6,455 research outputs found
Sensory information and associative cues used in food detection by wild vervet monkeys.
Understanding animals' spatial perception is a critical step toward discerning their cognitive processes. The spatial sense is multimodal and based on both the external world and mental representations of that world. Navigation in each species depends upon its evolutionary history, physiology, and ecological niche. We carried out foraging experiments on wild vervet monkeys (Chlorocebus pygerythrus) at Lake Nabugabo, Uganda, to determine the types of cues used to detect food and whether associative cues could be used to find hidden food. Our first and second set of experiments differentiated between vervets' use of global spatial cues (including the arrangement of feeding platforms within the surrounding vegetation) and/or local layout cues (the position of platforms relative to one another), relative to the use of goal-object cues on each platform. Our third experiment provided an associative cue to the presence of food with global spatial, local layout, and goal-object cues disguised. Vervets located food above chance levels when goal-object cues and associative cues were present, and visual signals were the predominant goal-object cues that they attended to. With similar sample sizes and methods as previous studies on New World monkeys, vervets were not able to locate food using only global spatial cues and local layout cues, unlike all five species of platyrrhines thus far tested. Relative to these platyrrhines, the spatial location of food may need to stay the same for a longer time period before vervets encode this information, and goal-object cues may be more salient for them in small-scale space
Contrasting impacts of land use change on phylogenetic and functional diversity of tropical forest birds
1. Biodiversity conservation strategies increasingly target maintaining evolutionary history and the resilience of ecosystem function, not just species richness (SR). This has led to the emergence of two metrics commonly proposed as tools for decision making: phylogenetic diversity (PD) and functional diversity (FD). Yet the extent to which they are interchangeable remains poorly understood. 2. We explore shifts in and relationships between FD and PD of bird communities across a disturbance gradient in Borneo, from old-growth tropical forest to oil palm plantation. 3. We show a marked decline in PD, and an increase in phylogenetic mean nearest taxon distance (MNTD) from forest to oil palm, in line with declining SR across the gradient. However, phylogenetic mean pairwise distance (MPD) is constrained by forest logging more than by conversion to oil palm, taking account of SR. 4. The decline in FD across the gradient is less severe than in PD, with all metrics indicating relatively high trait diversity in oil palm despite low SR, although functional redundancy is much reduced. Accounting for SR, levels of functional over- or under-dispersion of bird communities are strongly coupled to habitat disturbance level rather than to any equivalent phylogenetic metric. 5. Policy Implications. We suggest that while phylogenetic diversity (PD) is an improvement on species richness as a proxy for functional diversity (FD), conservation decisions based on PD alone cannot reliably safeguard maximal FD. Thus, PD and FD are related but still complementary. Priority setting exercises should use these metrics in combination to identify conservation targets
Crop raiding patterns of solitary and social groups of red-tailed monkeys on cocoa pods in Uganda
