Common Cuckoos(Cuculus canorus)dependent on parental care for post-hatching demonstrate an intriguing ability to modify their begging vocalizations to ensure maximum care and resources from their interspecific foster ...Common Cuckoos(Cuculus canorus)dependent on parental care for post-hatching demonstrate an intriguing ability to modify their begging vocalizations to ensure maximum care and resources from their interspecific foster parents.Here,we compared begging calls of the Common Cuckoo nestlings fed by four host species,the Grey Bushchat(Saxicola ferreus),Siberian Stonechat(Saxicola maurus),Daurian Redstart(Phoenicurus auroreus),and Oriental Magpie-robin(Copsychus saularis).Results showed that begging calls of the stonechat-,redstart-,and robin-cuckoo resemble those of host species'nestlings in various aspects like low frequency,high frequency,frequency bandwidth and peak frequency,while the bushchat-cuckoo chicks'begging calls were only comparable to their host species in terms of how long they lasted and their peak frequency.In addition,cuckoo nestlings raised in different host nests displayed significant variations in their begging calls in low and peak frequency.This study suggests that cuckoo nestlings do not mimic host species nestlings'begging calls throughout the nestling period,but may tune their begging calls according to host species,while begging calls vary with cuckoo and host species nestlings'ages.Future research should study the parents'reactions to these calls in different host species for a better understanding of the mechanisms underlying such adaptations.展开更多
Most studies on beggars in Nigeria have focused exclusively on the social course of indigenous begging activities in Nigerian cities. There exists dearth of knowledge about international migrant beggars and their heal...Most studies on beggars in Nigeria have focused exclusively on the social course of indigenous begging activities in Nigerian cities. There exists dearth of knowledge about international migrant beggars and their health-seeking behavior in Ibadan Southwestern Nigeria. A cross sectional survey data were collected through purposive sampling technique among a total of 250 international migrant beggars in six locations in Ibadan. Results showed that 56% of respondents were female, few had formal education, 85.6% were married, and 94.8% were Muslim. Respondents migrated from Niger (83.6%), Chad (11.2%), Mali (4.0%) and Benin (1.2%). None had a legal residence permit. Respondents’ mean residence duration in Nigeria was 8.5 years. Malaria was common to beggars both in their home country and in Nigeria. Treatment was received from patent medicine vendors by 51.2% respondents. Advice for appropriate treatment for illness was received from family members by 44.4% migrant beggars. Sex and country of beggars have a direct relationship with the treatment seeking (P Financial and legal status of migrant beggars dynamically limited their healthcare choices. Routine health education on hygiene practice and appropriate treatment-seeking should be taken to beggars at their different locations by health workers as means of prevention of the spread of diseases.展开更多
Begging brings benefits and costs for nestling birds:it can indicate their needs to their parents,but it can also be a cue used by predators to find the nest.The costs,like many variables related to nest predation,can...Begging brings benefits and costs for nestling birds:it can indicate their needs to their parents,but it can also be a cue used by predators to find the nest.The costs,like many variables related to nest predation,can be specific to what kinds of predators are present and their auditory capabilities.These costs and benefits could also be affected by human noise,as noise could disrupt communication to parents and eavesdropping by predators,although human-produced noise might be easily ignored if predators can hear high-frequency components of the begging.We studied nest predation on a generalist bird,the Red-whiskered Bulbul(Pycnonotus jocosus),in a tropical forest in which there are many kinds of nest predators,including birds,mammals and reptiles.In 20 natural nests in which artificial eggs were placed,and subsequently in 140 artificial nests,we broadcast recordings of begging nestlings,with and without traffic noise,at two volume levels.We hypothesized that playback would increase predation relative to a silent control,and that mixing in traffic noise with the begging would decrease predation,as the begging signal was masked.However,we hypothesized that some predators,particularly small mammals with sensitive high-frequency hearing,might ignore the traffic noise.We found that predation was lowest for the control treatment,and lower for treatments mixed with traffic noise than for those without it.Small mammals,however,showed an unexpected pattern,displaying less nest predation in the treatments with traffic noise.Our results demonstrate the human-associated noise can disturb nest predators and influence which kinds of predators use begging to locate nests.展开更多
