LA DEMOGRAFÍA Y LA COMPOSICIÓN DEL GRUPO

Savage A, Giraldo LH, Blumer ES, Soto LH, Snowdon CT. 1996a. Demography, group composition, and dispersal in wild cotton-top tamarin (Saguinus oedipus) groups. American Journal of Primatology 37:23-32.

Tamarins live in social groups of 2-10 individuals. Although, there have been a few cases of reported polygamy, most groups contain only one reproductively active male and female (Neyman 1977). Females, on average, give birth to twins annually. Social groups appear relatively stable, with an average rate of emigration of 0.71 ± 1.18 individuals/group/year. Males and females disperse to neighboring groups equally, however, adults move more frequently than juveniles and infants. Immigrant males are more likely to enter a group following the death of a resident male. Reproductive success of these immigrant males is difficult to quantify without paternity tests, however, an immigrant male may release subordinate females from reproductive suppression. A novel male avoids the constraints of incest avoidance, and may thus stimulate a reproductively inhibited female. If a female immigrates, she does not necessarily assume the breeding position. Emigration increased to 2.8 individuals/group/year during a drought , suggesting movement between groups may be a result of extreme environmental conditions leading to increased competition for limited resources.

A proposed model to illustrate the potential reproductive strategies of cotton-top tamarins:

ATENCIÓN A HIJOS

Savage A. Snowdon CT, Giraldo LH. 1996b. Cuidado Parental y patrones de vigilancia en el Tití Cabeciblanco (Saguinus oedipus). En radiaciones adaptativas de los primates neotropicales. Eds. M Norconk, Rosenberger A, P Garber. Nueva York: Plenum Press.

El cuidado parental en esta especie es compartido por todos los miembros de su grupo. La temprana experiencia de acarreo de críos, observada en cautiverio, se ha encontrado que influye en el futuro éxito reproductivo tanto en machos como en hembras. Si un animal nunca acarreó un crio mientras permanecía en su familia, esto irá en detrimento de su propia descendencia. Sin embargo, si el animal ha tenido experiencia en el acarreo de críos antes de la reproducción, él será exitoso en el cuidado de sus críos. Es interesante observar que, animales no natales están involucrados activamente en el cuidado de crios y a menudo son observados asumiendo la posición de vigilancia en sus nuevos grupos. Un animal nunca acarrea críos mientras está en la función de vigilancia. El centinela permanece vigilando mientras el grupo forrajea o descansa y es responsable de alertar al grupo de cualquier amenaza potencial para su seguridad.

Las observaciones de 12 nacimientos en el hábitat natural mostraron que los críos son acarreados únicamente durante las cuatro primeras semanas de desarrollo, con una disminución gradual durante las semanas 5-9, de tal forma que por la semana 10, los críos son acarreados solo cerca un 50 % del tiempo de observación. Todos los individuos en el grupo acarrean a los críos, aunque los adultos lo hacen un poco más que los juveniles. No hubo ninguna diferencia significativa en el tiempo de acarreo entre machos y hembras. Sin embargo, hembras primíparas, acarrean sus críos más durante las primeras dos semanas que hebras multíparas. La supervivencia infantil para un año de edad se incrementa con el tamaño del grupo(ver abajo la tabla 1). La contribución de la madre en el cuidado infantil permanece independiente del tamaño del grupo, sin embargo, en grupos más grandes, el acarreo de críos por machos adultos es menor. El macho adulto sin embargo, exhibe más comportamiento de vigilancia y asume la posición de centinela más a menudo que las hembras adultas durante el mismo tiempo. El comportamiento de vigilancia de los adultos también aumenta a medida que los infantes se hacen más independiente

Cuadro 1. Supervivencia de críos en función del tamaño del grupo.
Tamaño del grupo (N) La tasa de supervivencia infanti

TAMAÑO DE LA CAMADA Y SOBREVIVENCIA INFANTIL

Savage, A., Soto, L., Medina, F., Emeris, G., & Soltis, J. (2009). Litter Size and Infant Survivorship in Wild Groups of Cotton-top Tamarins (Saguinus oedipus) in Colombia. American Journal of Primatology, 71, 1-5.

