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1.
Results of comparative analysis of food selectivity patterns for two ecologically close hollow-nesting birds—red-breasted
flycatcher Ficedula parva (Muscicapidae) and Siberian tit Parus cinctus (Paridae)—according to the way of catching, the place of foraging and the daily activity in nestling feeding are considered. 相似文献
2.
The feeding and swimming behaviors of Pseudorasbora parva and Rasbora daniconius (Cyprinidae) with two different prey types (Daphnia pulex and Artemia salina) at different densities (0.5, 1, 2, 5, 10, or 25 per l) were studied after 36 h of food deprivation. Full satiation was defined
as the cumulative number of attacks performed until fish attain a constant attack rate which for P. parva was 425 and R. daniconius was 390 attacks. Initial feeding rates showed marked variation with prey availability. Feeding rates of fish in high prey
concentrations were higher at the beginning of the experiment and decreased faster than in low prey densities. Decreases in
the feeding rate at high prey densities were due to faster attainment of satiation. Feeding rates of fish across high prey
densities reached a steady level after satiation. Swimming speeds of fish were inversely proportional to prey density. Moreover,
the change in swimming speeds was directly related to the level of satiation. The ratios of the attack rate and the encounter
rate against prey density of both fish reveal that the search for prey triggered swimming and thereby feeding during the transition
from hungry to satiation. The findings of this study demonstrate that satiation plays an important role in fish foraging that
should be considered a significant factor in foraging analysis. 相似文献
3.
N. T. Dolganova N. V. Kolpakov V. I. Chuchukalo 《Russian Journal of Marine Biology》2008,34(7):482-489
The feeding interrelations and foraging of juvenile fish and shrimp were investigated in estuaries of Peter the Great Bay
in summer and fall 2006 and 2007. In total 3483 specimens were analyzed. The trophic spectra of 34 fish species and 3 shrimp
species were described for the first time. Three trophic groups were singled out depending on differences in diet compositions:
(i) detritophages (3 species of bitterlings—Acanthorhodeus sp., A. chankaensis and Rhodeus sericeus, redlip mullet Liza haematocheila and two species of shrimp-Palaemon macrodactylus and Crangon cf. septemspinosa); (ii) predators (lookup Culter alburnus and Amur catfish Silurus asotus); (iii) euryphages (28 fish species and the shrimp Palaemon paucidens). The detritus food chain was found to be the primary one in estuaries of Peter the Great Bay. Most of the species had two
peaks of feeding activity each day. Values of daily feeding rations were determined for 21 fish species; these varied from
1.6% to 8.0% of body weight. Similarity in diet composition was significant only for 10% of the species, which shows a low
level of competition for food in the community. 相似文献
4.
Charles Gowan 《Environmental Biology of Fishes》2007,78(4):317-331
Stream salmonids choose foraging locations to maximize the energy benefit of foraging within the constraints of size-mediated
dominance hierarchies and predation risk. But, because stream habitats are temporally variable, fish must use a search process
to monitor changing habitat conditions as a means of locating potentially-better foraging locations. I explored the cues used
by the cutthroat trout, Oncorhynchus clarki clarki, when searching for food at the pool scale by artificially increasing prey availability at different locations by using special
feeders and by manipulating pool velocities. Behavior of individually marked fish was monitored from stream bank platforms
under unmanipulated control conditions and under seven experimental sets of conditions involving different combinations of
feeder location and velocity manipulation. Under natural conditions fish elected to forage in the deepest (>50 cm), fastest
(0.10–0.25 m s−1) locations and within 1 m of structure cover, but would readily move to shallower (<30 cm) water away from cover if velocities
were manipulated to be highest there. Although fish did not locate feeders unless they were placed in high-velocity areas,
when high velocity was provided fish would move into very shallow water (<20 cm) if prey were delivered there. Responses of
individual trout to manipulations indicated that water velocity was the main physical cue used by fish to decide where to
forage, and that fish could also learn about new food sources by observing conspecifics. Overall, results indicated fish were
not “perfect searchers” that could quickly locate new food resources over short time scales, even when the new resources were
within a few meters of the fish’s normal foraging location. When given the correct cues, however, fish could detect new food
sources and defend them against subordinate fish. Movement of new fish into and out of the study pools during the ten-day
observation period was common, consistent with the idea that trout used movement as a means of exploring and learning about
habitat conditions at the reach scale. 相似文献
5.
