A chronological assessment of foraging activities of the Cotton Pigmy Goose,Nettapus coromandelianus Gmelin, 1789 at Dulahara pond,Ratanpur, Chhattisgarh,India

This study was planned to assess the foraging activity of ecological important avian species the N. coromandelianus at Dulahara pond of Ratanpur, Chhattisgarh. In present work we observed the effect of “time of the day” and “photoperiod” on daytime foraging activities of N. coromandelianus. The most applied foraging skills of N. coromandelianus were documented for two repetitive days each for the period of long days (March and April 2015) and short days (December 2015 and January 2016). One-way ANOVA (by SPSS 16.0) was employed to observe the effects of “photoperiod” and “time of the day” on daytime foraging pattern in order to the frequency of foraging techniques. The rhythms in daytime foraging movement were estimated by means of Cosinor rhythmometry at 24 h and 12 h. The current study clarified that the N. coromandelianus mostly applied three main techniques viz., head and neck dipping, diving and striking on which both the diving and striking were the most employed technique while the head and neck dipping was less employed technique during foraging. Moreover, the N. coromandelianus maximally involved for foraging activities during the short day than long day.     

A circadian rhythm influencing foraging behaviour in the saw-toothed grain beetle Oryzaephilus surinamensis

ABSTRACT. Adults of Oryzaephilus surinamensis (L.) (Coleoptera, Silvanidae) placed in an open arena containing a refuge showed a cyclic pattern of activity in light, dark (LD) cycles when food in the form of damaged wheat grains was placed in the arena outside the refuge. Placing food in the refuge reduced cyclic change and lowered the general activity of the beetles. Batches of fifty insects conditioned in LD 9:15 h or 15:9 h at 25°C , 65% r.h., and transferred to continuous darkness (DD) at the end of a photophase, showed a circadian rhythm of foraging activity of periodicity near 24 h. Those transferred to continuous light at the end of a scotophase showed a 6 h delay in the onset of the next peak of activity, but subsequent peaks, although damped, revealed a periodicity near that in DD. The mean number of beetles wandering in the arena ranged from about eight in LD 15:9 h with all food in the refuge to about twenty-one in LD 9:15 h with all food in the arena.     

Growth and behaviour of six species of amphibian larvae in a winter pond in Israel

The effect of different ecological niches on growth and behaviour of larvae of four frogs (Bufo viridis, Hyla arborea, Pelobates syriacus, Rana ridibunda), and two salamanders (Salamandra salamandra and Triturus vittatus) found in a winter pond was studied. S. salamandra, T. vittatus, R. ridibunda and B. viridis were found most of the time on the bottom of the pond. However, H. arborea tadpoles were found throughout the pond and were usually sedentary, as compared with P. syriacus which moved up and down constantly. S. salamandra, T. vittatus, R. ridibunda and R viridis tadpoles from the bottom of the pond grew faster than the tadpoles from the surface of the pond. However, tadpoles of H. arborea and P. syriacus growing at the bottom or on the surface developed at similar rates.The invertebrate biomass increases during the summer and was higher at the bottom of the pond than at the surface. However the amount of chlorophyll a was about the same at the surface and at the bottom of the pond. S. salamandra and T. vittatus tadpoles feed on various types of of invertebrates, R. ridibunda and H. arborea and B. viridis tadpoles feed on vascular plants and algae, and P. syriacus tadpoles feed on both invertebrates and plants.     