Developing successful conservation programs for endangered primates requires a complete understanding of the factors involved in successful reproduction and causes of infant mortality. In contrast to other nonhuman primates, callitrichids are unusual as litter size can vary between one to five offspring in captivity. Twins tend to be the norm for most callitrichids, but the incidence of triplet and quadruplet births can account for nearly 10–50% of the litters born in captive colonies. Litter size significantly influences the survivorship of infants with twins having a higher survivorship than triplets or quadruplets. In the wild, reports suggest that twin and singleton litters were the norm in most callitrichids studied to date. Incidence of triplet births is very low in the wild, but there have been triplets observed in a Golden Lion Tamarin family where none of the offspring survived and in a Common Marmoset family where evidence was found of survival.

In our study, there were fifty-eight litters from 21 females recorded at the two field sites. Twins were most common (81%), followed by singletons (16%), and we had the first report of triplet births (3%) in wild cotton-top tamarins. Mortality was not uniformly distributed across time with 33% of cases confined to the first week. Determining the sex of the offspring rarely occurred if infants died or were missing from the group, and carcasses of infants were rarely found. Thus, calculating an accurate sex ratio of infants was not possible. However, surviving offspring were comprised of 42 males and 32 females. Determining the immediate cause of mortality was also challenging. Two of the six carcasses that were recovered were too decomposed to determine the cause of death. The remaining four carcasses were from the two observed triplet births and malnutrition was deemed the cause of death.

Fourteen females produced more than one litter. For these females, the mean survival rate to 6 months for first litters was 57%710.3 SEM but the mean across subsequent litters rose to 86%77.6. However, the effects of parity were not as clear. One primiparous female (Nadia) left her family group and assumed the position of the reproductively active female in a neighboring group and she gave birth to twins that survived to 6 months. However, two primiparous females (Milena and Tamara) were identified in the Santa Catalina sample but do not represent ‘‘typical’’ primiparous females as they were in groups containing two pregnant females. Milena successfully cared for her twins until one was observed missing from the group at week 8 and Tamara’s twins were ‘‘kidnapped’’ by her mother and subsequently died. Litter size appeared to influence survival with triplet litters showing a lower infant survival to 6 months (33%) than twins (80%) or singletons (77%), although the number of triplet litters (n52) is too small for statistical analysis.

This study confirms that infant survival to 6 months of age in the wild (78% twins and 88% singletons), gathered from two distinct field sites, and was greater than has been reported in captive colonies. Similar to captive colonies mortality was highest during the first week of life; however, given the low rate of carcass retrieval we cannot determine the cause of mortality and infant mortality associated after 20 days may be related to the development of infant independence. Given that the parity of the majority of our study females could not be determined, we did find that infant mortality was higher in first litters than subsequent litters born to wild cotton-top tamarin females. We were unable to find a significant relationship between infant mortality and group size or the number of adult males in a social group. However, there was a trend toward higher mortality with a shorter inter-birth interval. The number of females that produce multiple litters in 1 year is rare, but infants born out of the normal birthing season may be at risk as food may not be as plentiful for a nursing female.

 EL COMPORTAMIENTO REPRODUCTIVO Y LA DETERMINACIÓN DE HORMONA

Savage A, Shideler SE, Soto LH, Causado J, Giraldo LH, Lasley BL, Snowdon CT. 1997. Los eventos reproductivos de Tití cabeciblanco silvestres en Colombia. American Journal of Primatología 43: 329-337.

En colaboración con los Drs. Bill Lasley y Susan Shideler de la Universidad de California-Davis, hemos desarrollado métodos de ensayo estrona glucurónido (E1C) y progesterona (PdG) en la orina y las heces de Tití cabeciblanco. También hemos desarrollado con éxito una técnica para recoger las muestras diarias de heces de Tití cabeciblanco. Estamos en el proceso de examinar los factores que controlan los acontecimientos reproductivos de las diferentes poblaciones de tities silvestres. Esto nos permitirá comparar los ciclos reproductivos de hembras de tities tanto en estado silvestre como en cautividad y examinar los mecanismos que regulan la fertilidad en el hábitat natural.

Las hembras de titíes en cautividad tienen una gestación de 183 días y un ciclo ovulatorio de 18 días (Ziegler et al. 1987). Las hembras tienen un estro de 18 días después del parto y el 80% de estas ovulaciones resultan en la concepción. En la naturaleza, las hembras tienen un promedio de 144 días de supresión de la fecundidad después del parto, que parece ser influenciado por las condiciones ambientales. Los ensayos reflejan la concepción E1C con niveles que van> 4000 ng / g y PdG> 8ug / g. Los niveles de la hormona decaen hasta el siguiente parto (E1C a <1000 ng / g y PdG a <3 ug / g).

