Patterns Of Resource Use Research Articles

Temporal invariance of social‐ecological catchments

Natural resources such as waterbodies, public parks, and wildlife refuges attract people from varying distances on the landscape, creating "social-ecological catchments." Catchments have provided great utility for understanding physical and social relationships within specific disciplines. Yet, catchments are rarely used across disciplines, such as its application to understand complex spatiotemporal dynamics between mobile human users and patchily distributed natural resources. We collected residence ZIP codes from 19,983 angler parties during 2014-2017 to construct seven angler-waterbody catchments in Nebraska, USA. We predicted that sizes of dense (10% utilization distribution) and dispersed (95% utilization distribution) angler-waterbody catchments would change across seasons and years as a function of diverse resource selection among mobile anglers. Contrary to expectations, we revealed that catchment size was invariant. We discuss how social (conservation actions) and ecological (low water quality, reduction in species diversity) conditions are expected to impact landscape patterns in resource use. We highlight how this simple concept and user-friendly technique can inform timely landscape-level conservation decisions within coupled social-ecological systems that are currently difficult to study and understand.

Among-individual diet variation within a lake trout ecotype: Lack of stability of niche use.

In a polyphenic species, differences in resource use are expected among ecotypes, and homogeneity in resource use is expected within an ecotype. Yet, using a broad resource spectrum has been identified as a strategy for fishes living in unproductive northern environments, where food is patchily distributed and ephemeral. We investigated whether specialization of trophic resources by individuals occurred within the generalist piscivore ecotype of lake trout from Great Bear Lake, Canada, reflective of a form of diversity. Four distinct dietary patterns of resource use within this lake trout ecotype were detected from fatty acid composition, with some variation linked to spatial patterns within Great Bear Lake. Feeding habits of different groups within the ecotype were not associated with detectable morphological or genetic differentiation, suggesting that behavioral plasticity caused the trophic differences. A low level of genetic differentiation was detected between exceptionally large‐sized individuals and other piscivore individuals. We demonstrated that individual trophic specialization can occur within an ecotype inhabiting a geologically young system (8,000–10,000 yr BP), a lake that sustains high levels of phenotypic diversity of lake trout overall. The characterization of niche use among individuals, as done in this study, is necessary to understand the role that individual variation can play at the beginning of differentiation processes.

Improving Inferences from Hydrological Isotope Techniques.

Plant water isotopic compositions are widely used to describe patterns of soils water uptake. Although valuable, the technique only provides relative uptake distributions, which can be misleading. Without information on total transpiration, the technique cannot address central questions on drought response, competition, and species coexistence.

Macroecological patterns of resource use in resident and migratory hummingbirds

Hummingbirds (Family Trochilidae) are key pollinators in several biodiversity hotspots, including the California Floristic Province in North America. Relatively little is known about how hummingbird diets change throughout the year, especially with regard to how migratory hummingbirds affect resident hummingbirds at stopover sites. In this study, we examine how hummingbird species, migratory status, sex, geographic region and local plant diversity influence floral resource use before, during, and after an influx of migratory hummingbirds (primarily Rufous hummingbirds, Selasphorus rufus) across California. We expected distinct floral resource use based upon species’ migratory status (resident vs. migrant), sex, sampling period, and geographic region. We employed DNA metabarcoding to detect plant DNA in hummingbird fecal samples to analyze diet diversity, composition, overlap, and interaction networks. We found significant effects of sex, sampling period, and migratory status on the alpha and beta diversity of plant taxa present in fecal samples. Analyses of Anna's hummingbirds (Calypte anna) alone revealed that female fecal samples contained higher plant species richness. In addition to hummingbird-pollinated plants, fecal samples also contained non-ornithophilous plants and species of agricultural importance. Diet overlap and plant-pollinator network analyses revealed high overlap in plant taxa used between hummingbird species, and networks were more connected, less nested, and less specialized than null models. DNA metabarcoding is minimally invasive and provides a detailed view of hummingbird diet, permitting large-scale studies. Insights into hummingbird diets are especially valuable given the logistical difficulties of directly observing floral visitation and foraging across broad temporal and spatial scales.

