In a greenhouse experiment plasticity of clonal growth and clonal morphology of the stoloniferous rosette herb Halerpestes nahenica Ovcz. in response to differing levels of light intensity and nutrient availability wa...In a greenhouse experiment plasticity of clonal growth and clonal morphology of the stoloniferous rosette herb Halerpestes nahenica Ovcz. in response to differing levels of light intensity and nutrient availability was studied. Total plant dry weight, leaf area of primary ramets, total number of ramets and of stolons, and total stolon length were significantly reduced, while specific internode length and specific petiole length significantly increased under deep shading (6.25% of high light intensity, 5.3% of full daylight) or under low nutrient availability. Under low nutrient availability, mean stolon internode length of H. ruthenica was significantly larger while branching intensity and number of ramets smaller than those under high nutrient availability. These responses are consistent with the foraging model of clonal plants, indicating that H. nahenica is able to forage nutrients through the plastic responses of clonal growth and clonal. morphology when it grows in heterogeneous environments. However, under deep shading, both mean stolon internode length and mean petiole length were significantly reduced, which disagrees with the findings of many other stoloniferous herbs in response to low or medium levels of shading (ca. 13%-75% of high light intensity, >10% of full daylight), suggesting that under deep shading stoloniferous herbs may not forage light through the plastic responses of spacer length. Many traits such as total plant dry weight, total number and length of stolons, total length of secondary and tertiary stolons. total number of ramets, leaf area of primary ramets and branching intensity were markedly influenced by the interaction effect of light intensity and nutrient availability. Under high light intensity nutrient availability affected these traits more pronouncedly, however under low light intensity nutrient availability either did not affect or affected less markedly on these traits, indicating that fight intensity had significant effect on nutrient foraging in H. nahenica. Under deep shading or low nutrient availability, H. ruthenica may increase its mean stolon internode length by means of thinning stolon internodes (i.e., an increase in specific internode length), which provides it with more chance to escape from resource-poor sites.展开更多
There is a lack of information of whether the behavior pattern and physical condition of the Hooded Crane (Grus monacha) have been limited by conditions encountered at stopover sites in Changgou village,which is adjac...There is a lack of information of whether the behavior pattern and physical condition of the Hooded Crane (Grus monacha) have been limited by conditions encountered at stopover sites in Changgou village,which is adjacent to Zhalong Nature Reserve in northeastern China,one of the most important stopover sites of this crane.The objective of our research was to investigatethe impact of human-caused disturbances on the Hooded Cranes.We investigated three behavior activities of the Hooded Cranes,i.e.,flying time,flushing distance and the duration of vigilance.The results indicate that the auditory stimuli caused by local people provoked the most pronounced disturbances to the Hooded Crane.Human-caused disturbances not only frequently interrupt the feeding process of the cranes,but also lead to an increase of 200% in the duration of their vigilance and a significant increase in flying time from 0.4 to 0.7 h (p < 0.05).In addition,high-intensity noise can cause larger flushing distances; foraging cranes will flush away by about 600 m when disturbed by the honking of vehicles.Whistles or shouts by local farmers in the field generated the largest sound intensity,about 120 dB,which caused a flushing distance of over 700 m.In order to reduce the negative effect of human-caused disturbances on these cranes,it is imperative to define a buffer zone around sensitive areas during the fall stopover period.To solve the conflict between the interest of farmers and the demand for crops on the part of the cranes requires financial compensation to the farmers for the crops consumed by the Hooded Crane in order to enhance the conservation of this vulnerable bird species.展开更多
