Efforts to reverse the decline of endangered golden lion tamarin monkeys have been relatively successful because the Brazilian organization dedicated to the species’ conservation (Associação Mico-Leão-Dourado, AMLD) relies on science-based computer modeling to determine the number of tamarins necessary to achieve demographic and genetic goals, and a process of strategic planning to achieve those goals. Accurate estimates of the numbers of tamarins in forest fragments are essential to evaluate progress in achieving goals and adapt strategies as necessary. In this report we present the results of a new method to survey the number of tamarins in the wild, a modification of the point transect with lures procedure. Using this method, we estimate that in 2014 there were approximately 3,700 golden lion tamarins in 41,400 hectares of Atlantic Forest. Of these, 59% are from remnant wild populations, 34% are descendants of captive-born reintroduced animals and 7% are descendants of wild translocated groups. The number of tamarins and amount of forest estimated in this survey exceeded values necessary to meet AMLD’s definition of a viable population, determined to be 2,000 tamarins in 25,000 hectares of connected and protected forest. However, the seven forest blocks and their tamarin populations are not yet adequately connected and protected. AMLD’s strategic plan to achieve a viable population of golden lion tamarins includes 12 strategies that mitigate these and other threats or contribute directly to the conservation goal. The point transect with lures survey method provides a way to evaluate progress in achieving that goal and adapt strategies as appropriate.

Callitrichidae is a unique primate family not only in terms of the large number of food transfers to infants but also for the prevalence of transfers that are initiated by the adults. It has been hypothesized that, as well as provisioning infants, callitrichid food transfers might function to teach the receiver what food types to eat. If food provisioning has a teaching function, we would expect successful food transfers to be more likely with food types that are novel to the juveniles. We would also expect juveniles to learn about foods from those transfers. We introduced different types of food (some familiar, some novel) to wild groups of golden lion tamarins ( Leontopithecus rosalia ). While novel foods were not more successfully transferred than familiar food in the experiment, transfers were more successful (i.e., the receiver obtained food) when the donor had previous experience with that food. Moreover, we found evidence suggesting that food transfers influenced the future foraging choices of juveniles. Our findings are consistent with the first and third criteria of the functional definition of teaching, which requires that tutors (the adults) modify their behavior in the presence of a naïve individual (a juvenile), and that the naïve individual learns from the modified behavior of the demonstrator. Our findings are also consistent with the provisioning function of food transfer. Social learning seems to play an important role in the development of young tamarins’ foraging preferences. Electronic supplementary material The online version of this article (10.1007/s10329-020-00835-0) contains supplementary material, which is available to authorized users.

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Numerous diseases are carried and can be transmitted from the African buffalo (Syncerus caffer) to livestock. Therefore, buffaloes may only be moved with a special transport permit. Disease-free buffaloes are in demand amongst private game farmers. Current disease-free animals derive from a small genetic pool and hence there is a special interest in bringing new genetic material into the disease-free populations. Different breeding programs were developed in the past, which allow producing disease-free offspring from an infected herd. In this study epididymal sperm from 16 mature African buffalo bulls were frozen with Triladyl™ and AndroMed ® (both Minitüb, Germany) with or without the addition of bovine seminal plasma. Post-thaw motility, longevity and acrosomal integrity were compared by means of paired two-tailed t-tests. For both cryodiluents the post-thaw motility was mostly higher when no seminal plasma was added: no differences could be seen for the acrosomal integrity. Triladyl™ was superior to AndroMed ® in regards to total post-thaw motility. This study indicates that the use of bovine seminal plasma in a concentration of 10% is detrimental rather than beneficial in regards to the post-thaw motility. Triladyl™ rather than AndroMed ® should be used to freeze buffalo epididymal sperm, since it is superior in terms of post-thaw motility, even though the former, containing egg yolk, is not a defined medium and therefore lacks quality standards and carries a hygiene risk. Cette étude montre que l'utilisation decplasma séminal bovin à la concentration de 10% est plus nuisible que bénéfique en ce qui concerne la motilité post-congélation. Triladyl TM devrait être préféré à Andromed ® pour congeler le sperme épididymal de bison, puisqu'il est meilleur en ce qui concerne la motilité post-congélation, même s'il contient du jaune d'oeuf et n'est pas un milieu défini ( pas de standards de qualité), ce qui sous-entend un risque hygienique. Zusammenfassung

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