scholarly journals Flexible Foraging Response of Wintering Hooded Cranes (Grus monacha) to Food Availability in the Lakes of the Yangtze River Floodplain, China

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 568
Author(s):  
Zhenhua Wei ◽  
Meng Zheng ◽  
Lizhi Zhou ◽  
Wenbin Xu
Keyword(s):  
Success Rate ◽  
Habitat Loss ◽  
Time Budget ◽  
Food Resources ◽  
Food Abundance ◽  
Foraging Strategies ◽  
Foraging Success ◽  
Habitat Differences ◽  
Grus Monacha ◽  
Foraging Time

Wetlands are disappearing or degrading at an unprecedented rate due to the increase in human encroachment and disturbance, eventually leading to habitat loss for waterbirds, which is the primary cause of the decline in the Hooded Crane (Grus monacha) population. The Hooded Cranes have to constantly adjust their foraging strategies to survive to cope with this situation. In order to study how cranes respond to food resources in mosaic habitat, we surveyed a total of 420 food quadrats and 736 behavioral samples from three habitats during three wintering periods in Shengjin Lake and Caizi Lake. We measured temporal and between-habitat differences in foraging time budget, foraging frequency, and foraging success rate. Akaike’s information criterion was selected between the models of food abundance and availability. The results indicated that the wintering cranes spent the majority of their time (66.55%) foraging and shifted their foraging behaviors based upon food abundance and availability in different habitats. Our analyses also indicated that cranes were willing to forage more food with poor sediment penetrability in sub-optimal habitats. Foraging time budget was based on the food depth, and the foraging frequency and foraging success rate were based on food abundance. Cranes adopted flexible foraging strategies in response to the alternative food resources in mosaic wetland habitats, as it could mitigate the negative impacts of habitat loss and facilitate survival.

scholarly journals Effects of Food Changes on Intestinal Bacterial Diversity of Wintering Hooded Cranes (Grus monacha)

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 433
Author(s):  
Nazhong Zhang ◽  
Lizhi Zhou ◽  
Zhuqing Yang ◽  
Jingjing Gu
Keyword(s):  
Bacterial Diversity ◽  
Seasonal Changes ◽  
High Throughput Sequencing ◽  
Negative Impact ◽  
Intestinal Bacteria ◽  
Food Resources ◽  
Foraging Strategies ◽  
Hooded Crane ◽  
Waterbird Species ◽  
Grus Monacha

As food is recognised as an important factor affecting the intestinal microbiota, seasonal changes in diet can influence the community composition. The hooded crane (Grus monacha) is an endangered migratory waterbird species, with some of the population wintering in the sallow lakes in the middle and lower Yangtze River floodplain. Their food resources have changed seasonally, with a reduction resulting from wetland degradation. To cope with seasonal changes in food availability, hooded cranes must constantly adjust their foraging strategies to survive. We studied the effect of changes in diet on the intestinal bacterial diversity of hooded cranes at Shengjin Lake, using faecal microanalysis and high-throughput sequencing. The results show that the main foods of hooded cranes were Polygonum criopolitanum, Oryza sativa, and Carex spp., which were significantly related to the composition of the intestinal bacterial community. In addition, foods available from the similar habitats were more similar, and the corresponding hooded crane intestinal bacteria were also more similar. The relative abundance of Lactobacillus acidipiscis in January and March was significantly higher than in November. Our research shows that the intestinal bacteria of hooded cranes actively adapt to diet changes to overcome the negative impact of the reduction in food resources, which is vital to the survival of hooded cranes.

scholarly journals An exploration of the relationship between recruitment communication and foraging in stingless bees

2021 ◽  
Author(s):  
Robbie I’Anson Price ◽  
Francisca Segers ◽  
Amelia Berger ◽  
Fabio S Nascimento ◽  
Christoph Grüter
Keyword(s):  
Stingless Bees ◽  
Sugar Content ◽  
Social Information ◽  
Food Resources ◽  
Food Sources ◽  
Foraging Strategies ◽  
High Quality ◽  
Recruitment Communication ◽  
Eusocial Bees ◽  
The Relationship

Abstract Social information is widely used in the animal kingdom and can be highly adaptive. In social insects, foragers can use social information to find food, avoid danger or choose a new nest site. Copying others allows individuals to obtain information without having to sample the environment. When foragers communicate information they will often only advertise high quality food sources, thereby filtering out less adaptive information. Stingless bees, a large pantropical group of highly eusocial bees, face intense inter- and intra-specific competition for limited resources, yet display disparate foraging strategies. Within the same environment there are species that communicate the location of food resources to nest-mates and species that do not. Our current understanding of why some species communicate foraging sites while others do not is limited. Studying freely foraging colonies of several co-existing stingless bee species in Brazil, we investigated if recruitment to specific food locations is linked to (1) the sugar content of forage, (2) the duration of foraging trips and (3) the variation in activity of a colony from one day to another and the variation in activity in a species over a day. We found that, contrary to our expectations, species with recruitment communication did not return with higher quality forage than species that do not recruit nestmates. Furthermore, foragers from recruiting species did not have shorter foraging trip durations than those from weakly-recruiting species. Given the intense inter- and intraspecific competition for resources in these environments, it may be that recruiting species favour food resources that can be monopolised by the colony rather than food sources that offer high-quality rewards.

