreos de los descriptores comunitarios para detectar cambios futuros en las comunidades de peces.

Abstract Lionfish (Pterois volitans) invaded the Caribbean region with the potential to alter the composition and structure of native coral reef fish communities. The objective of this study was to analyze the diversity indices of these fish communities potentially affected by lionfish predation and to compare with pre-invasion data. The study was undertaken in two Caribbean marine protected areas (MPAs): Guanahacabibes National Park (PNG) in W Cuba and Xcalak Reefs National Park (PNAX) in S Quintana Roo. We carried out visual censuses of fish species in reef habitats during the dry and rainy seasons of the period 2013-2015. For this, nine sites were defined and evaluated using stationary counts. Our results showed higher species richness (43.47 ± 5.14) and mean abundance (0.76 ± 1.25) in PNG than in PNAX (40.22 ± 4.96, 0.19 ± 0.46, respectively). Diversity decreased after the arrival of lionfish in a single site of PNG and in two sites of the PNAX, but apparently, these results are more related to the fishing activity effect than to the lionfish presence. Based on the results and assuming that changes in the native fish communities by lionfish may not yet be detected, we recommend to continue the monitoring community descriptions in order to detect future changes in native fish communities. Rev. Biol. Trop. 66(1): 189-203. Epub 2018 March 01.

Minimizing species extinctions through strategic planning for conservation fencing.

Conservation fences are an increasingly common management action, particularly for species threatened by invasive predators. However, unlike many conservation actions, fence networks are expanding in an unsystematic manner, generally as a reaction to local funding opportunities or threats. We conducted a gap analysis of Australia's large predator-exclusion fence network by examining translocation of Australian mammals relative to their extinction risk. To address gaps identified in species representation, we devised a systematic prioritization method for expanding the conservation fence network that explicitly incorporated population viability analysis and minimized expected species' extinctions. The approach was applied to New South Wales, Australia, where the state government intends to expand the existing conservation fence network. Existing protection of species in fenced areas was highly uneven; 67% of predator-sensitive species were unrepresented in the fence network. Our systematic prioritization yielded substantial efficiencies in that it reduced expected number of species extinctions up to 17 times more effectively than ad hoc approaches. The outcome illustrates the importance of governance in coordinating management action when multiple projects have similar objectives and rely on systematic methods rather than expanding networks opportunistically.

Critically evaluating best management practices for preventing freshwater turtle extinctions.

Ex situ conservation tools, such as captive breeding for reintroduction, are considered a last resort to recover threatened or endangered species, but they may also help reduce anthropogenic threats where it is difficult or impossible to address them directly. Headstarting, or captive rearing of eggs or neonate animals for subsequent release into the wild, is controversial because it treats only a symptom of a larger conservation problem; however, it may provide a mechanism to address multiple threats, particularly near population centers. We conducted a population viability analysis of Australia's most widespread freshwater turtle, Chelodina longicollis, to determine the effect of adult roadkill (death by collision with motor vehicles), which is increasing, and reduced recruitment through nest predation from introduced European red foxes (Vulpes vulpes). We also modeled management scenarios to test the effectiveness of headstarting, fox management, and measures to reduce mortality on roads. Only scenarios with headstarting from source populations eliminated all risks of extinction and allowed population growth. Small increases in adult mortality (2%) had the greatest effect on population growth and extinction risk. Where threats simultaneously affected other life-history stages (e.g., recruitment), eliminating harvest pressures on adult females alone did not eliminate the risk of population extinction. In our models, one source population could supply enough hatchlings annually to supplement 25 other similar-sized populations such that extinction was avoided. Based on our results, we believe headstarting should be a primary tool for managing freshwater turtles for which threats affect multiple life-history stages. We advocate the creation of source populations for managing freshwater turtles that are greatly threatened at multiple life-history stages, such as depredation of eggs by invasive species and adult mortality via roadkill.

An interdisciplinary review of current and future approaches to improving human-predator relations.

