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1.
Rev. biol. trop ; 71(1)dic. 2023.
Article in English | LILACS-Express | LILACS | ID: biblio-1449505

ABSTRACT

Introduction: Seed dispersal and seed predation have important impacts on plant diversity and community structure. Rodents participate in both of these types of interactions. Objectives: To evaluate the removal of the seeds of Crescentia alata, Randia capitata, and Zea mays by the squirrel Notocitellus adocetus to determine how it affects these plant species, by dispersing or preying on their seeds. Methods: We studied 14 individuals for C. alata, 24 for R. capitata, and for Z. mays 35 individuals. We observed foraging and used camera traps to determine the part of the fruit (seed and/or pulp) consumed by the squirrels and the amount of fruit or seed consumed. We also placed fine sand traps (FST) to measure the percentage of seed removal. We quantified the fruits produced by the plant species studied and the percentage of damage caused by N. adocetus throughout the plots. Results: Notocitellus adocetus feeds on the seeds and pulp of C. alata and Z. mays. The species with the highest removal rate and the highest percentage of damage was C. alata. Zea mays was the plant species that had the highest percentage of removal from FST, the largest number of fruits, and the lowest percentage of damage. On FST, R. capitata had the lowest seed remotion. Conclusions: Notocitellus adocetus is considered a seed predator; however, due to its behavior and the characteristics of the fruits of C. alata and R. capitata, this rodent could make the seeds available to secondary seed dispersers.


Introducción: La dispersión y depredación de semillas tienen efectos importantes en la diversidad de plantas y estructura de las comunidades. Los roedores participan en estos tipos de interacciones. Objetivos: Evaluar la remoción de semillas de Crescentia alata, Randia capitata y Zea mays por la ardilla Notocitellus adocetus, para determinar su efecto en estas especies de plantas, dispersando o depredando semillas. Métodos: Estudiamos 14 individuos de C. alata, 24 para R. capitata y 35 individuos para Z. mays. Observamos el forrajeo y usamos cámaras trampas para determinar la parte del fruto (semilla y/o pulpa) consumida y la intensidad de consumo por las ardillas. También colocamos trampas de arena fina (FST) para medir el porcentaje de remoción de semillas. Cuantificamos los frutos producidos por las especies estudiadas y el porcentaje de daño ocasionado por N. adocetus, mediante parcelas. Resultados: Notocitellus adocetus se alimenta de las semillas y pulpa de C. alata y Z. mays. La especie que tuvo mayor tasa de remoción y mayor porcentaje de daño fue C. alata. La especie con mayor porcentaje de remoción, mayor número de frutos y menor daño en las FST fue Z. mays. En las trampas de arena fina, R. capitata tuvo la menor remoción de semillas. Conclusiones: Notocitellus adocetus es considerada depredadora de semillas, no obstante, por su comportamiento y las características de los frutos de C. alata y R. capitata, este roedor podría dejar disponibles las semillas a dispersores secundarios de semillas.

2.
Rev. peru. biol. (Impr.) ; 30(4)oct. 2023.
Article in English | LILACS-Express | LILACS | ID: biblio-1530340

ABSTRACT

We report a case of predation on the basket worm Oiketicus sp. (Lepidoptera, Psychidae) by the Streak-backed Oriole (Icterus pustulatus) in the Municipality of Santa Cruz Xoxocotlán, Oaxaca, Mexico. The bird was photographed, and we describe the prey based on its basket, cephalic capsule, and fragments of thoracic segments. We describe the foraging strategy and provide a list of previously recorded food resources in the diet of I. pustulatus. This is the first documentation of a basket worm being consumed by I. pustulatus, which may be considered omnivorous.


Reportamos un caso de depredación sobre el gusano canasta Oiketicus sp. (Lepidoptera, Psychidae) por la calandria dorso rayado (Icterus pustulatus) en el Municipio de Santa Cruz Xoxocotlán, Oaxaca, México. El ave fue fotografiada y describimos la presa a partir de su canasta, cápsula cefálica y fragmentos de segmentos torácicos. Describimos la estrategia de forrajeo y presentamos una lista de recursos alimentarios previamente registrados en la dieta de I. pustulatus. Esta es la primera documentación de alimentación de un gusano canasta por parte de I. pustulatus, el cual puede ser considerada omnivora.

3.
Rev. biol. trop ; 71abr. 2023.
Article in English | LILACS-Express | LILACS | ID: biblio-1449493

ABSTRACT

Introduction: The fireworm Hermodice carunculata is a widespread polychaete that can prey upon many coral species. However, few studies have examined the effect of fireworm predation on coral demographics during non-outbreak periods. Objective: To determine whether predation by H. carunculata compromised the growth, survival, and population performance of the threatened coral Acropora cervicornis. Methods: Nursery-reared coral fragments (n = 99) were fixed to the bottom of Punta Melones reef in the Island Municipality of Culebra, Puerto Rico. Predation activity and its demographic consequences on coral outplants were assessed from December 2020 to August 2022. Susceptibility to predation was compared between colonies collected directly from the reef and those originating from outside sources (e.g., coral nurseries). With the demographic data, simple size-based population matrix models were developed to 1) examine whether fireworm predation led to a significant decline in population growth rate (λ), 2) determine the demographic transition(s) that contribute the most to λ, and 3) determining the demographic transition(s) that accounted for differences in λ when comparing scenarios that considered either only predated colonies or both predated and non-predated outplants. Results: Predation increased over time, being more frequently observed in the area with the highest topographic relief and on colonies foreign to the study site. Outplants that were partially consumed grew significantly slower than non-predated colonies; however, predation did not threaten their survival. The likelihood of being attacked by the fireworm increased with branching complexity. The estimated λ for a scenario considering only predated colonies was 0.99, whereas, for a scenario where both predated and non-predated colonies were considered, λ was 0.91. Population growth, under the two scenarios, was mainly influenced by the probability of a large colony surviving and remaining at the largest size. Conclusions: Although predation can negatively impact coral growth, the relatively high survival rate of predated colonies compensates for the adverse effect. Since survival is the demographic transition that contributes most to population growth, it could be concluded that under a non-outbreak scenario, fireworm predation may not be the primary cause of A. cervicornis population decline.


