Keyword: polygyny

Dominance relationships in Yangochiroptera: a review

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Yangochiroptera is a suborder recognized for having diversified food habits and unique social behavior. Based on a literature review, this study analyzed the inter-specific variation present in their social behavior, with an emphasis on dominance behavior. Harem formation, territoriality, and aggressiveness were shown to be connected to dominance behavior. The polygyny of defense of resources and defense of harem females appeared as mating systems in which the possibility of dominance appears to be greater. However, the small number of references dedicated specifically to this type of behavior makes it difficult to describe the patterns, and more studies focusing on the behavioral ecology of their species are needed.

Relações de dominância em Yangochiropteros: uma revisão. Yangochiroptera é subordem reconhecida por apresentar hábitos diversificados em relação à sua alimentação e também aos seus comportamentos sociais únicos. A partir de uma revisão bibliográfica, este estudo buscou analisar a variação interespecífica no comportamento social desse grupo — com ênfase em comportamentos de dominância. Formação de haréns, territorialidade e agressividade mostraram estar conectados ao comportamento de dominância. Já a poliginia de defesa de recursos e de defesa de fêmeas de harém, apareceram como sistemas de acasalamento nos quais a possibilidade da dominância aparenta ser maior. Contudo, o baixo número de referências voltadas especificamente para este tipo de comportamento dificulta a descrição de padrões, sendo necessários mais estudos focados na ecologia comportamental de suas espécies.

Graphical abstract for the article “Dominance relationships in Yangochiroptera: a review” (Luchesi & Parolin, 2023)

Reproductive flexibility in South American camelids: first records of alternative mating tactics in wild guanacos (Lama guanicoe)

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Intraspecific variation in mating behavior has been documented in diverse taxa, including ungulates. Here, we report and describe for the first time the existence of alternative mating tactics in a wild guanaco (Lama guanicoe) partially migratory population. We document (1) a resource-defense tactic, widely reported for different populations; and (2) a clustered territorial tactic, adopted by the solo territorial males of this population. Our results highlight the reproductive flexibility of this species and its relationship with external factors that could be influencing it.

Flexibilidad reproductiva en camélidos sudamericanos: primeros registros de tácticas de apareamiento alternativas en guanacos silvestres (Lama guanicoe). La variación intraespecífica en el comportamiento de apareamiento ha sido documentada en diversos taxones, incluyendo ungulados. Aquí reportamos y describimos por primera vez la existencia de tácticas alternativas de apareamiento en una población de guanacos silvestres (Lama guanicoe) parcialmente migratoria. Documentamos (1) una táctica de defensa de los recursos, ampliamente descripta para diferentes poblaciones; y (2) una táctica territorial agrupada, adoptada por los machos territoriales solitarios de esta población. Nuestros resultados destacan la flexibilidad reproductiva de esta especie y su relación con los factores externos que podrían estar influyendo en ella.

Jerarquía de dominancia y elección de machos por parte de hembras en Akodon azarae (Cricetidae: Sigmodontinae): un estudio experimental

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En roedores, la competencia indirecta entre machos cumple un rol importante en el establecimiento de jerarquías de dominancia y la evolución de tácticas de apareamiento. Considerando que Akodon azarae es poligínica con defensa de hembras, se plantearon las hipótesis de que los machos acceden al apareamiento a través del establecimiento de jerarquías de dominancia y que las hembras prefieren machos dominantes. Nuestros objetivos fueron estudiar el establecimiento de jerarquías de dominancia por parte de machos mediante marcado odorífico, y la elección de macho por parte de hembras en relación a su condición de dominancia. Además, se estudió si los machos dominantes reafirman su condición mediante el sobremarcado odorífico y el comportamiento agresivo. El estudio se realizó en laboratorio durante el período reproductivo del año 2015, utilizando animales adultos (32 machos y 23 hembras). Se utilizó una cámara de selección de tres compartimentos, separados por paredes perforadas para permitir el contacto visual y olfatorio, pero no el contacto físico directo. Los resultados permitieron identificar machos dominantes y subordinados, pero revelaron que los machos dominantes no reafirman su condición mediante sobremarcas ni agresión. Las hembras no exhibieron preferencia por los machos dominantes. Estudios futuros deberían incluir una estimación más precisa de los niveles de dominancia y un diseño que permita el contacto físico entre los individuos.

Dominance hierarchy and female mate choice in Akodon azarae (Cricetidae: Sigmodontinae): an experimental study. In rodents, indirect competition among males plays an important role in the establishment of dominance hierarchies and the evolution of mating strategies. Given that Akodon azarae is a polygynous species in which males guard females against other potential mates, we postulated that males access mating through the establishment of dominance hierarchies and that females prefer dominant males. Our objectives were to study the establishment of such hierarchies by means of scent marking and the relationship between mate choice by females in relation to male dominance status. In addition, we examined whether dominant males reinforced their condition by means of scent over-marking and aggressive behavior. The study was conducted in the laboratory during the reproductive season of 2015, using adult individuals (32 males and 23 females). We used a 3-chamber device, with chambers separated by perforated walls that allowed visual and olfactory communication, but not direct physical contact. We were able to identify dominant and subordinate males, but the former did not reinforce their condition with over-marking or aggression. Females did not appear to prefer dominant males. Future studies should include more precise assessments of dominance levels and a design that allows physical contact among individuals.