Diverse foraging strategies of breeding Swinhoe's Storm-petrel in the productive marginal sea of the Northwest Pacific

Understanding the foraging behavior is essential for investigating seabird ecology and conservation,as well as monitoring the well-being of the marine environment.Breeding seabirds adopt diverse foraging strategies to maximize energy gains and cope with the intensified challenges of parenting and self-maintenance.Such tradeoff may stem from the heterogeneity of food resources and the constraints of central place foraging.Nevertheless,abundant marine productivity could alleviate the energy limitation for seabirds,resulting in a consistent foraging approach.Here,we investigated the foraging strategy during the breeding season of a cryptic small-sized seabird,Swinhoe’s Storm-petrel(Hydrobates monorhis),in the Yellow Sea,a productive marginal sea of the Northwest Pacific.Using GPS tracking,we evaluated habitat preference,quantified the foraging strategy,and tested if environmental conditions and individual traits influence foraging trips.We found that Swinhoe’s Storm-petrels preferred nearshore areas with shallow water and engaged in primarily short foraging trips.Distinctive southeastward and southwestward strategies emerged when combining trip metrics,including foraging direction,duration,and maximum distance.The bathymetry,proximity to the coastline,and sea surface temperature differed in two foraging strategies.Foraging strategies exhibited flexibility between individuals,potentially explained by wing morphology,in which longer-winged birds are more likely to embark on longer-distance foraging trips.These findings highlight the impact of environmental factors and individual traits on seabirds’foraging decisions in productive marginal sea ecosystems.Our study also provides valuable insights into the foraging ecology of this Asian endemic storm-petrel.

Scaly-sided Merganser(Mergus squamatus)equalizes foraging costs with depth by switching foraging tactics

Throughout evolutionary history,animals are finely tuned to adjust their behaviors corresponding to environmental variations.Behavioral flexibility represents an important component of a species'adaptive capacity in the face of rapid anthropogenetic environmental change,and knowledge of animal behaviors is increasingly recognized in conservation biology.In aquatic ecosystem,variation of water depth is a key factor affecting the availability of food;thus,the foraging behaviors of many waterbirds,especially piscivores.In this study,we compared the foraging behaviors of the Scaly-sided Merganser(Mergus squamatus),an endangered migratory diving duck endemic to East Asia,in habitats with different water depths(Shallow waters:0–40 cm;Deep waters:40–300 cm),using video camera records obtained from the known wintering sites during three winters from 2018 to 2020.Further,the energy expenditure of foraging behavior profile and energy intake based on fish sizes were calculated to study the foraging energetics.In total,200 effective video footages that contained 1086 min with 17,995 behaviors and 163 events of catching fish were recorded.Results showed that:1)time length for fishing(including eye-submerging,head-dipping,diving and food handling)of M.squamatus in shallow waters was significantly more than in deep waters;2)M.squamatuss spent significantly more time for preparing(including vigilance,preening and swimming)in deep waters than in shallow waters;3)the mean catch rate was 0.28 fish/min in shallow waters,which is significantly higher than the value of 0.13 fish/min in deep waters;4)despite the distinct foraging behavior profiles and energy intakes,M.squamatus showed similar energetics in shallow and deep waters.We concluded that M.squamatus is a good example of behavioral flexibility that aligns with expectations of optimal foraging theory,in that it behaves in accordance to resource availability in different environments,resulting in high foraging efficiency.

Study of Wildebeest Foraging Processes Using Advection Diffusion Equation: Case of the Serengeti Ecosystem in Tanzania

We studied the foraging processes of wildebeest using an advection-diffusion equation. We equipped the model with data collected between 1999 and 2007 from the Serengeti ecosystem from 18 GPS-collared wildebeest. Results analysis show that wildebeest foraging behavior can be explained by advective and diffusive parameters in a heterogeneous habitat like the Serengeti ecosystem.

Can color vision variation explain sex differences in invertebrate foraging by capuchin monkeys?

