Feeding responses of carabid beetles to dimethoate-contaminated prey

1 The feeding responses of Pterostichus madidus Fab., P. melanarius Illiger and Nebria brevicollis Fab. (Coleoptera: Carabidae) to dimethoate-contaminated prey were investigated in 'no-choice' and 'choice' feeding tests. 2 In the no-choice tests, starved beetles were presented with aphid prey treated with four concentrations of dimethoate. In the choice tests, treated and untreated prey were presented together and the feeding preferences of the starved beetles observed. 3 No avoidance or rejection behaviour was seen in any of the carabids in either of the tests, i.e. no discrimination of the treated and untreated prey was observed. 4 Sufficient dimethoate was consumed with the aphid prey to cause significant mortality levels in the carabids. 5 The concentrations of dimethoate used in these experiments are comparable to field exposure, so carabids feeding in treated fields and field margins could potentially suffer lethal effects via the indirect exposure route of consuming contaminated prey.

Measuring the functional responses of farmland birds: an example for a declining seed-feeding bunting

1. Many farmland bird species have undergone significant declines. It is important to predict the effect of agricultural change on these birds and their response to conservation measures. This requirement could be met by mechanistic models that predict population size from the optimal foraging behaviour and fates of individuals within populations. A key component of these models is the functional response, the relationship between food and competitor density and feeding rate. 2. This paper describes a method for measuring functional responses of farmland birds, and applies this method to a declining farmland bird, the corn bunting Miliaria calandra L. We derive five alternative models to predict the functional responses of farmland birds and parameterize these for corn bunting. We also assess the minimum sample sizes required to predict accurately the functional response. 3. We show that the functional response of corn bunting can be predicted accurately from a few behavioural parameters (searching rate, handling time, vigilance time) that are straightforward to measure in the field. These parameters can be measured more quickly than the alternative of measuring the functional response directly. 4. While corn bunting violated some of the assumptions of Holling's disk equation (model 1 in our study), it still provided the most accurate fit to the observed feeding rates while remaining the most statistically simple model tested. Our other models may be more applicable to other species, or corn bunting feeding in other locations. 5. Although further tests are required, our study shows how functional responses can be predicted, simplifying the development of mechanistic models of farmland bird populations.

Did pterosaurs feed by skimming? Physical modelling and anatomical evaluation of an unusual feeding method

Similarities between the anatomies of living organisms are often used to draw conclusions regarding the ecology and behaviour of extinct animals. Several pterosaur taxa are postulated to have been skim-feeders based largely on supposed convergences of their jaw anatomy with that of the modern skimming bird, Rynchops spp. Using physical and mathematical models of Rynchops bills and pterosaur jaws, we show that skimming is considerably more energetically costly than previously thought for Rynchops and that pterosaurs weighing more than one kilogram would not have been able to skim at all. Furthermore, anatomical comparisons between the highly specialised skull of Rynchops and those of postulated skimming pterosaurs suggest that even smaller forms were poorly adapted for skim-feeding. Our results refute the hypothesis that some pterosaurs commonly used skimming as a foraging method and illustrate the pitfalls involved in extrapolating from limited morphological convergence.

Did pterosaurs feed by skimming? Physical modelling and anatomical evaluation of an unusual feeding method

Similarities between the anatomies of living organisms are often used to draw conclusions regarding the ecology and behaviour of extinct animals. Several pterosaur taxa are postulated to have been skim-feeders based largely on supposed convergences of their jaw anatomy with that of the modern skimming bird, Rynchops spp. Using physical and mathematical models of Rynchops bills and pterosaur jaws, we show that skimming is considerably more energetically costly than previously thought for Rynchops and that pterosaurs weighing more than one kilogram would not have been able to skim at all. Furthermore, anatomical comparisons between the highly specialised skull of Rynchops and those of postulated skimming pterosaurs suggest that even smaller forms were poorly adapted for skim-feeding. Our results refute the hypothesis that some pterosaurs commonly used skimming as a foraging method and illustrate the pitfalls involved in extrapolating from limited morphological convergence.