鄱阳湖滨藕塘生境中白鹤取食行为研究

2016年12月—2017年2月和2017年12月—2018年1月,采用焦点动物法对鄱阳湖滨藕塘生境中白鹤(Grus leucogeranus)的取食行为进行观察,共记录921只次成鹤和547只次幼鹤的取食行为。结果表明,白鹤栖息水深为(17.29±8.75)cm(n=1468),取食水深为(18.84±10.32)cm(n=600),单次取食持续时间为(3.10±1.69)s(n=600),取食频次为(12.24±3.89)次/min(n=1012),取食成功频次为(1.78±1.59)次/min(n=1468),取食成功率为(16.26±14.41)%(n=1012)。成鹤取食成功频次(SymbolcA@~2=70.797,df=1,P=0.000)和取食成功率(SymbolcA@~2=5.356,df=1,P=0.020)均显著高于幼鹤,表明成鹤取食能力较幼鹤强,成鹤可以获得更多的能量。成鹤除维持自身能量支出外,还需要花费较多的能量用于辅食和警戒行为。成幼鹤的取食频次和单次取食持续时间无显著差异,这与成幼鹤的体型大小、能量需求和体内氧气储存量类似有关,也与多数研究认为幼鹤觅食经验不足,觅食成功率低,需要靠多次取食来补偿能量的观点不同。成鹤取食水深极显著高于幼鹤(SymbolcA@~2=50.945,df=1,P0.0001),这可能与体型和取食经验有关。不同栖息水深下白鹤的取食成功率(SymbolcA@~2=15.297,df=4,P=0.004)和取食成功频次(SymbolcA@~2=23.155,df=4,P0.0001)均存在极显著差异。不同时段的取食频次、取食成功频次和取食成功率均无显著差异,这可能与藕塘生境中白鹤采取触觉取食有关。此外,白鹤昼间取食行为无明显节律性,因此昼间能量需求相似,取食参数没有显著差异。     

The foraging behaviour of a nectar feeding marsupial,Petaurus australis

Summary The foraging behaviour of non-flying nectar feeding mammals has been examined rarely. The exudivorous yellow-bellied glider (Petaurus australis) was observed to feed extensively (70% of the total feeding observation time) on the nectar of all species of Eucalyptus present at a site in southeastern Australia. Gliders harvested nectar, and presumably pollen also, whenever eucalypt flowers were available and selected trees with 2–3 times as many flowers as that on trees randomly selected along a transect. The abundance of flowering trees varied temporally and, at times when few flowering trees were present, gliders chose trees with fewer flowers than at times when flowering trees were abundant. When flowering trees were superabundant or scarce, there was no relationship between the number of flowers in a tree and the duration of visits by gliders. However, at intermediate levels of abundance, the amount of time a glider spent in a tree was related to the number of flowers in a tree. Gliders devoted 90% of the time outside their dens to foraging and the above relationship is suggested to reflect two foraging options which maximize net energy gain for different abundances of flowering trees. Although gliders spent considerable lengths of time in individual trees feeding, initial deposition of cross pollen when gliders first arrive in a tree may be substantial and thus, may provide significant amounts of outcrossing for these eucalypts.     

Learning in the nectar foraging behaviour of Helicoverpa armigera

Abstract .1. Learning may enable insects to obtain nectar from flowers more efficiently. Learning in nectar foraging has been shown primarily in studies of bees and butterflies. Here, learning is demonstrated in the nectar foraging behaviour of a noctuid moth, Helicoverpa armigera .
2. The present studies show that: (1) previous experience with a flowering host species increases the probability of that species being selected for nectar foraging, and (2) previous experience of a particular flower type (food source at bottom or top of the corolla tube) increases the likelihood of the food source being found when that flower type is being searched.
3. The implications of these findings for understanding the pattern of oviposition observed in wild populations of this important pest species are discussed.     

Effects of life phase and schooling patterns on the foraging behaviour of coral‐reef fishes from the genus Haemulon

During this study (December 2009 to December 2010), underwater visual surveys using the focal animal method were performed in the coastal reefs of Tamandaré, north‐eastern Brazil. The aim was to analyse the effects of the life phase (juvenile and adult) and schooling patterns (school and solitary) on the feeding behaviour (foraging rates and substratum preferences) of four species of the genus Haemulon (Haemulon aurolineatum, Haemulon parra, Haemulon plumieri and Haemulon squamipinna). PERMANOVA analysis (P < 0·05) indicated that ontogenetic changes and schooling patterns directly influence foraging behaviour. Schooling individuals had low foraging rates (mean ± s.d . = 2·3 ± 2·1 bites 10 min^?1) and mobility, usually remaining near the bottom; however, solitary fishes had high foraging rates (mean ± s.d . = 12·5 ± 4·6 bites 10 min^?1). Juveniles preferred feeding in the water column (75% of the total number of bites), whereas adults foraged mainly in sand (80%) and bare rock (20%). All four Haemulon species displayed similar patterns of feeding behaviour as well as preferences for foraging sites and display competition for food resources. In contrast, little is known about their habitat use and foraging behaviour over the diel cycle, particularly the newly settled and early juvenile stages.     

