Animal collective movements are a key example of a system that links two clearly defined levels of organization: the individual and the group. Most models investigating collective movements have generated coherent collective behaviours without the inclusion of individual variability. However, new individual-based models, together with emerging empirical information, emphasize that within-group heterogeneity may strongly influence collective movement behaviour. Here we (i) review the empirical evidence for individual variation in animal collective movements, (ii) explore how theoretical investigations have represented individual heterogeneity when modelling collective movements and (iii) present a model to show how within-group heterogeneity influences the collective properties of a group. Our review underscores the need to consider variability at the level of the individual to improve our understanding of how individual decision rules lead to emergent movement patterns, and also to yield better quantitative predictions of collective behaviour.This article is part of the theme issue 'Collective movement ecology'.

As humanity's demand for resources continues to rise and productive arable lands become increasingly scarce, many of Earth's remaining intact regions are at heightened risk of destruction from agricultural development. In situations where agricultural expansion is inevitable, it is important to manage intact landscape transformation so that impacts on environmental values are minimised. Here, we present a novel, spatially explicit, land use planning framework that addresses the decision making needed to account for different, competing economic-environment objectives (agricultural production value, biodiversity conservation, ecosystem service retention) when land use change is inevitable within an intact landscape. We apply our framework to the globally significant savannahs of the Orinoquia (Colombia), which in a post-conflict era is under increased agricultural development pressure. We show that while negative environmental impacts can be reduced through planning, the total area of land converted to agriculture is the unavoidable principal driver of biodiversity and ecosystem service loss. We therefore identify planning solutions that perform well across all objectives simultaneously, despite trade-offs among them. When 15%, 20%, 30% and 40% of the study area is allowed to be converted to agriculture, on average planning can improve species persistence and ecosystem service retention by up to 16%, 15%, 12%, and 9%, respectively, when compared to agricultural-focused solutions. Development in the region so far has had an unnecessarily large impact on environmental objectives due to a lack of effective land use planning, creating an 'opportunity debt'. Our study provides an evidence base to inform proactive planning and the development of environmentally sensible agricultural development policy and practice in the region. This framework can be used by stakeholders to achieve agriculture expansion goals and maximise economic profit while minimising impacts on the environment in the Orinoquia, or any relatively intact region that is being developed.

Pitheciids are known for their frugivorous diets, but there has been no broad-scale comparison of fruit genera used by these primates that range across five geographic regions in South America. We compiled 31 fruit lists from data collected from 18 species (three Cacajao, six Callicebus, five Chiropotes, and four Pithecia) at 26 study sites in six countries. Together, these lists contained 455 plant genera from 96 families. We predicted that 1) closely related Chiropotes and Cacajao would demonstrate the greatest similarity in fruit lists; 2) pitheciids living in closer geographic proximity would have greater similarities in fruit lists; and 3) fruit genus richness would be lower in lists from forest fragments than continuous forests. Fruit genus richness was greatest for the composite Chiropotes list, even though Pithecia had the greatest overall sampling effort. We also found that the Callicebus composite fruit list had lower similarity scores in comparison with the composite food lists of the other three genera (both within and between geographic areas). Chiropotes and Pithecia showed strongest similarities in fruit lists, followed by sister taxa Chiropotes and Cacajao. Overall, pitheciids in closer proximity had more similarities in their fruit list, and this pattern was evident in the fruit lists for both Callicebus and Chiropotes. There was no difference in the number of fruit genera used by pitheciids in habitat fragments and continuous forest. Our findings demonstrate that pitheciids use a variety of fruit genera, but phylogenetic and geographic patterns in fruit use are not consistent across all pitheciid genera. This study represents the most extensive examination of pitheciid fruit consumption to date, but future research is needed to investigate the extent to which the trends in fruit genus richness noted here are attributable to habitat differences among study sites, differences in feeding ecology, or a combination of both.

El estudio de siete muestras fecales de tigrillo, Leopardus pardalis, encontradas en un bosque andino colombiano, entre 2200 y 2900m de altitud, permitió obtener una visión preliminar de los hábitos alimentarios de este felino. Leopardus pardalis consumió principalmente mamíferos, ˜90% de las presas y también aves. Entre los mamíferos, los de <400 g y de > 400 g representaron ˜52% y ˜38% de las presas, respectivamente. La frecuencia relativa de presas de < 400 g es alta comparada con lo presentado por otros estudios; posiblemente, se deba a que depredadores de mayor tamaño han desaparecido del área de estudio, lo que permite al tigrillo ampliar su rango de tamaño de presas, al convertirse en el mayor depredador del bosque.

Ecosystems in the northern Andes face unprecedented habitat loss. Pumas are the top predators in the region and exert key ecological functions, such as population control and resource facilitation. However, little is known about the temporal niche of the species or its effects on behaviour of prey in the tropics. We hypothesized that there is a link between the activity patterns of pumas and their prey in a cloud forest of the Central Andes of Colombia. We installed 61 camera traps to estimate the degree of overlap between the daily activity curves of pumas and seven potential prey species, using conditional kernel density functions. Pumas, armadillos, mountain pacas, and white–eared opossums were mainly nocturnal, with little crepuscular activity and high temporal overlap. Central American agouti, mountain coati, little red brocket deer, and Cauca guan displayed a predominantly diurnal activity and temporal partitioning with pumas. As opportunistic predators, pumas were able to maximize foraging efficiency by preying on the crepuscular and nocturnal species. Conservation of this highland predator will largely depend on the suitable management of its native prey.

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Callicebus and the pitheciins are closely related; however, differences in their diets and dental morphology suggest that they differ in the use of mechanically protected food. We describe physical traits of fruits consumed by white-handed titi monkeys (Callicebus lugens) and determine their influence on fruit part selection and immediate seed fate after fruit handling. We tested two hypotheses about the effects of mechanical fruit traits on fruit part selection and seed fate: (1) fruits selected for seed consumption are harder than fruits selected for their fleshy parts and (2) consumed seeds are softer than seeds with other fates. In addition, we analyzed the influence of other physical fruit traits on fruit part selection and seed fate. C. lugens included 69 species in its diet, from which it mainly consumed their fleshy parts. It also consumed seeds, alone or with fleshy fruit parts, but most of them ended up close to parent trees after being dropped or spat out. The first hypothesis was supported while the second was rejected, indicating that C. lugens tends to rely on hard fruits for obtaining seeds, while seed hardness had no influence on fruit part selection and seed fate, contrasting with the pattern reported for Pithecia and Chiropotes in other studies. Ripeness was the most influential factor for fruit part and seed fate discrimination. Results suggest a tendency to sclerocarpic foraging in C. lugens when feeding on seeds.

<p>Este artículo se propone reflexionar sobre la ambigüedad del término <em>violencia </em>y la practicidad de su utilización en el campo de las ciencias sociales. Además, expone sus principales acepciones, tratando de pensar sobre las consecuencias que conlleva elegir cada una de ellas; debate la utilidad del uso del concepto teniendo en cuenta su evidente polisemia; y discute la posibilidad de aceptar una definición transcultural mínima. Por último, trata de responder a la pregunta sobre cuál concepto es el más adecuado para ser utilizado como herramienta en la investigación del conflicto político colombiano.</p>