Las hembras reproductivamente activas también son capaces de influir en la fertilidad de otras hembras en el grupo. Tanto en el medio silvestre como el cautiverio, las hembras post-pubescent son reproductivamente son suprimidas, mostrándose acíclicas, mientras permanezcan en su grupo. En consecuencia, para que una tití se vuelva reproductivamente activa, debe ser separada de su grupo y formar pareja con un macho nuevo. Las Feromonas han sido implicadas como uno de los factores que median en esta supresión. Hembras cautivas removidas de su grupo, emparejadas con un macho nuevo y expuestas al olfateo de las secreciones de su madre, toman un mayor tiempo para ovular que aquellas hembras en condiciones de control (no expuestas). Machos también influyen en la fertilidad de una hembra. Los machos pueden acelerar la pubertad en hembras prepubescentes. Además, apareando a una hembra con un macho "familiar" (p.ej. el hermano) no hará que la hembra se haga reproductivamente activa. Las hembras ovularan sólo con la presencia de un macho nuevo.

Los ciclos de las hijas fueron monitoreados mientras permanecían en su grupo natal. Una hembra cicla irregularmente durante el periodo de infertilidad de posparto de su madre. Cuando su madre concibe de nuevo se observó que ella o vulaba y concibió. El resultado fue la agresión entre madre e hija terminando en la expulsión de la hija del grupo antes del parto. La segunda hija exhibió ciclos normales, sin embargo, después del nacimiento de hermanos, tuvo una d isminución dramática en los niveles de hormonas que permanecieron bajos hasta la próxima concepción de la madre.

Mientras que las hembras en cautiverio se reproducen dos veces al año, las hembras silvestres dan sólo un nacimiento al año antes de la estación lluviosa. El período de nacimiento parece estar correlacionado con un gran consumo de frutos e insectos en su dieta. Y la composición de la dieta puede también influir en la fecundidad, si una hembra tiene uno o dos críos. Mirar la lista de plantas consumidas por los titíes.

Sociosexual development, pair bond formation, and mechanisms of fertility suppression in female cotton-top tamarins (Saguinus oedipus oedipus)
Savage, A., Zieger, T.E., and Snowdon, C.T. 1988. Sociosexual development, pair bond formation, and mechanisms of fertility suppression in female cotton-top tamarins (Saguinus oedipus oedipus). American Journal of Primatology 14:345-359.

ABSTRACT: The effect of various social environments on sociosexual behavior was examined in six young female cotton-top tamarins (Saguinus oedipus oedipus) and in three established breeding females. Behavioral observations and hormonal samples were collected on young females while they were living with their families, when they were isolated from conspecifics, and after they were paired with an unrelated male. While living with the family, all females showed a suppression of fertility and low frequencies of sociosexual behavior. Following removal from the family, isolated females displayed an increase in rate of scent marking and an increase in hormonal levels. When young females were paired with males, they were exposed to scent secretions from their natal families, from an unfamilar family, and from a control for a total of 24 weeks. After pairing, hormonal levels increased dramatically, and ovarian cyclicity began. An increase in sociosexual behavior and elevated levels of scent marking accompanied this physiological change. Newly paired females had higher rates of affiliative behavior and scent marking than did established breeding females. However, both newly paired and established breeding males were more likely to initiate contact, grooming bouts, and social sniffing than were females. Time to first ovulation was later in females who were exposed to scent secretions from their natal families than it was in those females given a control for the first 8 weeks following pairing. No female conceived during exposure to scent secretions. However, once normal ovarian cycling had begun or a pregnancy was established, exposure to scent secretions had no effect. Thus, the social environment influences the fertility, sociosexual behavior, and pair bond formation of cotton-top tamarins. In addition, chemical stimuli found in the scent secretions produced by the natal family are most likely involved in reproductive suppression.

 PROGRAMAS DE CONSERVACIÓN COMUNITARIA

Developing an Effective Community Conservation ProgramSavage, A., Guillen, R., Lamilla, I., & Soto, L. (2010). Developing an Effective Community Conservation Program for Cotton-Top Tamarins (Saguinus oedipus) in Colombia. American Journal of Primatology, 72, 379-390.