Naoki Agetsuma 《International journal of primatology》1994,15(5):595-609
I investigated the activity budget and diet of Yakushima macaques (Macaca fuscata yakui,)in warm temperate broad- leaved forest of Yakushima, Japan. Both time spent feeding and time spent moving varied considerably
between half- months. However, total time spent in active behaviors— feeding time plus moving time— was stable. The composition
of the diet also showed considerable variation between half- months. The macaques fed mainly on fruits, seeds,mature leaves, fallen seeds, flowers, and young leaves, each of which accounted for more than 30% of feeding time in at least
1 half- month. They also ate insects and fungi, but each of them comprised ≤ 25 and ≤ 8% of feeding time in any half- month,
respectively. Time spent feeding on mature leaves, young leaves, flowers, or fallen seeds is positively correlated with total
time feeding and is negatively correlated with time moving. In contrast, time feeding on fruits, seeds, insects or fungi is
negatively correlated with time feeding and is positively correlated with time moving. Foraging on foods that have a low energy
content, a high density, and a relatively even distribution— mature leaves— or that need much manipulation to be processed—
flowers and fallen seeds— increased feeding time, while foraging on foods for which monkeys must search intensively in the
forest— fruits, seeds, insects, and fungi— led to increased moving time. I examined foraging strategies of Yakushima macaques
in terms of moving costs and the quality of food items. Regarding time feeding on fruits, which have more energy and may need
less manipulation than other foods, as a benefit, and moving time as a cost, they seemed to employ a strategy that balanced
the costs and benefits of foraging. 相似文献
6.
We test the hypothesis that size distribution of a Daphnia population reflects the vulnerability of each size category (instar) to predation by planktivorous fish. We hypothesize that
due to the different reaction distances from which separate prey categories can be seen by a foraging fish, each category
is preyed upon until its density is reduced and its size-specific apparent density level (number of prey within a hemisphere
of radius equal to the reaction distance) or encounter rate (number of prey encountered per time within a tube with a cross
section of radius equal to the reaction distance) become equal to those of other size categories. An experiment was performed
with populations of Daphnia hyalina and D. pulicaria grown at two Scenedesmus + Chlamydomonas food levels (0.2 and 0.05 mg C per liter) in outdoor mesocosms (1000 l tanks) with predation by invertebrates (phantom midge)
prevented by mosquito netting. Once the populations had become established, roach were added to the tanks at dusk each day
and allowed to feed for 3 h, while control tanks were kept fish-free. After 20–60 days, while D. pulicaria was at low density level, the densities of D. hyalina in fish tanks were high enough to see that the age structure and size distribution matched those from simulations with the
age-structured population model based on size-specific encounter rate. This match, however, remained only up to the point
of first reproduction when—in contrast to the size/age distribution predicted by the model—the percentage share of adult instars
in the total population decreased rapidly with age. This deviation from the predicted densities of adult instars suggests
that neither encounter rates nor apparent densities derived from instar-specific reaction distances are sufficient to explain
the instar-specific impact of a visual predator on planktonic prey. This implies that a foraging fish may temporarily change
its feeding mode from the typical low-speed harvesting of small but abundant prey from within its visual field volume, to
high-speed hunting for more scarce but larger ovigerous females when their abundance allows higher net energy gain. Shifting
from one feeding mode to the other may be responsible for damping population density oscillations in Daphnia. 相似文献
7.
8.
9.
