Read by QxMD icon Read


Mona Franziska Giersberg, Birgit Spindler, Nicole Kemper
The assessment of plumage and integument condition in laying hens provides useful information about the occurrence of feather pecking and cannibalism. Although feather loss and skin injuries can result from mechanical abrasion or clinical diseases, they are valid animal-based indicators for behavioural disorders. This particularly applies to damage on the back and tail region of the hens. The aim was to evaluate the behaviour of dual-purpose breeds (Lohmann Dual, LD) and conventional layer hybrids (Lohmann Brown plus, LB+), and to compare a mere visual assessment (Visual Scoring, VSc), with a method involving the handling of individual animals (Hands-on Scoring, HSc)...
December 12, 2017: Animals: An Open Access Journal From MDPI
Mika Kadoi, Kotaro Morimoto, Yasuoki Takami
While competing males and choosy females may be common in animal mating systems, male choice can evolve under certain conditions. Sexual cannibalism is such a condition because of the high mortality risk for males. In mantids, female body condition is associated with male mate preference, with fat females preferred, due to at least two reasons: females in poor nutritional condition are likely to attack and predate males, and fat females can potentially increase the number of offspring. Thus, the risk of cannibalism and female fecundity can influence male mating behavior...
2017: Journal of Ethology
James C O'Hanlon, Anne E Wignall, Marie E Herberstein
Male reproductive performance can vary with condition, age and future reproductive opportunities. Web-building spiders are ideal models to examine the effects of senescence on fitness-related behaviours due to strong selection on male courtship to reduce pre-copulatory sexual cannibalism. Argiope keyserlingi spiders generate courtship vibrations, or 'shudders', that reduce female aggression. We found that male A. keyserlingi courtship slowed with chronological age. Older males took longer to travel across the courtship thread, and overall number of shudders increased...
December 5, 2017: Die Naturwissenschaften
Xiaodong Zhu, Zhe Wang, Yue Wang, Bangyi Li
Remanufactured products offer better environmental benefits, and governments encourage manufacturers to remanufacture through various subsidy policies. This practice has shown that, in addition to product sales, remanufactured product can also achieve its value through social donation. Based on the remanufactured product value realization approaches, governments provide two kinds of incentive policies, which are remanufactured product sales subsidies and remanufactured product donation subsidies. This paper constructs a two-stage Stackelberg game model including a government and a manufacturer under two different policies, which can be solved by backward induction...
December 1, 2017: International Journal of Environmental Research and Public Health
Roger W Byard, Hamish Maxwell-Stewart
Alexander Pearce was an Irish convict incarcerated on Sarah Island on the west coast of Van Diemen's Land (modern day Tasmania, Australia) in 1822, following his transportation to the colony from the United Kingdom for seven years in 1819. On two occasions he escaped from the island, in September 1822 and again in November 1823, and was only able to survive the harsh conditions by killing and consuming his fellow escapees. Given that Pearce utilized the only sustenance that was at hand (i.e. his five companions), and that there was a temporal separation between the two episodes, this may represent a separate category of anthropophagy, that of serial opportunistic cannibalism...
November 29, 2017: Forensic Science, Medicine, and Pathology
Altea Calabuig, Apostolos Pekas, Felix L Wäckers
Generalist arthropod predators not only prey on herbivores but also may engage in competitive interactions by attacking and consuming conspecifics (cannibalism) or other predators (intraguild predation [IGP] and hyperpredation). These types of interactions are quite common among predators used in biological control. Although there is evidence that nonprey food relaxes cannibalism and IGP, there is little information regarding the impact of the quality of the nonprey food. Herein, we examined how pollen of different nutritional quality (pine, narrow-leaf cattail, or apple) impacted 1) the cannibalism by females of Euseius stipulatus (Athias-Henriot) (Acari: Phytoseiidae) on conspecific larvae, 2) the reciprocal predation between gravid females of E...