Crop damage by wildlife is a very prevalent form of human-wildlife conflict adjacent to protected areas, and great economic losses from crop raiding impede efforts to protect wildlife. Management plans are needed to decrease damage by raiding wildlife, yet conservation biologists typically lack the basic information needed for informed conservation strategies. Red-tailed monkeys (Cercopithecus ascanius) raid a variety of crops adjacent to protected forests in East Africa; however, the role of group structure on crop raiding has not been explored. Here, crop raiding patterns of solitary males and social groups were investigated during 10 months in a plantation of mature cocoa in Uganda. Monkeys gained access to the plantation via trees planted as wind breaks and shade trees, and the sighting frequency of groups was negatively related to the distance from the forest edge. In contrast, solitary males were sighted more frequently far from the forest edge and caused proportionately greater damage than members raiding in a social group. These results highlight that for social animals, crop raiding behavior can vary among types of social groupings; appropriate strategies to cope with raiding must therefore respond to this variation. Deborah Baranga, G. Isabirye Basuta, Julie A. Teichroeb, and Colin A. Chapman
Bio.Phylo: A Unified Toolkit for Processing, Analyzing and Visualizing Phylogenetic Trees in Biopython
Background: Ongoing innovation in phylogenetics and evolutionary biology has been accompanied by a proliferation of software tools, data formats, analytical techniques and web servers. This brings with it the challenge of integrating phylogenetic and other related biological data found in a wide variety of formats, and underlines the need for reusable software that can read, manipulate and transform this information into the various forms required to build computational pipelines. Results: We built a Python software library for working with phylogenetic data that is tightly integrated with Biopython, a broad-ranging toolkit for computational biology. Our library, Bio.Phylo, is highly interoperable with existing libraries, tools and standards, and is capable of parsing common file formats for phylogenetic trees, performing basic transformations and manipulations, attaching rich annotations, and visualizing trees. We unified the modules for working with the standard file formats Newick, NEXUS and phyloXML behind a consistent and simple API, providing a common set of functionality independent of the data source. Conclusions: Bio.Phylo meets a growing need in bioinformatics for working with heterogeneous types of phylogenetic data. By supporting interoperability with multiple file formats and leveraging existing Biopython features, this library simplifies the construction of phylogenetic workflows. We also provide examples of the benefits of building a community around a shared open-source project. Bio.Phylo is included with Biopython, available through the Biopython website, http://biopython.org
Global academic response to COVID â19: Crossâsectional study
This study explores the response to COVIDâ19 from investigators, editors, and publishers and seeks to define challenges during the early stages of the pandemic. A crossâsectional bibliometric review of COVIDâ19 literature was undertaken between 1 November 2019 and 24 March 2020, along with a comparative review of Middle East respiratory syndrome (MERS) literature. Investigator responsiveness was assessed by measuring the volume and type of research published. Editorial responsiveness was assessed by measuring the submissionâtoâacceptance time and availability of original data. Publisherâresponsiveness was assessed by measuring the acceptanceâtoâpublication time and the provision of open access. Three hundred and ninetyâeight of 2,835 COVIDâ19 and 55 of 1,513 MERS search results were eligible. Most COVIDâ19 studies were clinical reports (n =â242; 60.8%). The submissionâtoâacceptance [median: 5âdays (IQR: 3â11) versus 71.5âdays (38â106); P <â.001] and acceptanceâtoâpublication [median: 5âdays (IQR: 2â8) versus 22.5âdays (4â48·5â; P <â.001] times were strikingly shorter for COVIDâ19. Almost all COVIDâ19 (n =â396; 99.5%) and MERS (n =â55; 100%) studies were openâaccess. Data sharing was infrequent, with original data available for 104 (26.1%) COVIDâ19 and 10 (18.2%) MERS studies (P =â.203). The early academic response was characterized by investigators aiming to define the disease. Studies were made rapidly and openly available. Only oneâinâfour were published alongside original data, which is a key target for improvement
Emergent group level navigation: an agent-based evaluation of movement patterns in a folivorous primate.
