Factors influencing the survival of wild cotton‐top tamarin (Saguinus oedipus) infants

Abstract

Studies of cooperative breeding species have suggested that helpers are needed for infant survival and that helpers gain skills to successfully raise their own offspring.Studies of callitrichids in managed care and early field studies suggested that group size correlated with infant survival and that helpers needed to learn parental skills to be successful breeders. We present infant survival data from a 20-year field study of cotton-top tamarins (Saguinus oedipus) in Colombia involving 126 litters born to 41 females. There was no difference in the survival of male and female offspring to 6 months of age. However, litter size impacted survival, with triplet litters having lower survival and male triplets having lower survival than females. Loss of infants was highest in the first week of life and, of the animals remaining in the group at 6 months of age, 90% of them survived to 1 year. The mean length of time in the natal group was 2.3 years but some young migrated to other groups after 4 months of age. Group size and number of male helpers (>1 year) was not related to infant survival. However, groups with only one male had fewer surviving infants.Primiparous females had lower infant survival, but previous infant care experience by mothers as helpers had no effect on survival. A major cause of infant loss was group disruption due to deaths/evictions/loss of the reproductively active animals, or immigration of pregnant females. Thus, factors that cause a change in the stability of the reproductively active animals can disrupt group cohesion. Capture of individuals for the illegal pet trade, as well as habitat fragmentation, may increase competition between groups for access to territories and breeding opportunities. This may have long-term impacts to infant survival in this critically endangered species.

Seasonality of reproduction in wild cotton‐top tamarins (Saguinus oedipus) in Colombia

“…As is typical for most callitrichids born in the wild or in managed care (Bales et al, 2001;Dietz et al, 1994;Goldizen, Terborgh, et al, 1988;Savage et al, , 2009Savage et al, , 2021, this study found that twins were most common, followed by singletons and triplets. Singletons, twins, and triplets all have similar seasonal patterns of birth timing.…”

“…Infants born during the seasonal peak (April-August) had a greater probability of surviving to 6 months of age than those infants born off-peak (September-March) regardless of the number of helpers (Savage et al, 2021). This suggests that females have undergone ).…”

“…Callitrichids have the flexibility to employ one or more strategies to balance the present reproductive demands with those of somatic maintenance and future reproduction (Schneider, 2004;Tardif et al, 2013). They can ovulate multiple ova per cycle (Windle et al, 1999), give birth to litters of one to three offspring in the wild (Bales et al, 2001;Dietz et al, 1994;Goldizen, Terborgh, et al, 1988;Savage et al, 2009Savage et al, , 2021, conceive and produce up to two litters in 1 year (Digby et al, 2011), and suppress reproduction in subordinate (or other) females (Savage et al, 1988).…”

“…Additionally, Callitrichids have a cooperative breeding system that allows all group members to participate in infant care (Garber, 1997;Tardif et al, 2013;Ziegler et al, 2009). However, there is considerable variability on whether the number of helpers or group size impacts infant survival (Heslin Piper et al, 2017;Savage et al, 2021;Watsa et al, 2017). The relatively "fast" life-history traits of callitrichids mean they may have more flexibility in their reproductive strategies and more flexibility in their response to changing environmental factors.…”

After short interbirth intervals, captive callitrichine monkeys have higher infant mortality

“…We would like to note some potential limitations to this study. First, we compiled data from zoos and biomedical laboratories, settings in which husbandry mitigates many perinatal risks, including predators, infection, intraspecific aggression ( Savage et al., 2021 ), and environmental stressors. Many of the species studied herein breed seasonally in the wild but more regularly in captivity (with artificial light cycles and constant humidity/food availability).…”