November 22, 2017: Journal of Economic Entomology
Viktor Nilsson-Örtman, Frank Johansson
How the ability to acclimate will impact individual performance and ecological interactions under climate change remains poorly understood. Theory predicts that the benefit an organism can gain from acclimating depends on the rate at which temperatures change relative to the time it takes to induce beneficial acclimation. Here, we present a conceptual model showing how slower seasonal changes under climate change can alter species' relative performance when they differ in acclimation rate and magnitude. To test predictions from theory, we performed a microcosm experiment where we reared a mid- and a high-latitude damselfly species alone or together under the rapid seasonality currently experienced at 62°N and the slower seasonality predicted for this latitude under climate change and measured larval growth and survival...
December 2017: American Naturalist
Thomas Schmickl, Istvan Karsai
We propose a new regulation mechanism based on the idea of the "common stomach" to explain several aspects of the resilience and homeostatic regulation of honeybee colonies. This mechanism exploits shared pools of substances (pollen, nectar, workers, brood) that modulate recruitment, abandonment and allocation patterns at the colony-level and enable bees to perform several survival strategies to cope with difficult circumstances: Lack of proteins leads to reduced feeding of young brood, to early capping of old brood and to regaining of already spent proteins through brood cannibalism...
2017: PloS One
R Preisinger
1. In commercial layer breeding, extensive gene pools are tested and selected for market requirements which must be anticipated at least five years ahead. Field results confirm a continuous positive genetic trend in egg output and better feed efficiency which can be converted into land savings. 2. Animal welfare and cage-free housing dominate future needs of the market. Nesting behaviour and minimal tendency to develop feather-pecking or cannibalism without beak treatment, are key trait complexes. Stronger shells for longer production cycles without moulting have to be combined with better bones...
November 13, 2017: British Poultry Science
Xinyi Jiang, Yao Zhao, Qian Yan, Changchun Li, Qinghong Jiang, Yueli Yun, Yu Peng
According to sexual selection theory, age affects the preference of mate choice, and this preference ultimately influences the fecundity of the female. Pardosa pseudoannulata (Araneae: Lycosidae) is a valued predator in many cropping systems. By determining oviposition rate, egg hatching rate, and also the number and carapace width of the 2nd instar spiderlings of the F1 generation, we explored the effects of age on fecundity of the female spider. There were no significant effects of age on courtship duration, sexual cannibalism rate, mating rate, oviposition rate, egg hatching rate, or the number and carapace width of 2nd instar spiderings of P...
November 3, 2017: Behavioural Processes
Inga C Christiansen, Peter Schausberger
Animals are commonly exposed to multiple environmental stimuli, but whether, and under which circumstances, they can attend to multiple stimuli in multitask learning challenges is elusive. Here, we assessed whether simultaneously occurring chemosensory stimuli interfere with each other in a dual-task learning challenge. We exposed predatory mites Neoseiulus californicus early in life to either only conspecifics (kin) or simultaneously conspecifics (kin) and food (thrips or pollen), to determine whether presence of food interferes with social familiarization and, vice versa, whether presence of conspecifics interferes with learning the cues of thrips...
November 2017: Animal Behaviour
Lin Op de Beeck, Julie Verheyen, Robby Stoks
There is increasing concern that standard laboratory toxicity tests may be misleading when assessing the impact of toxicants, because they lack ecological realism. Both warming and biotic interactions have been identified to magnify the effects of toxicants. Moreover, while biotic interactions may change the impact of toxicants, toxicants may also change the impact of biotic interactions. However, studies looking at the impact of biotic interactions on the toxicity of pesticides and vice versa under warming are very scarce...
October 26, 2017: Environmental Pollution
Alexandre N Maria, Alexandre Ninhaus-Silveira, Laura H Orfão, Ana T M Viveiros
The aim of this study was to describe, for the first time, the embryogenesis and larval growth of the Paraitinga Brycon nattereri Günther, 1864 reared in captivity. After artificial fertilization, eggs were incubated at constant temperature (~19°C) and collected every 15 min during the first 3 h and then every 3 h until hatching. Five larvae were collected daily over 15 days for evaluation of the length, yolk sac volume and specific growth rate. The following stages of embryonic development were identified: zygote, cleavage, gastrula, segmentation and larval...
