scholarly journals Ant social foraging strategies along a Neotropical gradient of urbanization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wesley Dáttilo ◽  
Ian MacGregor-Fors
Keyword(s):  
Species Coexistence ◽  
Cloud Forest ◽  
Biodiversity Loss ◽  
Food Resources ◽  
Urban Environments ◽  
Social Foraging ◽  
Foraging Strategies ◽  
Urban Gradient ◽  
Behavioral Strategies ◽  
Ant Communities

AbstractDuring the last decades, urbanization has been highlighted as one of the main causes of biodiversity loss worldwide. Among organisms commonly associated with urban environments, ants occupy urbanized green areas and can live both inside and around human settlements. However, despite the increasing number of studies on the ecological dynamics of ant species developed mainly in temperate urban ecosystems, there is still little knowledge about the behavioral strategies that allow ant species to live and even thrive within cities. In this study, we evaluated the role of urbanization in shaping ant communities, including their social foraging, considering built cover as a gradually changing variable that describes an urban gradient. Specifically, we assessed whether species richness, composition, and the proportion of exotic ant species are related to an urban gradient in a medium-sized Neotropical city immersed in a cloud forest context in Mexico. Moreover, we evaluated the social foraging strategies that could promote ant species coexistence in an urban environment. In general, and contrary to our hypothesis, we found no evidence that the built cover gradient affected the richness, composition, or proportion of exotic ant species foraging on food resources, indicating a filtering and simplification of ant communities given by urbanization. Moreover, we show for the first time that urban ant species exhibited a “discovery-defense strategy”, whereby the ant species with the greatest capacity to discover new food resources were those that showed the greatest ability to monopolize it after 120 min of observation, regardless of the type of resource (i.e., tuna or honey bait). Our findings have a direct impact on the knowledge about how urbanization shapes ant communities and behavior, by showing the foraging strategies of ant species that feed on similar food resources present that allows them to coexist in urban environments.

scholarly journals Hearing sensitivity: An underlying mechanism for niche differentiation in gleaning bats

2021 ◽  
Vol 118 (36) ◽  
pp. e2024943118 ◽  
Author(s):  
Inga Geipel ◽  
Ella Z. Lattenkamp ◽  
M. May Dixon ◽  
Lutz Wiegrebe ◽  
Rachel A. Page
Keyword(s):  
Species Coexistence ◽  
Ecological Factors ◽  
Niche Differentiation ◽  
Underlying Mechanism ◽  
Auditory Brainstem ◽  
Auditory Brainstem Responses ◽  
Foraging Strategies ◽  
Behavioral Strategies ◽  
Echolocation Calls ◽  
Hearing Sensitivity

Tropical ecosystems are known for high species diversity. Adaptations permitting niche differentiation enable species to coexist. Historically, research focused primarily on morphological and behavioral adaptations for foraging, roosting, and other basic ecological factors. Another important factor, however, is differences in sensory capabilities. So far, studies mainly have focused on the output of behavioral strategies of predators and their prey preference. Understanding the coexistence of different foraging strategies, however, requires understanding underlying cognitive and neural mechanisms. In this study, we investigate hearing in bats and how it shapes bat species coexistence. We present the hearing thresholds and echolocation calls of 12 different gleaning bats from the ecologically diverse Phyllostomid family. We measured their auditory brainstem responses to assess their hearing sensitivity. The audiograms of these species had similar overall shapes but differed substantially for frequencies below 9 kHz and in the frequency range of their echolocation calls. Our results suggest that differences among bats in hearing abilities contribute to the diversity in foraging strategies of gleaning bats. We argue that differences in auditory sensitivity could be important mechanisms shaping diversity in sensory niches and coexistence of species.

scholarly journals An exploration of the relationship between recruitment communication and foraging in stingless bees

2021 ◽  
Author(s):  
Robbie I’Anson Price ◽  
Francisca Segers ◽  
Amelia Berger ◽  
Fabio S Nascimento ◽  
Christoph Grüter
Keyword(s):  
Stingless Bees ◽  
Sugar Content ◽  
Social Information ◽  
Food Resources ◽  
Food Sources ◽  
Foraging Strategies ◽  
High Quality ◽  
Recruitment Communication ◽  
Eusocial Bees ◽  
The Relationship