Acorns of Quercus aliena var. acuteserrata Maxim. are often predated by small mammals and birds in natural forests. These animals not only eat the acorns during the acorn ripening season, but also cache and hoard most...Acorns of Quercus aliena var. acuteserrata Maxim. are often predated by small mammals and birds in natural forests. These animals not only eat the acorns during the acorn ripening season, but also cache and hoard most of the remaining acorns on the forest floor in the soil for their future use. These buried acorns form the main seed resource for regeneration. Burying depth is potentially important for germination and for seedling development. The effects of burying depth on germination and seedling development in relation to acorn size were studied in an experiment, in which acorns were planted at 6 cm-, 12 cm- and 18 cm-depth. The experimental results showed that fewer acorns germinated as burying depth increased. From the deeply buried acorns fewer seedlings emerged at later time than from those acorns buried less deeply. They appeared to have more difficulties to emerge above-ground than die seedlings from shallowly buried acorns. The deeply buried acorns and their seedlings also appeared to be more susceptible to rot. Acorn size did not significantly affect germination and emergence of the seedlings. As early emerged seedlings had longer developmental periods in their first growing season, and therefore grew better than die late emerged seedlings, seedlings from die shallowly buried acorns took the advantage.展开更多
Variable and unpredictable food resources at stopover sites bring severe challenges to migrating shorebirds. Opportunistic foraging strategies, referring to shorebirds consuming prey in proportion to their availabilit...Variable and unpredictable food resources at stopover sites bring severe challenges to migrating shorebirds. Opportunistic foraging strategies, referring to shorebirds consuming prey in proportion to their availability, allow shorebirds to replenish fuel and nutrient reserves efficiently for continuing their migration. Chongming Dongtan, located in the Yangtze River estuary of eastern China, is the first major stopover site of shorebirds on the Chinese mainland during their northward migration. We investigated the diet of Great Knots (Calidris tenuirostris) at Chongming Dongtan during the spring stopovers of 2009 and 2010 through benthos sampling and dropping analysis. The benthos samples were categorized into gastropods, bivalves, polychaetes, crustaceans and insect larvae. Dropping analysis indicated that gastropods and bivalves constituted more than 70% of the diet of the Great Knot, with Assiminea violacea and Corbicula fluminea being the most frequently consumed. Chi-square tests indicated that for each prey category, there was no significant difference between the frequency of its occurrence in the benthos samples and dropping samples during the early stopover periods of 2009 and 2010 and during the late stopover periods of 2010. Although there was a statistically significant difference between the frequency of occurrence of prey in the total macrobenthos and in the droppings of the Great Knots during the late stopover period in 2009, the more abundant prey were more frequently consumed by the Great Knots. This suggests that Great Knots adopted an opportunistic foraging strategy during their stopover at Chongming Dongtan.展开更多
While several studies have documented the large-scale, seasonal movements of horseshoe crabs, little is known about their fine-scale, daily movement patterns. In this study we used a fixed array ultrasonic telemetry s...While several studies have documented the large-scale, seasonal movements of horseshoe crabs, little is known about their fine-scale, daily movement patterns. In this study we used a fixed array ultrasonic telemetry system to track the movements of 12 male and 16 female horseshoe crabs in the Great Bay estuary, New Hampshire. Data were obtained during the mating season, as well as during the remainder of the summer and fall, in the years 2005-2008. During the mating season animals were often, but not always, active during the high tides when they were approaching and leaving the spawning beaches. On average, both males and females approached mating beaches during 33% of the high tides they experienced and they most often made the tran- sition from being inactive to active during the last two hours of an incoming tide. From April-October horseshoe crabs were significantly more active during high tide periods vs low tide periods, with no clear preference for diurnal vs nocturnal activity. After the mating season ended horseshoe crabs continued to move into shallower water at high tide and then return to deeper water at low tide. Observations by SCUBA divers suggest that during these excursions into the mudflats horseshoe crabs were digging pits in the sediment while foraging for food. Thus, the tidal rhythm of activity that has been so well documented during the mating season probably persists into the fall, and primarily involves foraging activities展开更多
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...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展开更多
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 prop...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.展开更多