Climate shock effects and mediation in fisheries

Climate shocks can reorganize the social-ecological linkages in food-producing communities, leading to a sudden loss of key products in food systems. The extent and persistence of this reorganization are difficult to observe and summarize, but are critical aspects of predicting and rapidly assessing community vulnerability to extreme events. We apply network analysis to evaluate the impact of a climate shock-an unprecedented marine heatwave-on patterns of resource use in California fishing communities, which were severely affected through closures of the Dungeness crab fishery. The climate shock significantly modified flows of users between fishery resources during the closures. These modifications were predicted by pre-shock patterns of resource use and were associated with three strategies used by fishing community member vessels to respond to the closures: temporary exit from the food system, spillover of effort from the Dungeness crab fishery into other fisheries, and spatial shifts in where crab were landed. Regional differences in resource use patterns and vessel-level responses highlighted the Dungeness crab fishery as a seasonal "gilded trap" for northern California fishing communities. We also detected disparities in climate shock response based on vessel size, with larger vessels more likely to display spatial mobility. Our study demonstrates the importance of highly connected and decentralized networks of resource use in reducing the vulnerability of human communities to climate shocks.

Resource use pattern among poultry enterprises in Abia State, Nigeria

The challenge to increase meat production in Nigeria appears to be more urgent now than ever. This is in view of the rapidly increasing population, the imminent decline in hunting and the low protein intake in rural areas. Poultry meal especially broiler is one of the easiest to produce, hence its purposive selection. Input-Output data were generated from selected poultry farmers in Abia State. The data were analyzed by use of descriptive statistics and econometric estimations. Efficiency in the resource use pattern was examined using Marginal Value Product of each of the examined resources with its unit price. It was identified that there are possibilities of increasing broiler mear supply through higher levels of resource-use pattern under the existing technology.

The resiliency of diet on the Copacabana Peninsula, Bolivia

Humans use dietary resources in many ways, employing varied subsistence strategies in response to local environmental fluctuations and innovative technologies. Documenting these patterns of resource use is an important part of our understanding of past societies and human relationships with the landscape, animals, and each other. In this paper, we present results from stable isotope analysis of 66 individuals buried on the Copacabana Peninsula, Bolivia, compared to a baseline of 28 modern floral and faunal samples, and explore individual and population access to certain types of food over time (3000 BCE–CE 1700). The data show that access to C4 and lacustrine resources shifted slightly over time, especially during the Early Intermediate Period (CE 1–500). We argue that Copacabana peoples used diverse subsistence strategies to navigate fluctuating environmental and social conditions. This was not a teleological nor one-way process; rather, people made choices about food in response to environmental patterns, shifting subsistence strategies, differential ritual use of maize, or, most likely, a combination of all of the above.

Resource Partitioning of Sympatric African Wolves (Canis lupaster) and Side-Striped Jackals (Canis adustus) in an Arid Environment from West Africa

Knowledge on interference competition between species, particularly for scarce crucial resources, such as water, is a topic of increasing relevance for wildlife management given climate change scenarios. This study focuses on two sympatric canids, the African wolf and the side-striped jackal, to evaluate their group size and spatiotemporal activity patterns in the use of a limited resource by monitoring artificial waterholes in a semi-arid environment located in Senegal (West Africa). Remote cameras were deployed at five artificial waterholes to evaluate the number of individuals, age and activity patterns of resource use. African wolves (n = 71; 31% of all carnivore detections) and side-striped jackals (n = 104; 45%) were the most detected carnivore species. While both canids tended to occur alone at waterholes, they showed an evident monthly variation in group size. Both species showed a high activity overlap, with a bimodal activity pattern in waterhole use. However, we found evidence of unidirectional spatiotemporal avoidance, suggesting African wolves might be dominant over side-striped jackals. Our findings provide useful insights to investigate niche partitioning on the use of limited resources and have conservation implications for regions with a prolonged dry season.

Predicting Geographic Ranges of Marine Animal Populations Using Stable Isotopes: A Case Study of Great Hammerhead Sharks in Eastern Australia

Determining the geographic range of widely dispersed or migratory marine organisms is notoriously difficult, often requiring considerable costs and typically extensive tagging or exploration programs. While these approaches are accurate and can reveal important information on the species, they are usually conducted on only a small number of individuals and can take years to produce relevant results, so alternative approaches may be preferable. The presence of latitudinal gradients in stable carbon isotope compositions of marine phytoplankton offers a means to quickly determine likely geographic population ranges of species that rely on productivity from these resources. Across sufficiently large spatial and temporal scales, the stable carbon isotopes of large coastal or pelagic marine species should reflect broad geographic patterns of resource use, and could be used to infer geographic ranges of marine populations. Using two methods, one based on a global mechanistic model and the other on targeted low-cost latitudinal sampling of fishes, we demonstrate and compare these stable isotope approaches to determine the core population geography of an apex predator, the great hammerhead (Sphyrna mokarran). Both methods indicated similar geographic ranges and suggested thatS. mokarranrecorded in south-eastern Australia are likely to be from more northern Australian waters. These approaches could be replicated in other areas where coastlines span predictable geographic gradients in isotope values and be used to determine the core population geography of highly mobile species to inform management decisions.

