Abstract Scorpions and assassin bugs are arthropod predators that may impact in trophic chain, coexisting in similar microhabitats and exhibiting antagonistic interactions. This study reports the first case of predation of the scorpion Physoctonus debilis by the assassin bug Microtomus tibialis in a Brazilian Seasonal Dry Tropical Forest biome. During a nocturnal collection, an adult individual of M. tibialis was observed, with the head and body facing downwards, while holding a female of P. debilis, with the aid of the mouthparts under the vegetation. Reports like these are important to understand the evolutionary dynamics and natural history of predators that cohabit in the same microhabitat.

Resumen Los escorpiones y las chinches asesinas son artrópodos depredadores que pueden impactar en la cadena trófica, coexistiendo en microhábitats similares y exhibiendo interacciones antagónicas. Este estudio reporta el primer caso de depredación del escorpión Physoctonus debilis por la chinche asesina Microtomus tibialis en un bioma de Bosque Tropical Seco Estacional Brasileño. Durante una colecta nocturna, se observó un individuo adulto de M. tibialis con la cabeza y el cuerpo hacia abajo, mientras sujetaba a una hembra de P. debilis con la ayuda del aparato bucal bajo la vegetación. Informes como estos son importantes para comprender la dinámica evolutiva y la historia natural de los depredadores que cohabitan en el mismo microhábitat.

ABSTRACT Chrysoperla externa (Hagen) and Hippodamia convergens (Guérin-Meneville) are voracious generalist predators, and important aphid control agents. In an environment containing a complex of species, the occurrence of intraguild interactions can interfere in the predator behavior and consumption. The aim of this work was to know the number of nymphs of Rhodobium porosum (Sanderson) and Macrosiphum rosae (Linnaeus) consumed by larvae of C. externa and H. convergens, and the interaction between these predators when confined together. First, second and third instar nymphs of R. porosum and M. rosae were provided in Petri dishes containing rose leaflets and second instar larvae of the predators. Intraguild interaction was studied in Petri dishes containing first instar nymphs of both aphid species and a second instar larva of C. externa plus one of H. convergens. A third treatment consisted of dishes containing a second instar larva of both predators maintained in the absence of prey. The evaluations took place throughout the entire instar of the predators. C. externa consumed a greater number of R. porosum nymphs and H. convergens a greater number of M. rosae nymphs. For both species of prey, the highest consumption was verified on the last day of evaluation. There was a positive interaction when the predator’s larvae were confined in the presence of aphid nymphs, with no mortality observed for any of them. In the absence of prey, there was 70% mortality of H. convergens larvae due to intraguild predation. Hagen (Hagen GuérinMeneville Guérin Meneville (Guérin-Meneville agents Sanderson (Sanderson Linnaeus (Linnaeus C H together First R M prey evaluation s them 70 predation 7

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. farms feces pig carcasses H M conditions experiment former 2 100 50 10 5 1