The mixed spin-2 and spin-3/2 Blume-Emery-Griffiths (BEG) Ising ferrimagnetic system is studied by the Bethe lattice approach. The ground-state phase diagram is constructed. The influence of the crystal-field and the ...The mixed spin-2 and spin-3/2 Blume-Emery-Griffiths (BEG) Ising ferrimagnetic system is studied by the Bethe lattice approach. The ground-state phase diagram is constructed. The influence of the crystal-field and the biquadratic interactions among neighboring spins on the thermal behaviors of the system is singled out. The system displays very rich critical behaviors with the existence of tricritical points. Compensation points where the global magnetization of the system vanishes have been detected for appropriate values of the system parameters.展开更多
Coevolutionary interactions between avian brood parasites and their hosts often lead to the evolution of discrimination and rejection of parasite eggs or chicks by hosts based on visual cues,and the evolution of visua...Coevolutionary interactions between avian brood parasites and their hosts often lead to the evolution of discrimination and rejection of parasite eggs or chicks by hosts based on visual cues,and the evolution of visual mimicry of host eggs or chicks by brood parasites.Hosts may also base rejection of brood parasite nestlings on vocal cues,which would in turn select for mimicry of host begging calls in brood parasite chicks.In cuckoos that exploit multiple hosts with different begging calls,call structure may be plastic,allowing nestlings to modify their calls to match those of their various hosts,or fixed,in which case we would predict either imperfect mimicry or divergence of the species into host-specific lineages.In our study of the little bronze-cuckoo(LBC)Chalcites minutillus and its primary host,the large-billed gerygone Gerygone magnirostris,we tested whether:(1)hosts use nestling vocalizations as a cue to discriminate cuckoo chicks;(2)cuckoo nestlings mimic the host begging calls throughout the nestling period;and(3)the cuckoo begging calls are plastic,thereby facilitating mimicry of the calls of different hosts.We found that the begging calls of LBCs are most similar to their gerygone hosts shortly after hatching(when rejection by hosts typically occurs)but become less similar as cuckoo chicks get older.Begging call structure may be used as a cue for rejection by hosts,and these results are consistent with gerygone defenses selecting for age-specific vocal mimicry in cuckoo chicks.We found no evidence that LBC begging calls were plastic.展开更多
On August 2,Zhuhai,a city in south China’s Guangdong Province, issued road safety regulations banning begging in vehicle lanes. The new regulations allow the police to impose fines on beggers.Drivers who buy anything...On August 2,Zhuhai,a city in south China’s Guangdong Province, issued road safety regulations banning begging in vehicle lanes. The new regulations allow the police to impose fines on beggers.Drivers who buy anything from vendors or give money to beg- gars will also be fined.展开更多
基金supported by the National Natural Science Foundation of China(Nos.32270526 to W.L.and 32260253 to L.W.)supported by the specific research fund of The Innovation Platform for Academicians of Hainan Provincesupported by the Hainan Province Postdoctoral Research Project。
文摘Common Cuckoos(Cuculus canorus)dependent on parental care for post-hatching demonstrate an intriguing ability to modify their begging vocalizations to ensure maximum care and resources from their interspecific foster parents.Here,we compared begging calls of the Common Cuckoo nestlings fed by four host species,the Grey Bushchat(Saxicola ferreus),Siberian Stonechat(Saxicola maurus),Daurian Redstart(Phoenicurus auroreus),and Oriental Magpie-robin(Copsychus saularis).Results showed that begging calls of the stonechat-,redstart-,and robin-cuckoo resemble those of host species'nestlings in various aspects like low frequency,high frequency,frequency bandwidth and peak frequency,while the bushchat-cuckoo chicks'begging calls were only comparable to their host species in terms of how long they lasted and their peak frequency.In addition,cuckoo nestlings raised in different host nests displayed significant variations in their begging calls in low and peak frequency.This study suggests that cuckoo nestlings do not mimic host species nestlings'begging calls throughout the nestling period,but may tune their begging calls according to host species,while begging calls vary with cuckoo and host species nestlings'ages.Future research should study the parents'reactions to these calls in different host species for a better understanding of the mechanisms underlying such adaptations.