Abstract Social information is widely used in the animal kingdom and can be highly adaptive. In social insects, foragers can use social information to find food, avoid danger or choose a new nest site. Copying others allows individuals to obtain information without having to sample the environment. When foragers communicate information they will often only advertise high quality food sources, thereby filtering out less adaptive information. Stingless bees, a large pantropical group of highly eusocial bees, face intense inter- and intra-specific competition for limited resources, yet display disparate foraging strategies. Within the same environment there are species that communicate the location of food resources to nest-mates and species that do not. Our current understanding of why some species communicate foraging sites while others do not is limited. Studying freely foraging colonies of several co-existing stingless bee species in Brazil, we investigated if recruitment to specific food locations is linked to (1) the sugar content of forage, (2) the duration of foraging trips and (3) the variation in activity of a colony from one day to another and the variation in activity in a species over a day. We found that, contrary to our expectations, species with recruitment communication did not return with higher quality forage than species that do not recruit nestmates. Furthermore, foragers from recruiting species did not have shorter foraging trip durations than those from weakly-recruiting species. Given the intense inter- and intraspecific competition for resources in these environments, it may be that recruiting species favour food resources that can be monopolised by the colony rather than food sources that offer high-quality rewards.

scholarly journals Individual-learning ability predicts social-foraging strategy in house sparrows

2010 ◽  
Vol 278 (1705) ◽  
pp. 582-589 ◽  
Author(s):  
Edith Katsnelson ◽  
Uzi Motro ◽  
Marcus W. Feldman ◽  
Arnon Lotem
Keyword(s):  
Personal Information ◽  
Passer Domesticus ◽  
Learning Task ◽  
Foraging Strategy ◽  
Individual Learning ◽  
Social Foraging ◽  
Learning Ability ◽  
Foraging Strategies ◽  
Learning Abilities ◽  
The Individual

Social foragers can use either a ‘producer’ strategy, which involves searching for food, or a ‘scrounger’ strategy, which involves joining others' food discoveries. While producers rely on personal information and past experience, we may ask whether the tendency to forage as a producer is related to being a better learner. To answer this question, we hand-raised house sparrow ( Passer domesticus ) nestlings that upon independence were given an individual-learning task that required them to associate colour signal and food presence. Following the testing phase, all fledglings were released into a shared aviary, and their social-foraging tendencies were measured. We found a significant positive correlation between individual's performance in the individual-learning task and subsequent tendency to use searching (producing) behaviour. Individual-learning score was negatively correlated with initial fear of the test apparatus and with body weight. However, the correlation between individual learning and searching remained significant after controlling for these variables. Since it was measured before the birds entered a social group, individual-learning ability could not be the outcome of being a producer. However, the two traits may be initially associated, or individual learning could facilitate producing behaviour. To our knowledge, this is the first evidence that associates individual-learning abilities with social-foraging strategies in animal groups.

scholarly journals Co-evolution of learning complexity and social foraging strategies

2010 ◽  
Vol 267 (4) ◽  
pp. 573-581 ◽  
Author(s):  
Michal Arbilly ◽  
Uzi Motro ◽  
Marcus W. Feldman ◽  
Arnon Lotem
Keyword(s):  
Social Foraging ◽  
Foraging Strategies

scholarly journals Eco-urban Nexus

2021 ◽  
Author(s):  
Sarah Burns
Keyword(s):  
Climate Change ◽  
New Zealand ◽  
Human Nature ◽  
Social Issues ◽  
Biodiversity Loss ◽  
Urban Environments ◽  
Urban Setting ◽  
Ecological Degradation ◽  
Biophilic Design ◽  
Human Wellbeing

<p><b>Urban environments in Aotearoa, New Zealand, face a series of challenges regarding the effects of climate change and urbanisation on ecosystems and human wellbeing. As a result of expansive urbanisation during the mid-19th century, the reshaping of natural landscapes saw the destruction of critical indigenous ecologies, causing ecological degradation and biodiversity loss and severely impacting people’s wellbeing; physically, mentally, and spiritually.</b></p> <p>The way we continue to live in and build cities is causing further ecological degradation through overconsumption and pollution, which contributes to the current climate crisis, and leads to storm surge events and sea-level rise, among other direct negative impacts.</p> <p>Porirua, New Zealand is no exemption to this condition. Its existing urban infrastructure and continued urban development to accommodate an expanding population are causing several environmental and social issues relating to ecosystem degradation. Regular flood events demonstrate the city’s inability to cope with storm water surges, which will only continue as the effects of climate change intensify (Daysh, 2019).</p> <p>How might urban environments adapt to and mitigate climate change impacts affecting ecosystems and human wellbeing in a way which preserves social and cultural identities?</p> <p>This thesis argues that a potential solution to address these issues is through increasing human-nature connections in the built environment at a range of scales and across disciplines. This research will test how biophilic design interventions (those related to increasing human/nature connections) could transform a city into a more livable, resilient place of wellbeing for a growing population. Challenging the typical juncture of ocean and land in an urban setting, The research reimagines Porirua as a ‘city on a wetland’ through a speculative biophilic design experiment ,exploring how architecture might respond to dynamic landscape conditions. Theories of biophilia are studied for their related effects on improved human cognitive, psychological and physiological wellbeing, creating anew typology for civic space which marries culture, environment and architecture.</p>

scholarly journals Parasitism effects on coexistence and stability within simple trophic modules