ABSTRACT Rose crops are attacked by many pests, including mealybugs. Although Planoccocus citri is not registered as a main pest of roses in Brazil, it is an increasing problem on roses inside greenhouses. Chrysoperla externa and Cryptolaemus montrouzieri are options against P. citri and other pests on roses, however using two predators in biological control programs may face problems like intraguild predation. This work aimed to assess the consumption of 1st instar nymphs and adult females of P. citri by adults of C. montrouzieri and 3rd instar larvae of C. externa, as well as the interaction between these predators when confined together. The following treatments were performed with ten replications in a completely randomized design: 1 - C. externa + 200 nymphs of P. citri; 2 - C. externa + 10 adults of P. citri; 3 - C. montrouzieri + 500 nymphs of P. citri; 4 - C. montrouzieri + 15 adults of P. citri. Each replication was set on rose leaflets inside a Petri dish (9cm Ø). Intraguild interaction was assessed by releasing both predators inside dishes containing 700 nymphs of P. citri. Before the releases, predators stayed 24 hours without food. We evaluated the prey consumption and intraguild predation for three hours. C. externa consumed significantly less (85,4±2,99) nymphs than did C. montrouzieri (387,0±3,02). There was no difference in adult mealybugs consumed, with an average of 1,85±0,19. No intraguild predation was observed, and an increase of 11,8% in consumption was observed when predators were released together compared to the scenario of no competition. Brazil greenhouses P st C rd design 20 50 9cm cm Ø. Ø . Ø) 70 releases food 85,4±2,99 854299 85 99 (85,4±2,99 387,0±3,02. 3870302 387,0±3,02 387 0 02 (387,0±3,02) 185019 19 1,85±0,19 118 11 8 11,8 competition 5 7 85,4±2,9 85429 9 (85,4±2,9 387030 387,0±3,0 38 (387,0±3,02 18501 1,85±0,1 11, 85,4±2, 8542 (85,4±2, 38703 387,0±3, (387,0±3,0 1850 1,85±0, 85,4±2 854 (85,4±2 3870 387,0±3 (387,0±3, 185 1,85±0 85,4± (85,4± 387,0± (387,0±3 18 1,85± 85,4 (85,4 387,0 (387,0± 1,85 85, (85, 387, (387,0 1,8 (85 (387, 1, (8 (387 ( (38 (3

Resumen: Los programas de control biológico en invernadero recurren cada vez más a la liberación de varios enemigos naturales en forma simultánea. En Uruguay, el manejo de plagas en pimiento se basa en la liberación de Orius insidiosus y Amblyseius swirskii, para controlar Frankliniella occidentalis y Bemisia tabaci. Amblyseius swirskii puede alimentarse de ambas presas. Los depredadores zoofitófagos no solo se alimentan de plagas o alimentos vegetales, sino también de enemigos naturales con quienes comparten presas (depredación intragremio). Por lo tanto, la liberación de depredadores generalistas podría dar resultado negativo en el control de la plaga objetivo. Por ello fue importante evaluar la compatibilidad entre O. insidiosus y A. swirskii como depredadores de F. occidentalis. A nivel de placas de Petri se estudió: (1) el efecto de la densidad y la composición de la presa sobre su depredación por O. insidiosus; (2) el cambio de presa por O. insidiosus, y (3) el efecto del género de O. insidiosus en la preferencia de presa. Se encontró que si las densidades relativas de F. occidentalis y A. swirskii variaban, O. insidiosus siempre cambiaba a la presa más abundante. Los machos y las hembras de O. insidiosus prefirieron las ninfas de F. occidentalis sobre A. swirskii, y las hembras mataron más presas que los machos. Dado que O. insidiosus depredó a A. swirskii, se recomienda precaución al combinar antocóridos y ácaros para el control de trips. Serán necesarios estudios en invernadero para esclarecer el efecto final de ambos depredadores.

Abstract: Biological control programs in greenhouses increasingly resort to the release of several natural enemies simultaneously. In Uruguay, pest management in peppers is based on the release of Orius insidiosus and Amblyseius swirskii, to control Frankliniella occidentalis and Bemisia tabaci. Amblyseius swirskii can feed on both preys. Zoophytophagous predators not only feed on pests or plant food, but also on natural enemies with which they share prey (intraguild predation). Hence, the combined release of generalist predators could have a negative result in the control of the target pest. Thus, it was important to evaluate the compatibility of O. insidiosus and A. swirskii as predators of F. occidentalis. Studies carried out at Petri dishes level assessed: (1) the effect of the density and the composition of the prey on their predation by O. insidiosus, (2) the change of prey by O. insidiosus and (3) the effect of the genus of O. insidiosus on prey preference. Results show that if the relative densities of F. occidentalis and A. swirskii varied, O. insidiosus always changed to the most abundant prey. Male and female O. insidiosus preferred nymphs of F. occidentalis over A. swirskii, and females killed more prey than males. Since O. insidiosus fed on A. swirskii, it is advisable to be cautious when combining anthocorids and phytoseid mites for the F. occidentalis control. Studies at greenhouse will be necessary to clarify the final effect of both predators.