In the wild, primate foraging behaviors are related to the diversity and nutritional properties of food, which are affected by seasonal variation. The goal of environmental enrichment is to stimulate captive animals t...In the wild, primate foraging behaviors are related to the diversity and nutritional properties of food, which are affected by seasonal variation. The goal of environmental enrichment is to stimulate captive animals to exhibit similar foraging behavior of their wild counterparts, e.g. to extend foraging time. We conducted a 12-month study on the foraging behavior of Japanese macaques in a semi-naturally forested enclosure to understand how they use both provisioned foods and naturally available plant foods and what are the nutritional criteria of their consumption of natural plants. We recorded time spent feeding on provisioned and natural plant foods and collected the plant parts ingested of their major plant food species monthly, when available. We conducted nutritional analysis (crude protein, crude lipid, neutral detergent fiber-‘NDF', ash) and calculated total non-structural carbohydrate - ‘TNC' and total energy of those food items. Monkeys spent 47% of their feeding time foraging on natural plant species. The consumption of plant parts varied significantly across seasons. We found that leaf items were consumed in months when crude protein, crude protein-to-NDF ratio, TNC and total energy were significantly higher and NDF was significantly lower, fruit/nut items in months when crude protein and TNC were significantly higher and crude lipid content was significantly lower, and bark items in months when TNC and total energy were higher and crude lipid content was lower. This preliminary investigation showed that the forested enclosure allowed troop members to more fully express their species typical flexible behavior by challenging them to adjust their foraging behavior to seasonal changes of plant item diversity and nutritional content, also providing the possibility for individuals to nutritionally enhance their diet .展开更多
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 200...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.展开更多
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 ...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].展开更多
Background:Investigations of running gait among barefoot and populations have revealed a diversity of foot strike behaviors,with some preferentially employing a rearfoot strike(RFS) as the foot touches down while othe...Background:Investigations of running gait among barefoot and populations have revealed a diversity of foot strike behaviors,with some preferentially employing a rearfoot strike(RFS) as the foot touches down while others employ a midfoot strike(MFS) or forefoot strike(FFS).Here,we report foot strike behavior and joint angles among traditional Hadza hunter-gatherers living in Northern Tanzania.Methods:Hadza adults(n = 26) and juveniles(n = 14) ran at a range of speeds(adults:mean 3.4 ± 0.7 m/s,juveniles:mean 3.2 ± 0.5 m/s) over an outdoor trackway while being recorded via high-speed digital video.Foot strike type(RFS.MFS.or FFS) and hind limb segment angles at foot strike were recorded.Results:Hadza men preferentially employed MFS(86.7%of men),while Hadza women and juveniles preferentially employed RFS(90.9%and85.7%of women and juveniles,respectively).No FFS was recorded.Speed,the presence of footwear(sandals vs.barefoot),and trial duration had no effect on foot strike type.Conclusion:Unlike other habitually barefoot populations which prefer FFS while running.Hadza men preferred MFS.and Hadza women and juveniles preferred RFS.Sex and age differences in foot strike behavior among Hadza adults may reflect differences in running experience,with men learning to prefer MFS as they accumulate more running experience.展开更多
To evaluate Apis mellifera adansonii Latreille impact on fruit and seed yields of Gossypium hirsutum L., its foraging and pollinating activities were studied in Ngaoundere for two seasons. Observations were made on 34...To evaluate Apis mellifera adansonii Latreille impact on fruit and seed yields of Gossypium hirsutum L., its foraging and pollinating activities were studied in Ngaoundere for two seasons. Observations were made on 340 flowers each year and divided in three treatments. The treatments included unlimited flowers access by all visitors; bagged flowers to deny all visits and limited visits by Apis mellifera adansonii only. The worker bees seasonal rhythm of activity, its foraging behaviour, its pollination efficiency, the fruiting rate, the number of seeds per fruit and the percentage of normal seeds were evaluated. Results show that this bee foraged G. hirsutum flowers throughout the whole blooming period. This bee species intensely harvested pollen and nectar. The mean foraging speed was 9.41 flowers per rain in 2009 and 8.41 flowers per min in 2010. The fruiting rate, the number of seeds per fruit and the percentage of normal seeds of unprotected flowers were significantly higher than those of flowers protected from insects. Through its pollination efficiency, Apis mellifera adansonii provoked a significant increment of the fruiting rate by 60.84% in 2009 and 36.48% in 2010, as well as the number of seeds per fruit by 94.16% in 2009 and 31.41% in 2010, and the percentage of normal seeds by 94.23% in 2009 and 33.49% in 2010. The installation ofA. m. adansonii colonies close to G. hirsutum fields could be recommended to increase fruit, seed and honey yields, and pollen production as a hive product in the region.展开更多