In a world of shrinking habitats and increasing competition for natural resources, potentially dangerous predators bring the challenges of coexisting with wildlife sharply into focus. Through interdisciplinary collaboration among authors trained in the humanities, social sciences, and natural sciences, we reviewed current approaches to mitigating adverse human-predator encounters and devised a vision for future approaches to understanding and mitigating such encounters. Limitations to current approaches to mitigation include too much focus on negative impacts; oversimplified equating of levels of damage with levels of conflict; and unsuccessful technical fixes resulting from failure to engage locals, address hidden costs, or understand cultural (nonscientific) explanations of the causality of attacks. An emerging interdisciplinary literature suggests that to better frame and successfully mitigate negative human-predator relations conservation professionals need to consider dispensing with conflict as the dominant framework for thinking about human-predator encounters; work out what conflicts are really about (they may be human-human conflicts); unravel the historical contexts of particular conflicts; and explore different cultural ways of thinking about animals. The idea of cosmopolitan natures may help conservation professionals think more clearly about human-predator relations in both local and global context. These new perspectives for future research practice include a recommendation for focused interdisciplinary research and the use of new approaches, including human-animal geography, multispecies ethnography, and approaches from the environmental humanities notably environmental history. Managers should think carefully about how they engage with local cultural beliefs about wildlife, work with all parties to agree on what constitutes good evidence, develop processes and methods to mitigate conflicts, and decide how to monitor and evaluate these. Demand for immediate solutions that benefit both conservation and development favors dispute resolution and technical fixes, which obscures important underlying drivers of conflicts. If these drivers are not considered, well-intentioned efforts focused on human-wildlife conflicts will fail.

Effects of invasive plants on arthropods.

Non-native plants have invaded nearly all ecosystems and represent a major component of global ecological change. Plant invasions frequently change the composition and structure of vegetation communities, which can alter animal communities and ecosystem processes. We reviewed 87 articles published in the peer-reviewed literature to evaluate responses of arthropod communities and functional groups to non-native invasive plants. Total abundance of arthropods decreased in 62% of studies and increased in 15%. Taxonomic richness decreased in 48% of studies and increased in 13%. Herbivorous arthropods decreased in response to plant invasions in 48% of studies and increased in 17%, likely due to direct effects of decreased plant diversity. Predaceous arthropods decreased in response to invasive plants in 44% of studies, which may reflect indirect effects due to reductions in prey. Twenty-two percent of studies documented increases in predators, which may reflect changes in vegetation structure that improved mobility, survival, or web-building for these species. Detritivores increased in 67% of studies, likely in response to increased litter and decaying vegetation; no studies documented decreased abundance in this functional group. Although many researchers have examined effects of plant invasions on arthropods, sizeable information gaps remain, specifically regarding how invasive plants influence habitat and dietary requirements. Beyond this, the ability to predict changes in arthropod populations and communities associated with plant invasions could be improved by adopting a more functional and mechanistic approach. Understanding responses of arthropods to invasive plants will critically inform conservation of virtually all biodiversity and ecological processes because so many organisms depend on arthropods as prey or for their functional roles, including pollination, seed dispersal, and decomposition. Given their short generation times and ability to respond rapidly to ecological change, arthropods may be ideal targets for restoration and conservation activities.

Strategic rat control for restoring populations of native species in forest fragments.

Forest fragments have biodiversity value that may be enhanced through management such as control of non-native predators. However, such efforts may be ineffective, and research is needed to ensure that predator control is done strategically. We used Bayesian hierarchical modeling to estimate fragment-specific effects of experimental rat control on a native species targeted for recovery in a New Zealand pastoral landscape. The experiment was a modified BACI (before-after-control-impact) design conducted over 6 years in 19 forest fragments with low-density subpopulations of North Island Robins (Petroica longipes). The aim was to identify individual fragments that not only showed clear benefits of rat control, but also would have a high probability of subpopulation growth even if they were the only fragment managed. We collected data on fecundity, adult and juvenile survival, and juvenile emigration, and modeled the data in an integrated framework to estimate the expected annual growth rate (λ) of each subpopulation with and without rat control. Without emigration, subpopulation growth was estimated as marginal (λ = 0.95-1.05) or negative (λ = 0.74-0.90) without rat control, but it was estimated as positive in all fragments (λ = 1.4-2.1) if rats were controlled. This reflected a 150% average increase in fecundity and 45% average increase in adult female survival. The probability of a juvenile remaining in its natal fragment was 0.37 on average, but varied with fragment connectivity. With juvenile emigration added, 6 fragments were estimated to have a high (>0.8) probability of being self-sustaining (λ > 1) with rat control. The key factors affecting subpopulation growth rates under rat control were low connectivity and stock fencing because these factors were associated with lower juvenile emigration and higher fecundity, respectively. However, there was also substantial random variation in adult survival among fragments, illustrating the importance of hierarchical modeling for fragmentation studies.