Developing effective primate conservation programs, which address the conservation needs of the animals and the needs of local communities that directly impact the habitats that the primates need to survive, is a challenging task. Proyecto Tití´ has provided economic alternatives to local communities that have dramatically reduced the illegal capture of cotton-top tamarins and forest destruction in the region that has positively impacted the long-term survival of this critically endangered primate. Although primate conservation programs can indeed focus on creating knowledgeable individuals, issues relating to poverty can override the most well-educated communities, thus putting the long-term conservation of primates and their habitats at continued risk. The trend in successful conservation programs has been one of integrated rural development that demonstrate direct benefit to the local people (money, jobs, access to health related resources, and food) by conserving species and their habitats.

Understanding the root causes of primate population decline is essential in the development of a comprehensive conservation program. Proyecto Titi has focused efforts on (1) long-term monitoring of the reproductive and behavioral biology of the cotton-top tamarin; (2) documenting the loss of forested habitat, developing techniques to accurately estimate the remaining wild population, and monitoring them over time; and (3) identifying factors that contribute to the decline of this critically endangered species.

Long-term monitoring of species

We began by developing field sites within the historic distribution of cotton-top tamarins, so that we could conduct long-term field studies to investigate the reproductive and behavioral biology of this species. Having data from two field sites allowed us to compare a variety of factors (fecundity, survival rates, home range size, feeding ecology, group dynamics, etc.) to determine if there were any biological causes that were influencing the long-term survival of the species. Our studies have shown that wild cotton-top tamarins do not appear to have high rates of adult or infant mortality, issues of disease exposure, or any obvious biological cause for their decline at our study sites. However, we have observed challenges with animals effectively dispersing, given the limited forested habitat in the area.

Documenting forest loss and species decline

Colombia is among the top ten countries to suffer significant loss of forested habitat with a 0.5% annual rate of destruction and the status of their forest habitat has been designated critically endangered throughout a significant portion of Colombia. A study by Miller et al. [2004] documented a 31% decrease in forested habitat within the tamarins’ historic distribution between 1990 and 2000, because of the conversion of tropical forest habitat to agricultural uses and urban development, extraction of forest resources for firewood and lumber, and logging on both private and protected areas.

Given the rapid rate of forest decline, it was imperative to develop a population monitoring program for the cotton-top tamarin. Given their small size, arboreal nature, and fear of humans, using standard line transect sampling methods dramatically underestimates the size of the population. We, therefore, developed a collaboration with scientists from the Centre for Research into Ecological and Environmental Modeling at the University of St. Andrews, and created a ‘‘lure strip transect,’’ which combines the use of playbacks of territorial vocalizations with traditional transect surveys to yield a robust method of estimating population size. The results from our census found a dramatic decline in the existing cotton-top tamarin population in Colombia. Given the marked decline in suitable forest habitat combined with a small population, the cotton-top tamarin has been reclassified as Critically Endangered by the International Union for Conservation of Nature (IUCN) [IUCN, 2008].

Factors influencing the long-term survival of cotton-top tamarins

Our studies show that the primary threats to the survival of the cotton-top tamarin has been the dramatic loss of habitat from the conversion of tropical forest habitat to agricultural uses, extraction of forest resources for firewood and lumber, and capture for sale in the illegal pet trade. This destruction and consumption of forest resources is driven by the fact that 65% of the population in Colombia lives below the poverty line. With a lack of sustainable income, limited access to employment opportunities, and lack of knowledge of the long-term impact of continued unsustainable extraction of forest products, the future of cotton-top tamarins and the biodiversity in Colombia is severely threatened.

Our early studies found that there were many myths and misconceptions about the forest and the wildlife of the area. More than 90% of the population we surveyed had no idea that cotton-top tamarins were endemic to Colombia and not found in other countries. Our educational strategy involved developing formal and informal programs that (1) increased awareness to the plight of the cotton-top tamarin and the biodiversity of the region; (2) addressed farming practices to minimize impact to the remaining forest habitat; (3) developed teacher training programs to increase scientific literacy in the schools; (4) addressed pet trade issues for rural, urban, and enforcement authorities; and (5) partnered with educational entities to integrate this information into existing school curriculum and established programming.