Foraging Behavior of the Mealybug Parasitoid Anagyrus sp.nov. nr. sinope (Hymenoptera: Encyrtidae)

2007 ◽  
Vol 42 (4) ◽  
pp. 481-495 ◽  
Author(s):  
Juang-Horng Chong ◽  
Ronald D. Oetting
Keyword(s):  
Biological Control Agent ◽  
Oviposition Behavior ◽  
Time Budget ◽  
Handling Time ◽  
Control Agent ◽  
Adult Females ◽  
Defensive Behaviors ◽  
The Difference ◽  
Phenacoccus Madeirensis ◽  
Foraging Time

Anagyrus sp. nov. nr. sinope Noyes and Menezes (Hymenoptera: Encyrtidae) is a candidate biological control agent against the Madeira mealybug, Phenacoccus madeirensis Green (Hemiptera: Pseudococcidae). This study reported on the components of the oviposition behavior of Anagyrus sp. nov. nr. sinope in relation to 6 developmental stadia of P. madeirensis: crawlers, second-instar nymphs, third-instar immature females, third-instar immature males, prereproductive adult females, and ovipositing adult females. A behavioral sequence and a time budget were prepared for Anagyrus sp. nov. nr. sinope, indicating that the parasitoids foraging in a patch containing third-instar and prereproductive adult females had the highest probability to encounter and eventually parasitize a host. The parasitoids attacking third-instar and prereproductive adult females also spent the largest proportion of total foraging time in oviposition (67 and 69%, respectively) and had the longest handling time (997 and 655 sec per event, respectively). No third-instar immature males, which were wrapped in thick tests constructed of wax filaments, were parasitized by the parasitoids. Anagyrus sp. nov. nr. sinope did not avoid superparasitism. Parasitoids foraging in patches of third-instar and adult females had a higher self-superparasitism rate (27–33%) than crawlers and second-instar nymphs (8–14%). The clutch sizes in the superparasitized mealybugs were slightly larger than those in the mealybugs parasitized only once, but the difference was only significant in the ovipositing female P. madeirensis. Older and larger mealybugs exhibited more vigorous defensive behaviors by walking away and flipping abdomens. However, such behavioral defenses were not effective against the persistent parasitoids.

THE EFFECT OF HANDLING TIME ON INTERFERENCE AMONG HOUSE SPARROWS FORAGING AT DIFFERENT SEED DENSITIES

Behaviour ◽  
2001 ◽  
Vol 138 (5) ◽  
pp. 597-614 ◽  
Author(s):  
Cheryl Johnson ◽  
James W.A. Grant ◽  
Luc-Alain Giraldeau
Keyword(s):  
Group Size ◽  
Ideal Free Distribution ◽  
Passer Domesticus ◽  
Handling Time ◽  
Foraging Success ◽  
House Sparrows ◽  
Interference Models ◽  
Foraging Time ◽  
Ideal Free ◽  
The Ideal

AbstractInterference models of the ideal free distribution (IFD) assume competition among foraging animals causes intake rates to decline with increasing competitor density and that the strength of the decline influences forager distributions among food patches. However, the resulting distributions of animals may depend on which components of foraging success contribute to interference. We examined the effect of group size (1-13 birds) on the prey encounter rates, handling times, and foraging rates of house sparrows, Passer domesticus, feeding at three seed densities in a suburban backyard. House sparrows did not experience interference during search. Interference arose primarily from foraging time lost handling seeds. Foraging rates decreased with increasing seed density as a consequence of increased handling times. Also, birds experiencing significant increases in handling time with group size suffered most from interference. Our results suggest that animals adjust handling time to avoid costly aggressive interactions, indicating that handling time may be an important component of interference in some foraging systems. Future studies estimating interference should try to identify which components of foraging contribute to interference, paying particular attention to handling times for species that monitor and avoid competitors.

scholarly journals The Energetics of Feeding Territoriality in Juvenile Coho Salmon (Oncorhynchus Kisutch)

Behaviour ◽  
1985 ◽  
Vol 92 (1-2) ◽  
pp. 97-111 ◽  
Author(s):  
K.J. Puckett ◽  
L.M. Dill
Keyword(s):  
Coho Salmon ◽  
Time Budget ◽  
Total Activity ◽  
Search Costs ◽  
Net Energy ◽  
Free Swimming ◽  
Activity Budgets ◽  
Agonistic Activity ◽  
Activity Costs ◽  
Foraging Time

