ABSTRACT Understanding tri-trophic interactions and the relationship among plants, herbivores, and their natural enemies is fundamental to advancing theoretical and practical ecology. Parasitoidism is among those interactions where tri-trophic levels are usually developed, with hyperparasitism and kleptoparasitism as examples. This study explores the interaction between fig wasps of the genera Physothorax Mayr, 1885 and Sycophila Walker, 1871 (Hymenoptera: Chalcidoidea) and the gall midge Ficiomyia brasiliensis Urso-Guimarães, 2024 (Diptera: Cecidomyiidae) associated with Ficus citrifolia Mill. in Ribeirão Preto, Brazil. Through behavioral observations and larval dissections we document the “drill on drill” strategy where Sycophila females utilize oviposition holes drilled by Physothorax females on the fig surface to access the host gall midge immatures. This behavior suggests a sophisticated adaptation for reducing oviposition time and conserving energy. Additionally, Sycophila behavior aligns with kleptoparasitic and hyperparasitic strategies, indicating a complex evolutionary history and ecological interaction. Our findings provide insight into the intricate relationships among non-pollinating fig wasps and their hosts, contributing to the broader understanding of tri-trophic interactions in fig microcosm.

ABSTRACT Facultative kleptoparasites face the risk of trying to steal food resources from competitors. This type of interaction is little known, but anecdotal observations indicate that birds of prey may take advantage of their accurate sight to detect the best opportunities for kleptoparasitism. We recorded a camera trap video of an attempt of kleptoparasitism by the white hawk, Pseudastur albicollis, that tried to steal food from a greater grison, Galictis vittata, in a recently selectively-logged forest site in central Brazilian Amazonia. The attempt was unsuccessful as the greater grison responded aggressively to the attack. The event occurred in a linear clearing, which may have increased the bird’s ability to detect its potential host. Kleptoparasitic interactions are difficult to detect in forest environments. Recording opportunistic kleptoparasitic interactions in tropical forests may not only depend on the increasing use of camera traps, but also on habitat conditions that facilitate the detection of potential hosts.

RESUMO Cleptoparasitas facultativos enfrentam os custos envolvidos no roubo do alimento em troca da compensação pelo valor nutricional do item roubado. Essa interação é pouco conhecida, mas observações anedóticas indicam que aves de rapina podem se beneficiar de sua visão acurada para cleptoparasitar. Reportamos uma tentativa de cleptoparasitismo de um furão-grande, Galictis vittata, por um gavião-branco, Pseudastur albicollis, em uma floresta na Amazônia central brasileira recentemente manejada para corte seletivo de impacto reduzido. Como o furão-grande respondeu agressivamente ao ataque, a tentativa de roubo falhou. O evento foi registrado por uma armadilha fotográfica em uma clareira linear. O ambiente mais aberto pode ter aumentado a habilidade do gavião-branco em encontrar o seu hospedeiro. Eventos de cleptoparasitismo são dificilmente registrados em ambientes florestais. Registros de cleptoparasitismo em florestas tropicais podem não depender apenas do uso intensivo de armadilhas fotográficas, mas também de condições ambientais favoráveis à detecção de possíveis hospedeiros pelo cleptoparasita.

Resumen La urbanización altera la composición de las comunidades biológicas y, por tanto, los procesos ecológicos como la depredación y destrucción de nidos de aves. La identificación de las especies depredadoras y destructoras es útil para diseñar investigaciones que busquen comprender los efectos de la urbanización sobre estos procesos ecológicos. En este estudio identificamos, utilizando cámaras web, a las especies diurnas depredadoras y destructoras de nidos artificiales de aves en sitios urbanos y periurbanos de la región metropolitana de La Paz, Bolivia. Describimos además los eventos de la depredación y destrucción de nidos según el número de huevos y nidos afectados, así como los tiempos de latencia para la aproximación y el ataque. La Ratona (Troglodytes aedon) fue la única especie destructora de nidos, registrada tanto en ambientes urbanos como periurbanos. Esta especie afectó los nidos extrayendo material. Registramos un evento de depredación por Matamico Andino (Phalcoboenus megalopterus) en un sitio periurbano y uno de Gato Doméstico (Felissilvestris catus) en un sitio urbano. La especie con mayor incidencia de depredación de nidos tanto en ambientes urbanos como periurbanos fue el Zorzal Chiguanco (Turdus chiguanco), comportamiento que no fue antes reportado para esta especie, y que además es muy poco frecuente para el género. Nuestros resultados resaltan la utilidad de implementar sistemas de filmación en los estudios de depredación y destrucción de nidos de aves.

