Altitude is one of the factors that decrease butterfly diversity due to the different types of habitats. Gunung Gede Pangrango National Park is one of the places at different altitudes, such as ...Situgunung Resort. This study aimed to investigate butterfly species' diversity, richness, and evenness at three altitude levels. This study was completed in October 2019 at altitudes 750, 850, and 950 meters above sea level (masl). Butterfly inventory (diversity) data were collected using the transect method, and data on habitat characteristics were acquired through direct observation. The richness, diversity, evenness, and community similarity of butterfly species and the biotic and abiotic habitat characteristics were then analyzed. The result showed 51 butterfly species at Situgunung Resort, Gunung Gede Pangrango National Park. The highest diversity index and richness index were found at an altitude of 750 masl (3.22 and 7.91) and the lowest at 950 masl (2.46 and 3.98). The highest evenness index was found at 750 masl, while the highest similarity community index was found at altitudes 750 and 850 masl. The relation between altitude and butterfly diversity is that the higherthe altitude, the lower the butterfly diversity.
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•A habitat assessment model considering both the quantity and quality of habitat is proposed.•Separate consideration of habitat quantity or quality will lead to deviation in ...assessment.•The novel habitat assessment considered the differences in vertical habits of fish.
With the economic development, social progress and the increase in power demand, the number of water conservancy projects has gradually increased. However, the reservoir dams inevitably lead to changes in the river connectivity and hydraulic characteristics of rivers, causing damage to fish habitats. Regulating the operation of dams to supplement the ecological flow required by fish is usually an effective way to protect river fish habitats. Based on the graph theory algorithm, we proposed an improved three-dimensional habitat model that comprehensively considered the quantity and quality of fish habitat and used it to the effect assessment of water conservancy project construction on fish habitat. The fish habitat quality evaluation indicators in this paper mainly emphasized the pivotal role of core habitat patches and the connectivity between habitat patches, namely, habitat importance index (HII) and habitat connectivity index (HCI). Then, the model was combined with the Instream Flow Incremental Methodology (IFIM) and applied to the habitat assessment of Schizothorax prenanti (S. prenanti) in the Anshunchang reach of the Dadu River. The results showed that the change trend of the habitat index curves of different water depths showed a trend of first increasing and then decreasing, but the inflection points of the curves and the habitat indexes of different water depths were different. Taking into account the bottom living habits of target fish, the most suitable flow range for S. prenanti was from 271.7 m3/s to 489.1 m3/s. Compared with previous studies, the improved three-dimensional habitat model effectively avoids simulation errors caused by ignoring habitat quality and differences in fish habits.
Grassland birds have experienced some of the steepest population declines of any guild of birds in North America. The shortgrass steppe contains some of North America's most intact grasslands, which ...makes the region particularly important for these species. It is well known that grassland birds differentially respond to variation in vegetation structure generated by spatiotemporally varying disturbance like grazing management. However, understanding how species respond to characteristics beyond vegetation structure or grazing could better inform management for these species in the shortgrass steppe. We analyzed point count data for 5 grassland bird species breeding on the Central Plains Experimental Range in northeastern Colorado from 2013 to 2017 to examine the predictive capacity of models representing fine-scale (∼5 ha) vegetation attributes (vegetation structure and cover type) and topography, combined with interannual precipitation variability (i.e. vegetation-abiotic models). We then compared these models to models based on grazing management treatments (applied to whole pastures, ∼130 ha) and edaphic conditions (ecological sites), which represented information more generally available to rangeland managers. Precipitation, vegetation structure, and vegetation