Olfactory feedback in the scent marking behaviour of foraging honeybees at the food source?

ABSTRACT. Raising or lowering the concentration of Nasonov scent around nectar gathering honeybees ( Apis mellifica ) had no influence on the following: duration of the scent fanning ('sterzeln') before drinking; duration of the sterzeln during drinking; time spent with the scent organ everted during drinking. The presence of citral at the food source also had no effect on any of the above durations. It is concluded that olfactory feedback is not involved in the control of this behaviour.     

Diving at the shallow end: Green turtle behaviour in near-shore foraging habitat

Green turtles Chelonia mydas of immature and adult size (n = 19, curved carapace length 49 to 118 cm) were equipped with time-depth recorders for short periods (≤ 7 d) to investigate diel and seasonal variation in diving behaviour. Research sessions were distributed over 2 years to cover seasonal variation in sea temperature from 14 °C to 30 °C. Diurnal dives were shallower and shorter than nocturnal dives, with diel patterns also evident in dawn and dusk peaks in occupation of depths within 1 m of the surface, elevated diurnal occupation of depths 1 to 2 m below the surface and elevated nocturnal occupation of depths > 2 m. Dive duration increased as sea temperature decreased, showing strong negative correlation by day and by night. Study turtles made resting dives that were 3 to 4 times longer in median duration, and six times longer in maximum duration, at cool temperatures than they were at warm temperatures, but there was no evidence of winter diapause or location shift to avoid cold water. The large majority of turtles spent 89 to 100% of their time at depths ≤ 5 m below the surface, three individuals did not exceed 3 m and the maximum depth recorded by any turtle was 7.9 m, although deeper water was available. Furthermore, the dive data indicated that study turtles collectively spent more than 80% of their time at charted (low tide) depths of 3 m or less, indicating that they consistently used the shallow margins of the bay where human activities tend to be concentrated, thereby potentially increasing their exposure to anthropogenic threats.     

Artificial light and season affects vertical distribution and swimming behaviour of post-smolt Atlantic salmon in sea cages

In winter, post-smolts of Atlantic salmon Salmo salar exposed to continuous additional light of different intensities (LL) in 14 m deep sea cages maintained a constant swimming speed in circular polarized schools with maximum fish density in the warmest water layers at 11 m depth. By contrast, fish exposed to natural light only (NL) ceased swimming at dusk, ascended from the warm layer to the thermocline c. 3 m depth and were more dispersed in the whole water column during the dark phase. In early spring, fish exposed to LL of medium (LL-MED) or high (LL-HIGH) light intensity ascended and maximum fish density was at 5 m depth. A similar ascent was delayed to late spring in both the low intensity group (LL-LOW) and the NL group, coinciding with a shift in maximum temperature to this depth. The advanced ascent in the LL-HIGH and LL-MED groups is interpreted as a light-induced shift in a seasonal rhythm of feeding motivation. In summer, most of the fish in all four treatment groups were observed in the warm and less saline 4 m surface layer. It is suggested that the seasonal and diel changes in vertical distribution of Atlantic salmon are related inversely to feeding motivation, with preferences for maximum temperature and darkness acting as modifying factors.     

Diel interactions between prey behaviour and feeding in an invasive fish, the round goby, in a North American river

1. We studied the diet of the invasive round goby (Neogobius melanostomus) on a diel basis in the Flint River, a warmwater stream in Michigan, U.S.A. Diet and available prey samples were collected seven times over a 24 h period in four consecutive months. The section of river studied lacked zebra mussels (Dreissena polymorpha), the primary prey of adult round gobies elsewhere in the Great Lakes region. 2. Diet changed on a diel basis with hydropsychid caddisfly and chironomid larvae predominating during the day, chironomid pupae dominating in the evening and heptageniid mayflies dominating at night. Simultaneous study of macroinvertebrate drift suggested that caddisfly and chironomid larvae were most likely picked from submerged rocks, chironomid pupae were most likely taken during their emergent ascent and mayflies were either captured from the drift or picked from rocks. 3. The Flint River lacks a diverse darter (Family: Percidae) and sculpin (Family: Cottidae) fauna and it appears that the round goby has occupied a generalised darter/sculpin niche. Our results indicate that round gobies have the potential to invade successfully riverine systems, particularly those lacking a diverse benthic fish assemblage.     