Resumo: Os programas de controle biológico com efeito de estufa dependem cada vez mais da liberação de vários inimigos naturais simultaneamente. No Uruguai, o manejo de pragas em pimentas é baseado na liberação de Orius insidiosus e Amblyseius swirskii, para o controle de Frankliniella occidentalis e Bemisia tabaci. Amblyseius swirskii pode se alimentar de ambas as presas. Predadores zoofitófagos não se alimentam apenas de pragas ou alimentos vegetais, mas também de inimigos naturais com os quais compartilham suas presas (predação intra-guilda). Portanto, a liberação de predadores generalistas pode controlar negativamente a praga alvo. Por esse motivo, foi importante avaliar a compatibilidade entre O. insidiosus e A. swirskii como predadores de F. occidentalis. Ao nível das placas de Petri, foram estudados: (1) o efeito da densidade e composição da presa na sua predação por O. insidiosus, (2) a mudança de presa por O. insidiosus e (3) o efeito -a do gênero de O. insidiosus em preferência de presa. Verificou-se que se as densidades relativas de F. occidentalis e A. swirskii variaram, O. insidiosus sempre mudou para a presa mais abundante. Machos e fêmeas de O. insidiosus preferiam ninfas de F. occidentalis a A. swirskii, e as fêmeas matavam mais presas do que os machos. Como O. insidiosus é anterior a A. swirskii, recomenda-se cautela ao combinar antocorídeos e ácaros para o controle de tripes. Estudos de estufa serão necessários para esclarecer o efeito final de ambos os predadores.

Abstract: Three species of mephitids coexist in the Tehuacán-Cuicatlán biosphere reserve (TCBR) and belong to a guild of mammalian carnivores that feed mainly on invertebrates. To infer the interspecific interactions that allow coexistence, we aimed to compare activity patterns and abundance of hog-nosed skunk (Conepatus leuconotus), hooded skunk (Mephitis macroura), and southern spotted skunk (Spilogale angustifrons) in a tropical dry forest with ecological integrity. We analyzed activity patterns and overlap, and compared the relative abundance index (IAR) of mephitids, between rainy and dry seasons and among species, and used 235 records for C. leuconotus, 39 for M. macroura, and 42 for S. angustifrons from 15 camera-trap stations in Mount Tepetroja, Puebla, from May 1st, 2013 to April 30th, 2020. The three mephitids were active mainly during the nocturnal period, although C. leuconotus showed a unimodal pattern with activity peak around midnight, M. macroura had a bimodal pattern with activity peaks during the crepuscular hours at sunset and sunrise, and S. angustifrons had a unimodal pattern with activity peak around 2:00 a.m. Mean activity of C. leuconotus (µ ± SE = 00:42 ± 00:12 h) and M. macroura (01:02 ± 00:33 h) were similar (P = 0.32), and differed from the mean activity of S. angustifrons (01:49 ± 00:23 h, P = 0.02). C. leuconotus had the highest IAR (2.53 to 7.90) and differed from M. macroura (0.44 to 1.21) and S. angustifrons (0.83 to 0.96) in both seasons (P < 0.01). C. leuconotus and M. macroura showed higher IAR during the rainy season, in contrast with S. angustifrons that had no differences in IAR between seasons. The mephitids presented temporal segregation and variability in seasonal abundance as coexistence mechanisms. S. angustifrons showed the most restricted circadian activity and avoided the other two mephitids’ activity peaks. C. leuconotus was the most abundant species; thus, we inferred that the hog-nosed skunk determined the dynamics of intraguild interactions among mephitids in the tropical dry forest in the TCBR.