cover type influenced all species in a manner consistent with, but more nuanced than, vegetation structure alone. These models also explained more variation in abundance for species that responded to grazing management. Thus, while grazing management can be applied adaptively to improve habitat for these species, our more detailed vegetation-abiotic models identified species-specific habitat components that could be targeted for management. For example, not grazing pastures with extensive, homogenous stands of mid-height grasses (e.g., Hesperostipa comata) for an entire growing season during wet years could be one strategy to enhance Grasshopper Sparrow (Ammodramus savannarum) abundance and stockpile residual forage for future utilization by livestock. Our models provide a better understanding of and reveal nuances in the suite of environmental conditions to which grassland birds respond in shortgrass steppe rangelands. LAY SUMMARY We lack clear understanding of which environmental characteristics might support declining bird species breeding in the shortgrass steppe of the United States. These bird species often breed on lands managed for cattle grazing and are known to respond to vegetation structure generated by grazing and/or soil conditions. We sought to evaluate how precipitation and different types of vegetation cover (e.g., shrubs, shortgrasses) could explain additional variation in bird abundance in this system. We found vegetation cover, vegetation structure, and precipitation could explain more variation in abundance than cattle grazing management and/or ecological sites (i.e. unique soil types with associated plant communities) for most bird species. For bird species that did not respond to grazing management, ecological site and year effects explained more variation in abundance than vegetation characteristics and precipitation. Precipitation conditions, types of vegetation cover, and ecological sites often are not considered when developing grazing management plans to support grassland birds; incorporating these factors into management plans may help support populations of these declining species.
The competitive exclusion principle states that ecologically similar species will be unable to coexist due to competition for resources, however, similar species coexist across a variety of ...ecosystems. Understanding mechanisms of coexistence is essential for managing a target species. Advances in monitoring technology have provided the ability to obtain reliable, high‐frequency data on wildlife. From these data, behavioral states can be approximated by analyzing turning angles and distances between locations. We monitored 8 ocelots Leopardus pardalis, 13 bobcats Lynx rufus and 5 coyotes Canis latrans on the East Foundation's El Sauz Ranch and the Yturria San Francisco Ranch in south Texas, USA, which were fitted with GPS collars that collected locations every 30 min. We characterized behavioral states using hidden Markov models. We assumed low turning angles and longer steps to represent patrolling territory, larger turning angles with shorter steps would represent hunting behavior, and low angles and minimal movement would indicate periods of rest. If differences in timing and space use exist between species, these differences may help facilitate coexistence. We predicted 1) each species exhibits three behavioral states: resting, hunting and territory patrolling; 2) ocelots moved farther (i.e. territory patrolling) in open areas and rested in dense cover; and 3) bobcats and coyotes would remain in more open areas than ocelots. We found ocelots and bobcats remained closer to heavy cover when resting and foraging and used open areas more when patrolling territory while coyotes rested in the open and selected for cover when hunting or patrolling. Further, we found evidence of temporal partitioning of behaviors both within and across species. Our study provides a novel approach to examining coexistence and identifies behaviorally mediated spatial and temporal differences in habitat use that may facilitate coexistence between ocelots, bobcats and coyotes.
•Effect mechanism of habitat fragmentation processes on habitat quality are revealed.•The effects of three habitat fragmentation processes on habitat quality are nonlinear.•Decrease in habitat area ...and increase in isolation cause significant decrease in habitat quality.•Increased habitat edge and habitat quality have more complex nonlinear relationship.•Combination of habitat fragmentation processes exacerbate impact on habitat quality.
