scholarly journals Niche partitioning in an assemblage of granivorous rodents, and the challenge of community-level conservation

Oecologia ◽  
2022 ◽  
Author(s):  
Rachel Y. Chock ◽  
Debra M. Shier ◽  
Gregory F. Grether
Keyword(s):  
Habitat Heterogeneity ◽  
Resource Selection ◽  
Activity Patterns ◽  
Niche Partitioning ◽  
Natural Disturbance ◽  
Community Level ◽  
Ecological Data ◽  
Subordinate Species ◽  
Species Specific ◽  
Management Recommendations

AbstractCoexistence of competing species in the same foraging guild has long puzzled ecologists. In particular, how do small subordinate species persist with larger dominant competitors? This question becomes particularly important when conservation interventions, such as reintroduction or translocation, become necessary for the smaller species. Exclusion of dominant competitors might be necessary to establish populations of some endangered species. Ultimately, however, the goal should be to conserve whole communities. Determining how subordinate species escape competitive exclusion in intact communities could inform conservation decisions by clarifying the ecological conditions and processes required for coexistence at local or regional scales. We tested for spatial and temporal partitioning among six species of native, granivorous rodents using null models, and characterized the microhabitat of each species using resource-selection models. We found that the species’ nightly activity patterns are aggregated temporally but segregated spatially. As expected, we found clear evidence that the larger-bodied kangaroo rats drive spatial partitioning, but we also found species-specific microhabitat associations, which suggests that habitat heterogeneity is part of what enables these species to coexist. Restoration of natural disturbance regimes that create habitat heterogeneity, and selection of translocation sites without specific competitors, are among the management recommendations to consider in this case. More generally, this study highlights the need for a community-level approach to conservation and the usefulness of basic ecological data for guiding management decisions.

scholarly journals Mammals adjust diel activity across gradients of urbanization

2021 ◽  
Author(s):  
Travis Gallo ◽  
Mason Fidino ◽  
Brian Gerber ◽  
Adam A. Ahlers ◽  
Julia L. Angstmann ◽  
...  
Keyword(s):  
Animal Behavior ◽  
Wildlife Management ◽  
Resource Selection ◽  
Activity Patterns ◽  
Niche Partitioning ◽  
Diel Activity ◽  
Mammal Species ◽  
Ecological Processes ◽  
Species Specific ◽  
Management And Conservation

Time is a fundamental component of ecological processes. How animal behavior changes over time has been explored through well-known ecological theories like niche partitioning and predator-prey dynamics. Yet, changes in animal behavior within the shorter 24-hour light-dark cycle have largely gone unstudied. Understanding if an animal can adjust their temporal activity to mitigate or adapt to environmental change has become a recent topic of discussion and is important for effective wildlife management and conservation. While spatial habitat is a fundamental consideration in wildlife management and conservation, temporal habitat is often ignored. We formulated a temporal resource selection model to quantify the diel behavior of eight mammal species across ten U.S. cities. We found high variability in diel activity patterns within and among species and species-specific correlations between diel activity and human population density, impervious land cover, available greenspace, vegetation cover, and mean daily temperature. We also found that some species may modulate temporal behaviors to manage both natural and anthropogenic risks. Our results highlight the complexity with which temporal activity patterns interact with local environmental characteristics, and suggest that urban mammals may use time along the 24-hour cycle to reduce risk, adapt, and therefore persist in human-dominated ecosystems.

scholarly journals Sound-identity processing in early areas of the auditory ventral stream in the macaque

2012 ◽  
Vol 107 (4) ◽  
pp. 1123-1141 ◽  
Author(s):  
Paweł Kuśmierek ◽  
Michael Ortiz ◽  
Josef P. Rauschecker
Keyword(s):  
Rhesus Macaques ◽  
Population Analysis ◽  
Activity Patterns ◽  
Dorsal Stream ◽  
Stimulus Onset ◽  
Ventral Stream ◽  
Underlying Mechanisms ◽  
Species Specific ◽  
Rostral Region ◽  
Identity Processing