Anticipating the impacts of the COVID-19 pandemic on wildlife.

Author(s): Gaynor, Kaitlyn M; Brashares, Justin S; Gregory, Gillian H; Kurz, David J; Seto, Katherine L; Withey, Lauren S; Fiorella, Kathryn J

Skin δ13C and δ15N reveal spatial and temporal patterns of habitat and resource use by free-ranging odontocetes from the southwestern Atlantic Ocean

Large diversity and abundance of cetacean species occur along the Brazilian outer continental shelf and slope waters. In the present study, we analyzed carbon (δ13C) and nitrogen (δ15N) stable isotopes in skin biopsies of ten odontocete species (Delphinidae and Physeteridae) to assess the intra- and inter-specific patterns in the use of resources along the region. Our isotopic analysis allowed us to identify two potential subpopulations of Stenella frontalis. High core isotopic niche overlap between S. frontalis from the southern range of the study area and Delphinus delphis, especially in spring, suggested that they share similar resources and rely on spatiotemporal segregation to achieve niche differentiation and to minimize competition. Our isotopic data also pointed to high similarity among Tursiops truncatus, S. frontalis, and Globicephala melas in the use of resources. Steno bredanensis had the highest δ15N and δ13C, which agrees with its occurrence in neritic waters. S. longirostris showed consistently low δ15N values, indicating that they feed at relatively lower trophic levels, and lack of niche overlap with most delphinid species, except S. attenuata. Orcinus orca and G. melas had very similar δ13C and δ15N values, that were consistent with feeding in offshore waters. δ13C and δ15N in Physeter macrocephalus suggested that individuals feed on similar trophic levels, but over a wide spatial range. The analyses of stable isotopes in skin biopsies helped us to refine our knowledge about the intra-specific resource and habitat use, ecological niches, and the trophic interactions amongst co-occurring cetaceans from the oceanic waters of the subtropical western South Atlantic.

Introduction: The Metabolism of Islands

This editorial introduces the Special Issue “Metabolism of Islands”. It makes a case why we should care about islands and their sustainability. Islands are hotspots of biocultural diversity, and home to 600 million people that depend on one-sixth of the earth’s total area, including the surrounding oceans, for their subsistence. Today, they are on the frontlines of climate change and face an existential crisis. Islands are, however, potential “hubs of innovation” and are uniquely positioned to be leaders in sustainability and climate action. We argue that a full-fledged program on “island industrial ecology” is urgently needed with the aim to offer policy-relevant insights and strategies to sustain small islands in an era of global environmental change. We introduce key industrial ecology concepts, and the state-of-the-art in applying them to islands. Nine contributions in this Special Issue are briefly reviewed to highlight the metabolic risks inherent in the island cases. The contributors explore how reconfiguring patterns of resource use will allow island governments to build resilience and adapt to the challenges of climate change.

Correction to: Fruits of the Veld: Ecological and Socioeconomic Patterns of Natural Resource Use across South Africa

Correction to: Fruits of the Veld: Ecological and Socioeconomic Patterns of Natural Resource Use across South Africa

Between Abundance and Constraints: The Natural Resource Equation of Asia’s Diverging, Higher-Income City Models

This paper investigates how natural resource conditions impact the physical development of cities and how, once built, the urban spatial structure leads to different patterns of resource use. The point of departure for this research is the common “resource urbanisms” assumption that cities are directly affected by the availability and costs of natural resources, and that in turn, different urbanisms result in substantial differences in resource use and consequent impact on the environment. Considering extreme and divergent, higher-income urban models of Kuwait, Abu Dhabi, Hong Kong and Singapore, the paper focusses on two resources, land and energy, and the case of building cooling and transport energy demand. The research uses a mixed methods approach which includes qualitative methods such as expert interviews, analysis of planning documents and historic planning decisions, alongside quantitative methods such as remote sensing, GIS and data analysis and energy modelling. The paper suggests that land availability is a major driver of urban form while energy prices may play a secondary role. It also finds that urban form-induced energy efficiencies for transport and cooling energy diverge in the four cities by a factor of five and two, respectively.