Resumen: Tres especies de mefítidos coexisten en la reserva de la biosfera Tehuacán-Cuicatlán (RBTC) y pertenecen a un gremio de mamíferos carnívoros que se alimentan principalmente de invertebrados. Para inferir sobre las interacciones interespecíficas que permiten la coexistencia, nuestros objetivos fueron comparar la actividad circadiana y la abundancia del zorrillo de espalda blanca (Conepatus leuconotus), zorrillo rayado sureño (Mephitis macroura) y zorrillo manchado del sur (Spilogale angustifrons) en selva baja caducifolia con integridad ecológica. Analizamos los patrones de actividad y su superposición, y comparamos el índice de abundancia relativa (IAR) de los mefítidos entre la temporada de lluvia y la temporada seca, y entre especies, a partir de 235 registros de C. leuconotus, 39 de M. macroura y 42 de S. angustifrons de15 estaciones de fototrampeo en el Cerro Tepetroja, Puebla, del 1 de mayo de 2013 al 30 de abril de 2020. Los tres mefítidos presentaron actividad principalmente durante el periodo nocturno, aunque C. leuconotus mostró un patrón unimodal con el pico de actividad alrededor de la media noche, M. macroura presentó un patrón bimodal con picos de actividad durante las horas crepusculares del atardecer y amanecer, y S. angustifrons tuvo un patrón unimodal con el pico de actividad alrededor de las 2:00 a.m. La actividad promedio de C. leuconotus (µ ± SE = 00:42 ± 00:12 h) y M. macroura (01:02 ± 00:33 h) fueron similares (P = 0.32), y difirieron de la actividad promedio de S. angustifrons (01:49 ± 00:23 h, P = 0.02). C. leuconotus presentó los mayores IAR (2.53 a 7.90) y difirió de M. macroura (0.44 a 1.21) y de S. angustifrons (0.83 a 0.96) en las dos temporadas del año (P < 0.01). C. leuconotus y M. macroura mostraron mayores IAR durante la temporada de lluvia, en contraste con S. angustifrons que no tuvo diferencias en los IAR entre temporadas. Los mefítidos presentaron segregación temporal y variaciones estacionales en la abundancia como mecanismos de coexistencia. S. angustifrons presentó la actividad circadiana más restringida y evitó los picos de actividad de los otros dos mefítidos. C. leuconotus fue el más abundante, por lo que inferimos que el zorrillo espalda blanca determinó la dinámica de las interacciones intragremiales entre mefítidos en la selva baja caducifolia de la RBTC.

Abstract Harmonia axyridis is an exotic species that can cause serious impacts on native biodiversity in areas where it is introduced to act as a biological control agent. This predator is often involved with intraguild predation, in most cases with aphids predators. Here, we report the results of experiments designed to understand the outcome of the invasion of H. axyridis on native coccinellid aphidophagous guilds using intraguild predation as a theoretical framework. Tests were conducted to determine the interactions between 1st and 4th instars larvae and H. axyridis adults, with Cycloneda sanguinea, Cycloneda pulchella, Eriopis connexa and Hippodamia convergens larvae, as well as eggs predation rate. Two treatments were used: absence and presence of food, Cinara atlantica. The results showed that 1st and 4th instars larvae and H. axyridis adults are able to prey on larvae and eggs of four Coccinellidae species analyzed, and also their own eggs, showing that this exotic species is a dominant predator in this guild of aphidophagous coccinellids. Adding to these results, studies are recommended, especially the monitoring of these species in the field in the long run, reporting their abundance and diversity as well as their behavior and impact within aphidophagous guilds, especially in Coccinellidae species.

Abstract Antagonistic interactions among predators have the potential to dampen top-down impacts on a shared pest. Strong cannibalism by adults and larvae on eggs along with a stronger intraguild predation by Eriopis connexa on Cycloneda sanguinea (Coccinellidae) than vice versa had been documented. The intensity and direction of these interactions could vary with the larval instar. We calculated aggressiveness, attack, and predation rates between larvae in the laboratory and studied both larval mortality and within-plant distribution in plants. Despite high attack rates, larvae of both species usually escaped from predation, except for the fourth vs. second–instar combinations, where the smaller larvae were more vulnerable to predation than the larger. Successful predation by E. connexa fourth-instars on C. sanguinea second-instars frequently occurred. All interactions between larvae became relaxed when extraguild prey were present. The larval mortality within the plants was influenced by the availability of extraguild prey only. Larvae of both species promptly dispersed outside the plant when prey became unavailable. With the extraguild prey present, the larvae of both species initially preferred the plant upper stratum in both combinations, but then dispersed. This study suggests that the defensive capability and larval dispersal could prevent cannibalism and intraguild-predation interactions.