A double-blind, placebo-controlled, crossover-designed probiotic feeding study in children diagnosed with autistic spectrum disorders

There is growing interest in the role of gastrointestinal (GI) pathology and clinical expression of autism. Recent studies have demonstrated differences in the faecal clostridial populations harboured by autistic and non-autistic children. The potential of Lactobacillus plantarum WCSF1 (a probiotic) to modulate the gut microbiota of autistic subjects was investigated during a double-blind, placebo-controlled, crossover-designed feeding study. The faecal microbiota, gut function and behaviour scores of subjects were examined throughout the 12-week study. Lactobacillus plantarum WCFS1 feeding significantly increased Lab158 counts (lactobacilli and enterococci group) and significantly reduced Erec482 counts (Clostridium cluster XIVa) compared to placebo. Probiotic feeding also resulted in significant differences in the stool consistency compared to placebo and behaviour scores (total score and scores for some subscales) compared to baseline. The major finding of this work was the importance of study protocol in relation to the specific considerations of this subject population, with an extremely high dropout rate seen (predominantly during the baseline period). Furthermore, the relatively high inter-individual variability observed suggests that subsequent studies should use defined subgroups of autistic spectrum disorders, such as regressive or late-onset autism. In summary, the current study has highlighted the potential benefit of L. plantarum WCFS1 probiotic feeding in autistic individuals.

Feeding association between benthic and nektonic Neotropical stream fishes

A interação nuclear-seguidor tem sido raramente registrada entre peixes de riachos Neotropicais. Este tipo de associação foi observada em um riacho de cabeceira, no sistema do Alto rio Paraná envolvendo o cascudinho, Aspidoras fuscoguttatus, como espécie nuclear, e Knodus moenkhausii, Poecilia reticulata e Astyanax altiparanae como seus seguidores. Indivíduos de Aspidoras fuscoguttatus revolveram o substrato durante alimentação, promovendo a suspensão de sedimento. Os seguidores, por sua vez, movimentaram-se pela nuvem de partículas em suspensão, capturando itens alimentares. As particulas alimentares em suspensão parecem não ser utilizadas pelo cascudinho, mas tornam-se disponíveis para K. moenkhausii, P. reticulata e A. altiparanae. O comportamento de seguidor representa uma tática alimentar alternativa para estas espécies, reforçando a idéia geral de plasticidade comportamental entre as espécies seguidoras.

Plankton-feeding aggregation and occasional cleaning by adult butterflyfish, Chaetodon striatus (Chaetodontidae), in Southwestern Atlantic

Butterflyfishes of the genus Chaetodon (Chaetodontidae) are mostly bottom-feeders, and juveniles of some Pacific species are known to clean other fish, Herein we report on occasional cleaning by adult individuals of the Western Atlantic butterflyfish Chaetodon striatus, during their plankton-feeding aggregation, Four species of reef fish solicited cleaning to the butterflyfish amidst the aggregation.

Biology and behaviour of the neotropical ant-mimicking spider Aphantochilus rogersi (Araneae: Aphantochilidae): nesting, maternal care and ontogeny of ant-hunting techniques

Aphantochilus rogersi is an ant-mimicking spider that preys exclusively on cephalotine ants. The spiders oviposit in close proximity to nests of the model ant Zacryptocerus pusillus, and emergent spiderlings tend to remain in the vicinity of natal egg sacs. Females of A. rogersi actively defend their egg sacs against approaching workers of Z. pusillus, but the latter may sometimes destroy the eggs. Feeding specialization on these ants is confirmed by more than 300 observations of young and adult A. rogersi carrying ant corpses in the held. Although A. rogersi possesses several behavioural traits which may reduce the risk of being injured by ants during subjugation, field and laboratory observations showed that social defence by Z. pusillus may cause mutilation to the spiders. Tests in captivity revealed an ontogenetic change in the prey-capture techniques employed by A. rogersi. Early-instar spiderlings can apparently only seize the ant's petiole tightly if they are able to approach the ant from the front. As the ant is paralysed, the spiderling positions itself vertically in relation to the substratum. Larger spiders, on the other hand, attack ants most frequently from behind, and seem better equipped to seize the ant's petiole firmly with their larger chelicerae. Owing to their greater strength, late-instar spiders are able to Lift the struggling ant aloft. The selection of a suitable oviposition site, the mother's ability to defend herself and the eggs from nearby ants, and the capacity to capture and subdue ants safely from emergence to maturity, are regarded as crucial traits inherent in the mimetic and feeding specialization by A. rogersi.