2018 ◽  
Author(s):  
Loïc Prosnier ◽  
Vincent Médoc ◽  
Nicolas Loeuille
Keyword(s):  
Food Webs ◽  
Species Coexistence ◽  
Prey Species ◽  
Foraging Strategies ◽  
Intrinsic Growth Rate ◽  
Direct Effects ◽  
Trophic Networks ◽  
Stabilizing Effect ◽  
Indirect Impacts ◽  
Infected Prey

AbstractParasites are important components of food webs. Although their direct effects on hosts are well-studied, indirect impacts on trophic networks, thus on non-host species, remain unclear.In this study, we investigate the consequences of parasitism on coexistence and stability within a simple trophic module: one predator consuming two prey species in competition. We test how such effects depend on the infected species (prey or predator). We account for two effects of parasitism: the virulence effect (parasites affect the infected species intrinsic growth rate through direct effects on fecundity or mortality) and the interaction effect (increased vulnerability of infected prey or increased food intake of infected predators).Results show that coexistence is favored when effects have intermediate intensity. We link this result to modifications of direct and apparent competitions among prey species. Given a prey infection, accounting for susceptible-infected population structure highlights that coexistence may also be reduced due to predator-parasite competition.Parasites affect stability by modulating energy transfer from prey to predator. Predator infection therefore has a stabilizing effect due to increased energy fluxes and/or predator mortality.Our results suggest that parasites potentially increase species coexistence. Precise predictions however require an assessment of various parasite effects. We discuss the implications of our results for the functioning of trophic networks and the evolution of foraging strategies within food webs.

scholarly journals Impact of Urbanization to an Island and the Continent: Species Turnover and Nestedness in Neotropical Bird Assemblages

2021 ◽  
Vol 9 ◽  
Author(s):  
Sabina A. Caula ◽  
Virginia Sanz D'Angelo
Keyword(s):  
Negative Impact ◽  
Species Turnover ◽  
Bird Species ◽  
Urban Environments ◽  
Individual Species ◽  
Similar Species ◽  
Urban Gradient ◽  
Building Density ◽  
Urbanized Areas ◽  
Urban Matrix

Islands are well-known as particular and vulnerable ecosystems with evolutionary histories, environmental characteristics, and original communities different from those of continents. On the contrary, urban environments are recent, artificial, and structurally similar among distant regions. To assess the relative importance of regional and local processes on urban biota, we chose two urban environments, i.e., one on the mainland and another on an island in the same ecoregion. We asked whether the urbanization process affects the avian biodiversity of the ISLAND in the same way as in the continent. We defined an urban gradient with three levels of building density, namely, patches of native vegetation (remnant woodlands in the urban matrix), medium density urbanized areas that maintain vegetation along the streets and gardens, and residential areas with less vegetation cover and higher building density. In each geographical locality, we selected three sites (replicates) for each level of the urban gradient and did bird surveys. We found two times as many species in the urban landscape of the continent (69) as on the island (35), with the analogous richness decrease along the gradient in both regions. Species similarity was higher between urbanized sites of both regions compared with the similarity between woodlands and urbanized sites, showing that urban matrix filters similar species of each pool regionally. Individual species responded to urban structure in different ways. We found 32% of bird species were urban exploiters, 48% urban tolerant, and 20% urban avoiders in both regions. However, some species showed different frequencies of occurrence on the island and the continent. Species turnover contributed more than richness differences to species dissimilarity along the urban gradient on the continent. Contrarily, the nestedness component (i.e., species being a strict subset of the species at a richer site) was higher on the island. We concluded that the negative impact of highly urbanized areas on birds was stronger on the island than on the continent. Our results may help to assess the implications of beta-diversity loss, especially on islands.

scholarly journals Do solitary foraging nocturnal mammals plan their routes?

2011 ◽  
Vol 7 (4) ◽  
pp. 638-640 ◽  
Author(s):  
Marine Joly ◽  
Elke Zimmermann
Keyword(s):  
Cognitive Skills ◽  
Large Scale ◽  
Deciduous Forest ◽  
Brain Size ◽  
Social Systems ◽  
Route Planning ◽  
Movement Pattern ◽  
Food Resources ◽  
Foraging Strategies ◽  
Detection Distance