Abstract Scorpion species often occur in sympatry, especially in tropical forests. Here, we analyse aspects of the intraguild interactions occurring between Centruroides limbatus (Pocock, 1898) and Tityus ocelote Francke & Stockwell, 1987 (Buthidae) in a tropical forest of Costa Rica. We divided the study in 2 areas: north and south. Results show differences in abundance and distribution of C. limbatus (north = 16, south = 8) and T. ocelote (north = 2, south = 37); a major frequency of females for both species (74% ♀ and 26% ♂ in C. limbatus, 78% ♀ and 22% ♂ in T. ocelote; 55 sexed scorpions); similar microhabitat preferences (trees with vines, palms) and significant differences (p = 0.037) in the height at which both species were located above ground in each zone. Significant differences in height between zones showed disparity in habitat selection (north and south), whereas non-significant differences in height between species indicated niche overlap in those areas where they coexist, confirmed by the Morisita index for niche overlap in the southern zone (M-NO = 0.686). Cannibalism was reported in C. limbatus. These intraguild interactions indicate the existence of some level of competition between these scorpions.

Resumen Las especies de escorpión coexisten en simpatría, especialmente en bosques tropicales. Aquí analizamos algunos aspectos de las interacciones intragremio entre Centruroides limbatus (Pocock, 1898) y Tityus ocelote Francke y Stockwell, 1987 (Buthidae) en un bosque tropical de Costa Rica. Dividimos el estudio en 2 áreas: norte y sur. Los resultados mostraron diferencias en abundancia y distribución de C. limbatus (norte = 16, sur = 8) y T. ocelote (norte = 2, sur = 37); mayor frecuencia de hembras en ambas especies (74% ♀ y 26% ♂ en C. limbatus, 78% ♀ y 22% ♂ en T. ocelote; 55 escorpiones sexados); preferencias de microhábitat similares (árboles con lianas, palmeras) y diferencias significativas (p = 0.0037) en la altura a la que ambas especies se encontraban en cada zona. Las diferencias significativas en la altura entre zonas mostraron disparidad en selección de hábitat (norte y sur), mientras que las diferencias no significativas en la altura entre especies mostraron solapamiento de nicho en áreas dónde coexistían, confirmado por el índice de Morisita para solapamiento de nicho en la zona sur (M-NO = 0.686). Se reportó canibalismo en C. limbatus. Estas interacciones intragremio manifiestan la existencia de cierto nivel de competencia entre estos escorpiones.

Abstract Coyote and kit fox are 2 canids that live in sympatry in the arid zones of North America, where it has been reported that one of the main causes of kit fox mortality is the predation by coyotes. However, no mortality event has been reported in the Chihuahuan Desert and little is known about the interaction of these 2 species. Therefore, the aim of this study is to analyze the co-occurrence patterns of both canids in the Biosphere Reserve of Mapimí (BRM), Mexico. For this reason, single and 2 species occupancy models were used, along with covariates. The results of the 2 species models indicate that both canids occur independently, so spatial segregation is not fulfilled. On the contrary, both species were more likely to be detected in the same sites. It is possible that fox adopt surveillance and evasion of predation strategies at a fine spatial scale, which together with the availability of prey allow it to coexist in low numbers at the same places as coyotes.

Resumen El coyote y la zorra del desierto son 2 cánidos que habitan en simpatría en las zonas áridas de Norteamérica, en donde se ha reportado que una de las principales causas de mortalidad de las zorras es la depredación por parte de los coyotes. Sin embargo, en el desierto chihuahuense no se ha reportado ningún evento de mortalidad y es poco lo que se conoce sobre la interacción de estas 2 especies. Por lo anterior, el objetivo del presente estudio fue analizar los patrones de coexistencia de ambos cánidos en la Reserva de la Biósfera de Mapimí (RBM), México. Para ello, se usaron modelos de ocupación de 1 y 2 especies, junto con covariables. Los resultados de los modelos de 2 especies indicaron que ambos cánidos cohabitaron de manera independiente, por lo que no se cumplió la segregación espacial esperada. Por el contrario, ambas especies fueron detectadas con mayor probabilidad en los mismos sitios. Es posible que las zorras adopten estrategias de vigilancia y evasión de depredación a una escala espacial fina, que junto con la disponibilidad de presas, les permiten estar presentes en los mismos sitios que los coyotes.