Auditory cortical processing is thought to be accomplished along two processing streams. The existence of a posterior/dorsal stream dealing, among others, with the processing of spatial aspects of sound has been corroborated by numerous studies in several species. An anterior/ventral stream for the processing of nonspatial sound qualities, including the identification of sounds such as species-specific vocalizations, has also received much support. Originally discovered in anterolateral belt cortex, most recent work on the anterior/ventral pathway has been performed on far anterior superior temporal (ST) areas and on ventrolateral prefrontal cortex (VLPFC). Regions of the anterior/ventral stream near its origin in early auditory areas have been less explored. In the present study, we examined three early auditory regions with different anteroposterior locations (caudal, middle, and rostral) in awake rhesus macaques. We analyzed how well classification based on sound-evoked activity patterns of neuronal populations replicates the original stimulus categories. Of the three regions, the rostral region (rR), which included core area R and medial belt area RM, yielded the greatest classification success across all stimulus classes or between classes of natural sounds. Starting from ∼80 ms past stimulus onset, clustering based on the population response in rR became clearly more successful than clustering based on responses from any other region. Our study demonstrates that specialization for sound-identity processing can be found very early in the auditory ventral stream. Furthermore, the fact that this processing develops over time can shed light on underlying mechanisms. Finally, we show that population analysis is a more sensitive method for revealing functional specialization than conventional types of analysis.

scholarly journals A sparse observation model to quantify species interactions in time and space

2019 ◽  
Author(s):  
Sadoune Ait Kaci Azzou ◽  
Liam Singer ◽  
Thierry Aebischer ◽  
Madleina Caduff ◽  
Beat Wolf ◽  
...  
Keyword(s):  
Species Interactions ◽  
Activity Patterns ◽  
Niche Partitioning ◽  
Camera Trap ◽  
Camera Traps ◽  
Observation Model ◽  
Occupancy Models ◽  
Time And Space ◽  
Imperfect Detection ◽  
Mobile Species

SummaryCamera traps and acoustic recording devices are essential tools to quantify the distribution, abundance and behavior of mobile species. Varying detection probabilities among device locations must be accounted for when analyzing such data, which is generally done using occupancy models. We introduce a Bayesian Time-dependent Observation Model for Camera Trap data (Tomcat), suited to estimate relative event densities in space and time. Tomcat allows to learn about the environmental requirements and daily activity patterns of species while accounting for imperfect detection. It further implements a sparse model that deals well will a large number of potentially highly correlated environmental variables. By integrating both spatial and temporal information, we extend the notation of overlap coefficient between species to time and space to study niche partitioning. We illustrate the power of Tomcat through an application to camera trap data of eight sympatrically occurring duiker Cephalophinae species in the savanna - rainforest ecotone in the Central African Republic and show that most species pairs show little overlap. Exceptions are those for which one species is very rare, likely as a result of direct competition.

Activity patterns and temporal niche partitioning of dogs and medium-sized wild mammals in urban parks of Xalapa, Mexico

2019 ◽  
Vol 22 (6) ◽  
pp. 1061-1070 ◽  
Author(s):  
Isac Mella-Méndez ◽  
Rafael Flores-Peredo ◽  
Jairo Pérez-Torres ◽  
Sergio Hernández-González ◽  
Dino Ulises González-Uribe ◽  
...  
Keyword(s):  
Activity Patterns ◽  
Niche Partitioning ◽  
Urban Parks ◽  
Wild Mammals ◽  
Temporal Niche

scholarly journals Species coexistence and overlapping distributions in a metacommunity are compatible with niche differences and competition at a local scale

2020 ◽  
Author(s):  
Maxime Dubart ◽  
Patrice David ◽  
Frida Ben-Ami ◽  
Christoph R. Haag ◽  
V. Ilmari Pajunen ◽  
...  
Keyword(s):  
Species Coexistence ◽  
Scale Up ◽  
Niche Partitioning ◽  
Niche Differentiation ◽  
Apparent Paradox ◽  
Extinction Rates ◽  
Interspecific Differences ◽  
Baltic Coast ◽  
Species Specific

AbstractNiche partitioning is the most studied factor structuring communities of competing species. In fragmented landscapes, however, a paradox can exist: different taxa may competitively dominate different types of habitat patches, resulting in a form of spatial niche partitioning, yet differences in long-term distributions among species can appear surprisingly small. This paradox is illustrated by an emblematic metacommunity - that of Daphnia spp. in rockpools on the Finnish Baltic coast, where three species compete with each other, have distinct ecological preferences, yet largely overlap in long-term distributions. Here we examine how metacommunity models that explicitly estimate species-specific demographic parameters can solve the apparent paradox. Our research confirms previous studies that local extinction rates are influenced by environmental variables in a strong and species-specific way and are considerably increased by interspecific competition. Yet, our simulations show that this situation exists alongside interspecific differences in realized niches that are, overall, small, and identified three main explanations for this compatibility. Our results illustrate how state-space modelling can clarify complex metacommunity dynamics and explain why local competition and niche differentiation do not always scale up to the landscape level.

scholarly journals Ecology and Conservation of the Endangered Banteng (Bos javanicus) in Indonesia Tropical Lowland Forest