Introducción: El gusano de fuego Hermodice carunculata es un poliqueto común que puede depredar muchas especies de coral. Sin embargo, pocos estudios han examinado el efecto de la depredación del gusano de fuego en la demografía de los corales durante periodos sin brotes poblacionales. Objetivo: Este estudio tuvo como objetivo determinar si la depredación por H. carunculata compromete el crecimiento, la supervivencia y el desempeño poblacional del coral amenazado Acropora cervicornis. Métodos: Fragmentos de coral criados en vivero (n = 99) se fijaron al fondo del arrecife Punta Melones en la Isla Municipio de Culebra, Puerto Rico. La actividad de depredación y sus consecuencias demográficas en los trasplantes de coral se evaluaron desde diciembre de 2020 hasta agosto de 2022. Se comparó la susceptibilidad a la depredación entre las colonias recolectadas directamente del arrecife y las que se originaron en fuentes externas (p. ej., viveros de coral). Con los datos demográficos, se desarrollaron modelos matriciales simples de población basados en el tamaño para 1) examinar si la depredación del gusano de fuego causa una disminución significativa en la tasa de crecimiento de la población (λ), 2) determinar las transiciones demográficas que más contribuyen a λ, y 3) determinar la(s) transición(es) demográfica(s) que explican las diferencias en λ al comparar escenarios que consideraron solo colonias depredadas o la combinación de colonias depredadas y no depredadas. Resultados: La depredación aumentó con el tiempo, observándose con mayor frecuencia en la zona de mayor relieve topográfico y en colonias ajenas al sitio de estudio. Los trasplantes consumidos parcialmente crecieron significativamente más lento que las colonias no depredadas; sin embargo, la depredación no amenazó su supervivencia. La probabilidad de ser atacado por el gusano de fuego aumentó con la complejidad morfológica de la colonia. El λ estimado para un escenario que consideraba solo las colonias depredadas fue de 0.99, mientras que, para un escenario en el que se consideraron tanto las colonias depredadas como las no depredadas, λ fue de 0.91. El crecimiento de la población, en ambos escenarios, estuvo influenciado principalmente por la probabilidad de que una colonia grande sobreviviera y permaneciera en el tamaño más grande. Conclusiones: Aunque la depredación puede tener un impacto negativo en el crecimiento de los corales, una tasa de supervivencia relativamente alta de las colonias depredadas compensa los efectos adversos. Dado que la supervivencia es la transición demográfica que más contribuye al crecimiento de la población, se podría concluir que, en un escenario sin brotes, la depredación por gusanos de fuego no debe ser la causa principal de la disminución de la población de A. cervicornis.

4.
Rev. bras. entomol ; 67(4): e20230054, 2023. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1529832

ABSTRACT

ABSTRACT Larvae of Hydrotaea species are facultative predators of larvae of other fly species on poultry farms, chicken feces, pig, and decaying carcasses. The Neotropical species H. albuquerquei occurs together with M. domestica in these environments and might be useful in the biological control of the latter. To verify the predatory capacity of H. albuquerquei larvae on the larvae of M. domestica, we varied the size of the larvae and the densities of the predators and prey under controlled laboratory conditions. Adults were collected from a poultry farm for the experiment, and the larvae they produced were reared in the laboratory. The second and third instar larvae of H. albuquerquei, when at higher densities, suppressed populations of house fly larvae when the latter were smaller than the former. This means that the functional response increases gradually with an increase in prey population density and predator size. In these conditions, one H. albuquerquei larva consumes up to 29 M. domestica larvae at high prey densities and could reduce 100% of the house fly population under a 50% prey density. This study confirmed a pattern previously observed in other predatory larvae and our results have implications for the biological control and integrated pest management programs of M. domestica in poultry and swine farms.

5.
Biota Neotrop. (Online, Ed. ingl.) ; 22(3): e20221370, 2022. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1403623

ABSTRACT

Abstract The Hooded Gnateater Conopophaga roberti Hellmayr, 1905 is an insectivorous understory passeriform with discrete behavior, whose reproductive attributes are poorly-known. In the present study, we describe the reproductive biology of the species and the growth pattern of the nestlings, based on observations conducted in remnants of the Cerrado savanna in eastern Maranhão state, in Brazil. The nests were identified during active searches conducted between June, 2018 and March, 2021. A total of 22 nests were found over the course of three breeding seasons. The cup-shaped nests were supported by small branches and were constructed at a mean height of 40.6 ± 16.1 cm (N = 21) above the ground. The nests were 23.1 ± 3.9 cm in length and 14.1 ± 1.6 cm in width (N = 21). The eggs were beige in color, with irregular brown mottling only at the rounded end of the egg, which had a mean length of 21.3 ± 0.8 mm, width of 17.2 ± 0.8 mm, and mass of 3.1 ± 0.1 g (N = 23). Hatchlings are completely naked and weigh 3.1 ± 0.2 g (N = 7), and when they abandon the nest, they have yet to reach full adult size, with the total length being 65.4% of that of the adult, the wing, 65.4%, the head, 73.9%, the culmen, 74.2%, the body mass, 73.3%, and the tarsus, 89.0% that of the adult. The growth curves are sigmoidal and all the coefficients of determination are at least 0.96, with the body length having the highest value (R2 = 0.98). During the breeding season, the adult pair emitted alarm calls constantly when observers were in the vicinity of the nest. On a number of occasions, members of the breeding pair were observed moving away from the nest as it was approached by observers, while engaging in broken-wing display. The nest architecture, the color of the eggs, and the behaviors presented by this gnateater were similar to those described for other Conopophaga. With this work we contributed to improve the knowledge on the breeding behavior of this poorly know group of understory insectivorous birds.


Resumo O chupa-dente-de-capuz Conopophaga roberti Hellmayr, 1905 é um passeriforme insetívoro de subbosque, de comportamento discreto e cujos atributos reprodutivos são pouco conhecidos. Aqui descrevemos a biologia reprodutiva da espécie e o padrão de desenvolvimento dos ninhegos, com base em observações realizadas em remanescentes de Cerrado no leste do Maranhão, Brasil. Os ninhos foram localizados por busca ativa entre junho de 2018 e março de 2021. Um total de 22 ninhos foram encontrados ao longo de três estações reprodutivas. Os ninhos, em forma de taça, foram sustentados por pequenos galhos e construídos a uma altura média de 40,6 ± 16,1 cm (N = 21) acima do solo. Mediram 23,1 ± 3,9 cm de comprimento por 14,1 ± 1,6 cm de largura. Os ovos são branco-amarelados e mediram 21,3 ± 0,8 mm por 17,2 ± 0,8 mm, com massa de 3,1 ± 0,1 g (N = 23). Ao eclodir, os ninhegos estão completamente nus e pesaram 3,1 ± 0,2 g (N = 7). Abandonam o ninho antes de atingirem o tamanho dos adultos, sendo o comprimento total equivalente a 65,4% do adulto, a asa 65,4%, a cabeça 73,9%, o cúlmen 74,2%, a massa corporal 73,3% e o tarso 89%. As curvas de crescimento apresentaram padrão sigmóide e todos os coeficientes de determinação foram maior ou igual a 0,96, sendo o comprimento do corpo o valor mais alto (R2 = 0.98). Durante o período reprodutivo, o casal adulto emitia alertas constantemente quando os observadores se aproximavam dos ninhos. Em diversas ocasiões foi observado o comportamento de defesa de "asa quebrada" pelo casal reprodutor. A arquitetura do ninho, a cor dos ovos e os comportamentos apresentados por Conopophaga roberti se assemelham aos descritos para outras espécies do gênero. Com este trabalho, melhoramos o conhecimento sobre a biologia reprodutiva deste grupo de aves insetívoras de sub-bosque pouco conhecido.