Attractabilities of different diets and dietary selectivity of Chinese shrimp, Fenneropenaeus chinensis were studied through behavior observation and feeding experiment, respectively. The five diets used in the experi...Attractabilities of different diets and dietary selectivity of Chinese shrimp, Fenneropenaeus chinensis were studied through behavior observation and feeding experiment, respectively. The five diets used in the experiment are: Fish Flesh (FF), Shrimp Flesh (SF), Clam Foot (CF), Polychaete Worm (PW), and Formulated Diet (FD). No significant differ- ences of attractability exist between any two different diets when every two natural diets or all five diets are provided simul- taneously. On the other hand, significant differences of attractability exist between FD and every single natural diet when they are provided simultaneously. Results of behavioral observation indicate that natural diets are more attractive than FD. In feeding experiment, Chinese shrimp has distinct selectivity on different diets. It positively selects CF and PW, negatively selects FF and SF, and excludes FD absolutely. The results of the present studies indicate that the dietary selectivity of shrimp was based not only on the attractabilities of the diets, but also on the responses such as growth and food conversion.展开更多
Foraging behavior in ant colonies has come to be viewed as a prototypical example to describe how complex group behavior can arise from simple individuals. In order to research the feature of self-organization in swar...Foraging behavior in ant colonies has come to be viewed as a prototypical example to describe how complex group behavior can arise from simple individuals. In order to research the feature of self-organization in swarm intelligence (SI), a mean field model is given and analyzed in foraging process with three sources in this paper. The distance of trails and the richness of each source are considered. Both of the theoretical numerical analysis and Monte Carlo simulation show the power law relationship between the completion time and the flux of foragers. The work presented here guides a better understanding on self-organization and swarm intelligence. It can be used to design more efficient, adaptive, and reliable intelligent systems.展开更多
Studying the ecology of ants can be a powerful tool for conservation, While the effect of logging is mainly investigated by the comparison of species richness and composition, the impact on individual species are ofte...Studying the ecology of ants can be a powerful tool for conservation, While the effect of logging is mainly investigated by the comparison of species richness and composition, the impact on individual species are often neglected. This study investigated the effect of selective logging on the nest density, foraging range and colony size on the ground-dwelling ant Aphaenogaster swammerdami in Kirindy forest--Madagascar. This ant is a common ground-dwelling species in Kirindy, a western dry deciduous forest of Madagascar. Sampling was done in two sites of the forest: One part that was selectively lodged and another that have not been logged. Here we show that selective logging led to a decrease in colony size and density, while the foraging range seemed to be unaffected. Higher desiccation stress and lower food availability in the logged forest are most likely to be responsible for these results.展开更多
Goat satisfying energy requirements of goat are determined by anatomical body and browse leaves. In High Bassin zone of Mandrare in Southern Madagascar, sampling area of 400 m^2 has been monitored to analysis floristi...Goat satisfying energy requirements of goat are determined by anatomical body and browse leaves. In High Bassin zone of Mandrare in Southern Madagascar, sampling area of 400 m^2 has been monitored to analysis floristic diversity and Shannon-Weaver index and to establish rangeland typology. With one ram, two castrated goats and three ewes, foraging behaviour, bite rate and forage nutritive value were analyzed in native pastureland during six days at two browsing periods. As results, four pastureland groups were classified with dominant shrubs plants Acacia farnesiana, Poupartia caffra, Kigelianthe madagascariensis and Rhigozum madagascariense. Rangelands sites have presented lower heterogeneity with floristic density (236-658 plants per hectare), Shannon-Weaver index (0.28-0.95), maximum diversity (1.04 ± 0.07) with P 〈 0.05. Most of 42 identified fodder plants presented significant difference (P 〈 0.05) and higher nutritive value (35-54% Dry Matter or DM); mineral matter (70-162 g·kg DM^-1); Crude Protein (124-175 g·kg DM^-1); Crude Fibre (203-376 g·kg DM^-1); Neutral Detergent Fiber (388-548 g·kg DM^-1) and gross energy (3617-4464 kcal·kg DM^-1). Acaciafarnesiana rangeland was overgrazed with 4.00 to 9.00 bites·mn^-1. In fact, relationships between phytosociology, nutritional parameters and foraging behaviour have been analyzed to improve with autochthonous plants and to manage rangeland in semi arid environment.展开更多