Large-scale loss and fragmentation of natural habitats is one of the critical factors in the global decline of biodiversity. Habitat quality is the foundation for supporting biodiversity, so exploring the mechanisms by which habitat fragmentation affects habitat quality is important for biodiversity protection. However, little is known about the specific forms that various processes of habitat fragmentation affect habitat quality. Taking China as an example, the three processes of habitat fragmentation (the decrease in habitat area, the increase in habitat isolation, and the increase in habitat edge) and variations in habitat quality were quantitatively assessed from 2000 to 2020. On this basis, Pearson coefficients, Generalized Additive Model (GAM) and Geographical detector were employed to examine the linear\non-linear\combined impacts of habitat fragmentation different processes on habitat quality. The results indicated that there was a clear trend of habitat fragmentation and degradation of habitat quality in 2000–2020. 56.94%, 42.33%, and 50.89% of the area experienced the decrease in habitat area, the increase in habitat isolation, and the increase in habitat edge, respectively, and 63.12% experienced degradation of habitat quality. All three of these habitat fragmentation processes result in a downward trend in habitat quality. However, the specific form of impacts of habitat fragmentation different processes on habitat quality showed non-linear characteristics. The decrease in habitat area and the increase in habitat isolation consistently had a significant negative influence on habitat quality, albeit with varying strengths at different segments. While the increase in habitat edge causes an overall decrease in habitat quality, the two have a more complex non-linear relationship, with response curves varied between positive and negative correlations. In addition, negative impacts on habitat quality are exacerbated when multiple habitat fragmentation processes occur simultaneously. These findings reveal the complex impacts of different habitat fragmentation processes on habitat quality and inform the development of more rational landscape planning and biodiversity conservation measures in China.
The federally threatened northern spotted owl (Strix occidentalis caurina) has been intensively studied across its range, and habitat needs for the species have influenced forest management in ...northwestern North America for decades. Dense forest canopies are often reported in the scientific literature and agency management plans as an important habitat attribute for spotted owls, though the means of measuring forest canopy and interpreting species requirements vary across studies and more importantly, among management plans. We used light detection and ranging (lidar) measurements of canopy cover, canopy surface heterogeneity, and upper canopy surface connectivity, and an index of the presence of a competitive invasive species, the barred owl (S. varia), in multinomial discrete choice models using a Bayesian framework to evaluate selection of forest cover types by spotted owls in Oregon, USA, 2008–2015. We designated yearly activity centers based on the most biologically significant observation during the nesting season (Mar–Aug), generally centered on the nest tree. Spotted owls selected activity centers with more canopy cover and higher heterogeneity of the canopy surface within 100 m than was available within their territories. The average proportion of canopy cover within 100 m of a spotted owl activity center was 0.79 ± 0.12 (SD; range = 0.34–0.99). The presence of barred owls did not explain variability in selection of spotted owl activity centers, but barred owls might not affect third-order habitat selection within territories, or our index was too spatially coarse to detect these effects on spotted owl resource selection. We demonstrate that lidar provides researchers and managers with a tool that can accurately measure forest canopies over large areas, and assist in mapping spotted owl habitat.
Linking ecology and cognition der Malsburg, Johanna Henke-von; Kappeler, Peter M.; Fichtel, Claudia
Behavioral ecology and sociobiology,
12/2020, Letnik:
74, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Variation in cognitive abilities is thought to be linked to variation in brain size, which varies across species with either social factors (Social Intelligence Hypothesis) or ecological challenges ...(Ecological Intelligence Hypothesis). However, the nature of the ecological processes invoked by the Ecological Intelligence Hypothesis, like adaptations to certain habitat characteristics or dietary requirements, remains relatively poorly known. Here, we review comparative studies that experimentally investigated interspecific variation in cognitive performance in relation to a species’ degree of ecological specialisation. Overall, the relevant literature was biased towards studies of mammals and birds as well as studies focusing on ecological challenges related to diet. We separated ecological challenges into those related to searching for food, accessing a food item and memorising food locations. We found interspecific variation in cognitive performance that can be explained by adaptations to different foraging styles. Species-specific adaptations to certain ecological conditions, like food patch distribution, characteristics of food items or seasonality also broadly predicted variation in cognitive abilities. A species’ innovative problem-solving and spatial processing ability, for example, could be explained by its use of specific foraging techniques or search strategies, respectively. Further, habitat generalists were more likely to outperform habitat specialists. Hence, we found evidence that ecological adaptations and cognitive performance are linked and that the classification concept of ecological specialisation can explain variation in cognitive performance only with regard to habitat, but not dietary specialisation.