Invertebrates are the main source of protein for many small-to-medium sized monkeys. Prey vary in size, mobility, degree of protective coveting, and use of the forest, i.e. canopy height, and whether they are exposed or embed themselves in substrates. Sex-differentiation in foraging patterns is well documented for some monkey species and recent studies find that color vision phenotype can also affect invertebrate foraging. Since vision phenotype is polymorphic and sex-linked in most New World monkeys - males have dichromatic vision and females have either dichromatic or trichromatic vision - this raises the possibility that sex differences are linked to visual ecology. We tested predicted sex differences for invertebrate foraging in white-faced capuchins Cebus capucinus and conducted 12 months of study on four free-ranging groups between January 2007 and September 2008. We found both sex and color vision effects. Sex： Males spent more time foraging for invertebrates on the ground. Females spent more time consuming embedded, colonial invertebrates, ate relatively more ＂soft＂ sedentary invertebrates, and devoted more of their activity budget to invertebrate foraging. Color Vision： Dichromatic monkeys had a higher capture efficiency of ex- posed invertebrates and spent less time visually foraging. Trichromats ate relatively more ＂hard＂ sedentary invertebrates. We con- elude that some variation in invertebrate foraging reflects differences between the sexes that may be due to disparities in size, strength, reproductive demands or niche preferences. However, other intraspecific variation in invertebrate foraging that might be mistakenly attributed to sex differences actually reflects differences in color vision [Current Zoology 56 （3）： 300-312, 2010].

Foraging behavior of parasitoid chalcid to the essential oil from bark of Populus pseudo-simonii P. nigra and Quadraspidiotus gigas

采用四臂式嗅觉仪测定了长棒四节蚜小蜂（Pteroptrix longgiclava(Girault)(Hymenoptera:Aphelinidae))和黄胸扑虱蚜小蜂（Encarsia gigas(Tshumakova)(Hymenoptera:Aphelinidae)),对健康的小青×黑杨（Populus pseudo-simonii×P.nigra)树皮、被杨圆蚧（Quadraspidiotus gigas(Thiem & Gerneck)）危害的杨树皮、杨圆蚧1齿固定若虫的虫体和介壳的挥发油的趋性反应。测定结果表明：被杨圆蚧危害后的小青×黑杨树皮和杨圆蚧1龄因定若虫的介壳对长棒四节蚜小蜂和黄胸扑虱蚜小蜂成虫具有较大的吸引力。3－7μL介壳挥发油和5－9μL受害杨树皮挥发油对长棒四节蚜小蜂的寄主搜寻行为具有较强的引导作用。虫体的挥发油对小蜂的寄生定位也起到了一定的引诱作用。两种小蜂对健康树皮的挥发油几乎没有反应。图4表1参20。

Modeling foraging habitats of Hume’s Pheasant (Syrmaticus humiae) in Dazhong Mountain, Yunnan, southwestern China

We modeled foraging habitats of Hume’s Pheasant (Syrmaticus humiae) on a macro-habitat level using ArcGIS in an attempt to provide scientific reference for management and restoration of habitats. Field work was conducted from March to April in 2006 and 2008, and from October to November in 2005 and 2008 in Dazhong Mountain, Yunnan Province, southwestern China. The selection of ecological factors was estimated by means of a resource selection index, distance analysis and the method of hierarchical habitat selection. The foraging habitat patches were modeled spatially by ArcGIS. The results show that actual and potential foraging patches overlapped considerably in spring and autumn. The number and total areas of patches in the autumn were smaller than those in the spring. The minimum and average areas of patches in the autumn were larger than those in the spring, while the maximum areas of actual and potential foraging patches in the autumn were equal to those in the spring. Similarity in the selection for survival and safety consideration in both seasons was the main strategy for landscape factors of habitats by Hume’s Pheasant, while seasonal difference in selecting a landscape matrix was their secondary strategy, affecting landscape factors in the habitat. Changes of foraging patches in both seasons reflect a difference of resources requirement by the bird. Fragmentation and miniaturization of foraging patches would result in the formation of a meta-population of Hume’s Pheasant.