Abstract Urbanization alters the composition of biological communities and, therefore, ecological processes such as predation and destruction of bird nests. It is useful to identify predator and destructive species in order to design research that aims to understand the effects of urbanization on these ecological processes. In this study, we identify, using web cameras, diurnal predator and destructive species of artificial bird nests in urban and periurban areas of the metropolitan region of La Paz, Bolivia. We further describe the events of predation and nest destruction according to the number of eggs and nests affected, as well as latency periods for approach and attack. The House Wren (Troglodytes aedon) was the only nest-destroying species, recorded in both urban and peri-ur-ban environments. This species affected nests by extracting material. We recorded one predation event by the Andean Caracara ('Phalcoboenus megalopterus) in a periurban area and one by the Domestic Cat (Felis silvestris catus) in an urban area. The Chiguanco Thrush (Turdus chiguanco) was the species with the highest incidence of nest predation in both urban and peri-urban areas a behavior that was not previously reported for this species and which is also very rare for the genus. Our results highlight the importance of implementing filming systems in studies of bird predation and nest destruction.

Resumen Se analizaron las interacciones intraespecíficas que ocurren durante la alimentación en grupo en sitios de invernada en individuos de Gaviota de Olrog, también denominada Gaviota Cangrejera (Larus atlanticus). Las interacciones se estudiaron por medio del análisis de observaciones de comportamiento sobre individuos alimentándose (n=171) en los cangrejales de la Laguna Costera de Mar Chiquita (provincia de Buenos Aires, Argentina). Se registraron en total 98 eventos de desplazamientos tróficos, de los cuales el 95% resultaron exitosos, y en un 77% fueron iniciados por individuo juveniles y machos. Los eventos de cleptoparasitismo registrados fueron 70, aunque solo el 24% resulto exitoso y el 65% fueron iniciados por individuos machos y juveniles. En el 55% de los desplazamientos tróficos y el 32% de los eventos de cleptoparasitismo los ataques fueron "con contacto físico”. La “huida” fue la principal respuesta de los receptores/hospedadores en ambas interacciones. La probabilidad de que ocurra un evento de cleptoparasitismo ante la captura de una presa tuvo relación con el tamaño de la misma. Concluimos que los individuos juveniles y machos fueron los que principalmente iniciaron las interacciones estudiadas y que la principal diferencia entre estas fueron los porcentajes de éxito. Este estudio es el primero en analizar y discutir las interacciones que ocurren entre individuos invernales de Gaviota de Olrog. Comprender su comportamiento de alimentación es importante para conocer nuevos aspectos de la historia natural y generar información de base para una especie endémica amenazada.

Abstract In this study, we analyzed the intra-specific interactions that occur between individuals of Olrog’s Gull (Larus atlanticus) while foraging in groups outside the breeding season. Interactions were studied by analyzing behavioral observations of foraging individuals (n=171) at the Mar Chiquita Coastal Lagoon (Buenos Aires Pro-vince, Argentina). We recorded a total of 98 trophic displacements events and 70 kleptoparasitic events, in which successful attacks were 95% and 24% respectively. Juveniles and males initiated de interactions in the 77% of the trophic displacements and 65% of the kleptoparasitic events. The attacks were "with physical con-tact” in the 55% and 32% of the trophic displacements and kleptoparasitic events, respectively. The main tactic response for both intra-specific interactions was “avoiding”. The probability of occurring a kleptoparasitism event was related to the prey size. We conclude that juveniles and males were the main initiators of the interac-tions studied and that the main difference between them was the success rate. This study is the first to analyze and discuss the intra-specific interactions that occur between individuals of Olrog’s Gull. Understanding their feeding behavior is important to discover new aspects of natural history and to provide background informa-tion for a threatened endemic species.

Kleptoparasitism of Crested caracara on Loggerhead shrike was recorded on July 18, 2013 in a fragmented habitat of desert Baja California Sur. An adult caracara kleptoparasitized a mammal prey (Peromyscus eva) that a loggerhead shrike had impaled in a shrub, an Adam's tree. This is the first record of kleptoparasitism of a 1050-1300 g raptor on a small passerine bird (45 g).