1. A foraging time budget was developed for territorial, nonterritorial, and floater fish. Territorial fish spend 76% of total time at the station, 3% free swimming, 13% feeding, and 5 % in agonistic activity. Floaters spend 18% of their time stationary swimming, 54% free swimming, 10% feeding, and 10% in agonistic activity. Nonterritorial fish spend 50% of their time stationary swimming, 43% free swimming, 2% feeding, and 3% in agonistic activity. 2. Stationary swimming tailbeat frequency for the floater (4.3) is significantly higher than for the territorial fish (3.6). The floater flight tailbeat frequency (8.2) is significantly higher than the territorial chase tailbeat frequency (6.9). Normal feed tailbeat frequencies are similar for all fish groups. Nonterritorial fish tend to move slowly (tailbeat frequency = 3.3) for all activities except normal feed. 3. The total activity budgets for territorial, floater, and nonterritorial fish are 1199, 1318, and 910 cal/kg/hr, respectively. The territorial fish uses 91 % as many calories as the floater fish and the nonterritorial fish utilizes 76% of the territorial budget. 4. Total agonistic costs represent 12 and 14% of the territorial and floater fish activity budgets, respectively. 5. The costs per feeding motion for the territorial, floater, and nonterritorial fish are 4.03, 4.91, 10.1 cal/motion, respectively. 6. The territorial fish has a net energy intake advantage over the floater, and probably over the nonterritorial fish, due to 1) reduced search costs, 2) reduced prey pursuit costs, and 3) reduced agonistic activity costs.

scholarly journals Diurnal feeding strategies of the Ferruginous Duck (Aythya nyroca) in Lake Tonga (Northeastern Algeria)

2019 ◽  
Vol 27 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Khalil Draidi ◽  
Badis Bakhouche ◽  
Naouel Lahlah ◽  
Imed Djemadi ◽  
Mourad Bensouilah
Keyword(s):  
Feeding Behaviour ◽  
Foraging Behaviour ◽  
Time Budget ◽  
Search Time ◽  
Environmental Parameters ◽  
Feeding Strategies ◽  
A Minor ◽  
Northeastern Algeria ◽  
Foraging Time ◽  
Minor Activity

Abstract Although the Ferruginous Duck (Aythya nyroca) has thoroughly been studied, the foraging behaviour of this species is still not completely known. In the present paper we studied the diurnal feeding behaviour of ducks. We monitored the annual cycle of birds through two fieldtrips per month. The instantaneous behaviour of birds was recorded in regular 30-minute intervals from 7 a.m. to 4:30 p.m., amounting a total of 456 observation hours. Food searching activity corresponds to a quarter of the total diurnal time budget of the Ferruginous Duck. Foraging behaviour was classified into five categories dominated by the “diving”, which is almost 45.61% of the total search time. Foraging activities at the water surface considered to be secondary activities, including feeding by “bill”, “neck and head”, and “beak and head” in a rate of 19.86%, 14.53%, and 13.98%, respectively. The “toggle” remains a minor activity and represents only 5.99% of foraging time. The feeding behaviour of this species correlated to several environmental parameters (rainfall, temperature and wind velocity), and linked to the group size of ducks visiting the lake. Regarding the food intensity, our results show the highest values for “bill and head” behaviour. “Diving” has the longest feeding interval (16.16±14.1 minutes), while foraging by “bill” has the shortest (0.69 ± 0.48 minutes).

Foraging success

2017 ◽  
Author(s):  
M.G.L. Mills ◽  
M.E.J. Mills
Keyword(s):  
Reproductive Cycle ◽  
Feeding Rate ◽  
Consumption Rate ◽  
Foraging Strategies ◽  
Foraging Success ◽  
Feeding Rates ◽  
Demographic Groups ◽  
Lactating Females

Foraging success for various demographic groups and females with different foraging strategies was measured by calculating overall and individual feeding rates in kg eaten/km moved. Overall and individual feeding rates were significantly higher for coalitions than single males. Females with large cubs had a significantly higher overall feeding rate than females at other times of their reproductive cycle, although lactating females had the highest individual feeding rate. Amongst females, springbok hunters had higher individual feeding rates than steenbok/duiker hunters or intermediates. However springbok hunting appeared to be energetically more costly. It would, therefore, seem that there are several strategies that female cheetahs can adopt in order to maximize foraging success. The overall mean consumption rate for all cheetahs in the southern Kalahari was calculated to be 3.0 kg/day.

scholarly journals Do solitary foraging nocturnal mammals plan their routes?