Fruits of the Veld: Ecological and Socioeconomic Patterns of Natural Resource Use across South Africa

Wild edible fruits (WEFs) are important non-timber forest products (NTFP) that are commonly grouped with other wild foods or NTFPs in general. We hypothesize that WEFs, other wild foods, and non-food NTFPs contribute in different ways to household economies. Using data collected through a survey of 503 households in South Africa, we describe patterns of use of WEFs across socioeconomic and geographical gradients and compare them to the patterns of use of other wild foods and non-food NTFPs. WEFs were used by one-fifth of all sampled households, independent of economic and urbanisation gradients and were grown in or collected mostly from surrounding areas. More households, usually in rural areas, used other wild foods and non-food NTFPs, which were often purchased from other collectors. We suggest improving access to WEFs through planting to extend their nutritional, medicinal, cultural, and livelihood value to the public.

Peace, sweet peace: ants become less aggressive when carbohydrates abound

1. An animal's energetic condition is causally related to its ability to display costly behaviours such as aggressive behaviours. Aggressive behaviours are used by animals interacting with heterospecifics when competing through interference. Therefore, how does the abundance of energetic resources influence the pattern of interspecific competition by interference at the community level? To answer this, ants were used as models because the aggressiveness of workers is fuelled by the consumption of carbohydrates.2. It was hypothesised that ant species are more aggressive when carbohydrates were more abundant. Consequently, the strength of competition by interference would increase, changing the patterns of ant species' resource use at the community level.3. This study experimentally increased the availability of carbohydrates and counted the number of aggressive behaviours, the probability of ant species exclusion, and the composition of ant morphospecies exploring protein baits before and after the addition of carbohydrates.4. After the addition of carbohydrates, ants displayed 42% less aggressive behaviour and were twice as prone to exclude other ant species from the protein baits. This led to changes in the composition of ants exploring the protein baits before and after carbohydrate addition.5. In general, ants became less motivated to engage in competitive interactions when carbohydrates were more available. However, this response was not homogeneous as the occurrence and aggressiveness of some species, such as the nectarivores, were higher when carbohydrates abound. As carbohydrates are mainly offered by plants, this study's results suggest that plants can indirectly shape the structure of ant communities through ant responses to the availability of carbohydrates.

Patterns of resource use by Asiatic black bear Ursus thibetanus during pre-hibernation in Kashmir Himalaya, India

ABSTRACT Resource use is the way in which an animal (or population) utilises the available resources, and is known to occur in a hierarchical fashion. The Asiatic black bear Ursus thibetanus is an opportunistic omnivore whose diet and intensity of habitat use fluctuates with season and availability of resources in the environment. In this study, we assessed the habitat use and food habits of black bears during the autumn season (pre-hibernation) in Dachigam National Park, Kashmir Himalaya, to understand the reasons behind recurrent bear–human conflict in the area. We walked 14 natural trails covering different habitats of the study area. At each bear sign location, we recorded habitat variables in plots of 10 m radius. Black bear diet was assessed from 192 scats using a standard protocol. Black bear scat encounter rate varied significantly between habitats and was highest in forest scrub. Bear habitat use exhibited a significant association with medium canopy cover represented by the forest scrub and riverine habitat, and a negative association with the distance from human habitation, indicating use of forest patches close to nearby villages. Scat analysis revealed the occurrence of 17 plant species, mainly dominated by hard mast fruit species (88.54%) including Celtis australis (55.21%), Quercus robur (39.06%), and Pyrus malus (13.54%), with no evidence of animal food. Overall resource use by black bears showed a strong association with hard mast and fruit-producing trees adjacent to human habitations (i.e. orchard plantations close to forest scrub and riverine habitats), thereby increasing the risk of bear–human conflict. By elucidating the factors affecting bear occurrence and resource use during the autumn season, this study is expected to assist in resolving issues related to bear–human conflict management in the Dachigam landscape, particularly during their pre-hibernation period.