The foraging activity of many organisms reveal strategic movement patterns, showing efficient use of spatially distributed resources. The underlying mechanisms behind these movement patterns, such as the use of spatial memory, are topics of considerable debate. To augment existing evidence of spatial memory use in primates, we generated movement patterns from simulated primate agents with simple sensory and behavioral capabilities. We developed agents representing various hypotheses of memory use, and compared the movement patterns of simulated groups to those of an observed group of red colobus monkeys (Procolobus rufomitratus), testing for: the effects of memory type (Euclidian or landmark based), amount of memory retention, and the effects of social rules in making foraging choices at the scale of the group (independent or leader led). Our results indicate that red colobus movement patterns fit best with simulated groups that have landmark based memory and a follow the leader foraging strategy. Comparisons between simulated agents revealed that social rules had the greatest impact on a group's step length, whereas the type of memory had the highest impact on a group's path tortuosity and cohesion. Using simulation studies as experimental trials to test theories of spatial memory use allows the development of insight into the behavioral mechanisms behind animal movement, developing case-specific results, as well as general results informing how changes to perception and behavior influence movement patterns
Effect of Dietary Components on Larval Life History Characteristics in the Medfly (Ceratitis capitata: Diptera, Tephritidae)
Background: The ability to respond to heterogenous nutritional resources is an important factor in the adaptive radiation of insects such as the highly polyphagous Medfly. Here we examined the breadth of the Medflyâs capacity to respond to different developmental conditions, by experimentally altering diet components as a proxy for host quality and novelty. Methodology/Principal Findings: We tested responses of larval life history to diets containing protein and carbohydrate components found in and outside the natural host range of this species. A 40% reduction in the quantity of protein caused a significant increase in egg to adult mortality by 26.5%±6% in comparison to the standard baseline diet. Proteins and carbohydrates had differential effects on larval versus pupal development and survival. Addition of a novel protein source, casein (i.e. milk protein), to the diet increased larval mortality by 19.4%±3% and also lengthened the duration of larval development by 1.93±0.5 days in comparison to the standard diet. Alteration of dietary carbohydrate, by replacing the baseline starch with simple sugars, increased mortality specifically within the pupal stage (by 28.2%±8% and 26.2%±9% for glucose and maltose diets, respectively). Development in the presence of the novel carbohydrate lactose (milk sugar) was successful, though on this diet there was a decrease of 29.8±1.6 ”g in mean pupal weight in comparison to pupae reared on the baseline diet. Conclusions: The results confirm that laboratory reared Medfly retain the ability to survive development through a wide range of fluctuations in the nutritional environment. We highlight new facets of the responses of different stages of holometabolous life histories to key dietary components. The results are relevant to colonisation scenarios and key to the biology of this highly invasive species
Microguards and micromessengers of the genome
The regulation of gene expression is of fundamental importance to maintain organismal function and integrity and requires a multifaceted and highly ordered sequence of events. The cyclic nature of gene expression is known as âtranscription dynamicsâ. Disruption or perturbation of these dynamics can result in significant fitness costs arising from genome instability, accelerated ageing and disease. We review recent research that supports the idea that an important new role for small RNAs, particularly microRNAs (miRNAs), is in protecting the genome against short-term transcriptional fluctuations, in a process we term âmicroguardingâ. An additional emerging role for miRNAs is as âmicromessengersââthrough alteration of gene expression in target cells to which they are trafficked within microvesicles. We describe the scant but emerging evidence that miRNAs can be moved between different cells, individuals and even species, to exert biologically significant responses. With these two new roles, miRNAs have the potential to protect against deleterious gene expression variation from perturbation and to themselves perturb the expression of genes in target cells. These interactions between cells will frequently be subject to conflicts of interest when they occur between unrelated cells that lack a coincidence of fitness interests. Hence, there is the potential for miRNAs to represent both a means to resolve conflicts of interest, as well as instigate them. We conclude by exploring this conflict hypothesis, by describing some of the initial evidence consistent with it and proposing new ideas for future research into this exciting topic
Mangroves enhance the biomass of coral reef fish communities in the Caribbean
Mangrove forests are one of the world's most threatened tropical ecosystems with global loss exceeding 35% (ref. 1). Juvenile coral reef fish often inhabit mangroves, but the importance of these nurseries to reef fish population dynamics has not been quantified. Indeed, mangroves might be expected to have negligible influence on reef fish communities: juvenile fish can inhabit alternative habitats and fish populations may be regulated by other limiting factors such as larval supply or fishing. Here we show that mangroves are unexpectedly important, serving as an intermediate nursery habitat that may increase the survivorship of young fish. Mangroves in the Caribbean strongly influence the community structure of fish on neighbouring coral reefs. In addition, the biomass of several commercially important species is more than doubled when adult habitat is connected to mangroves. The largest herbivorous fish in the Atlantic, Scarus guacamaia, has a functional dependency on mangroves and has suffered local extinction after mangrove removal. Current rates of mangrove deforestation are likely to have severe deleterious consequences for the ecosystem function, fisheries productivity and resilience of reefs. Conservation efforts should protect connected corridors of mangroves, seagrass beds and coral reefs
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