Test of a digestion optimization model: effect of variable-reward feeding schedules on digestive performance of a migratory bird 总被引:1,自引:0,他引:1
Birds on migration often alternate between feeding and nonfeeding periods, in part because food resources may be patchily
distributed and in part because birds on migration may adopt a risk-prone foraging strategy characterized by selection of
variable rather than constant food rewards. Optimal digestion models predict that increases in intermeal interval like those
encountered by some migratory birds should result in longer retention time of digesta and higher digestive efficiency if birds
are maximizing their rate of energy intake. We tested these predictions by comparing residence time of digesta and extraction
efficiency of lipid for captive yellow-rumped warblers (Dendroica coronata) feeding adlibitum and when we added intervals of time when the birds received no food. We increased the likelihood that the warblers were maximizing
their rate of energy intake by increasing light levels during spring to induce hyperphagia (treatment birds (16L:8D light:
dark cycle) ate 2.13 ± 0.14 g dry food day−1 (n = 8) while control birds (10L:14D) ate 1.25 ± 0.03 g dry food day−1 (n = 6)). Treatment birds offered food only every other 2–3 h ate 50% more during the 4-h test period than when they were always
feeding adlibitum. Despite these differences in food intake, extraction efficiency of glycerol trioleate remained high and constant (93%),
and mouth-to-anus total mean retention time (TMRT) did not change (overall mean: 54.8 ± 6.0 min). Residence time of lipid
in the stomach increased whereas residence time of lipid in the intestine decreased when birds fed only every other 2–3 h
compared to when birds always fed ad libitum. None of the results were consistent with the predictions of the optimal digestion model unless we assume that birds were
minimizing their feeding time rather than maximizing their rate of energy gain. Furthermore, the ability of yellow-rumped
warblers to maintain high extraction efficiency with no change in TMRT suggests some spare digestive capacity when food intake
increases by as much as 50%.
Received: 14 June 1997 / Accepted: 20 November 1997 相似文献
10.
Dariusz Jakubas Lech Iliszko Katarzyna Wojczulanis-Jakubas Lech Stempniewicz 《Polar Biology》2012,35(1):73-81
During the chick-rearing period, little auks Alle alle adopt a bimodal foraging strategy, alternating long trips with several short ones. It has been postulated that they reach
more remote areas during long feeding trips than during short ones. However, the range of their foraging flights has never
actually been measured. The aims of this study were to find the exact location of the little auk feeding grounds and to investigate
whether they reach remote areas during long foraging trips using miniature GPS and temperature loggers. The study was conducted
in 2009 in Magdalenefjorden (79°34′N, 11°04′E), one of the main breeding grounds of little auks on Spitsbergen. The temperature
logger records indicated that during short trips, little auks visit warmer waters (situated close to the colony) than during
long ones. The tracks of two GPS-equipped birds indicated that during long trips little auks foraged in the distant, food-abundant
marginal sea ice zone, at least 100 km away from the colony. During long trips, birds make several stops at sea, perhaps sampling
the foraging area with respect to prey distribution. Since food conditions near the studied colony are usually suboptimal,
little auks may be exploiting distant feeding areas to compensate for the poorer-quality food available at nearby foraging
grounds. The extended duration of long foraging trips may enable birds to collect food for chicks on food-abundant, remote
foraging grounds as well as acquire, process and excrete food needed for self-maintenance, reducing the costs of flight to
the colony. 相似文献
11.
The chaenopsid blenny Acanthemblemaria spinosa occupies topographically high locations on coral reefs where flow speeds and turbulence are frequently greater than those
experienced by its congener, A. aspera, which occupies locations close to the reef surface. To investigate the adaptive mechanisms resulting in this microhabitat
differentiation, the foraging effort and success of these fishes were determined in laboratory flumes that produced flow conditions
approximating those experienced in the field. Individual fish were subjected to unidirectional (smooth and turbulent) and
oscillatory flows while they fed on calanoid copepods, Acartia tonsa, whose vulnerability to predation varies with water flow. In unidirectional flow both blenny species had their greatest foraging
success at intermediate flow speeds (ca. 10 cm s−1) and under turbulent flow. Under all conditions, Acanthemblemaria spinosa exhibited greater foraging effort and attacked at greater distances, greater mean water speeds, and in oscillatory flow,
over a greater proportion of the wave cycle than did A. aspera. A. spinosa also exhibited greater foraging success under turbulent flow conditions. These differences in feeding patterns allow A. spinosa, with its higher metabolic rate, to occupy the more energetic higher locations in corals where planktonic food is more abundant.