Reef fishes abundance and assemblages in six islands (Kapoposang, Lanyukang, Lumu-Lumu, Badi, Ballang Lompo and Karanrang island) of spermonde archipelago during El Nino 2016, South Sulawesi, Indonesia

Overfishing in the Spermonde Archipelago has resulted in long-term changes in fishery composition and structure, as well as in resource utilization patterns. Later on, the patterns of resource use are highly variable, with new activities and new target species, e.g., ornamental corals and intensive coral reef fishery being a relatively recent phenomenon in the area. This research aims at measuring the coral fishes abundance and assemblages in six islands (Kapoposang, Lanyukang, Lumu-Lumu, Badi, Ballang Lompo, and Karanrang), representing off-shore and in-shore of Spermonde Archipelago waters during the occurrence of the 2016 El Nino. Underwater Visual Census (UVC) method was done to measure coral fish abundance, once every seasonal interval, totaling four times for every island, on 70 meter transects covering an area of 350 m2 (2.5 m to the right and left and 5 m above). Fish species found were identified by following several coral fish identification books Data was analyzed for their total species abundance based on the family. Results showed that coral fish abundance by the family was found to be lowest (less than 10.000 individuals/hectare) all through the year in Karanrang Island. The most abundance was found in Lanyukang Island (84.600 individu/hectare) during the month of September, followed by Badi Island (59.971 individu/hectare). In February, fish abundance of 35. 743 and 46.886 individu/hectare were only found in Kapoposang and Badi islands. All in all, on average, Badi island showed for having relatively equal coral fish abundance in all four seasons. One hundred species were found in Lanyukang, while 78 species were found in Lumu-Lumu, totaling 136 species of coral fishes of 28 families. Coral fishes species always found in all trips were 20 species in Lanyukang and 11 species in Lumu-Lumu. Four species always found in both islands were Thalassoma hardwicke, Neoglyphidodon nigroris, Labroides dimidiatus, Cirrhilabrus ryukyuensis. Fishes found most abundance were from Labridae and Pomacentridae families, each of 31 and 30 species. The temporary conclusion was that Lanyukang has more species than Lumu-Lumu.

Trophic Niche and Diversity of a Pelagic Squid (Dosidicus gigas): A Comparative Study Using Stable Isotope, Fatty Acid, and Feeding Apparatuses Morphology

Commercially important pelagic squid such as jumbo squid Dosidicus gigas play a key role in energy and nutrient transfer in marine ecosystem. Geographic variations in the foraging strategy of D. gigas can provide valuable information on cephalopod trophic diversification and adaption to natural and anthropogenic impacts. Here, we used a novel combination of stable isotope (SI) and fatty acid (FA) analyses of muscle tissues and morphometric measurements of feeding apparatuses to evaluate spatial patterns of habitat and resource use of D. gigas collected from three main fishing grounds in the tropical and southern temperate Pacific Ocean. Results showed that the δ13C and δ15N values were different among geographic stocks within D. gigas, possibly because of site-specific dietary sources and isotopic baseline values. Spatial variabilities in FA profiles/biomarkers, combined with SI results, suggests two foraging patterns: utilization of resources mainly from oceanic food webs or from both neritic and oceanic food webs. This behavior likely promotes the site-specific trophic niche width, increases adaptation to inhabiting oceanographic conditions, and could be driven by differences in feeding apparatuses morphology, body size, and trophic position. These results emphasize the dietary flexibility of D. gigas and their important ecological roles in ecosystems as cross-biome trophic linkages. Trophic diversification of pelagic squid like D. gigas may have important implications for their population dynamics, ecological associations, and subsequent management.

Fifty years of European ungulate dietary studies: a synthesis

Over recent decades, ungulate populations across Europe have undergone a rapid recovery. While this constitutes a conservation success, there is increasing concern about their impacts on shared resources with humans. Understanding ungulate food choices is crucial for predicting such impacts. Numerous studies have focused on single species or communities at narrow spatial scales. Here, we used 265 published diets from 87 European studies to investigate patterns of resource use by four common deer species (moose Alces alces, red deer Cervus elaphus, roe deer Capreolus capreolus and fallow deer Dama dama), and wild boar Sus scrofa at the continental scale. On average, deer diets separated mostly along a gradient from grass to browse. Fallow deer diets contained the most and moose diets the least amount of grass, but we also found large intraspecific variation among all deer species. Diets of roe deer, a presumed browser, frequently contained ≥ 25% grass. Wild boar diet contained grass in amounts similar to red deer but otherwise differed strongly from deer diets. All five ungulate species shifted to eating higher proportions of woody browse during winter. Habitat influenced variation in intraspecific diets, but the proportions of key forage types related to feeding type (i.e. grass for intermediate feeders red and fallow deer, and shrubs for the browsers moose and roe deer) remained fairly consisted across habitat types. In northern and central Europe, diet similarity between roe deer and red deer was highest during winter and spring and lowest during summer and autumn but remained constant across the seasons in southern Europe. We foresee that, as interspecific interactions driven by land‐use and climatic changes increase across Europe, further monitoring and testing will be needed to understand the dynamics of dietary niche partitioning among ungulates.