6.
Rev. biol. trop ; 69(3)sept. 2021.
Article in English | LILACS, SaludCR | ID: biblio-1387668

ABSTRACT

Abstract Introduction: Although olive ridley sea turtle (Lepidochelys olivacea) are the most abundant sea turtles in the world, quantitative information is scarce and unevenly distributed among regions. There are many management and conservation programs for this species, and assessments are necessary to identify nesting trends and effectively manage current conservation programs. PROTORMAR-UAS is a Research and Conservation program for the olive ridley turtle created by the Autonomous University of Sinaloa, Mexico. The program utilizes two biological stations: Santuario Playa Ceuta (SPC) and Playa Caimanero (PC). Objective: To evaluate the nesting trend of olive ridley turtles on two beaches in Northwestern Mexico and to predict prospective nesting trends for the next 30 years. Methods: Using annual nesting data collected over 40 years at SPC (1976-2016) and 30 years at PC (1986-2016), we evaluated nesting trends, hatching success, predation and poaching of olive ridley turtles on the two beaches in Northwestern Mexico. Then, prospective nesting estimates for the next 30 years were calculated predictive time series model. Results: A positive and significant correlation was identified between the number of annual nests and time for both beaches (rho = 0.850, P ≤ 0.01 for SPC; rho = 0.677, P ≤ 0.01 for PC); the average hatching success rates were 65.09 at SPC and 60.72 % at PC. The predictive time-series model indicated that the numbers of nests will continue to increase through 2045, increasing three-fold at SPC and six-fold at PC with respect to the last year of monitoring. Conclusions: There was a clear positive trend in the number of olive ridley sea turtle nests at both sites, which is consistent with trends found in other recent studies from the region. Therefore, we suggest that PC be designated a legally protected nesting area since it is located within the latitudinal limits of olive ridley nesting and given the need for resources for camp operation considering increased nesting and current problems with predation and poaching. Because in Mexico operating a nesting beach without any protection status implies not having a budget for its management.


Resumen Introducción: A pesar de que las tortugas golfinas (Lepidochelys olivacea) son las tortugas marinas más abundantes del mundo, su información cuantitativa disponible es escasa y se encuentra distribuida de manera desigual entre regiones. Existen muchos programas de manejo y conservación para esta especie, y sus evaluaciones son necesarias para identificar tendencias de anidación y poder manejar de manera efectiva los programas de conservación actuales. PROTORMAR-UAS es un programa de Investigación y Conservación de la tortuga golfina creado por la Universidad Autónoma de Sinaloa, México. El Programa cuenta con dos estaciones biológicas: Santuario de Playa Ceuta (SPC) y Playa Caimanero (PC). Objetivo: Evaluar la tendencia de anidación de la tortuga golfina en dos playas del noroeste de México y predecir las tendencias prospectivas de anidación para los próximos 30 años. Métodos: A partir de los datos de registros anuales de anidación de 40 años para SPC (1976-2016) y 30 años para PC (1986-2016), evaluamos las tendencias de anidación, el éxito de la eclosión y los problemas de depredación y saqueo de nidos de la tortuga golfina en las dos playas del noroeste de México. Posteriormente, se calcularon las estimaciones prospectivas de anidación para los próximos 30 años usando un modelo predictivo de series de tiempo. Resultados: Se identificó una correlación positiva y significativa entre el registro anual de nidos y el tiempo de estudio para ambas playas (rho = 0.850, P ≤ 0.01 para SPC; rho = 0.677 y P ≤ 0.01 para PC); así como el éxito de eclosión promedio de 65.09 para SPC y de 60.72 % para PC. El modelo predictivo de series de tiempo indicó que las anidaciones continuarán aumentando para el 2045, tres veces para SPC y seis para PC, con respecto al último año de monitoreo. Conclusiones: Hay una clara tendencia positiva de anidación de la tortuga golfina en ambos sitios, lo cual es consistente con la tendencia observada en otros estudios recientes de la región. Por lo tanto, sugerimos incluir a PC como un área de anidación legalmente protegida, la cual se ubica en los límites latitudinales de anidación de la tortuga golfina, dada la necesidad de contar con recursos disponibles para la operación del campamento ante el aumento de anidaciones y de problemas de depredación y saqueo. Porque en México operar una playa de anidación sin ningún estatus de protección implica no tener presupuesto para su manejo.


Subject(s)
Animals , Reproduction , Turtles , Conservational Biological Control , Mexico
7.
Braz. j. biol ; 81(3): 845-853, July-Sept. 2021. tab, graf
Article in English | LILACS | ID: biblio-1153412

ABSTRACT

Abstract The Toltén river is located in the 137 years old Araucania region, Chile (38° S), and is characterized by low alterations through human interference due agriculture and towns in its surrounding basin, the presence of native fishes and salmonids, and by its lake effluent regime originated from Villarrica lake. The aim of the present study was to make a review of ecological role of the benthic inland water macroinvertebrates as preys for native fishes of the River Toltén, in order to understand their importance in the ecosystem of the river. The literature revealed that the main prey for native fishes are Chironomidae larvae, nevertheless there are not specific reports for Tolten river. The exposed results are similar with similar native species for Patagonia, and these native species would have prey for introduced salmonids, or these species would have prey competition with introduced salmonids in according to the literature descriptions for Argentinean and Chilean Patagonia.


Resumo O rio Toltén está localizado na região da Araucanía, com 137 anos de idade, Chile (38° S), e é caracterizado por baixas alterações por interferência humana devido à agricultura e cidades da bacia circundante, pela presença de salmonídeos e pelo regime de efluentes dos lagos. do lago Villarrica. O objetivo do presente estudo foi fazer uma revisão do papel ecológico dos macroinvertebrados bentônicos de águas interiores do rio Toltén, a fim de entender sua importância no ecossistema do rio. A literatura revelou que as principais presas de peixes nativos são as larvas de Chironomidae, no entanto, não há relatos específicos para o rio Tolten. Os resultados expostos são semelhantes com espécies nativas semelhantes para a Patagônia, e essas espécies nativas teriam presa por salmonídeos introduzidos, ou essas espécies teriam competição de presas com salmonídeos introduzidos de acordo com as descrições da literatura para a Patagônia Argentina e Chilena.