文摘In a greenhouse experiment plasticity of clonal growth and clonal morphology of the stoloniferous rosette herb Halerpestes nahenica Ovcz. in response to differing levels of light intensity and nutrient availability was studied. Total plant dry weight, leaf area of primary ramets, total number of ramets and of stolons, and total stolon length were significantly reduced, while specific internode length and specific petiole length significantly increased under deep shading (6.25% of high light intensity, 5.3% of full daylight) or under low nutrient availability. Under low nutrient availability, mean stolon internode length of H. ruthenica was significantly larger while branching intensity and number of ramets smaller than those under high nutrient availability. These responses are consistent with the foraging model of clonal plants, indicating that H. nahenica is able to forage nutrients through the plastic responses of clonal growth and clonal. morphology when it grows in heterogeneous environments. However, under deep shading, both mean stolon internode length and mean petiole length were significantly reduced, which disagrees with the findings of many other stoloniferous herbs in response to low or medium levels of shading (ca. 13%-75% of high light intensity, >10% of full daylight), suggesting that under deep shading stoloniferous herbs may not forage light through the plastic responses of spacer length. Many traits such as total plant dry weight, total number and length of stolons, total length of secondary and tertiary stolons. total number of ramets, leaf area of primary ramets and branching intensity were markedly influenced by the interaction effect of light intensity and nutrient availability. Under high light intensity nutrient availability affected these traits more pronouncedly, however under low light intensity nutrient availability either did not affect or affected less markedly on these traits, indicating that fight intensity had significant effect on nutrient foraging in H. nahenica. Under deep shading or low nutrient availability, H. ruthenica may increase its mean stolon internode length by means of thinning stolon internodes (i.e., an increase in specific internode length), which provides it with more chance to escape from resource-poor sites.
文摘There is a lack of information of whether the behavior pattern and physical condition of the Hooded Crane (Grus monacha) have been limited by conditions encountered at stopover sites in Changgou village,which is adjacent to Zhalong Nature Reserve in northeastern China,one of the most important stopover sites of this crane.The objective of our research was to investigatethe impact of human-caused disturbances on the Hooded Cranes.We investigated three behavior activities of the Hooded Cranes,i.e.,flying time,flushing distance and the duration of vigilance.The results indicate that the auditory stimuli caused by local people provoked the most pronounced disturbances to the Hooded Crane.Human-caused disturbances not only frequently interrupt the feeding process of the cranes,but also lead to an increase of 200% in the duration of their vigilance and a significant increase in flying time from 0.4 to 0.7 h (p < 0.05).In addition,high-intensity noise can cause larger flushing distances; foraging cranes will flush away by about 600 m when disturbed by the honking of vehicles.Whistles or shouts by local farmers in the field generated the largest sound intensity,about 120 dB,which caused a flushing distance of over 700 m.In order to reduce the negative effect of human-caused disturbances on these cranes,it is imperative to define a buffer zone around sensitive areas during the fall stopover period.To solve the conflict between the interest of farmers and the demand for crops on the part of the cranes requires financial compensation to the farmers for the crops consumed by the Hooded Crane in order to enhance the conservation of this vulnerable bird species.
文摘Acorns of Quercus aliena var. acuteserrata Maxim. are often predated by small mammals and birds in natural forests. These animals not only eat the acorns during the acorn ripening season, but also cache and hoard most of the remaining acorns on the forest floor in the soil for their future use. These buried acorns form the main seed resource for regeneration. Burying depth is potentially important for germination and for seedling development. The effects of burying depth on germination and seedling development in relation to acorn size were studied in an experiment, in which acorns were planted at 6 cm-, 12 cm- and 18 cm-depth. The experimental results showed that fewer acorns germinated as burying depth increased. From the deeply buried acorns fewer seedlings emerged at later time than from those acorns buried less deeply. They appeared to have more difficulties to emerge above-ground than die seedlings from shallowly buried acorns. The deeply buried acorns and their seedlings also appeared to be more susceptible to rot. Acorn size did not significantly affect germination and emergence of the seedlings. As early emerged seedlings had longer developmental periods in their first growing season, and therefore grew better than die late emerged seedlings, seedlings from die shallowly buried acorns took the advantage.