Drivers of seabird population recovery on New Zealand islands after predator eradication.

Eradication of introduced mammalian predators from islands has become increasingly common, with over 800 successful projects around the world. Historically, introduced predators extirpated or reduced the size of many seabird populations, changing the dynamics of entire island ecosystems. Although the primary outcome of many eradication projects is the restoration of affected seabird populations, natural population responses are rarely documented and mechanisms are poorly understood. We used a generic model of seabird colony growth to identify key predictor variables relevant to recovery or recolonization. We used generalized linear mixed models to test the importance of these variables in driving seabird population responses after predator eradication on islands around New Zealand. The most influential variable affecting recolonization of seabirds around New Zealand was the distance to a source population, with few cases of recolonization without a source population ≤25 km away. Colony growth was most affected by metapopulation status; there was little colony growth in species with a declining status. These characteristics may facilitate the prioritization of newly predator-free islands for active management. Although we found some evidence documenting natural recovery, generally this topic was understudied. Our results suggest that in order to guide management strategies, more effort should be allocated to monitoring wildlife response after eradication.

Trophic cascades following the disease-induced decline of an apex predator, the Tasmanian devil.

As apex predators disappear worldwide, there is escalating evidence of their importance in maintaining the integrity and diversity of the ecosystems they inhabit. The largest extant marsupial carnivore, the Tasmanian devil (Sarcophilus harrisii) is threatened with extinction from a transmissible cancer, devil facial tumor disease (DFTD). The disease, first observed in 1996, has led to apparent population declines in excess of 95% in some areas and has spread to more than 80% of their range. We analyzed a long-term Tasmania-wide data set derived from wildlife spotlighting surveys to assess the effects of DFTD-induced devil decline on populations of other mammals and to examine the relative strength of top-down and bottom-up control of mesopredators between 2 regions with different environmental conditions. Collection of the data began >10 years before DFTD was first observed. A decrease in devil populations was immediate across diseased regions following DFTD arrival, and there has been no indication of population recovery. Feral cats (Felis catus) increased in areas where the disease was present the longest, and feral cat occurrence was significantly and negatively associated with devils. The smallest mesopredator, the eastern quoll (Dasyurus viverrinus), declined rapidly following DFTD arrival. This result suggests the species was indirectly protected by devils through the suppression of larger predators. Rainfall deficiency was also a significant predictor of their decline. Environmental variables determined the relative importance of top-down control in the population regulation of mesopredators. In landscapes of low rainfall and relatively higher proportions of agriculture and human settlement, top-down forces were dampened and bottom-up forces had the most effect on mesopredators. For herbivore prey species, there was evidence of population differences after DFTD arrival, but undetected environmental factors had greater effects. The unique opportunity to assess population changes over extensive temporal and spatial scales following apex predator loss further demonstrated their role in structuring ecosystems and of productivity in determining the strength of top-down control.