Subject(s)
Humans , Animals , Aged, 80 and over , Ecosystem , Rivers , Lakes , Chile , Fishes
8.
Acta biol. colomb ; 25(3): 359-367, sep.-dic. 2020. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1149016

ABSTRACT

ABSTRACT Cities have grown throughout the Andes and we know little about the ecology of those species that tolerate them, limiting our options to do conservation. We applied optimal foraging theory to examine the behavior of the Andean White-eared Opossum (Didelphispernigra), in a suburban area in Bogotá, Colombia. We used the giving-up density technique, which uses the amount of food left in a feeding patch, to evaluate whether the opossum's foraging costs were affected by the height of food from the ground, and the quality and quantity of food. We also evaluated whether the spatial heterogeneity of the study site affected the opossum's foraging. We used an artificial feeding patch to test these ideas. When food was either concentrated and, in less amount (concentrated food) or diluted and more amount (diluted food), the opossums preferred to forage at 2 m than at 0.5 m, and they showed a preference for concentrated food at 0.5 m, but not at 2 m. The opossums' habitat use was affected by the spatial heterogeneity at the study site and animals preferred foraging along metal fences than on live fences made of trees. When a cable allowed connection between the metallic and live fences, the value of food patches at the live fence appeared to increase. Thus, although the opossums need resources associated with natural environments, our results suggest that there are human modifications that can benefit them, such as those that reduce the risk of predation and favor their mobility in suburban environments.


RESUMEN En los Andes las ciudades han crecido y sabemos poco sobre la ecología de aquellas especies que toleran dicho crecimiento, limitando las opciones para su apropiada conservación. Aplicamos la teoría de uso óptimo de parches para examinar el comportamiento de forrajeo del fara (Didelphispernigra) en un área suburbana de Bogotá, Colombia. Utilizamos la técnica de densidad de abandono, que usa la cantidad de alimento dejada en un parche, para evaluar si los costos de forrajeo de este marsupial fueron afectados por la altura de los parches desde el suelo, así como la calidad y cantidad de alimento. Igualmente, evaluamos el efecto de la heterogeneidad espacial del área de estudio sobre el forrajeo del fara. Usamos un parche alimentario artificial con alimento líquido para evaluar estas hipótesis. Cuando el alimento era concentrado y en menor cantidad (concentrado) o diluido y en mayor cantidad (diluido), los faras prefirieron forrajear a 2 m, y prefirieron el alimento concentrado sobre el diluido a 0.5 m, pero no a 2 m. El uso del hábitat del fara fue afectado por la heterogeneidad espacial en el sitio de estudio y ellos prefirieron forrajear a lo largo de cercas metálicas, más que sobre cercas vivas. Cuando un cable permitió la conexión entre las cercas metálicas y vivas, el valor de algunos parches en la cerca viva pareció aumentar. Aunque los faras necesitan recursos asociados con ambientes naturales, nuestros resultados sugieren que las modificaciones humanas, como las que reducen el riesgo de depredación y favorecen su movilidad, pueden beneficiarlos.

9.
Rev. bras. entomol ; 64(3): e20200046, 2020. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1137747

ABSTRACT

ABSTRACT Biotic factors such as predation, although important drivers of the black fly community, are rarely investigated in the literature. This study aimed to test the hypothesis that the patterns of co-occurrence of black fly larvae and its potential predators is not random and that there is a correlation between its frequencies and Simuliidae larvae abundances. Larvae were sampled from two localities in the Pedra Branca State Park, Rio de Janeiro, Brazil, during the dry season in june 2018. We collected Simulium pertinax Kollar, 1832, Simulium subpallidum Lutz, 1910, Simulium (Inaequalium) sp., Simulium (Psaroniocompsa) sp. and Simulium (Trichodagmia) sp. The predators families present were Perlidae, Hydropsychidae, Leptoceridae, Libellulidae and Chironomidae. The null models showed that species co-occurred significantly more than expected by chance. The canonical correlation analyses for the Vargem Grande and Pau da Fome areas area showed a significant relationship between black fly abundances and predator abundances. In Vargem Grande the abundance of Chironomidae showed a highly significant positive correlation to S. (Psaroniocompsa) sp., while Hydropsychidae was significantly correlated to Simulium sp. On the other hand, in Pau da Fome Libellulidae was significantly correlated to S. (Psaroniocompsa) sp. and Simulium sp. and Chironomidae correlated significantly to Simulium sp. The result is consistent with what would be expected of organisms that exercise mutual population regulation, although other factors than biotic interactions may be causing these patterns. However the lack of mechanistic evidences on the effect of biotic interactions on black fly populations pose a challenge on the understanding of these patterns.

10.
Biota Neotrop. (Online, Ed. ingl.) ; 20(4): e20190943, 2020. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1131948

ABSTRACT

Abstract: Anurans are predator and prey, playing an important role in ecosystem functioning. The diet composition is closely related to feeding strategy, and the information about prey items is useful to understand intra and interspecific interactions in trophic webs. Here we determined diet composition, feeding strategy, and relation between prey ingestion and body measures of Crossodactylus timbuhy, a recently described anuran species. We found 466 prey items from 20 prey categories in the stomach of 66 specimens (15 males and 51 females) of C. timbuhy. The diet consists mostly of Formicidae and Coleoptera, the items with the highest number, frequency of occurrence and prey importance. The diet composition was relatively similar to other species of Crossodactylus. Prey volume was positively related to frog size and weight, suggesting frogs may feed upon any prey they can swallow. Diet showed some variation between sexes. Despite females were larger and heavier than males, females had higher consumption of smaller prey, and ingested a larger number of prey categories. We suggest C. timbuhy has an invertebrate-opportunistic feeding habit. It is likely C. timbuhy uses a combination of 'sit-and-wait' and 'active search' strategies due to high consumption of both highly mobile and sedentary prey.


Resumo: Os anuros são predadores e presas, desempenhando um importante papel no funcionamento dos ecossistemas. A composição da dieta está intimamente relacionada à estratégia de forrageamento das espécies e as informações sobre os itens consumidos são úteis para compreensão das interações intra e interespecíficas nas redes tróficas. O presente estudo objetivou determinar a composição da dieta, a estratégia de forrageamento e a relação entre a ingestão de presas e as medidas corporais de Crossodactylus timbuhy, uma espécie de anuro descrita recentemente. Foi analisado o conteúdo estomacal de 66 espécimes (15 machos e 51 fêmeas) de C. timbuhy e registrados 466 itens alimentares, distribuídos em 20 categorias de presas. A dieta consistiu principalmente de Formicidae e Coleoptera, as quais apresentaram maior número de itens consumidos, maior frequência de ocorrência e maior importância entre as presas registradas. A composição da dieta foi relativamente semelhante à de outras espécies do gênero Crossodactylus. O volume das presas foi positivamente relacionado com o tamanho e o peso dos espécimes, sugerindo que os indivíduos podem se alimentar de qualquer presa que eles possam engolir. A dieta apresentou variação entre os sexos. Apesar das fêmeas serem maiores e mais pesadas do que os machos, elas consumiram mais presas menores e ingeriram mais categorias de presas. Sugere-se que C. timbuhy tenha hábito alimentar invertebrado-oportunista. É provável que C. timbuhy apresente uma combinação de estratégias "senta-e-espera" e "forrageador ativo" devido ao alto consumo de presas altamente móveis e de presas sedentárias.