BACKGROUND: Skuas and jaegers (Charadriiformes: Stercorariidae) are seabirds breeding at moderate to high latitudes and some perform extensive post-breeding transequatorial migrations. Most species overwinter and perform significant portions of their migratory flyways along the Pacific coast of South America, but scant information is available on their at-sea ecology in this waters. Our aims in this study were to determine: 1) the timing of occurrence and fluctuations in abundance of skua and jaeger species, 2) their spatial distribution within the coastal zone and 3) at-sea behavior of birds, including flock size and interactions with other seabird species. RESULTS: Between July 2006 and October 2013, we conducted at-sea bird counts at Valparaiso Bay (33°S) in central Chile and confirmed the occurrence of Chilean skuas (Stercorarius chilensis), Brown skuas (S. antarcticus), and Parasitic jaegers (S. parasiticus). Parasitic jaegers are regular austral summer visitors (November to March), whereas Brown skuas occur in the area only in winter (July to October). Chilean skuas were regularly recorded year-round in the area with higher abundances between late winter and early spring (August to October). Brown and Chilean skuas where observed comparatively offshore, whereas Jaegers presented a more coastal distribution, probably associated to host presence. Chilean skuas kleptoparasitized similar-sized (shearwaters and fulmars) and larger seabird species (boobies), whereas jaegers chased only smaller coastal birds (gulls and terns). Brown skuas engaged in no kleptoparasitic behaviors. All three species were observed mostly as solitary individuals. CONCLUSIONS: Skuas and jaegers showed in general a marked seasonality in their occurrence and abundance (only Chilean skua occurs year-round) and use this area as a commuting and stopover zone within their extensive migratory flyway along the southeastern Pacific.

Em 06 de outubro de 2012 um grupo de golfinhos-de-dentes-rugosos Steno bredanensis (Delphinidae) foi observado capturando e despedaçando diversas guaiviras Oligoplites saliens (Carangidae) próximo à ilha Montão de Trigo, litoral norte de São Paulo. As massas de vísceras flutuantes atraíram uma agregação de 120-150 almas-de-mestre Oceanites oceanicus (Hydrobatidae), um migrante transequatorial que passa pela região em outubro. Esta associação interespecífica ainda não havia sido reportada, mas seria esperada, uma vez que S. bredanensis se alimenta de peixes de maior porte e O. oceanicus é atraído pelos restos de presas capturadas por cetáceos como orcas.

On 06 October 2012 a pod of Rough-toothed Dolphins Steno bredanensis (Delphinidae) was observed catching and tearing apart several Castin Leatherjacks Oligoplites saliens (Carangidae) near Montão de Trigo Island, northern coast of São Paulo, Brazil. The resulting floating masses of viscera attracted a feeding aggregation of 120-150 Wilson's Storm-petrels Oceanites oceanicus (Hydrobatidae), a transequatorial migrant passing through the area during October. This interspecific association has not been recorded before, although it could be expected given that S. bredanensis feeds on large fish and O. oceanicus is a known scavenger of kills made by cetaceans such as Killer Whales.

O hábito da fregata (Fregata magnificiens) de roubar peixes do atobã marrom (Sula lecogaster) é bem conhecido na literatura, comportamento este que tem nos levado a classificar a primeira espécie como sendo cleptoparasita da segunda. Este trabalho, no entanto, mostra que a relação entre estas duas espécies é mais complexa e que o comportamento cleptoparasitãrio pode ser interpretado como sendo apenas parte de todo um processo de exploração mutua. Quando estas aves voam no encalço de embarcações pesqueiras, as fregatas localizam a fonte de alimento, sendo então seguidas pelos atobas que aparecem logo apos, apanhando os peixes mortos com muito mais eficiencia, de tal maneira que as fregatas não conseguem mais pescar, tendo que abandonar a atividade, Quando os atobas terminam sua atividade pesqueira, ou mesmo apos um numero deste ciclo, sugere-se que a fregata venha a procurar os atobas, roubando-lhes parte do pescado, fenomeno este bem descrito na literatura. Esta observação conduz a uma revisão da interpretação acerca da relação entre estas espécies, até então, considerada como cleptoparasitismo para a de exploração mútua.

The frigatebird (Fregata magnificiens) often is referred to as a kleptoparasite of the brown booby (Sula lecogaster). This paper however, shows that the relationship between these species is more complex and that kleptoparasitism can be interpreted as just a part of a whole process of mutual exploration. When these birds fly behind fishing boats, F. magnificens locates the food source first and S. lecogaster then moves in and catches fish more efficiently in such a way that the frigatebird can no longer fish and has to fly away. When the fishing period is over then the frigatebird is thought to approach the brown boobies in order to get fish from them, as described in the literature, This leads to a revision on the interpretation about the relation between these species, from that of kleptoparasitism to this of mutual exploration.