A. aspera occupies the poorer quality habitat in terms of planktonic food availability but its lower metabolic rate allows it to thrive
there. Consequently, these species divide the resource in short supply, i.e., shelter holes, based on their differing abilities
to capture prey in energetic water conditions in conjunction with their differing food energy requirements.
Communicated by Biology Editor Dr. Mark McCormick 相似文献
12.
Abstract The possible endogenous circadian rhythm in the feeding activity of rainbow trout (Oncorhynchus mykiss) was investigated using individual fish previously trained for self‐feeding. Under LD 12:12 conditions, the fish showed a diurnal behaviour, in many cases with a feeding rhythm with two main peaks of food demand at dawn and dusk, with an 8h interval of low feeding activity, and the actograms showed an expected 24 h rhythm. Fish kept under constant conditions (L : L, 15°±0.5°C), showed free‐running feeding activity for about 12 days. Food demands were concentrated at dawn, with a periodogram of 25.3 hour, under continuous environmental conditions. Results showed evidence for the endogenous origin of the circadian rhythm of feeding in this species. 相似文献
13.
We describe short-term changes in foraging behavior by wild Yakushima macaques (Macaca fuscata yakui),which inhabit a warm-temperate broad—leaved forest on Yakushima Island (30°N, 131°E), Japan. Rapid changes of dietary composition,
activity budget, and range use by the monkeys occurred from May to June, apparently associated with changes in the availability
of the fruit of Myrica rubraBefore the fruit ripened, monkeys spent less time moving and more time feeding on many species of leaves, which accounted
for 40% of feeding time. However, when M. rubrabegan to ripen, they fed intensively on the fruit, which accounted for three-fourths of feeding time,though the activity budget remained unaffected As fiuit of M. rubradecreased,the monkeys fed more on the fruit of other species and on insects, and spent more time moving at higher speeds. There marked
shifts in foraging pattern occurred within only two months. In terms of moving cost and dietary quality,Yakushima macaques shifted their foraging pattern according to the availability of M. rubrafrom a “low-cost, low-yield” strategy to a “low-cost, high-yield” strategy, and then to a more costly strategy. The ability
to make such rapid shifts in foraging pattern may allow the macaques to effectively use the highly variable food supply within
their small range. 相似文献
14.
Although there is accumulating evidence of growth-rate optimization by natural selection, the coevolution of growth rate and
risk-taking behavior has not been sufficiently documented. The Atlantic silverside fish, Menidia
menidia, displays countergradient variation in growth across a latitudinal gradient: genotypes from Nova Scotia (NS), for example,
grow in length twofold faster than those from South Carolina (SC). Past work has established that fast growth is adaptive
in northern climates, but the trade-off is poorer swimming performance and higher susceptibility to predators. We compared
escape behavior and willingness to forage under threat of predation among growth genotypes reared and tested under common-garden
conditions. When chased with a predator model, NS fish occupied shelter more quickly than SC fish. When food was supplied
after a chase, NS fish reemerged from the shelter much more quickly than SC fish and immediately commenced feeding, whereas
many SC fish displayed timid behavior and did not feed. When food was absent following a chase, however, NS fish remained
in the shelter longer than did SC fish and both displayed timid behavior. Hence, the fast-growing NS genotype was bolder than
SC fish in the presence of food, but shyer in the absence of food. These behaviors are adaptive given the physiological constraints
intrinsic to each genotype. Experiments on captive populations of silversides that had been artificially selected for fast
or slow growth confirmed that foraging behavior is genetically correlated with intrinsic growth rate, although in these trials
the fast-growth genotype was always more bold, regardless of food availability, as would be expected in the absence of predators.
