RIASSUNTO-In due aree della città di Brescia si è accertata la presenza non occasionale di Cornacchiegrigie.Queste aree sono localizzate a nord ed a ovest(dove è stata rilevata la presenza di un nido)de...RIASSUNTO-In due aree della città di Brescia si è accertata la presenza non occasionale di Cornacchiegrigie.Queste aree sono localizzate a nord ed a ovest(dove è stata rilevata la presenza di un nido)del centro storico della città.La presenza delle Cornacchie è simile nelle due aree di studio e varia infunzione della stagione e della presenza umana.L’Autore discute il vantaggio adattativo di tale colonizza-zione,anche se il limite imposto dall’esiguo numero di soggetti per ora presenti impone cautela nell’inter-pretazione dei dati.First data on the presence of Hooded Crows Corvus corone cornix in Brescia(NorthernItaly).Two areas near the centre of the town of Brescia were kept under observation in the courseof the day and of the year to ascertain the non occasional presence of hooded crows.These areas arelocalized north and west from the centre of the town.The number of Hooded Crows is similar in bothareas but,throughout the year,it fluctuates with seasons and human presence.A nest presence hasbeen ascertained in the western area were the animals are more regularly present throughout the year.I argue the adaptive advantage of this colonization.展开更多
Reaction of wild Hooded Crows to conspecific mummified in particolar postures and exposedin the field.A method for preparing bird specimens to be used as stimulus-objects in the field was tested bymeasuring the respon...Reaction of wild Hooded Crows to conspecific mummified in particolar postures and exposedin the field.A method for preparing bird specimens to be used as stimulus-objects in the field was tested bymeasuring the response of wild Hooded Crows,Corvus corone cornix.In a first series of experiments,HoodedCrows specimens were tested for general responsiveness and posture discrimination by conspecific.Moreapproaches were consistently made to Bristle-head posture than to Sleeked posture.In a combination of bristle-head specimens of different subspecies and species,C.c.corone was approached more times than C.c.cornix,whereas C.frugilegus elicited intermediate interest.In a different combination of bristle-head specimens,C.c.corone was more attractive than C.c.cornix,whereas a hybrid C.c.corone x cornix was less attractive than eachpure form.The approaches were usually aggressive.Bristle-head posture was confirmed to be a self advertisingposture and the comparisons between subspecies provided suggestions about the mechanism againsthybridation.展开更多
文摘RIASSUNTO-In due aree della città di Brescia si è accertata la presenza non occasionale di Cornacchiegrigie.Queste aree sono localizzate a nord ed a ovest(dove è stata rilevata la presenza di un nido)del centro storico della città.La presenza delle Cornacchie è simile nelle due aree di studio e varia infunzione della stagione e della presenza umana.L’Autore discute il vantaggio adattativo di tale colonizza-zione,anche se il limite imposto dall’esiguo numero di soggetti per ora presenti impone cautela nell’inter-pretazione dei dati.First data on the presence of Hooded Crows Corvus corone cornix in Brescia(NorthernItaly).Two areas near the centre of the town of Brescia were kept under observation in the courseof the day and of the year to ascertain the non occasional presence of hooded crows.These areas arelocalized north and west from the centre of the town.The number of Hooded Crows is similar in bothareas but,throughout the year,it fluctuates with seasons and human presence.A nest presence hasbeen ascertained in the western area were the animals are more regularly present throughout the year.I argue the adaptive advantage of this colonization.
文摘Reaction of wild Hooded Crows to conspecific mummified in particolar postures and exposedin the field.A method for preparing bird specimens to be used as stimulus-objects in the field was tested bymeasuring the response of wild Hooded Crows,Corvus corone cornix.In a first series of experiments,HoodedCrows specimens were tested for general responsiveness and posture discrimination by conspecific.Moreapproaches were consistently made to Bristle-head posture than to Sleeked posture.In a combination of bristle-head specimens of different subspecies and species,C.c.corone was approached more times than C.c.cornix,whereas C.frugilegus elicited intermediate interest.In a different combination of bristle-head specimens,C.c.corone was more attractive than C.c.cornix,whereas a hybrid C.c.corone x cornix was less attractive than eachpure form.The approaches were usually aggressive.Bristle-head posture was confirmed to be a self advertisingposture and the comparisons between subspecies provided suggestions about the mechanism againsthybridation.