基金supported by the National Natural Science Foundation of China(Grant No.30670269,31071939)
文摘Variable and unpredictable food resources at stopover sites bring severe challenges to migrating shorebirds. Opportunistic foraging strategies, referring to shorebirds consuming prey in proportion to their availability, allow shorebirds to replenish fuel and nutrient reserves efficiently for continuing their migration. Chongming Dongtan, located in the Yangtze River estuary of eastern China, is the first major stopover site of shorebirds on the Chinese mainland during their northward migration. We investigated the diet of Great Knots (Calidris tenuirostris) at Chongming Dongtan during the spring stopovers of 2009 and 2010 through benthos sampling and dropping analysis. The benthos samples were categorized into gastropods, bivalves, polychaetes, crustaceans and insect larvae. Dropping analysis indicated that gastropods and bivalves constituted more than 70% of the diet of the Great Knot, with Assiminea violacea and Corbicula fluminea being the most frequently consumed. Chi-square tests indicated that for each prey category, there was no significant difference between the frequency of its occurrence in the benthos samples and dropping samples during the early stopover periods of 2009 and 2010 and during the late stopover periods of 2010. Although there was a statistically significant difference between the frequency of occurrence of prey in the total macrobenthos and in the droppings of the Great Knots during the late stopover period in 2009, the more abundant prey were more frequently consumed by the Great Knots. This suggests that Great Knots adopted an opportunistic foraging strategy during their stopover at Chongming Dongtan.
基金supported by NSF IOB 0517229 and NSF IOS 0920342 grants to WHW Ⅲ and CCC
文摘While several studies have documented the large-scale, seasonal movements of horseshoe crabs, little is known about their fine-scale, daily movement patterns. In this study we used a fixed array ultrasonic telemetry system to track the movements of 12 male and 16 female horseshoe crabs in the Great Bay estuary, New Hampshire. Data were obtained during the mating season, as well as during the remainder of the summer and fall, in the years 2005-2008. During the mating season animals were often, but not always, active during the high tides when they were approaching and leaving the spawning beaches. On average, both males and females approached mating beaches during 33% of the high tides they experienced and they most often made the tran- sition from being inactive to active during the last two hours of an incoming tide. From April-October horseshoe crabs were significantly more active during high tide periods vs low tide periods, with no clear preference for diurnal vs nocturnal activity. After the mating season ended horseshoe crabs continued to move into shallower water at high tide and then return to deeper water at low tide. Observations by SCUBA divers suggest that during these excursions into the mudflats horseshoe crabs were digging pits in the sediment while foraging for food. Thus, the tidal rhythm of activity that has been so well documented during the mating season probably persists into the fall, and primarily involves foraging activities
基金the National Estuarine Research Reserve Graduate Research FellowshipUNH Marine ProgramNew Hampshire Seagrant
文摘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
基金Project(61173032)supported by the National Natural Science Foundation of ChinaProject(20090406)supported by the Tianjin Scientific and Technological Development Fund of Higher Education of China
文摘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.