The pervasive influence of island biogeography theory on forest fragmentation research has often led to a misleading conceptualization of landscapes as areas of forest/habitat and ...'non-forest/non-habitat' and an overriding focus on processes within forest remnants at the expense of research in the human-modified matrix. The matrix, however, may be neither uniformly unsuitable as habitat nor serve as a fully-absorbing barrier to the dispersal of forest taxa. In this paper, we present a conceptual model that addresses how forest habitat loss and fragmentation affect biodiversity through reduction of the resource base, subdivision of populations, alterations of species interactions and disturbance regimes, modifications of microclimate and increases in the presence of invasive species and human pressures on remnants. While we acknowledge the importance of changes associated with the forest remnants themselves (e.g. decreased forest area and increased isolation of forest patches), we stress that the extent, intensity and permanence of alterations to the matrix will have an overriding influence on area and isolation effects and emphasize the potential roles of the matrix as not only a barrier but also as habitat, source and conduit. Our intention is to argue for shifting the examination of forest fragmentation effects away from a patch-based perspective focused on factors such as patch area and distance metrics to a landscape mosaic perspective that recognizes the importance of gradients in habitat conditions.
•GAM and RF models were applied for predicting the habitat preference of S. coeruleoalba and T. truncatus.•Main variables affecting the spatial distribution of both species were identified.•RF ...revealed the highest accuracy and precision.
Although the EU Marine Strategy Framework Directive (MSFD) is largely based on the establishment of environmental targets and associated proxies to achieve Good Environmental Status (GES), a full suite of ecological indicators for all the ecosystem components is not currently available for ongoing assessment and regular update of GES targets. This is because effective indicators and management actions aimed at preserving/rebuilding marine biodiversity should be found from the knowledge of the spatial distribution of target species and extension of critical habitats as well as their overlapping with human activities, pressure and impacts. In this regard, the spatial distributions of the striped dolphin Stenella coeruleoalba and the common bottlenose dolphin Tursiops truncatus in the Gulf of Taranto (Northern Ionian Sea, Central-eastern Mediterranean Sea) were investigated by means of a generalized additive model (GAM) and a Random Forest (RF) based on sighting data collected during standardized vessel-based surveys carried out from 2009 to 2015. Eight predictive variables were considered, taking into account both the local physiographic features and human activities existing in the investigated area, suggesting an innovative approach to habitat modeling. In particular, the explanatory variables depth, distance from industrial areas and distance from the coast proved to significantly influence the distribution of both dolphin species. In addition, the distribution of S. coeruleoalba and T. truncatus were also significantly shaped by the distance from the navy exercise areas and the fishing areas, respectively. On the contrary, the slope and the distance from the main commercial routes never provided any significant influence. The reliability of GAM and RF models in predicting the spatial distribution of both dolphins was tested by applying the Youden Index method to the ROC curves. The RF model allowed the projection of the expected presence/absence pattern of S. coeruleoalba and T. truncatus to produce the preference habitat versus non habitat map. In particular, the RF model predicted that the striped dolphin is widely present in the central and deeper part of the Gulf of Taranto. In contrast, the common bottlenose dolphin seems to be mainly distributed along the coasts in both the eastern and western sector of the basin. A clear overlapping of the preference habitats estimated for S. coeruleoalba and T. truncatus is shown north of Punta Alice and in front of Policoro as well as offshore from Ugento in the eastern and western parts of the investigated area, respectively. Finally, the critical habitats of S. coeruleoalba and T. truncatus are the outcome of both the influence of environmental conditions and anthropogenic pressures presently occurring in the Gulf of Taranto, basically indicating the need for conservation measures, especially considering that the area is expected to be considered for hydrocarbon prospecting. These results contribute to setting up a baseline reference for future assessment of environmental marine disturbances using cetaceans, which are considered a key group in the MSFD, as an ecological indicator.
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