文摘Most studies on beggars in Nigeria have focused exclusively on the social course of indigenous begging activities in Nigerian cities. There exists dearth of knowledge about international migrant beggars and their health-seeking behavior in Ibadan Southwestern Nigeria. A cross sectional survey data were collected through purposive sampling technique among a total of 250 international migrant beggars in six locations in Ibadan. Results showed that 56% of respondents were female, few had formal education, 85.6% were married, and 94.8% were Muslim. Respondents migrated from Niger (83.6%), Chad (11.2%), Mali (4.0%) and Benin (1.2%). None had a legal residence permit. Respondents’ mean residence duration in Nigeria was 8.5 years. Malaria was common to beggars both in their home country and in Nigeria. Treatment was received from patent medicine vendors by 51.2% respondents. Advice for appropriate treatment for illness was received from family members by 44.4% migrant beggars. Sex and country of beggars have a direct relationship with the treatment seeking (P Financial and legal status of migrant beggars dynamically limited their healthcare choices. Routine health education on hygiene practice and appropriate treatment-seeking should be taken to beggars at their different locations by health workers as means of prevention of the spread of diseases.
基金supported by the National Natural Science Foundation of China(grant 31870370)Guangxi 1000 Young and Middle-Aged College and University Backbone Teachers Cultivation Program(2019.5)。
文摘Begging brings benefits and costs for nestling birds:it can indicate their needs to their parents,but it can also be a cue used by predators to find the nest.The costs,like many variables related to nest predation,can be specific to what kinds of predators are present and their auditory capabilities.These costs and benefits could also be affected by human noise,as noise could disrupt communication to parents and eavesdropping by predators,although human-produced noise might be easily ignored if predators can hear high-frequency components of the begging.We studied nest predation on a generalist bird,the Red-whiskered Bulbul(Pycnonotus jocosus),in a tropical forest in which there are many kinds of nest predators,including birds,mammals and reptiles.In 20 natural nests in which artificial eggs were placed,and subsequently in 140 artificial nests,we broadcast recordings of begging nestlings,with and without traffic noise,at two volume levels.We hypothesized that playback would increase predation relative to a silent control,and that mixing in traffic noise with the begging would decrease predation,as the begging signal was masked.However,we hypothesized that some predators,particularly small mammals with sensitive high-frequency hearing,might ignore the traffic noise.We found that predation was lowest for the control treatment,and lower for treatments mixed with traffic noise than for those without it.Small mammals,however,showed an unexpected pattern,displaying less nest predation in the treatments with traffic noise.Our results demonstrate the human-associated noise can disturb nest predators and influence which kinds of predators use begging to locate nests.
文摘The mixed spin-2 and spin-3/2 Blume-Emery-Griffiths (BEG) Ising ferrimagnetic system is studied by the Bethe lattice approach. The ground-state phase diagram is constructed. The influence of the crystal-field and the biquadratic interactions among neighboring spins on the thermal behaviors of the system is singled out. The system displays very rich critical behaviors with the existence of tricritical points. Compensation points where the global magnetization of the system vanishes have been detected for appropriate values of the system parameters.
基金supported by an Australian Research Council Discovery Grant(DP180100021,DP150101652)the Holsworth Grant,Australia&Pacific Science Foundation(APSF1406)Birdlife Australia(2015).
文摘Coevolutionary interactions between avian brood parasites and their hosts often lead to the evolution of discrimination and rejection of parasite eggs or chicks by hosts based on visual cues,and the evolution of visual mimicry of host eggs or chicks by brood parasites.Hosts may also base rejection of brood parasite nestlings on vocal cues,which would in turn select for mimicry of host begging calls in brood parasite chicks.In cuckoos that exploit multiple hosts with different begging calls,call structure may be plastic,allowing nestlings to modify their calls to match those of their various hosts,or fixed,in which case we would predict either imperfect mimicry or divergence of the species into host-specific lineages.In our study of the little bronze-cuckoo(LBC)Chalcites minutillus and its primary host,the large-billed gerygone Gerygone magnirostris,we tested whether:(1)hosts use nestling vocalizations as a cue to discriminate cuckoo chicks;(2)cuckoo nestlings mimic the host begging calls throughout the nestling period;and(3)the cuckoo begging calls are plastic,thereby facilitating mimicry of the calls of different hosts.We found that the begging calls of LBCs are most similar to their gerygone hosts shortly after hatching(when rejection by hosts typically occurs)but become less similar as cuckoo chicks get older.Begging call structure may be used as a cue for rejection by hosts,and these results are consistent with gerygone defenses selecting for age-specific vocal mimicry in cuckoo chicks.We found no evidence that LBC begging calls were plastic.
文摘On August 2,Zhuhai,a city in south China’s Guangdong Province, issued road safety regulations banning begging in vehicle lanes. The new regulations allow the police to impose fines on beggers.Drivers who buy anything from vendors or give money to beg- gars will also be fined.
