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Seasonal availability of resources can influence the timing and success of reproduction in primates. This study examines the annual pattern of conceptions, mid‐term (13 weeks) and full‐term (26 weeks) pregnancy losses, births, and infant survivorship of the Critically Endangered cotton‐top tamarin (Saguinus oedipus) at Proyecto Tití's long‐term field site in Santa Catalina, Colombia. Using 18 years of behavior, physical exam, and fecal steroid data (N = 51 females, 168 conceptions, 121 liters), fecal estrone conjugate (E1C) and pregnanediol‐3‐glucuronide (PdG) or progesterone (P4) profiles were examined to investigate the relationships between female reproductive patterns and reproductive success with feeding and climatic data. Cotton‐top tamarins demonstrated seasonal patterns of reproduction and pregnancy losses. We found positive correlations between peak conception and nectarivory, births and rainfall, and mid‐lactation and frugivory. High body mass mothers reproducing during the peak season were more likely to have infants survive. Overall, these results suggest that tamarins use a "relaxed income‐breeder" strategy. Cotton‐top tamarins appear to maximize reproductive output at the time of ovulation, and can reduce their investment in the current reproductive effort at many stages. Changes in food availability due to habitat loss and climate change will require the Critically Endangered cotton‐top tamarins to alter their reproductive strategies to survive. Research highlights: Wild cotton‐top tamarin reproduction was seasonal. Conception correlated with increased consumption of nectar. Births correspond to the onset of the rainy season. Lactation and weaning occurred at times of high fruit consumption.Mid‐ and full‐term (13 and 26 weeks) pregnancy losses revealed by endocrine monitoring occurred predominantly at the end of the rainy season as fruit consumption seasonally declined and available energy for the current reproductive effort was lowest.Survivorship of infants was also seasonal. Infants born to "high" body mass females during the peak birth season had higher survivorship than those born outside of that period regardless of litter size at birth.Females demonstrated a "relaxed income breeder" strategy, modifying investment at every reproductive stage based on physiological and environmental factors, balancing short‐term needs and individual survival with long‐term reproductive success. [ABSTRACT FROM AUTHOR]

U/Pb LA-MC-ICP-MS zircon ages and whole-rock geochemistry from a biotite granitoid, recovered at ∼2.1 km depth from the Ranchería-2 well in the Baja Guajira basin, southern Caribbean region, reveal the existence of a ca. 70 Ma silicic plutonic event. This granitoid intrudes ca. 76-80 Ma intraoceanic arc fragments and continental margin sediments that experienced continental subduction and collision since ca. 76 Ma. The major compositional shift recorded by this granitoid, including light rare earth element (LREE) enrichment ([La/Yb]N = 11.28), the increase in the arc maturity and its postcollisional affinity, suggests that this magmatism may have been formed during the waning stages of collision due to slab break-off that followed the end of the continental subduction. This interpretation would constrain arc-continent collision of the allochthonous Caribbean plate with this segment of the continental margin by ca. 70-76 Ma. Contemporaneous and slightly diachronous accretionary events are seen along most of the northwestern South American margin. We therefore suggest that the oblique geometry of the Caribbean-South American plate interactions facilitates the accretion of the eastern and northern segments of the oceanic plate margins. Unconformable contact with Late Oligocene-Early Miocene sediments suggests that the granitoid and its host rocks were uplifted and exhumed between the Late Maastrichtian and the Late Oligocene as a consequence of the major changes on the Caribbean-South American convergence. [ABSTRACT FROM AUTHOR]