基金a Graduate Studies Scholarship 'Monbukagakusho' (Ministry of Education, Culture, Sports, Science and Technology, Japan)greatly facilitatde by an ecological assessment of the site conducted by Profgranted by the 'Research and Animal Care' committee at PRI
文摘In the wild, primate foraging behaviors are related to the diversity and nutritional properties of food, which are affected by seasonal variation. The goal of environmental enrichment is to stimulate captive animals to exhibit similar foraging behavior of their wild counterparts, e.g. to extend foraging time. We conducted a 12-month study on the foraging behavior of Japanese macaques in a semi-naturally forested enclosure to understand how they use both provisioned foods and naturally available plant foods and what are the nutritional criteria of their consumption of natural plants. We recorded time spent feeding on provisioned and natural plant foods and collected the plant parts ingested of their major plant food species monthly, when available. We conducted nutritional analysis (crude protein, crude lipid, neutral detergent fiber-‘NDF', ash) and calculated total non-structural carbohydrate - ‘TNC' and total energy of those food items. Monkeys spent 47% of their feeding time foraging on natural plant species. The consumption of plant parts varied significantly across seasons. We found that leaf items were consumed in months when crude protein, crude protein-to-NDF ratio, TNC and total energy were significantly higher and NDF was significantly lower, fruit/nut items in months when crude protein and TNC were significantly higher and crude lipid content was significantly lower, and bark items in months when TNC and total energy were higher and crude lipid content was lower. This preliminary investigation showed that the forested enclosure allowed troop members to more fully express their species typical flexible behavior by challenging them to adjust their foraging behavior to seasonal changes of plant item diversity and nutritional content, also providing the possibility for individuals to nutritionally enhance their diet .
基金funded by the National Natural Science Foundation of China (30800119)Doctoral Fund of Ministry of Education of China (200802001011)Youth Scholar grant of Northeast Normal University for Z.H. Tang (120401044)
文摘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.
基金supported by grants from The Leakey Foundationthe Alberta Ingenuity Fund+4 种基金the Animal Behavior Societythe National Sciences and Engineering Research Council of Canada (NSERC)NSERC and the Canada Research Chairs Programthe Grants-in-Aid for Scientific Research (B) (16405015)(A) (19207018) from JSPS
文摘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].
基金the National Science Foundation(BCS-0850815)Hunter College
文摘Background:Investigations of running gait among barefoot and populations have revealed a diversity of foot strike behaviors,with some preferentially employing a rearfoot strike(RFS) as the foot touches down while others employ a midfoot strike(MFS) or forefoot strike(FFS).Here,we report foot strike behavior and joint angles among traditional Hadza hunter-gatherers living in Northern Tanzania.Methods:Hadza adults(n = 26) and juveniles(n = 14) ran at a range of speeds(adults:mean 3.4 ± 0.7 m/s,juveniles:mean 3.2 ± 0.5 m/s) over an outdoor trackway while being recorded via high-speed digital video.Foot strike type(RFS.MFS.or FFS) and hind limb segment angles at foot strike were recorded.Results:Hadza men preferentially employed MFS(86.7%of men),while Hadza women and juveniles preferentially employed RFS(90.9%and85.7%of women and juveniles,respectively).No FFS was recorded.Speed,the presence of footwear(sandals vs.barefoot),and trial duration had no effect on foot strike type.Conclusion:Unlike other habitually barefoot populations which prefer FFS while running.Hadza men preferred MFS.and Hadza women and juveniles preferred RFS.Sex and age differences in foot strike behavior among Hadza adults may reflect differences in running experience,with men learning to prefer MFS as they accumulate more running experience.
文摘To evaluate Apis mellifera adansonii Latreille impact on fruit and seed yields of Gossypium hirsutum L., its foraging and pollinating activities were studied in Ngaoundere for two seasons. Observations were made on 340 flowers each year and divided in three treatments. The treatments included unlimited flowers access by all visitors; bagged flowers to deny all visits and limited visits by Apis mellifera adansonii only. The worker bees seasonal rhythm of activity, its foraging behaviour, its pollination efficiency, the fruiting rate, the number of seeds per fruit and the percentage of normal seeds were evaluated. Results show that this bee foraged G. hirsutum flowers throughout the whole blooming period. This bee species intensely harvested pollen and nectar. The mean foraging speed was 9.41 flowers per rain in 2009 and 8.41 flowers per min in 2010. The fruiting rate, the number of seeds per fruit and the percentage of normal seeds of unprotected flowers were significantly higher than those of flowers protected from insects. Through its pollination efficiency, Apis mellifera adansonii provoked a significant increment of the fruiting rate by 60.84% in 2009 and 36.48% in 2010, as well as the number of seeds per fruit by 94.16% in 2009 and 31.41% in 2010, and the percentage of normal seeds by 94.23% in 2009 and 33.49% in 2010. The installation ofA. m. adansonii colonies close to G. hirsutum fields could be recommended to increase fruit, seed and honey yields, and pollen production as a hive product in the region.