Demand-feeding behaviour and diel pattern of feeding activity in Oncorhynchus mykiss held under different photoperiod regimes

Demand-feeding behaviour was studied in Oncorhynchus mykiss held at 7–10°C in groups of 30 individuals, under a 16:8, 12:12 or 8 : 16 light : dark regime, using self-feeders connected to a computer. The daily food demand was variable between tanks from 1.5 to 5% of the body weight, the specific growth rate ranged between 1.4 and 2.6% of body weight increase per day, and the feed: gain ratio ranged between 0.84 and 3.17, regardless of the photoperiod length. More than 98% of the feeding demand occurred during the photophase, regardless of the photoperiod, with a main peak at dawn and an occasional peak at dusk.     

Diet of the black-headed heron Ardea melanocephala during the breeding season in South African grasslands

The diet of the black-headed heron was studied using analysis of pellets and prey remnants (225 prey items identified) collected from four sites in South African Highveld Grassland, transformed into cultivated fields. Small vertebrates comprised the staple food of chicks. Rodents were the most important vertebrate prey. Otomys irroratus comprised ca. 50% of the total biomass of vertebrate prey consumed. The diet was supplemented by small lizards, snakes, frogs and fishes. Grasshoppers, beetles, crabs and other arthropods were occasionally preyed upon.     

Synapse-specific changes in serotonin signalling contribute to age-related changes in the feeding behaviour of the pond snail, Lymnaea

This study utilised the pond snail, Lymnaea to examine the contribution that alterations in serotonergic signalling make to age-related changes in feeding. Age-related decreases in 5-HIAA levels in feeding ganglia were positively correlated with a decrease in the number of sucrose-evoked bites and negatively correlated with an increase in inter-bite interval, implicating alterations in serotonergic signalling in the aged phenotype. Analysis of the serotonergic cerebral giant cell (CGC) input to the protraction motor neurone (B1) demonstrated that fluoxetine (10–100 nM) increased the amplitude/duration of the evoked EPSP in both young and middle aged but not in old neurones, suggesting an age-related attenuation of the serotonin transporter. 5-HT evoked a concentration-dependent increase in the amplitude/duration of B1 EPSP, which was greater in old neurones compared to both young and middle aged. Conversely, the 5-HT-evoked depolarisation and conditional bursting of the swallow motor neurone (B4) were attenuated in old neurones, functions critical for a full feeding rhythm. The CGCs' ability to excite B1 was blocked by cinanserin but not by methysergide. Conversely, the CGC to B4 connection was completely blocked by methysergide and only partially by cinanserin suggesting that age-related changes may be receptor-specific. In summary, synapse-specific attenuation of the CGC-B4 connection and enhancement of the CGC-B1 connection would slow the swallow phase and maintain protraction, consistent with behavioural observations.     

Climatic determinants of diet and foraging behaviour in baboons

Baboons (Papio spp.) are characterised by a large degree of variation in foraging behaviour and dietary composition. Previous analyses have suggested that much of this can be traced to differences in ecological conditions between sites. The proximate mechanism underlying these relationships is assumed to be mediated via the impact of climatic conditions on food availability, and ultimately the impact that this has on dietary composition. This paper examines these relationships more explicitly. Data from 15 baboon populations were used to assess the relationship between foraging variables and dietary composition. Only feeding time showed significant relationships with dietary composition, with percentage of time spent feeding decreasing with proportion of fruit in the diet, and increasing with the proportion of subterranean items. No relationships were found between diet composition and moving time or day journey length, although significant relationships were found between these variables and group size. The proportions of feeding time spent feeding on fruit, subterranean items and leaves were functions of the ecological conditions experienced by that population, although no relationships were found for the percentage of feeding time devoted to flowers or animal material. The relationships between the proportion feeding time spent on fruits, leaves and subterranean items and ecological variables could be best explained through understanding the way in which bush and tree level vegetation respond to the climatic environment and the impact this has on fruit availability. In this respect, temperature and seasonality are the key climatic parameters. This provides good support for the idea that the proximate mechanism underlying the relationship between foraging time and ecological variables is mediated via the impact of the climatic environment on vegetation structure and food availability. Similar factors have been proposed to explain much of the geographic variation in species diversity, suggesting that these relationships have far wider relevance and may account for much of the observed geographical variation in mammalian behaviour.     