CARÁBIDOS Y HORMIGAS DEL SUELO EN DOS ÁREAS CULTIVADAS CON MARACUYÁ AMARILLO (Passiflora edulis) EN EL VALLE DEL CAUCA, COLOMBIA / Soil Carabids and Ants in Two Farming Areas of Yellow Passion Fruit (Passiflora edulis) at Valle del Cauca, Colombia

Se examinó la fauna de carábidos (Coleoptera: Carabidae) y de hormigas (Hymenoptera: Formicidae) que sobreviven en el suelo de un cultivo de maracuyá bajo condiciones de manejo convencional en Roldanillo, Valle del Cauca, en los meses de marzo y mayo (período lluvioso) y junio y julio (período poco lluvioso) de 2012. Se realizaron cuatro muestreos de intensidad mensual en dos lotes con edades contrastantes, registrándose las especies presentes. Se encontraron 149 individuos de Carabidae distribuidos en diez especies y 2447 hormigas distribuidas en 19 morfoespecies. La especie más abundante de hormigas fue Solenopsis geminata, mientras que Megacephala (Tetracha) sobrina fue la especie más abundante de Carabidae. Se encontró además que la abundancia y riqueza de carábidos tienden a ser mayor en la temporada lluviosa, mientras que algunas especies de hormigas mostraron una preferencia por alguno de los períodos estacionales. Se concluye que en el área de estudio sobrevive una rica fauna de carábidos y hormigas del suelo, que podrían contribuir al control de poblaciones de insectos fitófagos asociados al cultivo de maracuyá.

The fauna of beetles (Coleoptera: Carabidae) and ants that survive in the soil of a passion fruit crop under conventional management in Roldanillo-Valle del Cauca was examined, in March and May (rainy season) and in June and July (dry season), 2012. We carried out four samplings of monthly intensity in two plots with plants of different ages, and registered the species found. We found 149 individuals of Carabidae, distributed into ten species and 2447 ants, distributed in 19 morphospecies. The most abundant species of ants was Solenopsis geminata, while Megacephala (Tetracha) sobrina was the most abundant species of Carabidae. It was also found that the abundance and richness of carabid beetles tend to be higher in the rainy season, while some ant species showed a preference for specific seasonal periods. We conclude that a rich fauna of ground carabids and ants survives in the study area, which could contribute in the control of phytophagous insects populations associated with the crops of passion fruit.

The shallow-water fish assemblage of Isla del Coco National Park, Costa Rica: structure and patterns in an isolated, predator-dominated ecosystem / El conjunto de peces de aguas poco profundas del Parque Nacional Isla del Coco, Costa Rica: estructura y patrones en un ecosistema aislado dominado por depredadores

Fishes at Isla del Coco National Park, Costa Rica, were surveyed as part of a larger scientific expedition to the area in September 2009. The average total biomass of nearshore fishes was 7.8 tonnes per ha, among the largest observed in the tropics, with apex predators such as sharks, jacks, and groupers accounting for nearly 40% of the total biomass. The abundance of reef and pelagic sharks, particularly large aggregations of threatened species such as the scalloped hammerhead shark (up to 42 hammerheads ha-1) and large schools of jacks and snappers show the capacity for high biomass in unfished ecosystems in the Eastern Tropical Pacific. However, the abundance of hammerhead and reef whitetip sharks appears to have been declining since the late 1990s, and likely causes may include increasing fishing pressure on sharks in the region and illegal fishing inside the Park. One Galapagos shark tagged on September 20, 2009 in the Isla del Coco National Park moved 255km southeast towards Malpelo Island in Colombia, when it stopped transmitting. These results contribute to the evidence that sharks conduct large-scale movements between marine protected areas (Isla del Coco, Malpelo, Galápagos) in the Eastern tropical Pacific and emphasize the need for regional-scale management. More than half of the species and 90% of the individuals observed were endemic to the tropical eastern Pacific. These high biomass and endemicity values highlight the uniqueness of the fish assemblage at Isla del Coco and its importance as a global biodiversity hotspot.