基金the Major State Basic Research of China(Grant No.G1999012011)the State Agriculture Program(Grant No.K2002-16) the Initializing Fund for Teachers of Ocean University of China.
文摘Attractabilities of different diets and dietary selectivity of Chinese shrimp, Fenneropenaeus chinensis were studied through behavior observation and feeding experiment, respectively. The five diets used in the experiment are: Fish Flesh (FF), Shrimp Flesh (SF), Clam Foot (CF), Polychaete Worm (PW), and Formulated Diet (FD). No significant differ- ences of attractability exist between any two different diets when every two natural diets or all five diets are provided simul- taneously. On the other hand, significant differences of attractability exist between FD and every single natural diet when they are provided simultaneously. Results of behavioral observation indicate that natural diets are more attractive than FD. In feeding experiment, Chinese shrimp has distinct selectivity on different diets. It positively selects CF and PW, negatively selects FF and SF, and excludes FD absolutely. The results of the present studies indicate that the dietary selectivity of shrimp was based not only on the attractabilities of the diets, but also on the responses such as growth and food conversion.
基金Sponsored by the National High Technology Research and Development Program 863(Grant No.2009AA04Z215)the National Natural Science Foundation of China(Grant No.60975071)the Fund for Basic Research from Harbin Engineering University(Grant No.002060260750)
文摘Foraging behavior in ant colonies has come to be viewed as a prototypical example to describe how complex group behavior can arise from simple individuals. In order to research the feature of self-organization in swarm intelligence (SI), a mean field model is given and analyzed in foraging process with three sources in this paper. The distance of trails and the richness of each source are considered. Both of the theoretical numerical analysis and Monte Carlo simulation show the power law relationship between the completion time and the flux of foragers. The work presented here guides a better understanding on self-organization and swarm intelligence. It can be used to design more efficient, adaptive, and reliable intelligent systems.
文摘Studying the ecology of ants can be a powerful tool for conservation, While the effect of logging is mainly investigated by the comparison of species richness and composition, the impact on individual species are often neglected. This study investigated the effect of selective logging on the nest density, foraging range and colony size on the ground-dwelling ant Aphaenogaster swammerdami in Kirindy forest--Madagascar. This ant is a common ground-dwelling species in Kirindy, a western dry deciduous forest of Madagascar. Sampling was done in two sites of the forest: One part that was selectively lodged and another that have not been logged. Here we show that selective logging led to a decrease in colony size and density, while the foraging range seemed to be unaffected. Higher desiccation stress and lower food availability in the logged forest are most likely to be responsible for these results.
文摘Goat satisfying energy requirements of goat are determined by anatomical body and browse leaves. In High Bassin zone of Mandrare in Southern Madagascar, sampling area of 400 m^2 has been monitored to analysis floristic diversity and Shannon-Weaver index and to establish rangeland typology. With one ram, two castrated goats and three ewes, foraging behaviour, bite rate and forage nutritive value were analyzed in native pastureland during six days at two browsing periods. As results, four pastureland groups were classified with dominant shrubs plants Acacia farnesiana, Poupartia caffra, Kigelianthe madagascariensis and Rhigozum madagascariense. Rangelands sites have presented lower heterogeneity with floristic density (236-658 plants per hectare), Shannon-Weaver index (0.28-0.95), maximum diversity (1.04 ± 0.07) with P 〈 0.05. Most of 42 identified fodder plants presented significant difference (P 〈 0.05) and higher nutritive value (35-54% Dry Matter or DM); mineral matter (70-162 g·kg DM^-1); Crude Protein (124-175 g·kg DM^-1); Crude Fibre (203-376 g·kg DM^-1); Neutral Detergent Fiber (388-548 g·kg DM^-1) and gross energy (3617-4464 kcal·kg DM^-1). Acaciafarnesiana rangeland was overgrazed with 4.00 to 9.00 bites·mn^-1. In fact, relationships between phytosociology, nutritional parameters and foraging behaviour have been analyzed to improve with autochthonous plants and to manage rangeland in semi arid environment.