Foraging behavior of the Eurasian Three-toed Woodpecker subspecies Picoides tridactylus funebris in southern Gansu, China

The Three-toed Woodpecker subspecies Picoides tridactylus funebris is endemic to the Qinghai-Tibet plateau in China. No part of its life history was ever reported since its discovery in 1870. To close this gap, we observed foraging behavior of a pair between April and August 2007. A total of 117 observations (28 for male and 89 for female) were obtained by following the birds within their home-ranges using radio-tracking. P. t. funebris preferred foraging on live spruces and snags bigger than available with an average diameter of breast height (DBH) of 32.7 ± 9.2 cm. The most frequent foraging technique was pecking (39.8% of foraging time) and peeling (13.2%). Moreover, sap-sucking was observed more often in P. t. funebris than in P. t. alpinus, suggesting that P. t. funebris was more dependent on the tree sap than the other subspecies. We found distinct niche partitioning between the sexes with respect to use of three out of four investigated parameters of the foraging substrates. These differences were likely related to sexual dimorphism pronounced by slightly larger bill of the male. We concluded that the subspecies P. t. funebris displayed foraging behavior which was very similar to that of other subspecies of the Three-toed Woodpecker.

Mobile robot path planning based on adaptive bacterial foraging algorithm

The utilization of biomimicry of bacterial foraging strategy was considered to develop an adaptive control strategy for mobile robot, and a bacterial foraging approach was proposed for robot path planning. In the proposed model, robot that mimics the behavior of bacteria is able to determine an optimal collision-free path between a start and a target point in the environment surrounded by obstacles. In the simulation, two test scenarios of static environment with different number obstacles were adopted to evaluate the performance of the proposed method. Simulation results show that the robot which reflects the bacterial foraging behavior can adapt to complex environments in the planned trajectories with both satisfactory accuracy and stability.

Improved quantum bacterial foraging algorithm for tuning parameters of fractional-order PID controller

The quantum bacterial foraging optimization(QBFO)algorithm has the characteristics of strong robustness and global searching ability. In the classical QBFO algorithm, the rotation angle updated by the rotation gate is discrete and constant,which cannot affect the situation of the solution space and limit the diversity of bacterial population. In this paper, an improved QBFO(IQBFO) algorithm is proposed, which can adaptively make the quantum rotation angle continuously updated and enhance the global search ability. In the initialization process, the modified probability of the optimal rotation angle is introduced to avoid the existence of invariant solutions. The modified operator of probability amplitude is adopted to further increase the population diversity.The tests based on benchmark functions verify the effectiveness of the proposed algorithm. Moreover, compared with the integerorder PID controller, the fractional-order proportion integration differentiation(PID) controller increases the complexity of the system with better flexibility and robustness. Thus the fractional-order PID controller is applied to the servo system. The tuning results of PID parameters of the fractional-order servo system show that the proposed algorithm has a good performance in tuning the PID parameters of the fractional-order servo system.

Intensive use of an intertidal mudflat by foraging adult American horseshoe crabs Limulus polyphemus in the Great Bay estuary, New Hampshire

Although concerns about harvesting levels of the American Horseshoe Crab, Limulus polyphemus have prompted increased research into its ecology, current understanding of the species＇ foraging ecology is mostly limited to mid-Atlantic populations. This study elucidates the spatial and temporal pattern of Limulus foraging on an intertidal mudflat of a northern New Eng- land estuary. A novel survey method was used to monitor Limulus foraging activity without disturbing the sediment. A fixed 50 mx2 m transect was monitored with monthly surveys of the number of Limulus feeding pits from June to October 2009, May and June 2010. Snorkelling surveys were also carried out to observe individual behavior and examine the spatial scale of activity of individual animals. Results showed frequent and intensive use of the mudflat by foraging Limulus. Limulus were actively foraging within the survey area during all months surveyed. Foraging patterns exhibited a seasonal pattern with activity levels peaking in August 2009 and increased significantly towards the end of the study in June 2010. It was also shown that Limulus intertidal foraging persisted and peaked after the spring breeding season. Observations of foraging Limulus revealed that individual predators dig multiple pits within a single high tide, with little disturbance to the sediment in between. In addition to altering the perception of Limulus as a subtidal predator outside of the breeding season, findings from this study suggests a segregation of spawning and feeding habitats, thus underscoring the need to consider a wider range of critical habitats in the management of Limulus populations