We conclude that risk-taking foraging behavior coevolves adaptively with intrinsic growth rate in M. menidia. 相似文献
15.
Isotopic signatures, foraging habitats and trophic relationships between fish and seasnakes on the coral reefs of New Caledonia 总被引:1,自引:0,他引:1
A predator’s species, sex and body size can influence the types of prey that it consumes, but why? Do such dietary divergences
result from differences in foraging habitats, or reflect differential ability to locate, capture or ingest different types
of prey? That question is difficult to answer if foraging occurs in places that preclude direct observation. In New Caledonia,
amphibious sea kraits (Laticauda laticaudata and L. saintgironsi) mostly eat eels—but the species consumed differ between snake species and vary with snake body size and sex. Because the
snakes capture eels within crevices on the sea floor, it is not possible to observe snake foraging on any quantitative basis.
We used stable isotopes to investigate habitat-divergence and ontogenetic shifts in feeding habits of sympatric species of
sea kraits. Similarities in δ15 N (~10.5‰) values suggest that the two snake species occupy similar trophic levels in the
coral-reef foodweb. However, δ13C values differed among the eight eel species consumed by snakes, as well as between the two
snake species, and were linked to habitat types. Specifically, δ13C differed between soft- vs. hard-substrate eel species,
and consistently differed between the soft-bottom forager L. laticaudata (~ −14.7‰) and the hard-bottom forager L. saintgironsi (~ −12.5‰). Differences in isotopic signatures within and between the two sea krait species and their prey were consistent
with the hypothesis of habitat-based dietary divergence. Isotopic composition varied with body size within each of the snake
species and varied with body size within some eel species, reflecting ontogenetic shifts in feeding habits of both the sea
kraits and their prey. Our results support the findings of previous studies based on snake stomach contents, indicating that
further studies could usefully expand these isotopic analyses to a broader range of trophic levels, fish species and spatial
scales. 相似文献
16.
V. V. Napazakov 《Russian Journal of Marine Biology》2008,34(7):452-460
The food spectra, trophic statuses, and feeding interrelations of three most abundant benthic carnivorous fish species inhabiting
the Shelikhov Bay—the Pacific cod Gadus macrocephalus, the great sculpin Myoxocephalus polyacanthocephalus, and the Okhotsk sculpin M. ochotensis—are considered based on materials collected during the complex survey of the RV Professor Kaganovsky of the TINRO-Center, in September 2004. It was found that these species were facultative predators with wide food spectra.
The significance of prey objects in the diet of the Okhotsk sculpin was as follows: crustaceans, fish, and mollusks. Great
sculpin and Pacific cod preyed mostly on fish, then on crustaceans, and mollusks. Pacific cod ate equal proportions of fish
and decapods. All the species had age-related variability of diet. The potential competition of great sculpin and Okhotsk
sculpin for food was mitigated by the difference in the depths of their ranges, as well as by morphological (body size) and
behavioral peculiarities in the areas where their habitats overlapped, and in microecosystems. The most probable competition
was among Pacific cod 30–60 cm long and Okhotsk sculpin 20–50 cm in length, as well as among cod and great sculpins of all
sizes. 相似文献
17.