Scent-marking behaviour in free-ranging golden-faced saki monkeys, Pithecia pithecia chrysocephala: Sex differences and context

Scent-marking behaviour of golden-faced saki monkey, Pithecia pithecia chrysocephala, was observed intermittently between 1987 and 1990 for a family group in a Central Amazonian forest fragment. of 95 scent-marking events (during 275.5 hours of observation), throat-and-chest rubbing accounted for all except one anogenital rubbing. Nine of the throat-and-chest markings also involved touching groin with hands and eight markings (including the anogenital), urinating on the marked branch. Marking behaviour is strongly sex related, with the adult male making 88.4% of the markings. Scent-marking frequency by the adult male increased during breeding periods. Scent-marking behaviour seems related to courtship, and possibly stimulates sexual behaviour. All regularly marked spots consisted of horizontal branches on commonly travelled routes. Eleven occurred in feeding trees and lianas, but none in sleeping trees. Scent-marking behaviour in the monkeys studied here was not related to intergroup encounters and probably did not have a territorial function, although it may do so where different groups interact.

Larval dispersal in Chrysomya megacephala, Chrysomya putoria and Cochliomyia macellaria (Dipt., Calliphoridae): Ecological implications of aggregation behaviour

In this study we investigate aggregated patterns as a consequence of post-feeding larval dispersal in three blowfly species, based on the frequency distribution of sampling units in the substrate having 0, 1, 2,..., n pupae. Statistical analysis revealed that aggregated patterns of distribution emerge as a consequence of larval dispersal, and Cochliomyia macellaria has higher levels of aggregation when compared to Chrysomya megacephala and C. putoria. Aggregation during dispersal is associated with a spatial pattern where most larvae in the species tend to pupariate near the food source. The possible consequences for the population ecology of these species are discussed.

Maternal offspring behaviour in curraleiro pé duro naturalized cattle in brazil

The objective of the present study consisted of describing dam and calf suckling behaviour of Curraleiro Pé Duro cattle. In this study, 38 mother-offspring pairs and one mother-offspring-orphan trio were observed for 10 hours daily during three consecutive days spaced every four months over a period of one year. After identification,theanimalswereobserved under field conditions where calf posture and the number of sucklingepisodes(NS),meansucklingduration(MSD),total suckling duration per day (TSD) as well as natural weaning of these animals were recorded. The model assessed the effects of calf sex and age as well as feeding time. Suckling episodes (70.6%) had a duration of one to five minutes and the calf that suckled in the inverted parallel position had greater chances of success during suckling (99.5%); the younger animals had a shorter mean suckling duration (4.0±0.6 minutes) than the older ones (7.5±1.2 minutes) but they showed a higher number of suckling episodes (6.29±1.00 vs. 1.33±0.04 feeds in 10 hours for young and older calves). Only the factor age in the firstthree months was significant for NS,MSD,and TSD;males and females had similar suckling episode length and distribution. While these animals show some traits similar to other cattle breeds such as feeding their calves early in the morning and late in the afternoon, the dams spend large periods of the day away from their calves and suckling is more frequent but for shorter periods of time compared with other breeds. Other unique features such as allo-suckling and formation of day-long crèches are observed in this breed. © 2013 Sociedade Brasileira de Zootecnia;.