Effects of variation in food resources on foraging habitat use by wintering Hooded Cranes(Grus monacha)

Background:The ideal habitat use of waterbirds can be considered to be fixed,but current habitat use depends on environmental conditions,especially those of food characteristics,considered crucial to their use of habitats.Understanding how waterbirds respond to variation in food availability at degraded wetland sites and change their habitat use patterns over spatial and temporal scales should direct future conservation planning.The objectives of this study were to identify these spatial-temporal foraging habitat use patterns of Hooded Cranes(Grus monacha)and their relationship with food characteristics in the severely degraded wetlands of the Shengjin and Caizi lakes along with the Yangtze River floodplain.Methods:We investigated the changes in food characteristics,relative abundance and density of Hooded Cranes in various habitat types across three winter periods from November 2012 to April 2013.We examined the effect of these winter periods and habitat types on the pattern of use by the cranes and explored the relationship between these patterns and food characteristics using linear regression.Results:The food characteristics and habitat use clearly changed over spatial-temporal scales.In the early and mid-winter periods,the most abundant,accessible and frequented food resources were found in paddy fields,while in the late period the more abundant food were available in meadows,which then replaced the paddy fields.There were fewer effects of winter periods,habitat types and their interactions on habitat use patterns except for the effect of habitat types on the relative abundance,determined as a function of food abundance,but independent of food depth and sediment permeability.Conclusions:In response to the degradation and loss of lake wetlands,the cranes shifted their habitat use patterns by making tradeoffs between food abundance and accessibility over spatial-temporal scales that facilitated their survival in the mosaic of these lake wetlands.

Foraging behavior of the Greater White-fronted Goose(Anser albifrons) wintering at Shengjin Lake: diet shifts and habitat use

Background: The habitat use and foraging behaviors of waterbirds are closely related to the distribution and abundance of their food resources. Reductions in food supply can cause waterbirds to shift their habitats and adjust their foraging behaviors to meet their nutritional requirements and increase fitness. Seasonal withdraw of the water levels in the river-connected lakes in the middle and lower Yangtze River floodplain provides abundant food resources for the wintering Greater White-fronted Goose(Anser albifrons). Sedge(Carex) meadows are critical foraging habitats for herbivorous waterbirds in the hydro-fluctuation belt, which changes with hydrological conditions and climate. This study aimed to examine the behavioral responses of the Greater White-fronted Goose to temporal-spatial changes of food availability in the Sedge meadows.Methods: Fields surveys were carried out at Shengjin Lake from November 2017 to April 2018. According to the phenology of Shengjin Lake, we divided the wintering season into three periods. The food density, minimum temperature, food items, grass height, and number of foraging geese were surveyed, and samples of the foraging behavior were collected. We analyzed the relationship of the foraging behavior and habitat use relative to the food resources, using correlation and linear regression analyses.Results: Along with the temporal-spatial variation and exploitation of food resources, the food abundance and items varied widely among the foraging sites. Over the whole wintering period, the foraging habitat with the highest utilization rate was the meadows, followed by the paddy fields, and then mudflats. Furthermore, the utilization of the meadows showed a bimodal distribution trend, while the paddy fields showed a unimodal trend, and a decreasing trend was seen in the mudflats over the whole wintering period. The results of the generalized linear model showed that the foraging rate was related to the food density and grass height, with a linearly increasing trend during the winter.Conclusions: With the change of food resources in the three habitats, the habitats used by the Greater White-fronted Geese shifted from meadows in the hydro-fluctuation belt to the paddy fields, and then back to the meadows. The time budget for foraging activities increased correspondingly, and there was an increase in the foraging rate to compensate for food shortages.