2019 ◽  
Vol 26 (2) ◽  
pp. 68
Author(s):  
Dede Aulia Rahman ◽  
Riki Herliansyah ◽  
Puji Rianti ◽  
Ujang Mamat Rahmat ◽  
Asep Yayus Firdaus ◽  
...  
Keyword(s):  
National Park ◽  
Secondary Forest ◽  
Conservation Status ◽  
Activity Patterns ◽  
Habitat Preferences ◽  
Conservation Strategy ◽  
Ecological Data ◽  
Lowland Forest ◽  
Bos Javanicus ◽  
Distribution Point

Banteng, Bos javanicus, as wild cattle is a vital and importance source of germplasm in Indonesia. Various human activities currently threaten their conservation status. Nonetheless, no long-term monitoring programmes are in place for this species. Using distribution point and statistical analysis based on 46,116 camera trap days from December 2015 to January 2017, we aimed to provide habitat preferences, activity patterns and ecological data for banteng population in Ujung Kulon National Park (UKNP). It is the largest population of banteng in Indonesia and is living in a limited habitat area. According to the best occupancy model, the most suitable areas for this species were the secondary forest located at the center portion of UKNP. The presence of the invasive cluster sugar palm, Arenga obtusifolia, in dry season provides additional alternative food for banteng when its main food is scarcer in the forest. Banteng was cathemeral all year round, with the proportion of cathemeral records and the recording rate did not change with the protection of the level area, moon phase or season. To reduce the probability of encountering predators, banteng avoided the space use of dholes. Selection and avoidance of habitats was stronger than avoidance of the predator activity areas. Habitat competition from domestic cattle which grazed illegally in the national park appears to be a problem to the species since zoonosis appears from domestic cattle to banteng. Therefore, effective law enforcement and an adequate conservation strategy are required to eliminate the impacts of both direct and indirect threats.

scholarly journals Temporal niche partitioning as a novel mechanism promoting co-existence of sympatric predators in marine systems

2021 ◽  
Vol 288 (1954) ◽  
pp. 20210816
Author(s):  
Karissa O. Lear ◽  
Nicholas M. Whitney ◽  
John J. Morris ◽  
Adrian C. Gleiss
Keyword(s):  
Activity Patterns ◽  
Interference Competition ◽  
Niche Partitioning ◽  
Common Mechanism ◽  
Multiple Predators ◽  
Temporal Partitioning ◽  
Marine Systems ◽  
Temporal Niche ◽  
Time Space ◽  
Sensory Adaptations

Niche partitioning of time, space or resources is considered the key to allowing the coexistence of competitor species, and particularly guilds of predators. However, the extent to which these processes occur in marine systems is poorly understood due to the difficulty in studying fine-scale movements and activity patterns in mobile underwater species. Here, we used acceleration data-loggers to investigate temporal partitioning in a guild of marine predators. Six species of co-occurring large coastal sharks demonstrated distinct diel patterns of activity, providing evidence of strong temporal partitioning of foraging times. This is the first instance of diel temporal niche partitioning described in a marine predator guild, and is probably driven by a combination of physiological constraints in diel timing of activity (e.g. sensory adaptations) and interference competition (hierarchical predation within the guild), which may force less dominant predators to suboptimal foraging times to avoid agonistic interactions. Temporal partitioning is often thought to be rare compared to other partitioning mechanisms, but the occurrence of temporal partitioning here and similar characteristics in many other marine ecosystems (multiple predators simultaneously present in the same space with dietary overlap) introduces the question of whether this is a common mechanism of resource division in marine systems.

scholarly journals Diurnal activity patterns of the temporary fish ectoparasite,Gnathia africanaBarnard, 1914 (Isopoda, Gnathiidae), from the southern coast of South Africa

2017 ◽  
Vol 98 (7) ◽  
pp. 1715-1723 ◽  
Author(s):  
Rachel L. Welicky ◽  
Maryke L. Ferreira ◽  
Paul Sikkel ◽  
Nico J. Smit
Keyword(s):  
South Africa ◽  
Activity Patterns ◽  
Fish Predation ◽  
Early Morning ◽  
Trophic Dynamics ◽  
Ecological Data ◽  
Tidal Zone ◽  
Cleaner Fish ◽  
Tropical Oceans ◽  
Stage 1