11.
E-Cienc. inf ; 9(2): 141-163, jul.-dic. 2019.
Article in Spanish | LILACS, SaludCR | ID: biblio-1089871

ABSTRACT

RESUMEN En el marco del presente ensayo, esta discusión tiene como propósito poner en evidencia el embargo que ha venido sufriendo las producciones académica y la científica, en el ámbito de las publicaciones escritas, por parte de bases de datos propiedad de consorcios comerciales transnacionales, cuya misión corporativa ha estado orientada fundamentalmente al lucro. En este proceso de embargo, quienes investigan han perdido el dominio y la soberanía sobre su producción intelectual. La investigación se ha visto reducida a criterios de gestión, y la comunicación del conocimiento ha quedado restringida por las transacciones monetarias y la mercadotecnia empresarial.


ABSTRACT Within the framework of this essay, the purpose of this discussion is to highlight the embargo that academic and scientific productions have been suffering, in the field of written publications, by databases owned by transnational commercial consortia, whose corporate mission has been fundamentally oriented to profit. In this embargo process, researchers have lost control and sovereignty over their intellectual production. Research has been reduced to management criteria, and the communication of knowledge has been restricted by monetary transactions and corporate marketing.


Subject(s)
Serial Publications/standards , Database Management Systems , Editorial Policies , Scientific and Technical Publications , Information Technology , Negotiating
12.
Acta amaz ; 49(4): 307-310, out. - dez. 2019.
Article in English | LILACS | ID: biblio-1118953

ABSTRACT

Although relatively common among omnivorous primates, anurophagy is still poorly documented in frugivorous species. Here we report the predation of a giant gladiator treefrog (Boana boans) by a large arboreal frugivore, the gray woolly monkey (Lagothrix lagotricha cana). The predation event occurred in a stretch of riparian forest located in a fragmented region in Cacoal, Rondônia state, in southwestern Brazilian Amazonia. Anurans can be a profitable, non-contested, and relatively easily acquired alternative resource for gray woolly monkeys, helping to fulfill their demand for protein, especially in periods of fruit scarcity. This new record broadens the knowledge on the natural history and predators of the giant gladiator frog. (AU)


Subject(s)
Anura , Primates , Amazonian Ecosystem , Diet , Atelinae
13.
Neotrop. ichthyol ; 17(1): e180165, 2019. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-990195

ABSTRACT

Studies of mixed-species groups of animals can reveal emergent complexities of collective behaviors. In this study we collected data on mixed-species hunting groups composed primarily of piscivorous fishes (species composition, abundance, behavioral interactions) and used both multivariate and network analyses to quantify pair-wise and guild level behavioral relationships. Our results indicate that such collective behaviors exhibit consistent patterns of associations (33 species with 282 pair-wise links within the observed network) with 10 dominant species accounting for 60% of pair-wise interactions. Species richness within groups varied (mean = 2.4, range 2-6 species) as did group size (mean = 8.1 individuals, range 2-80). Mixed-species groups, in general, were composed of species representing morphologically diverse forms that appeared to enhance access to shelter sites and implement diverse strategies for prey capture. It is noteworthy that the composition of groups did not reflect the relative abundances of their component species within the overall community of fishes, suggesting that group membership was an elective choice. The identification of these patterns, assuming they are persistent features of these communities, can be used as a foundation for studies to assess dynamics of mixed-species relationships, rates of predator success based on group membership, demographic consequences, and responses to variations in habitat attributes and associated prey resources. Such information could be used to interpret the nature of multispecies interactions within predator communities and potentially aid in conservation and management.(AU)


Estudios de grupos mixtos de animales puede revelar complejidades y sutilezas del comportamiento colectivo. En este estudio recolectamos datos sobre depredación de grupos mixtos de especies, compuestos principalmente por piscívoros (composición de especies, abundancia, interacciones) y usamos tanto análisis multivariado como de redes para cuantificar relaciones de comportamiento entre pares de especies y a nivel de gremios. Nuestros resultados indican que los comportamientos colectivos exhiben patrones consistentes de asociaciones (33 especies con 382 interacciones entre pares de especies dentro de la red) con 10 especies dominantes que constituyen el 60% de las interacciones entre dos especies. La riqueza de especies dentro de grupos varió (media = 2.4, ámbito 2-6 especies) cómo también el tamaño del grupo (media = 8.1, ámbito 2-80). Los grupos de especies mixtas, en general, estaban compuestos por especies con diversas morfologías que aparentemente aumentan el accesos a lugares estrechos y además, implementa diversas estrategias de captura de presas. Vale la pena resaltar que la composición de los grupos no reflejaba la abundancia relativa de las especies en la comunidad total de peces, sugiriendo que la membresía en el grupo era algo electivo. La identificaión de estos patrones, asumiendo que son características persistentes de la comunidad, se podrán usar en estudios para determinar la dinámica de las relaciones de grupos mixtos, tasa de éxito de depredación basado en la membresía del grupo, consecuencias demográficas y respuestas a varicaciones en las habitat y presas. Esta información servirá para interpretar la naturaleza de las interacciones multiespecíficas dentro de la comunidad de depredadores y potencialmente ayudar en la conservación y manejo de recursos.(AU)


Subject(s)
Animals , Predatory Behavior , Symbiosis , Behavior, Animal , /analysis
14.
Neotrop. ichthyol ; 17(3): e180116, 2019. graf
Article in English | LILACS, VETINDEX | ID: biblio-1040658

