Assessing the genetic composition of cotton-top tamarins (Saguinus oedipus) before sweeping anthropogenic impact.

During the last century, the critically endangered cotton-top tamarin (Saguinus oedipus) has been threatened by multiple anthropogenic factors that drastically affected their habitat and population size. As the genetic impact of these pressures is largely unknown, this study aimed to establish a genetic baseline with the use of temporal sampling to determine the genetic makeup before detrimental anthropogenic impact. Genomes were resequenced from a combination of historical museum samples and modern wild samples at low-medium coverage, to unravel how the cotton-top tamarin population structure and genomic diversity may have changed during this period. Our data suggest two populations can be differentiated, probably separated historically by the mountain ranges of the Paramillo Massif in Colombia. Although this population structure persists in the current populations, modern samples exhibit genomic signals consistent with recent inbreeding, such as long runs of homozygosity and a reduction in genome-wide heterozygosity especially in the greater northeast population. This loss is likely the consequence of the population reduction following the mass exportation of cotton-top tamarins for biomedical research in the 1960s, coupled with the habitat loss this species continues to experience. However, current populations have not experienced an increase in genetic load. We propose that the historical genetic baseline established in this study can be used to provide insight into alteration in the modern population influenced by a drastic reduction in population size as well as providing background information to be used for future conservation decision-making for the species.

Proyecto Titi: Teaching children that cotton-top tamarins (Saguinus oedipus) are not appropriate pets.

Cotton-top tamarins (Saguinus oedipus) are a critically endangered species found only in Colombia. Their survival is threatened by extensive habitat destruction and the illegal pet trade. Because many people in Colombia have a low level of awareness of cotton-top tamarins and even less understanding of the impacts that the illegal pet trade has on the species and its long-term survival, Proyecto Tití has developed a series of programs for children in rural elementary schools that introduce children to cotton-top tamarins. This study examines Proyecto Titi's efforts to reduce the desire to have a cotton-top tamarin as a pet with outcomes focused specifically on (1) creating an emotional connection between people and cotton-top tamarins, (2) identifying the feelings and understanding the challenges that cotton-top tamarin face when they are kept as pets, and (3) empowering students to make positive choices to help cotton-top tamarins. Both TITI KIDS and TITIRITIANDO programs helped students to (1) increase their knowledge of cotton-top tamarins, (2) understand the damage that the pet trade has on individual animals and the long-term survival of cotton-top tamarins and (3) provide practical actions that they can engage in to protect cotton-top tamarins for the future. Our hope is that students from our programs become advocates for conservation in their communities and assist in the long-term conservation activities to protect cotton-top tamarins in Colombia.

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

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 (E1 C) 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.

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

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.

An Assessment of the Population of Cotton-Top Tamarins (Saguinus oedipus) and Their Habitat in Colombia.

Numerous animals have declining populations due to habitat loss, illegal wildlife trade, and climate change. The cotton-top tamarin (Saguinus oedipus) is a Critically Endangered primate species, endemic to northwest Colombia, threatened by deforestation and illegal trade. In order to assess the current state of this species, we analyzed changes in the population of cotton-top tamarins and its habitat from 2005 to 2012. We used a tailor-made "lure strip transect" method to survey 43 accessible forest parcels that represent 30% of the species' range. Estimated population size in the surveyed region was approximately 2,050 in 2005 and 1,900 in 2012, with a coefficient of variation of approximately 10%. The estimated population change between surveys was -7% (a decline of approximately 1.3% per year) suggesting a relatively stable population. If densities of inaccessible forest parcels are similar to those of surveyed samples, the estimated population of cotton-top tamarins in the wild in 2012 was 6,946 individuals. We also recorded little change in the amount of suitable habitat for cotton-top tamarins between sample periods: in 2005, 18% of surveyed forest was preferred habitat for cotton-top tamarins, while in 2012, 17% percent was preferred. We attribute the relatively stable population of this Critically Endangered species to increased conservation efforts of Proyecto Tití, conservation NGOs, and the Colombian government. Due to continued threats to cotton-top tamarins and their habitat such as agriculture and urban expansion, ongoing conservation efforts are needed to ensure the long-term survival of cotton-top tamarins in Colombia.