Effect of water level fluctuations on temporal-spatial patterns of foraging activities by the wintering Hooded Crane(Grus monacha)

Background:The Yangtze River floodplain provides important wintering habitats for Hooded Cranes(Grus monacha) in China.Fluctuations in the water level change foraging habitat and food availability,affecting their temporal-spatial patterns of foraging activities.It is of considerable importance to investigate the effect of these fluctuations on food availability for wintering Hooded Cranes and their foraging response to these changes.Understanding their behavior patterns is beneficial in protecting the wintering crane population and restoring their wintering habitats.Methods:A field survey of the winter behavior of cranes was carried out at Shengjin Lake from November in 2013 to April in 2014.Habitat variables,as well as the spatial distribution and behavior patterns of wintering cranes at their foraging sites during five stages of water level fluctuation were collected.Based on this data we analyzed the relationship of foraging behavior relative to water level fluctuations and habitat types.Results:The foraging habitats used by Hooded Cranes varied at the different water level stages.As the water level decreased,the use of meadows and mudflats increased.When the water dropped to its lowest level,the use by the Hooded Crane in the mudflats reached a peak.There were statistically significant differences in time budget in the three types of habitats over the five stages of the water level.In the mudflats,the foraging behavior and maintenance behavior varied significantly with the water level,while the alert behavior showed little variation.Analysis of a generalized linear model showed that the five water level stages and three habitat types had a significant effect on foraging behavior,while the combined effect of these two variables was significant on the foraging time budget and the length of foraging activity of the Hooded Crane.Conclusions:With the decrease in the water level,the use of mudflats by Hooded Cranes increased correspondingly.Food availability in different habitats was affected by changes in the water level.The Hooded Crane adjusted its foraging patterns and made full use of the three available types of habitat in order to acquire enough food in response to fluctuations in the water level.

Optimization of Fused Deposition Modelling (FDM) Process Parameters Using Bacterial Foraging Technique

Fused deposition modelling (FDM) is a fast growing rapid prototyping (RP) technology due to its ability to build functional parts having complex geometrical shapes in reasonable build time. The dimensional accuracy, surface roughness, mechanical strength and above all functionality of built parts are dependent on many process variables and their settings. In this study, five important process parameters such as layer thickness, orientation, raster angle, raster width and air gap have been considered to study their effects on three responses viz., tensile, flexural and impact strength of test specimen. Experiments have been conducted using central composite design (CCD) and empirical models relating each response and process parameters have been developed. The models are validated using analysis of variance (ANOVA). Finally, bacterial foraging technique is used to suggest theoretical combination of parameter settings to achieve good strength simultaneously for all responses.

Foraging areas of Rousettus leschenaulti on the Hainan Island of China

We investigated the foraging area of three individuals (1 female and 2 males) of Rousettus leschenaulti (Chiroptera,Pteropodidae) in suburban Haikou City, Hainan Province, South China from November 2005 to January 2006 using radio telemetry.These animals left the daytime roosting sites about 90 min after sunset with no significant difference in departure time betweenthe male and female bats. The average active times were 391.8 min for males and 533.7 min for the female, respectively.By reconstructing 93 radio-telemetry recording positions, we found that the long axis of foraging area of the bats ranged from7.45 to 11.70 km. The foraging area of the female (3867 ha) was larger than that of the males (1138 ha), and there was overlapbetween the foraging areas of different individuals. These bats usually kept the same flight routes across a few successive daysfrom the daytime roosting site to the foraging areas. Our findings suggested that female R. leschenaulti may explore a larger foragingarea than males. No obvious territorial behaviors were observed in our studied area.

Foraging habitat selection of overwintering Black-necked Cranes in the farming area surrounding the Caohai Wetland, Guizhou Province, China

Background: Understanding how overwintering birds choose foraging habitats is very important for conservation management. The overwintering Black-necked Crane(Grus nigricollis) feeds on crop remains in farmlands;thus, reasonable conservation management of this type of farmland that surrounds wetlands is critical for the overwintering populations of the Black-necked Crane;however, it is not clear how the Black-necked Crane chooses the foraging land in the farmland.Methods: A thorough field positioning survey of all foraging sites in farmland areas around the Caohai Wetland and a-sampling analysis of habitat selection by the Black-necked Crane were conducted during the winters from 20162017 and 2017-2018.Results: Multiple factors contributed to the selection of foraging habitat in farmlands, i.e., food factors(crop remains and tillage methods) > human disturbance factors(distance to road and settlement) > topography factors(slope aspect), listed according to the strength of influence. Additionally, Black-necked Cranes tend to choose farmland sites where there was no machine tillage, the crop remains were > 500 g/m^2, the distance to residences ranged from 100 to 500 m, the distance to roads ranged from 50 to 100 m, and the slopes exhibited western or eastern aspects. As the winters progressed, the volume of the edible crop remains declined, and the influences of the other main factors also changed, i.e., the factors of human disturbance(distance to road and settlement) became less important, while the effect of the food factor(crop remains) was strengthened. Thus, the foraging sites near the road became more important.Conclusion: The farming area surrounding the Caohai Wetland is very important for the overwintering Black-necked Crane. Food factors and human disturbance factors are the main factors that influence the choice of feeding ground.