ABSTRACT

The predator-prey relationships between juvenile Nile Tilapia Oreochromis niloticus and native fish species of the Paraná River basin, Brazil, were experimentally examined. Juveniles of O. niloticus were offered to three native predator species (Salminus brasiliensis, Pseudoplatystoma corruscans, and Brycon orbignyanus) in 2,000-L tanks with four levels of habitat complexity (0%, 50%, 100% and RD (rocks and driftwood)). Predator efficiency was more variable among species (S. brasiliensis consumed 86.6% of the prey, P. corruscans 22.5% and B. orbignyanus 18.3%) than among levels of habitat complexity, and S. brasiliensis was faster than the others in detecting and consuming the prey. The higher predatory efficiency observed for S. brasiliensis can be partially explained by its more aggressive behavior (it fed earlier and for longer) and its presence in the surface layer. Here, the presence of predators led to O. niloticus juveniles spending more time at the surface or remaining in schools to coexist at the bottom with the predators, as expected for cichlids under predatory pressure in natural environments. Our results suggest that preserving and restoring populations of S. brasiliensis (and also to some extent P. corruscans and B. orbignyanus) might help to control O. niloticus in the Paraná River basin.(AU)


As relações predador-presa entre alevinos de Tilápia-do-Nilo Oreochromis niloticus e espécies de peixes nativos da bacia do rio Paraná, Brasil, foram examinadas experimentalmente. Dez alevinos de O. niloticus foram oferecidos a três espécies nativas de predadores (Salminus brasiliensis, Pseudoplatystoma corruscans e Brycon orbignyanus) em tanques de 2000L com quatro níveis de complexidade ambiental (0%, 50%, 100% e RD (rochas e galhos)). A eficiência predatória foi mais variável entre espécies (S. brasiliensis consumiu 86,6%, P. corruscans 22,5% e B. orbignyanus 18,3% dos alevinos) do que para complexidade ambiental, e S. brasiliensis foi mais rápido do que os outros em detectar e consumir a presa. A eficiência predatória de S. brasiliensis pode ser parcialmente explicada pelo seu comportamento mais agressivo (alimentou-se mais cedo e por mais tempo de experimento) e pela presença na área de superfície. A presença de predadores levou os alevinos de O. niloticus a passar mais tempo na superfície ou formar cardume para coexistir no fundo com os predadores, como o esperado para ciclídeos sob pressão predatória no campo. Nossos resultados sugerem que preservar e restaurar as populações de S. brasiliensis (principalmente, mas também P. corruscans e B. orbignyanus) podem ajudar no controle de O. niloticus na bacia do rio Paraná.(AU)


Subject(s)
Animals , Behavior, Animal , Food Chain , Cichlids/growth & development
15.
Braz. J. Vet. Res. Anim. Sci. (Online) ; 56(3): [e154252], out. 2019.
Article in English | VETINDEX, LILACS | ID: biblio-1025168

ABSTRACT

The objective of this study was to evaluate the in vivo predatory viability of the nematophagous fungus, Duddingtonia flagrans, after storage (36 months) and refrigeration (2-8 °C). This viability was evaluated using the infective larvae of gastrointestinal nematodes of sheep in the Northeastern semi-arid region of Brazil. Sixteen Santa Inês sheep with negative counting of eggs per gram of feces (EPG) were divided into four experimental groups, each group comprised of four animals. The pellets were administered at the dose of 3 g/10 kg of live weight (20% fungal micelyum), and a single administration was performed for each animal. Group I was administered pellets that had been stored for 36 months; Group II, freshly produced pellets; Group III, freshly produced pellets that did not contain fungi; and Group IV, pellets were not administered, and this was the control group. Feces were collected for 5 days, every 24 h for analysis. There was a significant decrease in the number of infective larvae of sheep nematodes that received D. flagrans pellets in a sodium alginate matrix, 82% was observed for Group I and 71% for Group II, compared to the control group. It is therefore concluded that the fungus, D. flagrans, pelleted in sodium alginate matrix after 36 months of storage at 2-8 °C, showed efficacy in reducing the number of infective larvae of gastrointestinal nematodes of sheep. (AU)


O objetivo deste trabalho foi avaliar a viabilidade predatória in vivo do fungo nematófago Duddingtonia flagrans, após armazenamento (36 meses) e refrigeração (2-8 °C). Esta viabilidade foi avaliada utilizando larvas infectantes de nematódeos gastrintestinais de ovinos no semi-árido nordestino do Brasil. 16 ovinos Santa Inês com contagem negativa de ovos por grama de fezes (GEP) foram divididos em quatro grupos experimentais, compostos por quatro animais. Os péletes foram administrados na dose de 3 g/10 kg de peso vivo (20% de micélio fúngico), e uma única administração foi realizada para cada animal. Grupo I foi administrado péletes que foram armazenados por 36 meses; Grupo II, péletes recém-produzidos; Grupo III, péletes recém-produzidos que não continham fungos; e o Grupo IV, péletes não foram administrados, e este foi o grupo controle. As fezes foram coletadas por cinco dias, a cada 24 horas, para análise. Houve uma diminuição significativa no número de larvas infectantes de nematóides ovinos que receberam pellets de D. flagrans, 82% foi observado para o Grupo I e 71% para o Grupo II, comparado ao grupo controle. Conclui-se, portanto, que o fungo D. flagrans, peletizado em matriz de alginato de sódio após 36 meses de armazenamento a 2-8 °C, apresenta eficácia na redução do número de larvas infectantes de nematódeos gastrintestinais de ovinos.(AU)


Subject(s)
Animals , Sheep/microbiology , Duddingtonia , Nematode Infections , Predatory Behavior , Refrigeration
16.
Neotrop. ichthyol ; 17(4): e190064, 2019. graf
Article in English | LILACS, VETINDEX | ID: biblio-1056802

ABSTRACT

Predation avoidance is a primary factor influencing survival. Therefore, any trait that affects the risk of predation, such as camouflage, is expected to be under selection pressure. Background matching (homochromy) limits habitat use, especially if the habitat is heterogeneous. Another camouflage mechanism is disruptive coloration, which reduces the probability of detection by masking the prey's body contours. Here we evaluated if disruptive coloration in the longsnout seahorse, Hippocampus reidi, allows habitat use diversification. We analyzed 82 photographs of animals, comparing animal and background color, and registering anchorage substrate (holdfast). We tested whether the presence (disruptive coloration) or absence of bands (plain coloration) predicted occupation of backgrounds of different colors. We also calculated the connectance between seahorse morph and background color or holdfast, as well as whether color morph differed in their preferences for holdfast. Animals with disruptive coloration were more likely to be found in environments with colors different from their own. Furthermore, animals with disruptive coloration occupied more diversified habitats, but as many holdfasts as plain colored animals. Therefore, animals with disruptive coloration were less selective in habitat use than those lacking disruptive color patterns, which agrees with the disruptive coloration hypothesis.(AU)