RESUMO A introdução de espécies não nativas é uma ameaça aos ecossistemas de água doce. Embora a onivoria e a predação intraguilda sejam comuns nesses sistemas, os efeitos da introdução de peixes onívoros nas comunidades pelágicas e litorâneas é pouco conhecido. Nós testamos as previsões da teoria da teia trófica considerando os efeitos da introdução de um peixe onívoro em um lago previamente desprovido de peixes localizado na Serra dos Carajás, Pará, Brasil. A estrutura trófica em dois lagos similares, um com a presença do peixe onívoro introduzido Astyanax bimaculatus, e outro sem peixes, foi comparada através de uma série de dados bióticos amostrados entre 2010 e 2013. A comunidade zooplanctônica foi mais abundante no lago com peixe e sua composição diferiu entre os dois lagos. Apesar da limitação por fósforo no lago com peixe, a riqueza do fitoplâncton e a concentração de clorofila-a foram maiores nesse lago. A comunidade de macroinvertebrados bentônicos apresentou maior riqueza e biomassa no lago sem peixe. Nossos resultados também indicam que A. bimaculatus tem o potencial de acoplar as comunidades litorâneas e pelágicas através da reciclagem de nutrientes. Apesar das limitações relacionadas à ausência de replicação no nível de ecossistemas, nós argumentamos que o nosso estudo mostra que a introdução do peixe onívoro pode ter causado mudanças no funcionamento do lago.

ABSTRACT The introduction of nonnative species is one of the main threats to freshwater ecosystems. Although omnivory and intraguild predation are common in those systems, little is known about the effects of introduced omnivorous fish on pelagic and littoral communities. This study tested predictions of food-web theory regarding the effects of omnivorous fish introduction on previously fishless lakes in the Amazonian uplands of Serra dos Carajás, Pará, Brazil. The trophic structure of two similar lakes, one with and the other without the introduced omnivorous fish Astyanax bimaculatus, was compared using a data series of biotic variables collected from both lakes twice a year from 2010 to 2013. Zooplankton was more abundant in the lake with fish, and the zooplankton composition differed between lakes. Phytoplankton richness and chlorophyll-a were higher in the lake with the introduced fish than in the fishless lake regardless of phosphorus limitation. For the benthic macroinvertebrate communities, species richness and biomass were higher in the fishless lake. Our results also indicate that A. bimaculatus has the potential to link pelagic and littoral habitats through nutrient cycling. The differences observed between the studied lakes are consistent with predictions from food-web theory regarding the effects of multichain omnivorous fish on trophic dynamics. Despite limitations regarding replication at the ecosystem level, it is possible to infer from our findings that the introduction of an omnivorous fish might have changed lake overall functioning.

Abstract Small birds constitute a significant portion of the Boa constrictor diet. There are few reports on the consumption of larger birds, even fewer of intraguild predation (among top predators). We report the unusual finding of a barn owl, Tyto furcata, depredated by an approximately 220 cm Boa constrictor on January 25, 2017. The discovery was made on the grounds of the Comisión Panamá - Estados Unidos para la Erradicación y Prevención del Gusano Barrenador del Ganado (COPEG) (coordinates 09°05’16.7” N, 79°17’10.8” W), in the community of Pacora, Panama. This report contributes to the understanding of ecological relationships between two rarely documented predators.