Large-brained diurnal mammals with complex social systems are known to plan where and how to reach a resource, as shown by a systematic movement pattern analysis. We examined for the first time large-scale movement patterns of a solitary-ranging and small-brained mammal, the mouse lemur ( Microcebus murinus ), by using the change-point test and a heuristic random travel model to get insight into foraging strategies and potential route-planning abilities. Mouse lemurs are small nocturnal primates inhabiting the seasonal dry deciduous forest in Madagascar. During the lean season with limited food availability, these lemurs rely on few stationary food resources. We radio-tracked seven lemurs and analysed their foraging patterns. First change-points coincided with out-of-sight keystone food resources. Travel paths were more efficient in detecting these resources than a heuristic random travel model within limits of estimated detection distance. Findings suggest that even nocturnal, solitary-ranging mammals with small brains plan their route to an out-of-sight target. Thus, similar ecological pressures may lead to comparable spatial cognitive skills irrespective of the degree of sociality or relative brain size.

scholarly journals Tropical arboreal ants form dominance hierarchies over nesting resources in agroecosystems

2018 ◽  
Author(s):  
Senay Yibarek ◽  
Stacy M. Philpott
Keyword(s):  
Species Interactions ◽  
Dominance Hierarchy ◽  
Species Coexistence ◽  
Relative Fitness ◽  
Motif Analysis ◽  
Agricultural Ecosystem ◽  
Ant Communities ◽  
Dominance Hierarchies ◽  
Species Dominance ◽  
Nesting Resources

AbstractInterspecific dominance hierarchies have been widely reported across animal systems. While some dominant individuals (winners) get to monopolize resources, during dyadic interactions, they can increase their relative fitness as compared to subdominant individuals (losers). In some ant species, dominance hierarchies have been used to explain species coexistence and community structure. However, it remains unclear whether or in what contexts dominance hierarchies occur in tropical ant communities. Furthermore, it can be challenging to infer and quantify reliable dominance hierarchies from observed interactions. This study seeks to examine whether arboreal twig-nesting ants competing for nesting resources in a Mexican coffee agricultural ecosystem are arranged in a dominance hierarchy. Using network analysis, we quantified interactions between ten species by measuring the uncertainty and steepness in the dominance hierarchy. We also assessed the orderliness of the hierarchy by considering species interactions at the network level. Based on the Elo-ranking method, we found that the twig-nesting ant species Myrmelachista mexicana ranked highest in the ranking, while Pseudomyrmex ejectus was ranked as the lowest in the hierarchy. We quantified the uncertainty in the dominance hierarchy and found that the hierarchy was intermediate in its steepness, suggesting that the probability of higher ranked individuals winning contests against lower ranked individuals was fairly high. Motif analysis and significant excess of triads further revealed that the species networks were largely transitive. This study highlights that some tropical arboreal ant communities self-organize into dominance hierarchies.

scholarly journals Corvids in Urban Environments: A Systematic Global Literature Review

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3226
Author(s):  
Isma Benmazouz ◽  
Jukka Jokimäki ◽  
Szabolcs Lengyel ◽  
Lajos Juhász ◽  
Marja-Liisa Kaisanlahti-Jokimäki ◽  
...  
Keyword(s):  
Large Scale ◽  
Behavioral Plasticity ◽  
Biodiversity Loss ◽  
Single Species ◽  
Home Range Size ◽  
Urban Environments ◽  
Food Sources ◽  
Global Literature ◽  
Factors Affecting ◽  
Positive Effects

Urbanization is one of the most prevalent drivers of biodiversity loss, yet few taxonomic groups are remarkably successful at adapting to urban environments. We systematically surveyed the global literature on the effects of urbanization on species of family Corvidae (crows, choughs, jackdaws, jays, magpies, nutcrackers, ravens, rooks, treepies) to assess the occurrence of corvids in urban environments and the factors affecting their success. We found a total of 424 primary research articles, and the number of articles has increased exponentially since the 1970s. Most studies were carried out in cities of Europe and North America (45.5% and 31.4%, respectively) and were directed on a single species (75.2). We found that 30 corvid species (23% of 133 total) regularly occur in urban environments. The majority (72%) of the studies reported positive effects of urbanization on corvids, with 85% of studies detecting population increases and 64% of studies detecting higher breeding success with urbanization. Of the factors proposed to explain corvids’ success (availability of nesting sites and food sources, low predation and persecution), food availability coupled with diet shifts emerged as the most important factors promoting Corvidae to live in urban settings. The breeding of corvids in urban environments was further associated with earlier nesting, similar or larger clutches, lower hatching but higher fledging success, reduced home range size and limited territoriality, increased tolerance towards humans and increasing frequency of conflicts with humans. Despite geographic and taxonomic biases in our literature sample, our review indicates that corvids show both flexibility in resource use and behavioral plasticity that enable them to exploit novel resources for nesting and feeding. Corvids can thus be urban exploiters of the large-scale modifications of ecosystems caused by urbanization.

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