Evitar a predação é um dos principais fatores que influenciam a sobrevivência. Portanto, qualquer traço que afete o risco de predação, como a camuflagem, deverá estar sob forte pressão de seleção. Confundir-se com a cor do fundo (homocromia) limita o uso do habitat, especialmente se ele é heterogêneo. Outro mecanismo de camuflagem é a coloração disruptiva, que reduz a probabilidade de detecção mascarando o contorno do corpo da presa. Aqui nós avaliamos se a coloração disruptiva no cavalo-marinho de focinho comprido, Hippocampus reidi, permite diversificar o uso do habitat. Analisamos 82 fotografias de animais, comparando a cor do animal à do fundo, e registrando o substrato de apoio (holdfast). Nós testamos se a presença (coloração disruptiva) ou ausência de bandas (coloração lisa) predizia a ocupação de substratos de cores diferentes. Nós também calculamos a conectância entre o morfo do cavalo-marinho e a cor do fundo ou o substrato de apoio, bem como se o morfo diferiu em suas preferências por substratos de apoio. Animais com coloração disruptiva eram mais encontrados em ambientes com cores diferentes de sua própria cor. Além disso, os animais com coloração disruptiva ocupavam habitats mais diversificados, mas tantos substratos de apoio quanto animais lisos. Portanto, animais com cores disruptivas eram menos seletivos do que animais lisos quanto ao habitat que utilizavam, o que concorda com a hipótese da coloração disruptiva.(AU)


Subject(s)
Animals , Ecosystem , Smegmamorpha/classification , Disruptive Technology/classification , Staining and Labeling/veterinary
17.
Biota Neotrop. (Online, Ed. ingl.) ; 19(3): e20180678, 2019. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1011466

ABSTRACT

Abstract: Amazonian floodplain lakes host a high diversity of predatory fish which coexist and exploit the high diversity of available prey. Morphology could be the characteristic most closely associated with their preferred feeding sources (prey). However, it is unclear whether this association is direct or indirect. If it is indirect, swimming performance or preferential position in the water column could be the most evident characteristic. To examine the degree to which fish morphology of predator fish species is correlated to their dietary inputs, we compared the existence of morphological and feeding dissimilarity among eight predator species with the association between predator morphologies and preferred prey. We collected, measured, and sampled the stomach contents of fish from two lowland floodplain lakes associated with the Solimões River, Brazil, in May, August, and November of 2014. Of 187 collected fish across eight species, five species showed fish to be the most important item in their diets and three preferentially ate shrimp. Principal components analyses of ecomorphological attributes divided the species according to their ability to find the prey, swimming performance of the predator, and prey size. While there was significant distinction between the varying morphologies of predators, we were unable to distinguish between the specific diet of these species and did not find a correlation between morphology and feeding. These results are likely due to the fact that there is great abundance and diversity of available prey in the Amazonian floodplain lakes, so opportunistic feeding may be the primary foraging strategy of predator fish species living in these environments.


Resumo: Os lagos da várzea amazônica abrigam uma elevada riqueza de peixes predadores, com características morfológicas distintas, possibilitando explorar com sucesso várias presas disponíveis. Estas características morfológicas podem ser a associação mais próxima com suas fontes de alimentação preferidas (presa). Todavia, esta associação pode ser de forma direta ou indireta. Neste último caso, o desempenho da natação ou a posição preferencial na coluna d'água pode ser uma característica mais evidente. Para examinar o grau com que a morfologia de peixes predadores está correlacionada com seus itens alimentares, foram comparadas a existência de dissimilaridade morfológica e de alimentação entre oito espécies predadoras e a associação entre suas morfologias e suas presas. Foram coletados, medidos e amostrados o conteúdo estomacal de peixes de dois lagos de várzea associados ao rio Solimões, nos meses de maio, agosto e novembro de 2014. Dos 187 peixes coletados, em oito espécies, cinco mostraram que peixe era o item mais importante em suas dietas e três apresentaram preferência por camarão. A análise dos componentes principais dos atributos ecomorfológicos dividiu as espécies de acordo com a capacidade de encontrar sua presa, o desempenho de natação do predador e o tamanho da presa. Embora apresentasse distinção significativa entre suas características morfológicas, não foi encontrado distinção entre a dieta dessas espécies e nem correlação entre morfologia e alimentação. Esses resultados provavelmente se devem ao fato de que há grande abundância e diversidade de presas disponíveis nos lagos da planície de inundação da Amazônia, de modo que a alimentação oportunista pode ser a principal estratégia de forrageamento das espécies de peixes predadores que vivem nesses ambientes.

18.
Pesqui. vet. bras ; 38(12): 2266-2277, dez. 2018. tab, ilus
Article in Portuguese | LILACS, VETINDEX | ID: biblio-976417

ABSTRACT

Em diversas partes da América Latina, a perda e diminuição do habitat natural de animais silvestres ocorre em função do aumento das atividades agropecuárias. Nos últimos anos o número de mortes de animais de criação por depredação tem aumentado, bem como a consequente retaliação aos predadores. Como resultado destas ações, ocorre à extinção ou redução das populações destes predadores de topo, provocando perdas ecológicas. Esse estudo teve como objetivo apontar medidas preventivas e mitigatórias da depredação de ovinos por onça-parda (Puma concolor). Através da análise de dois estudos de casos de depredação no Centro-Oeste brasileiro e na região dos Andes Colombianos, levantamos soluções alternativas sustentáveis para que profissionais e criadores possam se prevenir desta ameaça ao rebanho ovino. Um estudo de caso foi realizado em fazenda no município de Alto Paraguai, Mato Grosso. Entre os anos 2005 e 2014 houve visitas na propriedade para diagnóstico de doenças e realizou-se estudo comparativo da quantidade de mortes por doenças com as mortes por depredação. No ano de 2010 ocorreu um ataque depredatório que resultou em morte de seis ovinos. Em 2014, realizou-se um estudo na região central do Departamento del Valle del Cauca, há 2814m de altitude nos Andes colombianos, para diagnosticar a depredação de gado na região e implementar medidas para prevenir sua ocorrência e avaliar sua eficácia. No total, foram implementadas medidas anti-depredação sobre oito propriedades, e entre elas, um curral com cerca elétrica para ovelhas foi implementada em uma fazenda no município de Tuluá. Os resultados mostram que as perdas econômicas por depredação são graves nas duas regiões estudadas e se equiparam a perdas por doenças no estudo de caso em Mato Grosso, Brasil. Portanto recomenda-se a combinação entre o manejo sanitário, métodos de prevenção e, se necessário, mitigação de ataques depredatório. Além disso, legisladores devem se associar a pesquisadores para traçar estratégias efetivas para esse sério problema na América Latina.(AU)