Resumen Las aves pequeñas constituyen una porción significativa en la dieta de Boa constrictor, sin embargo, pocos son los reportes sobre el consumo de aves de mayor tamaño, y mucho menos de una depredación de tipo intragremial (entre depredadores tope). Reportamos el inusual hallazgo de depredación de una lechuza de campanario, Tyto furcata, por una Boa constrictor de aproximadamente 220 cm, el 25 de enero de 2017, en los predios de la Comisión Panamá - Estados Unidos para la Erradicación y Prevención del Gusano Barrenador del Ganado (COPEG) con coordenadas (09°05’16.7” N, 79°17’10.8” O), en la comunidad de Pacora, Panamá. Este reporte contribuye al entendimiento de las relaciones ecológicas entre dos depredadores, pocas veces documentada.

Resumo O gato-mourisco (Puma yagouaroundi) é o segundo carnívoro com maior distribuição nas Américas, e considerado vulnerável a extinção no Brasil. No entanto, grande parte de sua ecologia é desconhecida, e há pouca informação disponível sobre espécies que poderiam atuar como seu predador. Nesse estudo, apresentamos evidências da predação do gato-mourisco por onça-parda (Puma concolor) em uma unidade de conservação (Parque Estadual Carlos Botelho) no estado de São Paulo. Coletamos amostras fecais de onça-parda em trilhas e estradas de terra na área estudada, e por meio da análise de microestrutura dos pelos, identificamos pelos e garras de um gato-mourisco em uma das amostras fecais. As onças-pardas normalmente consomem carnívoros, mas a predação de outros felinos é incomum, especialmente no Brasil. Essa poderia ser considerada uma interação antagonista, mas a onça-parda e o gato-mourisco não competem por território ou presas em grandes áreas protegidas, uma vez que as onças-pardas consomem preferencialmente presas maiores (> 1 kg). Portanto, concluímos que esse é um episódio de predação intraguilda com propósito alimentar da onça-parda, e não uma predação por conta de competição por território ou presas. Esse registro é importante e ajuda a compreender um pouco mais sobre as complexas relações tróficas em florestas tropicais.

Abstract The jaguarundi (Puma yagouaroundi) is the second most widespread carnivore of the Americas, and considered a threatened species in Brazil. However, most of its ecology is unknown, and few information is available about species that may act as its predator. In this study we present evidence of the predation of a jaguarundi by puma (Puma concolor) in a protected area (Carlos Botelho State Park) in the state of São Paulo, southeastern Brazil. We collected fecal samples in trails and dirt roads in the study area, and by using hair cuticle imprints and medullar patterns, we identified a puma scat containing hair and claws of a jaguarundi. Pumas usually consume carnivores, but the presence of felids is uncommon, especially in Brazil. This could be considered an antagonist interaction, but pumas and jaguarundis do not compete for territory or prey in large protected areas, since pumas have a high intake of larger prey (> 1 kg). Thus, we conclude that this an episode of intraguild predation for feeding purposes, not a kill in response to competition for prey or territory. This is an important record that helps to understand a bit more of the complex trophic relationships in tropical forests.

Abstract: Sociality in carnivorans seems to have evolved as a strategy for preying on big mammals and enhancing intraguild competition. In canids, the relationship between high sociality levels and hypercarnivory has been widely discussed, but there are few attempts for testing it in a phylogenetic context. As a result, there are still doubts regarding the relationship between diet and sociality; particularly if variation in the latter is associated with trophic pressures. Here, we test if social behavior and feeding preferences are associated in extant canids, and establish how this relationship is in terms of the variability of both traits and their transition tendencies. We obtained information about diet and sociality after literature review, and tested their association with phylogenetic comparative methods. Cladistic and probabilistic approaches indicate a direct relationship between higher carnivory and higher sociality. Our results also indicate that social behavior tends to evolve first, and that carnivorous preferences are more likely to evolve under social evolutionary contexts.