La biomasa promedio de peces costeros en el Parque Nacional Isla del Coco en septiembre de 2010 fue de 7,8 toneladas por hectárea, entre las más elevadas halladas jamás en zonas tropicales. Los grandes depredadores representaron el 40% de la biomasa total. La abundancia de tiburones costeros y pelágicos, particularmente las enormes agregaciones de tiburón martillo (hasta 42 individuos por hectárea) y los extensos bancos de carángidos y lutjánidos, muestran la capacidad que tienen los ecosistemas marinos no pescados para albergar elevadas biomasas de peces, y hacen de la Isla del Coco un lugar único en el mundo. No obstante, la abundancia de tiburones parece estar decreciendo desde 1999, probablemente a causa de la creciente presión pesquera en la región y la pesca ilegal en el interior del Parque. Un tiburón de Galápagos marcado se dirigió 255km en dirección a la Isla de Malpelo, Colombia. Estos resultados sugieren que los tiburones realizan importantes movimientos entre áreas marinas protegidas (Isla del Coco, Malpelo, Galápagos) en el Pacífico Tropical Oriental y remarcan la necesidad de una gestión regional de estos animales. Más del 50% de las especies y el 90% de individuos observados en los contajes eran endémicos del Pacífico Tropical Oriental.

EFECTO DE DIFERENTES TIEMPOS DE ALMACENAMIENTO EN FRÍO SOBRE ALGUNOS PARAMETROS DE Phytoseiulus persimilis (ATHIAS HENRIOT) Y Neoseiulus californicus (PARASITIFORMES: PHYTOSEIIDAE) / Effect of Different Times of Cold Storage on Some Parameters of Phytoseiulus persimilis (Athias Henriot) and Neoseiulus californicus. (Parasitiformes: Phytoseiidae)

Phytoseiulus persimilis Athias-Henriot y Neoseiulus californicus, (Mc. Gregor) son ácaros depredadores utilizados en programas de producción masiva para el control de ácaros fitófagos. En este trabajo se estudió el efecto sobre la supervivencia, longevidad, capacidad depredadora y fecundidad de estos ácaros después de almacenarlos a una temperatura de 8 ºC y humedad relativa de 85+/-5% durante diferentes tiempos (0, 7, 14, 21, 28 y 35 días). Durante el tiempo de evaluación los depredadores fueron individualizados y mantenidos a una temperatura de 25 °C y humedad relativa de 85+/-5%. Se presentó disminución en la supervivencia, longevidad, capacidad depredadora y fecundidad durante todo el periodo de evaluación de P. persimilis, después de ser almacenados por 21 o más días, al igual que la supervivencia y el consumo de presas de N. californicus. Sin embargo, la longevidad y oviposición durante todo el periodo de evaluación para N. californicus se afectaron después de ser almacenados por 28 o más días. No se presentaron efectos sobre el consumo y fecundidad diaria de ambos depredadores, con excepción del consumo diario de huevos por P. persimilis y el consumo diario de ninfas por N. californicus después de ser almacenados por 35 días.

The predatory mites Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus are used in programs of mass rearing for the control of phytofagous mites. The effect on survival, longevity, predator capacity and fecundity of this predators was studied after storage them to a temperature of 8 °C and relative humidity of 85+/-5 % during different periods of time (0, 7, 14, 21, 28 y 35 days). During the time of evaluation the predators were individualized and kept at 25 °C of temperature and relative humidity of 85+/-5 %. The survival, longevity predator capacity and fecundity presented during all the time of evaluation of P. persimilis displayed a decrease after being stored during 21 o more days, the same happened to the survival and consumption of N. californicus sp. However, the longevity and oviposition during all time of evaluation for N. californicus was reduced after storing them for 28 o more days. Daily consumption and daily fecundity of both predators had no effect, except on daily consumption of eggs for P. persimilis and daily consumption of nymphs for N. californicus after storing them for 35 days.