Advancement in Information Foraging Theory

This paper presents the advantages of information foraging theory matched with traditional information retrieval theory and user behavior analysis theory, a search content framework for information foraging theory is described, on a thor- ough review of the two research branches i.e. the basic concept of information foraging theory and the elementary mod- els of information foraging theory, an extended framework is proposed,. Several problems for future research are also identified through.

Fractional-Order Control of a Wind Turbine Using Manta Ray Foraging Optimization

In this research paper,an improved strategy to enhance the performance of the DC-link voltage loop regulation in a Doubly Fed Induction Generator(DFIG)based wind energy system has been proposed.The proposed strategy used the robust Fractional-Order(FO)Proportional-Integral(PI)control technique.The FOPI control contains a non-integer order which is preferred over the integer-order control owing to its benefits.It offers extra flexibility in design and demonstrates superior outcomes such as high robustness and effectiveness.The optimal gains of the FOPI controller have been determined using a recent Manta Ray Foraging Optimization(MRFO)algorithm.During the optimization process,the FOPI controller’s parameters are assigned to be the decision variables whereas the objective function is the error racking that to be minimized.To prove the superiority of the MRFO algorithm,an empirical comparison study with the homologous particle swarm optimization and genetic algorithm is achieved.The obtained results proved the superiority of the introduced strategy in tracking and control performances against various conditions such as voltage dips and wind speed variation.

Wintering Swan Geese maximize energy intake through substrate foraging depth when feeding on buried Vallisneria natans tubers

Background: Foraging theory predicts that animals select patches that offer the highest net rate of energy gain. Hence, prey distribution patterns and spatiotemporal heterogeneity play important roles in determining animal feeding patch selection. For waterfowl foraging on buried aquatic plant tubers, the distribution and biomass of these plant organs vary with depth in the substrate. Since excavation costs also increase with depth, the energy intake of the animals foraging on these plants is highly sediment depth dependent. Methods: Here, using observations of Swan Geese (Anser cygnoides) foraging on Vallisneria natans tubers, we test our hypothesis that geese feeding on tubers buried at intermediate sediment depth maximize their daily energy intake because of the interaction between tuber size and abundance with depth. To do this, we measured the distribution patterns of buried Vallisneria tubers under both undisturbed conditions and post-exploitation by geese (i.e. giving-up conditions). We investigated the relationship between tuber size and burial depth, and total tuber biomass within each sediment layer in undisturbed and exploited plots. Finally, we compared modelled Swan Goose daily energy intake feeding on Vallisneria tubers buried at different sediment layers (1–10, 11–20 and 21–30 cm below the surface). Results: Dry weight of Vallisneria tubers linearly increased with burial depth, while average total dry weight density of tubers showed a unimodal relationship, peaking at intermediate levels. Not surprisingly, Swan Geese foraged most intensively on tubers buried at intermediate sediment depths, where they maximize their daily energy intake. Our results support our hypothesis that Swan Geese feeding on tubers at intermediate depths maximize their daily energy intake. Conclusions: Our study is the first to quantify foraging strategies of Swan Geese during the wintering period, emphasizing the importance of plant traits on foraging selection of belowground foragers.

Foraging Behavior,Direct Interference and Habitat Use in Three Species of Flamingos(Phoenicopterus Chilensis,Phoenicoparrus Andinus and Phoenicoparrus Jamesi) in Mar Chiquita Lagoon,Córdoba,Argentina

The Laguna Mar Chiquita,located northeast of the province of Córdoba in Argentina,is the only non-Andean place where three flamingo species regularly coexist in the southern part of South America.Two of these species,