2011 ◽  
Vol 7 (4) ◽  
pp. 638-640 ◽  
Author(s):  
Marine Joly ◽  
Elke Zimmermann
Keyword(s):  
Cognitive Skills ◽  
Large Scale ◽  
Deciduous Forest ◽  
Brain Size ◽  
Social Systems ◽  
Route Planning ◽  
Movement Pattern ◽  
Food Resources ◽  
Foraging Strategies ◽  
Detection Distance

Large-brained diurnal mammals with complex social systems are known to plan where and how to reach a resource, as shown by a systematic movement pattern analysis. We examined for the first time large-scale movement patterns of a solitary-ranging and small-brained mammal, the mouse lemur ( Microcebus murinus ), by using the change-point test and a heuristic random travel model to get insight into foraging strategies and potential route-planning abilities. Mouse lemurs are small nocturnal primates inhabiting the seasonal dry deciduous forest in Madagascar. During the lean season with limited food availability, these lemurs rely on few stationary food resources. We radio-tracked seven lemurs and analysed their foraging patterns. First change-points coincided with out-of-sight keystone food resources. Travel paths were more efficient in detecting these resources than a heuristic random travel model within limits of estimated detection distance. Findings suggest that even nocturnal, solitary-ranging mammals with small brains plan their route to an out-of-sight target. Thus, similar ecological pressures may lead to comparable spatial cognitive skills irrespective of the degree of sociality or relative brain size.

Mechanisms driving postfire abundance of a generalist mammal

2012 ◽  
Vol 90 (1) ◽  
pp. 51-60 ◽  
Author(s):  
R. Zwolak ◽  
D.E. Pearson ◽  
Y.K. Ortega ◽  
E.E. Crone
Keyword(s):  
Forest Fires ◽  
Deer Mouse ◽  
Food Resources ◽  
Foraging Efficiency ◽  
Seed Removal ◽  
Foraging Success ◽  
Underlying Mechanisms ◽  
Source Sink ◽  
Resource Conditions ◽  
Predation Rates

Changes in vertebrate abundance following disturbance are commonly attributed to shifts in food resources or predation pressure, but underlying mechanisms have rarely been tested. We examined four hypotheses for the commonly reported increase in abundance of deer mouse ( Peromyscus maniculatus (Wagner, 1845)) following forest fires: source–sink dynamics, decreased predation, increased food resources, and increased foraging efficiency. We found that reproduction of deer mouse was considerably higher in burned versus unburned forests and survival did not differ between habitats, indicating that burned forests were not sink habitats. Comparable survival also suggested that predation rates were similar between habitats. Increased reproduction in burned versus unburned forest suggested better resource conditions, but abundance of seeds and arthropods (the primary food resources for mice) either did not differ between habitats or were higher overall in unburned forest. Foraging experiments indicated that seed removal from depots was substantially higher in burned versus unburned forests after controlling for mouse density. Additionally, in both habitats, mice were captured more often in open microhabitats and the odds of individual insect removal increased with decreasing cover during certain sampling periods. Of the four hypotheses tested, greater foraging efficiency provided the best explanation for elevated populations of deer mouse. However, predation risk may have influenced foraging success.

Aerial surveillance by a generalist seed predator: food resource tracking by Meyer's parrotPoicephalus meyeriin the Okavango Delta, Botswana

2010 ◽  
Vol 26 (4) ◽  
pp. 381-392 ◽  
Author(s):  
Rutledge S. Boyes ◽  
Michael R. Perrin
Keyword(s):  
Relative Abundance ◽  
Feeding Activity ◽  
Food Resource ◽  
Food Resources ◽  
Aerial Surveillance ◽  
Seed Predator ◽  
Resource Abundance ◽  
Resource Decisions ◽  
Landscape Level ◽  
Foraging Time

Abstract:As a proven food resource generalist, Meyer's parrot (Poicephalus meyeri) was expected to track the availability of all significant food resources in its diet over time. Here we recorded all feeding activity during 366 standardized road transects for correlation with an index of relative food resource abundance over 18 mo. As expected, Meyer's parrot made food resource decisions according to relative abundance at landscape level. Feeding activity on food resources available throughout the year (e.g. ripeKigelia africanafruit) or not visible from the air (e.g. unripeDiospyros lycoidesfruit), however, did not correlate significantly with fluctuations in their relative resource abundance. In addition, over 70% of all feeding bouts were in the high canopy and over 70% of all food items consumed formed bi-coloured displays. The influence of estimated protein and energy acquisition rates from different food resources was insignificant. Therefore, important selection criteria for utilization by Meyer's parrot include relative abundance and visibility from the air (i.e. food resources with the highest probability of encounter when dispersing from a central roost). Sensitivity to fluctuations in resource abundance at landscape level demonstrates the relative importance of maximizing net gain per unit foraging time by minimizing foraging flight distance.

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