Katie Thomas Tom Hansen Deirdre Brophy Niall Ó Maoiléidigh Per Gunnar Fjelldal 《Journal of fish biology》2019,94(6):896-908
Salmo salar post-smolts were reared in seawater under controlled laboratory conditions for 12 weeks. The fish were exposed to three constant temperature treatments (15, 10.5 and 6°C) and four feeding treatments (constant feeding, food withheld for 7 days, food withheld for 14 days and food withheld intermittently for four periods of 7 days). Scale growth was proportional to fish growth across all treatments, justifying the use of scale measurements as a proxy for growth during the early marine phase. The rate of circuli deposition was dependant on temperature and feeding regime and was generally proportional to fish growth but with some decoupling of the relationship at 15°C. Deposition rates varied from 4.8 days per circulus at 15°C (constant feeding) to 15.1 days per circulus at 6°C (interrupted feeding). Cumulative degree day (°D) was a better predictor of circuli number than age, although the rate of circuli deposition °D−1 was significantly lower at 6°C compared with 15 and 10.5°C. Inter-circuli distances were highly variable and did not reflect growth rate; tightly packed circuli occurred during periods without food when growth was depressed, but also during periods of rapid growth at 15°C. The results further current understanding of scale growth properties and can inform investigations of declining marine growth in S. salar based on interpretations of scale growth patterns. 相似文献
18.
The dependence of the mean mass (M) of great ramshorn (Planorbarius corneus) individuals on the number of individuals (N) that reached 82-days age in culture with constant conditions—water volume 50 ml, temperature 25°C, and redundant food (dandelion
leaves)—has been studied. The relationship between these parameters has been shown to be approximated by the equation M = 139/N mg. Consequently, at least in these conditions the total biomass of same-aged ramshorn individuals in the culture is relatively
constant and does not depend on the number of individuals in the population. 相似文献
19.
In this study we examined differences in feeding behevior of populations of the marine temperate herbivorous fish Aplodactylus punctatus, in three different localities off the Chilean coast, which differ qualitatively and quantitatively in food availability. We test whether food selection follows optimal foraging strategics, whether there is any modification of the fishes' digestive tracts in relation to their diets, and whether differences in diet quality affect the allocation of energy into reproduction and maintenance in these populations. Samples of this fish and of the understore algal assemblages were taken seasonally from May 1989 to February 1990. For each population we analyzed dietary composition, weight of the digestive tract and of the food content, the condition factor (K), and the gonadosomatic index (GSI). Our results showed that the diet observed in the three populations closely resembled the differences in macro-algal abundance and composition among the three localities studied. Local differences in diet quality were inversely related to the amount of food consumption and size of the digestive tract, suggesting that under differential conditions of food availability A. punctatus is able to compensate for variations in food quality through a flexibility in its digestive strategies. The nutritional status (K) of individuals, and their reproductive pattern (GSI) were directly related to diet quality. These results indicate that although A. punctatus is able to adjust its digestive processes to different algal food regimes, the digestive modifications observed in food-poor environments are not sufficient to compensate for the lack of food and allow fish to reach the nutritional status and reproductive output reached in a food-rich environment. This study represents the first natural experiment demonstrating a direct relationship among food availability, feeding patterns, digestive processes, and reproductive effort. 相似文献
20.
The ontogenetic niche concept predicts that resource use depends on an organism’s developmental stage. This concept has been
investigated primarily in animals that show differing resource use strategies as juveniles and as adults, such as amphibians.
We studied resource use and performance in the grasshopper Chorthippus parallelus (Orthoptera, Acrididae) provided with food plant mixtures of either one, three or eight plant species throughout their development.
C. parallelus survival and fecundity was highest in the food plant mixture with eight plant species and lowest in the treatments where
only one single plant species was offered as food. C. parallelus’ consumption throughout its ontogeny depended on sex, and feeding on different plant species was dependent on a grasshopper’s
developmental stage. To depict grasshopper foraging in food plant mixtures compared to foraging on single plant species, we
introduce the term “relative forage total” (RFT) based on an approach used in biodiversity research by Loreau and Hector (Nature
413:548–274, 2001). RFT of grasshoppers in food plant mixtures was always higher than what would have been expected from foraging
in monocultures. The increase in food consumption was due to an overall increase in feeding on plant species in mixtures compared
to consumption of the same species offered as a single diet. Thus we argue that grasshopper foraging exhibits complementarity
effects. Our results reinforce the necessity to consider development-related changes in insect herbivore feeding. Thorough
information on the feeding ontogeny of insect herbivores could not only elucidate their nutritional ecology but also help
to shed light on their functional role in plant communities.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献