One challenge facing cotton-top tamarins was the amount of wood that was harvested from the forest and consumed for firewood. It is estimated that globally, nearly 2.5 billion people consume firewood, charcoal, crop residues, and dung as their primary source of energy. In discussions with local villagers in Colombia, we discovered the traditional Colombian ‘‘binde’’ a small cook stove that was made from a termite mound. Interviews with local villagers indicated that bindes required less firewood than cooking over an open fire. Although accepted by local communities in Colombia, there were limitations with bindes made from termite mounds because they often cracked and disintegrated with repeated use. Given that bindes were already a part of the culture; our goal was to make bindes better. We designed a durable binde made of clay. A family of five used approximately 15 logs a day to cook their food over an open fire but using a binde, the number of logs consumed each day was reduced by 2/3rds.

In December 2008, a survey was administered to 107 families that had received a binde. All 107 individuals that participated in the survey were still using the binde they received in 2006. Although 57% of these original bindes had cracks or were slightly damaged during the 2-year study, they were still in use. One hundred percent of the respondents believed that they used less fuel when cooking in a binde than over an open fire and they estimated a 50% reduction in firewood needed annually for cooking. Our studies have suggested that communities readily used bindes and found them to be of value, and also were cutting fewer trees in the forest.

Regardless of effectiveness of the conservation education programs, our experience has shown that if basic human needs are not met, local communities will not engage in activities that positively benefit wildlife. Our goal was to create an artisan group that would create a product from plastic bags that were littering the environment and jeopardizing the future survival of cotton-top tamarins. By providing a stable source of income to the artisan group combined with effective conservation education messaging, they would then commit to protecting the forests and not capture cotton-top tamarins for the illegal pet trade. Today, the artisans have a thriving business selling a variety of products crocheted from plastic bags.

This type of collaborative approach that combines educational programs that increase awareness to the plight of the cotton-top tamarin with opportunities for direct economic benefit results in creating new local champions that are committed to protecting these resources for the future.

ASOCIACIÓN DE ARTESANAS UNIDAS DE LOS LÍMITES (ASOARTESANAS) - Equator Initiative Case Studies
United Nations Development Programme. 2013. United Women Artisans’ Association of Los Límites (ASOARTESANAS), Colombia. Equator Initiative Case Study Series. New York, NY.

Las comunidades locales e indígenas de todo el mundo están promoviendo soluciones innovadoras de desarrollo sostenible que funcionan para las personas y para la naturaleza. Pocas publicaciones o estudios de caso revelan la historia completa de cómo evolucionan estas iniciativas, la amplitud de sus impactos, o cómo cambian con el tiempo. Menos aún se han dado a la tarea de contar estas historias usando a los profesionales de las propias comunidades como narradores de la historia.
Con motivo de su décimo aniversario, la Iniciativa Ecuatorial busca llenar este vacío. El siguiente estudio de caso forma parte de una serie, cada vez mayor, de estudios que detallan el trabajo de los ganadores del premio Ecuatorial–mejores prácticas examinadas y revisadas por expertos, para la conservación comunitaria del medio ambiente y los medios de vida sostenibles. Estos estudios de caso buscan promover el diálogo sobre políticas necesarias para escalar las prácticas locales exitosas, mejorar la base de conocimientos globales sobre el medio ambiente y las soluciones locales para el desarrollo, y servir de modelos replicables en otros lugares del mundo. Los estudios de caso se ven y se entienden mejor haciendo referencia a ‘El Poder de la Acción Local: 10 Años de Lecciones del Premio Ecuatorial’, un compendio de lecciones aprendidas y guías de políticas basadas en el material de los estudios de caso.

RESUMEN DEL PROYECTO
La Asociación de Artesanas Unidas de Los Límites opera en un área del norte de Colombia en la que se encuentran los últimos reductos de titíes cabeciblancos del planeta. Este tipo de mono se ve amenazado por la deforestación, la caza furtiva y la venta ilegal para su uso como mascotas. Esta cooperativa artesana fabrica peluches del tití cabeciblanco, un producto que ha proporcionado beneficios a la vez que ha contribuido en la concienciación de las amenazas que sufre esta especie.
El grupo de mujeres también convierte en bolsos bolsas de plástico usadas, creando así una fuente adicional de ingresos y disminuyendo la contaminación. Dichas mujeres, que apenas contaban con trabajo o ingresos, ahora ganan una media de 150 dólares al mes. Esta actividad artesana de reciclaje se ha traducido en la recogida de más de tres millones de bolsas de plástico de los bosques y arroyos locales. Las actividades de conservación de la asociación incluyen un compromiso con la comunidad y formación en energías alternativas, incluyendo el uso de cocinas de leña hechas de arcilla y de pellets de biomasa.