The diet of ungulates is often characterized by low protein levels and the presence of indigestible and defensive compounds.It also often lacks micronutrients(vitamins and minerals)essential for growth,health and repr...The diet of ungulates is often characterized by low protein levels and the presence of indigestible and defensive compounds.It also often lacks micronutrients(vitamins and minerals)essential for growth,health and reproduction.Ungulates select rich plant organs to compensate for nutrient shortages and may consume soil,faeces and even bones.It is common for ungulates to incidentally ingest plant-dwelling insects(PDI)while feeding.It is well known that insects contain protein and essential nutrients that can feed livestock,potentially replacing conventional feed.Based on this,we propose the‘nutritional benefit of incidental ingestion'hypothesis,suggesting that ungulates may nutritionally benefit from ingesting PDI while foraging.Based on evidence from the literature on PDI ingestion by ungulates and on the nutritional properties of different insects,we discuss how and whether the ingestion of PDI while foraging might improve the nutrient balance of ungulates and recommend a set of controlled experiments to test it.We provide a new and unfamiliar dimension of nutritional ecology,which is relevant to various grazing ecosystems.We propose to modify“trivial”food web structures,as direct trophic interactions between ungulates and PDI may hold greater significance for ungulate performance and behaviour.展开更多
The aim of this work is to investigate the existence and non-existence of traveling wave solutions for a diffusive three-species intraguild predation model which means that one predator can eat its potential resource ...The aim of this work is to investigate the existence and non-existence of traveling wave solutions for a diffusive three-species intraguild predation model which means that one predator can eat its potential resource competitors. The method of upper-lower solution is implemented to show the existence of traveling wave solutions. In order to simplify the construction of an admissible pair of upper lower solution, the scheme of strictly con- tracting rectangle is applied. Finally, the minimal speed c＊ of traveling wave solutions of the model is characterized. If the wave speed is greater than c＊, we show the exis- tence of traveling wave solutions connecting trivial and positive equilibria by combining the upper and lower solutions with the contracting rectangle. On the other hand, if the wave speed is less than c＊, the non-existence of such solutions is also established. Furthermore, to illustrate our theoretical results, some numerical simulations are performed and biological meanings are interpreted.展开更多
文摘The diet of ungulates is often characterized by low protein levels and the presence of indigestible and defensive compounds.It also often lacks micronutrients(vitamins and minerals)essential for growth,health and reproduction.Ungulates select rich plant organs to compensate for nutrient shortages and may consume soil,faeces and even bones.It is common for ungulates to incidentally ingest plant-dwelling insects(PDI)while feeding.It is well known that insects contain protein and essential nutrients that can feed livestock,potentially replacing conventional feed.Based on this,we propose the‘nutritional benefit of incidental ingestion'hypothesis,suggesting that ungulates may nutritionally benefit from ingesting PDI while foraging.Based on evidence from the literature on PDI ingestion by ungulates and on the nutritional properties of different insects,we discuss how and whether the ingestion of PDI while foraging might improve the nutrient balance of ungulates and recommend a set of controlled experiments to test it.We provide a new and unfamiliar dimension of nutritional ecology,which is relevant to various grazing ecosystems.We propose to modify“trivial”food web structures,as direct trophic interactions between ungulates and PDI may hold greater significance for ungulate performance and behaviour.
文摘The aim of this work is to investigate the existence and non-existence of traveling wave solutions for a diffusive three-species intraguild predation model which means that one predator can eat its potential resource competitors. The method of upper-lower solution is implemented to show the existence of traveling wave solutions. In order to simplify the construction of an admissible pair of upper lower solution, the scheme of strictly con- tracting rectangle is applied. Finally, the minimal speed c＊ of traveling wave solutions of the model is characterized. If the wave speed is greater than c＊, we show the exis- tence of traveling wave solutions connecting trivial and positive equilibria by combining the upper and lower solutions with the contracting rectangle. On the other hand, if the wave speed is less than c＊, the non-existence of such solutions is also established. Furthermore, to illustrate our theoretical results, some numerical simulations are performed and biological meanings are interpreted.