Gnathiid isopods are one of the most common fish ectoparasites, and are found in both temperate and tropical oceans. On coral reefs, gnathiids are most active at dusk and dawn, and contribute significantly to trophic dynamics, as they are a prey resource for cleaner fish and parasitize numerous fishes. Gnathiids also inhabit temperate intertidal waters, but their activity patterns and contribution to intertidal trophic dynamics remain unstudied. To provide the first ecological data on temperate intertidal gnathiid activity patterns, 172 gnathiid-freeClinus superciliosuswere set in an intertidal system in Tsitsikamma National Park, South Africa, during early morning, morning, afternoon, early evening, and evening, high and low tide, and within the inter- and infra-tidal zone to examine gnathiid infestation levels. After exposure, gnathiids from each fish were identified to the species level, counted, and their developmental stage was recorded. All gnathiids were identified asGnathiia africana. On average, 1 ± 5SD gnathiids were collected from each fish, and the majority of gnathiids collected were stage 1. Significantly more gnathiids were collected during morning and afternoon compared with all other time periods. The number of gnathiids collected was not influenced by the fish's exposure to high or low tide, or placement within the tide zone. AlthoughG. africanais free from cleaner fish predation because cleaner fish do not reside in temperate intertidal habitat,G. africanaabundance is surprisingly small. Future studies should examine what regulatesG. africanapopulation size and the role they play in temperate intertidal food webs.

scholarly journals Resolving issues of imprecise and habitat-biased locations in ecological analyses using GPS telemetry data

2010 ◽  
Vol 365 (1550) ◽  
pp. 2187-2200 ◽  
Author(s):  
Jacqueline L. Frair ◽  
John Fieberg ◽  
Mark Hebblewhite ◽  
Francesca Cagnacci ◽  
Nicholas J. DeCesare ◽  
...  
Keyword(s):  
Resource Selection ◽  
Ad Hoc ◽  
Animal Behaviour ◽  
Ecological Analysis ◽  
Location Data ◽  
Technological Advances ◽  
Global Positioning ◽  
Species Specific ◽  
Insight Into ◽  
Predominant Effect

Global positioning system (GPS) technologies collect unprecedented volumes of animal location data, providing ever greater insight into animal behaviour. Despite a certain degree of inherent imprecision and bias in GPS locations, little synthesis regarding the predominant causes of these errors, their implications for ecological analysis or solutions exists. Terrestrial deployments report 37 per cent or less non-random data loss and location precision 30 m or less on average, with canopy closure having the predominant effect, and animal behaviour interacting with local habitat conditions to affect errors in unpredictable ways. Home-range estimates appear generally robust to contemporary levels of location imprecision and bias, whereas movement paths and inferences of habitat selection may readily become misleading. There is a critical need for greater understanding of the additive or compounding effects of location imprecision, fix-rate bias, and, in the case of resource selection, map error on ecological insights. Technological advances will help, but at present analysts have a suite of ad hoc statistical corrections and modelling approaches available—tools that vary greatly in analytical complexity and utility. The success of these solutions depends critically on understanding the error-inducing mechanisms, and the biggest gap in our current understanding involves species-specific behavioural effects on GPS performance.

Foraging ecology and time budgets of non-breeding shorebirds in coastal Cuba

2014 ◽  
Vol 30 (4) ◽  
pp. 347-357 ◽  
Author(s):  
Erica Nol ◽  
Kate MacCulloch ◽  
Lisa Pollock ◽  
Laura McKinnon
Keyword(s):  
Breeding Season ◽  
Foraging Ecology ◽  
Niche Partitioning ◽  
Time Budgets ◽  
Factors Affecting ◽  
Breeding Grounds ◽  
Main Determinants ◽  
Species Specific ◽  
Average Body ◽  
Foraging Time

Abstract:During the non-breeding season, shorebirds, a large and important group of wetland vertebrates, divide their time between foraging, resting and maintenance activities. We examined factors affecting time budgets, foraging techniques and rates, and spacing patterns of 14 to 92 individuals each of 10 shorebird species spending the non-breeding season in Cayo Guillermo, Cuba. We hypothesized that all species would spend the majority of their time foraging. Time spent foraging ranged from 20–85% of total time and was significantly negatively related to average body size. Apparent aggression (e.g. chasing or being chased) occurred in < 10% of individuals in all species and was not related to maximum counts of conspecifics. Aggression was most common in the black-necked stilt but did not vary in frequency as a function of activity. Vigilance varied in occurrence from 0–53% of individuals, but the frequency was not related to maximum counts. Intraspecific distances were generally greater between foraging than non-foraging birds. For most species interspecific distances were similar to intraspecific distances during foraging but greater than intraspecific differences during non-foraging, suggesting some overlap in foraging habitat and niche partitioning during non-foraging. Shorebirds that used primarily tactile techniques foraged closer together than primarily visual foragers. Low rates of aggression, as an index of potential competition, suggest that species-specific energy requirements rather than competitive interactions are the main determinants of foraging behaviour on these tropical non-breeding grounds.

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