Trait variation and trait stability in common marmosets (Callithrix jacchus) inhabiting ecologically distinct habitats in northeastern Brazil

Abstract

Understanding the set of factors that promote and constrain a species' ability to exploit ecologically distinct habitats is central for addressing questions of intraspecific variability in behavior and morphology. In this study, we compared newly collected data with published data on body measurements, group size and composition, daily path length, home range, and reproductive output in wild common marmosets naturally inhabiting two contrasting environments in northeastern Brazil: the Atlantic Forest (AF), which is characterized by high biodiversity and reduced seasonality in food availability and the Caatinga (CAT), which is characterized by a severe hot and dry season lasting from 5 to 11 months, drought-resistant plant species, and reduced primary productivity.Despite marked differences in ecological conditions, CAT marmosets and AF marmosets differed minimally in daily path length, home range, reproductive output, and infant survivorship. CAT marmosets were found to live in smaller groups containing fewer adult females than AF marmosets, and also were characterized by a greater surface area to body mass ratio, a trait that may represent an adaptation to the hot and dry conditions of the Caatinga. We propose that in conjunction with body mass reduction, minor adjustments in behavior, the exploitation of cacti as a source of water and nutrients, and access to exudates as a dependable year-round food resource, common marmosets successfully used the same adaptive pattern to maintain high reproductive output and infant survivorship in exploiting these two ecologically distinct environments. K E Y W O R D SAtlantic forest, Caatinga, intraspecific variability, phylogenetic constraints, surface area to body mass ratio

Life in a harsh environment: the effects of age, sex, reproductive condition, and season on hair cortisol concentration in a wild non-human primate

“…The monkeys were trapped using the Peruvian Capture Method, which involved habituating each marmoset group to a single large trap containing 10 separate compartments, each with its own individually operated door (Garber et al, 2019, for additional information). The traps were baited with bananas and during each capture session we were able to trap all or most group members.…”

“…In this study we assess the effects of age, sex, reproductive condition and season on HCC in a wild New World primate, the common marmoset (C. jacchus, Callitrichinae). Common marmosets are small monkeys (adult body mass = 265−325 g; Garber et al, 2019) endemic to forested habitats of two highly distinct biomes in northeastern Brazil: the Caatinga (CAT) and the Atlantic Forest (AF) (Garber et al, 2019;Rylands, Coimbra-Filho & Mittermeier, 2009). The CAT is a semi-desert biome characterized by a hot (daytime temperatures in the dry season commonly exceed 33 C) and extended (5-8-month-long) dry season, limited rainfall (250-1,200 mm per year), drought-resistant plant species, and reduced productivity compared with the AF, which is a region of high biodiversity, higher annual rainfall (1,400-2,000 mm per year) and high primary productivity (Araújo, Castro & Alburquerque, 2007).…”

“…Common marmosets live in small multimale-multifemale social groups composed of 5-16 individuals (Garber et al, 2019;Yamamoto et al, 2009). Wild groups contain from one to six adult females and one to five adult males.…”

“…Wild groups contain from one to six adult females and one to five adult males. Regardless of the number of adult females per group, generally only a single female in each group breeds (Garber et al, 2019;Schiel & Souto, 2017). Reproductive competition among resident females for the sovereign or primary breeding position is high (Garber, 1997), and the breeding female is socially dominant to all other group members (De la Fuente et al, 2019).…”

“…Reproductive competition among resident females for the sovereign or primary breeding position is high (Garber, 1997), and the breeding female is socially dominant to all other group members (De la Fuente et al, 2019). In both the AF and the CAT, a breeding female can produce two litters or a total of four offspring per year (Garber et al, 2019).…”