Resumen: La sociabilidad en los carnívoros parece haber evolucionado como una estrategia para depredar sobre otros mamíferos de gran tamaño y mejorar las ventajas de competencia intragremial. En cánidos, la relación entre altos niveles de sociabilidad e hipercarnivoría ha sido ampliamente discutida, pero son escasos los intentos de ponerla a prueba en un contexto filogenético. Debido a esto, aún existen dudas sobre la relación entre dieta y sociabilidad, particularmente si la variación en este último rasgo se asocia con presiones tróficas. En este trabajo buscamos identificar si el comportamiento social y las preferencias alimentarias están asociados en los cánidos actuales, y establecer cómo es esa relación en términos de la variabilidad de ambos rasgos y sus tendencias de cambio. Se obtuvo información sobre dieta y sociabilidad a partir de la revisión de literatura y probamos su relación mediante métodos de filogenética comparada. Aproximaciones cladísticas y probabilísticas indican que existe una relación directa entre una mayor tendencia a la carnivoría y mayor sociabilidad. Nuestros resultados también indican que el comportamiento social tiende a evolucionar primero y que en un contexto evolutivo social las probabilidades de adoptar preferencias carnívoras se incrementan.

ResumenLa zorra gris (Urocyon cinereoargenteus Schreber) es un cánido de tamaño mediano que se distribuye ampliamente en México. La mayoría de los estudios sobre esta especie se han enfocado en el uso de hábitat, el ámbito hogareño, la dieta, la competencia con otros carnívoros y su distribución en diferentes paisajes tanto urbanos como rurales. Se tiene conocimiento de su presencia en fragmentos de bosque mesófilo de montaña y cafetales de sombra en el centro de Veracruz, aunque no se ha comparado su abundancia con otras coberturas vegetales como los cultivos presentes en la región. En este estudio describimos las variaciones de la abundancia mensual de zorra gris a través del registro de excretas en transectos de 500 m en cañaverales, cafetales de sombra y fragmentos de bosque mesófilo de montaña entre octubre del 2008 y mayo del 2009. Reportamos el índice de abundancia relativa para cada cobertura y cada mes, y evaluamos la relación de cuatro variables del paisaje (porcentaje de sombra, densidad de caminos, densidad de población humana y entremezcla de hábitats) en áreas de influencia de 450 ha alrededor de los sitios de muestreo. La comparación de la abundancia entre coberturas, mostró abundancias menores en los fragmentos de bosque mesófilo y mayores en los cafetales de sombra y cañaverales. No se encontró diferencia significativa a través de los meses (P= 0.476). Se plantea que la abundancia mayor en los cultivos puede estar asociada a las plagas de roedores y a la presencia de árboles frutales que ofrecen alimento a la zorra gris. De las variables del paisaje evaluadas solo la densidad de caminos de impacto medio y la densidad de población se correlacionaron positivamente con la abundancia de zorra gris, lo que demuestra que puede cohabitar con el humano sobre todo en zonas rurales. Se destaca la capacidad de la zorra gris para aprovechar los paisajes heterogéneos.

AbstractThe gray fox, Urocyon cinereoargenteus, is a medium-size canid widely distributed in México. Most studies on this species focus on habitat use, home range, diet, intraguild competence, and lanscape distribution between urban and rural sites. In central Veracruz, gray foxes are present in fragments of cloud forest and in shaded coffee plantations; nevertheless, its abundance has not yet been compared among other vegetation types found in the area, such as sugarcane plantations. In this study we described gray foxes abundance variations using 500 m transects, among sugarcane plantations, shaded coffee plantations, and cloud forest fragments throughout eight months, by scat counting in three sites of each cover type. We reported the relative abundance index for each cover type and each month, and evaluated its relationship with four landscape features: (a) shade percent, (b) trail density, (c) human population density, and (d) habitat juxtaposition, in influence areas of 450 ha around sampling sites. Abundance comparison among cover types showed lower abundances in cloud forest fragments and higher abundances in coffee and sugarcane plantations. No significant differences were found throughout months (p = 0.476). We proposed that higher abundances in plantations may be related to the presence of rodent plagues and fruit trees which offer food resources to gray foxes. The evaluation of landscape features showed that only medium-impact trail density and human population density were positively correlated with gray fox abundance; fact that demonstrates that this canid can coexist with humans in rural sites. We highlight the gray fox capacity to take advantage of heterogeneous landscapes.