October 30, 2017: Zygote: the Biology of Gametes and Early Embryos
Margrethe Brantsæter, Janicke Nordgreen, Tone B Hansen, Karianne Muri, Ane Nødtvedt, Randi O Moe, Andrew M Janczak
Feather pecking, toe pecking, cannibalism, smothering, social clumping, hens laying eggs outside the nest boxes, and reduced feather quality are examples of problem behaviors and consequences reported by egg producers. The aim of this study was to identify rearing- and production-related risk factors associated with producer-reported problem behaviors in Norwegian layer flocks. Questionnaires were distributed to 410 egg producers nationwide, and 120 producers responded to the survey (response rate 29%). After exclusion of data that did not comply with the instructions, the final dataset included 78 flocks (19%)...
October 25, 2017: Poultry Science
Michael P Moore, Cassandra Lis, Ryan A Martin
Organisms with complex life cycles commonly exhibit adaptive plasticity in the timing of transitions between life stages. While the threat of predation is predicted to induce earlier transitions, empirical support has been equivocal. When predation risk affects both the propensity to transition to the next life stage and the ability to reach the energetic thresholds necessary to complete the transition, only those individuals in the best physiological condition may be able to accelerate development and emerge earlier...
October 25, 2017: Ecology
Mini Singh, Isabelle Ruhnke, Carolyn de Koning, Kelly Drake, Alan G Skerman, Geoff N Hinch, Philip C Glatz
Baseline information on demographics and practices on semi-intensive free-range egg farms with an outdoor stocking density of ≤1500 hens/hectare in Australia is presented. Free-range egg production is changing the structure of the egg industry in Australia and a broad variety and tiers of free-range systems have emerged due to lack of concrete legislative standards on outdoor stocking densities in the past. Information was extracted from a pre-existing online free-range poultry survey dataset, consisting of a total of 79 questions related to nutrition, pasture management, welfare and health, animal housing, environmental impact and economics...
2017: PloS One
György Barabás, Matthew J Michalska-Smith, Stefano Allesina
The stability of complex ecological networks depends both on the interactions between species and the direct effects of the species on themselves. These self-effects are known as 'self-regulation' when an increase in a species' abundance decreases its per-capita growth rate. Sources of self-regulation include intraspecific interference, cannibalism, time-scale separation between consumers and their resources, spatial heterogeneity and nonlinear functional responses coupling predators with their prey. The influence of self-regulation on network stability is understudied and in addition, the empirical estimation of self-effects poses a formidable challenge...
October 23, 2017: Nature Ecology & Evolution
Benjamin J Toscano, Vincent Hin, Volker H W Rudolf
Predators often exert strong top-down regulation of prey, but in many systems, juvenile predators must compete with their future prey for a shared resource. In such life-history intraguild predation (LHIGP) systems, prey can therefore also regulate the recruitment and thus population dynamics of their predator via competition. Theory predicts that such stage-structured systems exhibit a wide range of dynamics, including alternative stable states. Here we show that cannibalism is an exceedingly common interaction within natural LHIGP systems that determines what coexistence states are possible...
November 2017: American Naturalist
John Orrock, Brian Connolly, Anthony Kitchen
Plants are attacked by myriad herbivores, and many plants exhibit anti-herbivore defences. We tested the hypothesis that induced defences benefit tomato plants by encouraging insects to eat other members of their species. We found that defences that promote cannibalism benefit tomatoes in two ways: cannibalism directly reduces herbivore abundance, and cannibals eat significantly less plant material. This previously unknown means of defence may alter plant-herbivore dynamics, plant evolution and pathogen transmission...
August 2017: Nature Ecology & Evolution
Hui-Siang Tee, Chow-Yang Lee
Many female parasitoid wasps optimize host selection to balance the benefits of high-quality hosts and the costs of predator- or hyperparasitoid-induced mortality risks to maximize their fitness. Cannibalism exists in many insect species and affects survival of parasitoid larvae developing in or on parasitized hosts. However, little is known about how parasitoid wasps resolve the fitness consequence of host cannibalism-induced mortality risk during host selection. We examined the effect of oothecal age on cannibalism in the American cockroach Periplaneta americana (L...
September 27, 2017: Journal of Economic Entomology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"