Urban ecosystems are evolutionarily recent novel environments acting as biodiversity filters.Psittacidae birds are considered successful urban adapters mainly due to their generalist feeding and opportunistic behavior...Urban ecosystems are evolutionarily recent novel environments acting as biodiversity filters.Psittacidae birds are considered successful urban adapters mainly due to their generalist feeding and opportunistic behavior,allowing them to occupy environments from cold temperate to dry xeric areas.Therefore,it is important to understand how these species interact in the urban environment.We studied the interannual(2013–2016)abundance of the White-fronted Parrot(Amazona albifrons)in the Neotropical cities of Xalapa and Coatepec,in Central Veracruz,México.Additionally,we studied the feeding ecology during 13 months of 6 parrot species detected in the city of Xalapa.The abundance of the White-fronted Parrot was significantly higher in Xalapa than in Coatepec,and it was homogeneous across years.Non-native plants represented 30–41%of Psittacidae diets in Xalapa,where seeds were the most commonly consumed resource.We recorded the highest Psittacidae species richness and highest diet overlap among species by the end of the dry season(April–May).The White-fronted Parrot had the highest plant richness in its diet,followed by the Monk Parakeet(Myiopsitta monachus)and the Green Parakeet(Psittacara holochlorus);yet,the White-fronted Parrot had a specialized diet dominated by two plant species(Grevillea robusta and Ficus aurea).The diet overlap among the three above-mentioned parrot species was not significantly different to a null model,where the White-fronted Parrot and the Monk Parakeet overlapped during the months of February,April,June,and September.The White-fronted Parrot is an urban adapter that has successfully expanded its geographic range via natural means and by human activities.The invasive Monk Parakeet is currently restricted to one park in Xalapa,and it has remained in that stage for many years(i.e.,pre-expansion phase).Exotic plant species in Xalapa represent∼55%of the woody vegetation,some of which have longer flowering and fruiting periods that may have aided the successful establishment of parrot species in urban environments.展开更多
Robots have primarily been developed for warfare, yet they also serve peaceful purposes. Their use in ecology is in its infancy, but they may soon become essential tools in a broad variety of ecological sub-discipline...Robots have primarily been developed for warfare, yet they also serve peaceful purposes. Their use in ecology is in its infancy, but they may soon become essential tools in a broad variety of ecological sub-disciplines. Autonomous robots, in particular drones sent to previously inaccessible areas, have revolutionized data acquisition, not only for abiotic parameters, but also for recording the behavior of undisturbed animals and collecting biological material. Robots will also play an essential role in population ecology, as they will allow for automatic census of individuals through image processing, or via detection of animals marked electronically. These new technologies will enable automated experimentation for increasingly large sample sizes, both in the laboratory and in the field. Finally, interactive robots and cyborgs are becoming major players in modern studies of animal behavior. Such rapid progress nonetheless raises ethical, environmental, and security issues.展开更多
Competitive systems defined by Lotka-Volterra equations where ri>0, aij>0, have been extensively studied in the literature. Much attention has been drawn to, among other things, the non-periodic oscillation phen...Competitive systems defined by Lotka-Volterra equations where ri>0, aij>0, have been extensively studied in the literature. Much attention has been drawn to, among other things, the non-periodic oscillation phenomenon, or May-type trajectory as it is called by some authors, since the discovery of that kind of trajectories in competitive LotkaVolterra systems made by May and Leonard[2] . Recently, the same phenomenon was reported to be existing in prey-predator systems. In this paper it is clear that one can expect the appearance of such phenomenon in a broader class of Lotka-Volterra systems, namely quasi-competitive systems (i.e. ri >0, (aij/ajj)+(aji/aii)>0 in (I)), which cover both competitive and some prey-predator systems in addition to others. Conditions are established in terms of the parameters of the systems for the existence of stable equilibrium, periodic oscillation and non-periodic oscillation.展开更多
基金supported by the Consejo Nacional de Ciencia y Tecnologia (CONACYT) who provided study grant (450578) to CA-C to conduct her master’s studies at INECOLsupported by CONACYT program Problemas Nacionales project number 2015-01-1628
文摘Urban ecosystems are evolutionarily recent novel environments acting as biodiversity filters.Psittacidae birds are considered successful urban adapters mainly due to their generalist feeding and opportunistic behavior,allowing them to occupy environments from cold temperate to dry xeric areas.Therefore,it is important to understand how these species interact in the urban environment.We studied the interannual(2013–2016)abundance of the White-fronted Parrot(Amazona albifrons)in the Neotropical cities of Xalapa and Coatepec,in Central Veracruz,México.Additionally,we studied the feeding ecology during 13 months of 6 parrot species detected in the city of Xalapa.The abundance of the White-fronted Parrot was significantly higher in Xalapa than in Coatepec,and it was homogeneous across years.Non-native plants represented 30–41%of Psittacidae diets in Xalapa,where seeds were the most commonly consumed resource.We recorded the highest Psittacidae species richness and highest diet overlap among species by the end of the dry season(April–May).The White-fronted Parrot had the highest plant richness in its diet,followed by the Monk Parakeet(Myiopsitta monachus)and the Green Parakeet(Psittacara holochlorus);yet,the White-fronted Parrot had a specialized diet dominated by two plant species(Grevillea robusta and Ficus aurea).The diet overlap among the three above-mentioned parrot species was not significantly different to a null model,where the White-fronted Parrot and the Monk Parakeet overlapped during the months of February,April,June,and September.The White-fronted Parrot is an urban adapter that has successfully expanded its geographic range via natural means and by human activities.The invasive Monk Parakeet is currently restricted to one park in Xalapa,and it has remained in that stage for many years(i.e.,pre-expansion phase).Exotic plant species in Xalapa represent∼55%of the woody vegetation,some of which have longer flowering and fruiting periods that may have aided the successful establishment of parrot species in urban environments.
基金funded by CNRS and by the French Polar Institute IPEV(Grants 137 to YLM,333 to TB and 388 to DG).
文摘Robots have primarily been developed for warfare, yet they also serve peaceful purposes. Their use in ecology is in its infancy, but they may soon become essential tools in a broad variety of ecological sub-disciplines. Autonomous robots, in particular drones sent to previously inaccessible areas, have revolutionized data acquisition, not only for abiotic parameters, but also for recording the behavior of undisturbed animals and collecting biological material. Robots will also play an essential role in population ecology, as they will allow for automatic census of individuals through image processing, or via detection of animals marked electronically. These new technologies will enable automated experimentation for increasingly large sample sizes, both in the laboratory and in the field. Finally, interactive robots and cyborgs are becoming major players in modern studies of animal behavior. Such rapid progress nonetheless raises ethical, environmental, and security issues.
文摘Competitive systems defined by Lotka-Volterra equations where ri>0, aij>0, have been extensively studied in the literature. Much attention has been drawn to, among other things, the non-periodic oscillation phenomenon, or May-type trajectory as it is called by some authors, since the discovery of that kind of trajectories in competitive LotkaVolterra systems made by May and Leonard[2] . Recently, the same phenomenon was reported to be existing in prey-predator systems. In this paper it is clear that one can expect the appearance of such phenomenon in a broader class of Lotka-Volterra systems, namely quasi-competitive systems (i.e. ri >0, (aij/ajj)+(aji/aii)>0 in (I)), which cover both competitive and some prey-predator systems in addition to others. Conditions are established in terms of the parameters of the systems for the existence of stable equilibrium, periodic oscillation and non-periodic oscillation.