In several parts of Latin America, the expansion of agriculture over the years has caused loss and reduction of wild fauna natural habitat. Recently, deaths of sheep and cattle have increased due to predation by large carnivores and the resulting retaliation by farmers on predators. Consequently, populations of these top predators have been reduced or have got even locally extinct, leading to imbalances on ecosystems, altered because of the carnivore effects on prey dinamics. The objective of this study is to analyse sheep depredation by puma (Puma concolor), in Central Brazil and in the Colombian Andes and point out preventive and mitigating measures that can be implemented in rural areas. From 2005 to 2014, we visited a ranch in Alto Paraguai, Mato Grosso, Brazil for diagnostic purposes and we compared the death of sheep from diseases and depredation attacks. In 2014, we visited a rural area in the central region of Departamento del Valle del Cauca, at 2814m of altitude in the Colombian Andes, to diagnose sheep predation, implement preventive measures, and evaluate their effectiveness. The results reveal that economic losses due to predation are critical on both studied regions and similar to losses by diseases in Mato Grosso state, Brazil. Thus, we recommend the integration of health management, preventive measures as well as mitigation of depredatory attacks at the local scale and we discuss potential sustainable measures that can be locally implemented by farmers. Furthermore, we recommend that public policies should incorporate scientific results on human-wildlife conflicts to be effective, considering both livestock management and biodiversity conservation.(AU)


Subject(s)
Animals , Sheep , Conservation of Natural Resources , Puma , Animal Husbandry , Endangered Species , Environmental Policy , Animals, Wild
19.
Rev. biol. trop ; 66(4): 1496-1503, oct.-dic. 2018. tab
Article in Spanish | LILACS | ID: biblio-1003340

ABSTRACT

Resumen Pequeñas y aisladas poblaciones de borrego cimarrón (Ovis canadensis; especie sujeta a protección especial) son susceptibles a la depredación en hábitat simpátrico con venado bura. Entender las causas específicas de muerte y supervivencia es importante para el desarrollo de estrategias de conservación para el borrego cimarrón y otros ungulados que comparten el mismo hábitat, tal como el venado bura (Odocoileus hemionus). El objetivo de este estudio fue evaluar la tasa de depredación por puma (Puma concolor) en el borrego cimarrón y compararla con la del venado bura, para conocer la selección de presa del puma entre estas dos especies en un mismo hábitat, así como el impacto que podría tener en las poblaciones. Se plantea la hipótesis de que el puma como depredador oportunista no discrimina entre especies de ungulados simpátricos generando mayor impacto a la especie de menor densidad. Evaluamos la tasa de depredación por puma en 12 borregos cimarrones (10 hembras, 2 machos) y de 10 hembras adultas de venado bura con radio collares a través de micromorts y se comparó por medio una prueba de Wilcoxon, más la estimación de densidades de borrego y venados. Encontramos resultados similares en la causa específica de muerte por puma y supervivencia en ambas especies; 88 % (8/9) muertes debido a depredación por puma en borrego cimarrón con una tasa de supervivencia mensual promedio de 0.79 y una tasa mensual de depredación que va del rango 0.17-0.30. En venado bura la depredación debido a puma fue 83 % (5/6) con una tasa de supervivencia mensual promedio de 0.86 y una tasa de depredación por puma mensual en el rangos 0.10-0.25. Sin embargo, al comparar con la tasa de depredación por puma encontramos una diferencia significativa (Z = 1.826; df = 6; P = 0.05) siendo el borrego cimarrón la presa más selecta. En este estudio se concluye que el puma seleccionó a la presa de menor densidad (borrego cimarrón) y por ende la más impactada en un hábitat simpátrico con venado bura.(AU)


Abstract Small and isolated populations of bighorn sheep are vulnerable to predation by mountain lion in habitat sympatric with mule deer. Understanding the specific causes of death and survival is important for the development of conservation strategies for bighorn sheep and other ungulates that share the same habitat, such as mule deer. We evaluated and compared the rate of predation by puma in 12 bighorn sheep (10 females, two males) and 10 adult females of mule deer with radio collars through measure risk program (micromorts). The impact of predation in both populations of herbivores is evaluated through the estimation of densities of sheep and mule deer. 88 % (8/9) deaths by puma in bighorn sheep with an average monthly survival rate of 0.79 and predation rates due to puma range from 0.17 to 0.30. In mule deer predation due to puma was 83 % (5/6) with an average monthly survival rate of 0.86 and predation rates due to puma range from 0.10 to 0.25, however when comparing the mountain lion depredation rate we found a significant difference between species (Z = 1.826, df = 6, P = 0.05). The density in mule deer was 9x more that bighorn. The bighorn sheep being the prey most selected and the one most affected as the population with the lowest density.(AU)


Subject(s)
Animals , Deer , Ecosystem , Sheep, Bighorn , Puma , Survival Rate , Mexico
20.
Braz. j. biol ; 78(3): 457-463, Aug. 2018. tab
Article in English | LILACS | ID: biblio-951582

ABSTRACT

Abstract Carabids are recognized worldwide as biological control agents of agricultural pests. The objective was to compare the life cycle of Abaris basistriata Chaudoir (Coleoptera: Carabidae) on three substrates: soil, fine vermiculite, or paper napkins. The biological cycle of A. basistriata presented different durations in soil and paper. The viability of eggs and larvae survival of the first and second instars were similar on all three substrates, while the third instar and pupa in the soil presented higher survival when compared with vermiculite and paper. The soil substrate was more favorable for the longevity of the carabid beetle. Abaris basistriata showed a shorter pre-oviposition period and a higher oviposition and post-oviposition period in the soil. Fecundity and fertility were higher when A. basistriata was reared on soil. The soil was most favorable substrate for rearing of A. basistriata in the laboratory. This information may make this species useful for the biological control.


Resumo Os carabídeos são reconhecidos mundialmente como agentes de controle biológico de pragas agrícolas. O objetivo foi comparar o ciclo de vida de Abaris basistriata Chaudoir (Coleoptera: Carabidae) em três substratos: solo, vermiculita fina, ou guardanapos de papel. O ciclo biológico de A. basistriata apresentou diferentes durações no solo e no papel. A viabilidade dos ovos e a sobrevivência das larvas do primeiro e segundo instares foram semelhantes nos três substratos, enquanto que o terceiro instar e a pupa apresentaram maior sobrevivência no solo quando comparados com vermiculita e papel. O substrato solo foi mais favorável à longevidade do carabídeo. Abaris basistriata mostrou menor período de pré-oviposição e maior período de oviposição e pós-oviposição no solo. A fecundidade e a fertilidade foram maiores quando A. basistriata foi criado no solo. O solo foi o substrato mais favorável para a criação de A. basistriata no laboratório. Estas informações são importantes e podem tornar essa espécie útil para o controlo biológico.


Subject(s)
Animals , Female , Oviposition/physiology , Reproduction/physiology , Soil/parasitology , Coleoptera/growth & development , Larva/growth & development , Life Cycle Stages/physiology , Coleoptera/physiology , Ecosystem , Agriculture , Longevity
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