The development of the vermiculate pattern in the brow region of crania from Indian Knoll, Kentucky

A convoluted brow surface consisting of fine ridges, grooves, and depressions, first identified in ancient fossil hominids and termed the vermiculate pattern (VP), is often low in frequency and of moderate rugosity in crania of anatomically modern human populations. Burials at Indian Knoll, Kentucky, constitute an excellent series for study of the development of the VP, since cranial surfaces are usually well preserved, there are hundreds of immature and mature individuals previously assessed for age, and the VP is high in frequency and rugosity. While a surface pattern resembling a miniature VP is found on the supraorbital surface of all newborns, it is not found on any children age 2 or older. This newborn pattern is probably different in structure and origin from the adult VP. The smooth surface characteristic of children shows evidence of changing to the VP in some adolescents, but the fullest development of the VP occurs in adults. The VP continues to develop in rugosity into the fourth decade, especially in males. These observations indicate that the human VP is different in etiology from somewhat similar brow surfaces found sporadically in immature individuals of some species of nonhuman primates. Statements lumping all vermiculate bone surfaces as "fine cancellous bone" are premature. The human VP development shows no apparent relationship to phases of tooth eruption, as postulated for the appearance of areolar surfaces on brow ridges of immature non-human primates.     

Fire induced changes in the foraging behaviour of impala Aepyceros melampus in Lake Mburo National Park, Uganda

The impact of fire on the foraging behaviour of impala (Aepyceros melampus), was studied in the Lake Mburo National Park, Uganda. Two indices of foraging efficiency were used to establish differences in feeding behaviour in burnt and unburnt control areas. These are acceptable grass/browse abundance (AGA/ABA), expressed in terms of feeding time achieved per 50 steps and food ingestion rate (FIR), expressed as the cumulative percentage. Accumulation of above ground grass biomass was also measured in burnt and control areas. After burning, the grazing efficiency remains constant throughout the dry season, while the browsing time achieved per 50 steps decreases drastically. In the control areas AGA decreased with increasing length of the dry season while ABA increased. When expressed in terms of cumulative percentage (FIR), the results show a significant increase of 31% in foraging time spent grazing and a 24% decrease in foraging time spent browsing, in burnt areas. The results confirm the classification of impalas as intermediate or mixed feeders with a distinct preference for grass. Impala foraging patterns after burning are discussed and compared with investigations on the effect of burning on the behaviour of impalas and Buffon's kob (Kobus kob kob) in other areas of Africa.     

Observations on the intensity of diapause and cold tolerance in larvae from twelve populations and two reciprocal crosses of the Indian meal moth, Plodia interpunctella

ABSTRACT. The duration of diapause in larvae of Plodia interpunctella (Hübner) (Lepidoptera, Pyralidae) was assessed at 20°C in LD 11:13. Mean times from hatch to pupation for diapausing larvae from different populations ranged from 88 to 236 days. Most non-diapausing larvae pupated within 70 days at this temperature. Transferring diapausing larvae to 25°C and LD 9:15, or to 20°C and LD 15:9, 70 days after hatch reduced the subsequent mean time to pupation by 18–82% and 9–63% respectively. Only two population samples terminated diapause faster under LD 15:9 at 20°C than under LD 9:15 at 25°C. The mortality of diapausing larvae caused by 6- or 10-week exposures at 5, 7.5 or 10°C was generally less than 25%. Hybrids produced from a reciprocal cross between a temperate and a tropical African stock survived well. For other stocks there was some correlation between survival and diapause intensity. The low temperature regime which resulted in the greatest shortening of pupation time after return to the conditions used to induce diapause, did not always coincide with the temperature permitting the best survival. Results, however, indicate that some individuals of all stocks but one from the tropics are likely to survive in the U.K.