Lecithotrophic behaviour in zoea and megalopa larvae of the ghost shrimp Lepidophthalmus siriboia Felder and Rodrigues, 1993 (Decapoda: Callianassidae)

A alimentação é considerada crítica em cultivo de larvas de decápodes. No entanto, algumas espécies podem apresentar reservas nutritivas suficientes para completar o desenvolvimento larval sem a necessidade de alimentação externa (conhecido como desenvolvimento larval lecitotrófico). No presente estudo, dois experimentos foram realizados para verificar se o callianassídeo Lepidophthalmus siriboia tem comportamento lecitotrófico ou se precisa de alimento externo para completar o desenvolvimento larval: Experimento 1, larvas submetidas a um período inicial de alimentação e, Experimento 2, larvas submetidas a um período inicial de inanição. Em ambos os experimentos, observou-se altas taxas de sobrevivência, com apenas 2 megalopas e 1 zoea III mortos. Estes resultados sugerem fortemente que larvas de L. siriboia são lecitotróficas, tendo reservas suficientes para completar o desenvolvimento larval, enquanto o estágio de megalopa apresenta lecitotrofia facultativa. Os períodos larvais de cada estágio nos tratamentos foram bastante semelhantes. No entanto, foram observadas algumas diferenças significantes entre alguns períodos, os quais podem estar relacionados às condições de cultivo, provavelmente devido a fatores abióticos, à variabilidade individual da condição larval, ou ainda a fatores como estresse causado às fêmeas ovígeras durante embriogênese.

The importance of feeding in the larval development of the ghost shrimp Callichirus major (Decapoda: Callianassidae)

O presente estudo investigou se o callianassid Callichirus major apresenta um comportamento lecitotrófico durante o desenvolvimento larval. Dois experimentos foram realizados. No primeiro experimento, larvas foram submetidas a um período inicial de alimentação, enquanto no segundo elas foram submetidas a um período inicial de inanição. No experimento 1, 80% das larvas de C. major mudaram com sucesso para o estágio de juvenil no tratamento com larvas alimentadas diariamente. Nos tratamentos com larvas alimentadas por 1, 2 e 3 dias, houve uma mortalidade total antes de alcançarem o estágio de megalopa. No experimento 2, as larvas zoés mostraram mais resistência quando submetidas a um período inicial de inanição. Nos tratamentos nos quais as larvas estiveram em inanição por 1, 2 e 3 dias, as taxas de sobrevivência foram100%, 60% e 90%, respectivamente. Porém atrasos na duração do desenvolvimento dos estágios de zoés foram observados. Houve mortalidade total para as larvas cultivadas no tratamento com ausência constante de alimento. Os resultados sugerem não existir um comportamento lecitotrófico nas zoés de C. major.

Feeding entrainment of locomotor activity and clock gene expression in Senegalese sole, Solea senegalensis

The present study was conducted to investigate the influence of restricted food access on Solea senegalensis behaviour and daily expression of clock genes in central (diencephalon and optic tectum) and pheripheral (liver) tissues. The Senegalese sole is a marine teleost fish belonging to the Class of Actinopterygii, Order Pleuronectiformes and Family Soleidae. Its geographical distribution in the Mediterranean sea is fairly broad, covering the south and east of the Iberian Peninsula, the North of Africa and Middle East until the coast of Turkey. From a commercial perspective Solea senegalensis has acquired in recent years, a key role in aquacolture industry of the Iberian Peninsula. The Senegalese sole is also acquiring an important relevance in chronobiological studies as the number of published works focused on the sole circadian system has increased in the last few years. The molecular mechanisms underlying sole circadian rhythms has also been explored recently, both in adults and developing sole. Moreover, the consideration of the Pleuronectiformes Order as one of the most evolved teleost groups make the Senegalese sole a species of high interest under a comparative and phylogenetic point of view. All these facts have reinforced the election of Senegalese sole as model species for the present study. The animals were kept under 12L:12D photoperiod conditions and divided into three experimental groups depending on the feeding time: fed at midlight (ML), middark (MD) or random (RND) times. Throughout the experiment, the existence of a daily activity rhythm and it synchronization to the light-dark and feeding cycles was checked. To this end locomotor activity was registred by means of two infrared photocells placed in pvc tube 10 cm below the water surface (upper photocell) and the other one was located 10 cm above the bottom of the tank (bottom photocell). The photocell were connected to a computer so that every time a fish interrupted the infrared light beam, it produced an output signal that was recorded. The number of light beam interruptions was stored every 10 minutes by specialized software for data acquisition.