In-vitro predatory activity of nematophagous fungi from Costa Rica with potential use for controlling sheep and goat parasitic nematodes

In tropical and subtropical regions of the world, parasitic diseases are a main cause of losses in livestock productivity. The increased acquired resistence to anthelmintics by gastrointestinal nematodes, requires biological control be considered as a potential feasible and effective alternative. The most effective natural soil enemies of nematodes are nematophagous fungi. In order to collect and identify predator nematophagous fungi (PNF), samples were obtained from 51 farms distributed throughout the seven provinces of Costa Rica. The origin samples included: soil from different crops (potatoes, tomatoes, bananas, ornamental plants, squash and coffee); animal feces (cattle, sheep, goat and horse); soil and fallen leaves from forest; and plants with signs of nematode infection. Each sample was processed using three techniques for the extraction of fungi from soil: sprinkling technique, soil dilution and humidity chamber. Twenty four strains of nematophagous fungi were found in 19 farms; 83.3% of the fungi were isolated by sprinkling technique. The following fungi were idenified: Arthrobotrys oligospora (n=13); Candelabrella musiformis (n=9); and for the first time there was isolation of A. conoides (n=1) and A. dactyloides (n=1) in the country. Moreover, 16 strains from Trichoderma (n=13), Beauveria (n=1), Clonostachys (n=1) and Lecanicillium (n=1) were obtained. In addition, pH of each possible fungal isolation source was measured, and it varied from 5.2 to 9.9, however PNF isolates fell within the range of 5.6 to 7.5. The PNF strains were cultivated in four different media for the production of chhlamydospores: potato dextrose agar (PDA); corn meal agar (CMA); malt extract agar (MEA) and potato carrot agar (PCA). Out of these cultures, 95.8% of the strains formed chlamydospores primarily in the PCA. Of these strains, the profilic spore producers were subjected to ruminant artificial gastrointestinal conditions. A total of 14 fungi were tested, out of which 42.9% survived the digestive analysis. Neither A. conoides nor A. dactyloides were viable following the in vitro gastrointestinal test. The PNF isolated in this study demostrated an action against ovine and caprine gastrointestinal nematodes and are candidates for use in biological control of these organisms. Among these microorganisms, Candelabrella musiformis appears to be the most promising fungi for use as a biological control agent in Costa Rica. Rev. Biol. Trop. 59 (1): 37-52. Epub 2011 March 01.

El control biológico es en la actualidad una alternativa para el control de los nematodos gastrointestinales que desarrollaron resistencia a los principales grupos de antihelmínticos. Para el aislamiento e identificación de hongos nematófagos depredadores, se tomaron muestras de 51 fincas distribuidas entre todas las provincias de Costa Rica. La naturaleza de las muestras incluyó: suelos de diferentes sembradíos (papa, tomate, banano, plantas ornamentales, chayote y café), heces de animales (bovinos, ovinos, caprinos y equinos), suelo y hojarasca de bosques y plantas con signos de enfermedad causada por nematodos. Las muestras se procesaron mediante 3 técnicas diferentes para la extracción de hongos a partir del suelo: espolvoreado en placa, dilución de suelos y cámara húmeda. Veinticuatro cepas de hongos nematófagos fueron aisladas de 19 fincas; el 83.3% de éstos fueron aislados mediante las técnica de espolvoreado en placa. Los hongos fueron identificados como: Arthrobotrys oligospora (n=13), Candelabrella musiformis (n=9) y por primera vez se reporta el aislamiento de A. conoides (n=1) y A. dactyloides (n=1) en el país. Asimismo, se aislaron 16 cepas de hongos de los géneros Trichoderma (n=13), Beauveria (n=1), Clonostachys (n=1) y Lecanicillium (n=1). Adicionalmente se les midió el pH, el cual varió entre 5.2-9.9, ubicándose los HND dentro de un rango entre 5.6-7.5. Las cepas de HND fueron cultivadas en 4 medios diferentes para la producción de clamidosporas: papa dextrosa agar, harina de maíz, extracto de malta y agar papa-zanahoria. El 95.8% de las cepas aisladas produjeron clamidosporas, principalmente en el medio agar papa-zanahoria. De estas cepas, se escogieron las de mayor producción para ser sometidas a la prueba de digestibilidad in vitro. Un total de 14 cepas fueron sometidos a esta prueba, de las cuales el 42.9% resultaron viables; de éstas, las cepas de A. conoides y A. dactyloides no sobrevivieron a la prueba de digestibilidad in vitro. De los microorganismos aislados, Candelabrella musiformis se considera el más promisorio de los hongos como agente biológico en Costa Rica.