Over-shadowed by eye-catching vocal and visual signals, chemical communication has long been overlooked in birds. This study aimed at exploring whether volatile composition of the uropygial gland secretion （UGS） of ...Over-shadowed by eye-catching vocal and visual signals, chemical communication has long been overlooked in birds. This study aimed at exploring whether volatile composition of the uropygial gland secretion （UGS） of birds was associated with the information about sex, individual and species. By using dichloromethane extraction and gas chromatography-mass spectrometry （GC-MS）, we analyzed the UGS volatiles of domesticated Bengalese finches （ Lonchura striata, Estrildiea） which is also known as white-rumped munias. We characterized 16 volatile molecules from the UGS, including eight n-alkanols, five diesters, an ester, an aldehyde and a fatty acid, and quantified them in terms of GC peak area percentages （relative abundances） . Among these compounds, hexadecanol and octadecanol were major components in both sexes. The former was richer in males than in females and the latter richer in females than in males, suggesting that they might be male and female pheromone candidates, respectively. The high inter-individual variations, in relative abundance, of the UGS volatiles implied that these compounds might carry information about individuality. The similarity between GC profiles of the UGS and wing feather from same individuals indicates that the birds might preen the secretion to their feathers to transmit chemical cues. Additionally, by comparing with three sympatric passerine species, i. e., zebra finches Taeniopygia guttata, yellow-bowed buntings Emberiza chrysophrys and rooks Corvus frugilegus, we found that the composition of C13 - C18 alkanols in the UGS might code for information about species. Our study also showed that quantitative differences （degree） of same UGS volatiles might be the key for the Bengalese finch to code for information about sex and individuality whereas both the kind and degree of UGS constituents could be utilized to code for information about species [ Current Zoology 55 （5）： 357-365, 2009].展开更多
Costs and benefits of brain lateralization may depend on environmental conditions.Growing evidence indicates that the development of brain functional asymmetries is adaptively shaped by the environmental conditions ex...Costs and benefits of brain lateralization may depend on environmental conditions.Growing evidence indicates that the development of brain functional asymmetries is adaptively shaped by the environmental conditions experienced during early life.Food availability early in life could act as a proxy of the environmental conditions encountered during adulthood,but its potential modulatory effect on lateralization has received little attention.We increased food supply from egg laying to early nestling rearing in a wild population of lesser kestrels Falco naumanni,a sexually dimorphic raptor,and quantified the lateralization of preening behavior(head turning direction).As more lateralized individuals may perform better in highly competitive contexts,we expected that extra food provisioning,by reducing the level of intra-brood competition for food,would reduce the strength of lateralization.We found that extra food provisioning improved nestling growth,but it did not significantly affect the strength or direction of nestling lateralization.In addition,maternal body condition did not explain variation in nestling lateralization.Independently of extra food provisioning,the direction of lateralization differed between the sexes,with female nestlings turning more often toward their right.Our findings indicate that early food availability does not modulate behavioral lateralization in a motor task,suggesting limited phenotypic plasticity in this trait.展开更多
The uropygial gland has been hypothesized to play a role in sexual signaling through a "make-up" function derived from the effects of secretions from the gland on the appearanee of the plumage and bare parts...The uropygial gland has been hypothesized to play a role in sexual signaling through a "make-up" function derived from the effects of secretions from the gland on the appearanee of the plumage and bare parts of the body. Here we show that plumage brightness of dorsal feathers of individual barn swallows Hirundo rustica was greater in mated than in unmated individuals. In addition, plumage brightness in creased with colony size. Furthermore, plumage bright ness was positively correlated with the amount of wax in the uropygial gland, negatively correlated with time of sampling of uropygial wax (perhaps because more wax is present early in the morning after an entire night of wax production without any preening), and negatively correlated with the number of chewing lice that degrade the plumage. Experimentally preventing barn swallows from access to the uropygial gland reduced plumage brightness, showing a causal link between secretions from the uropygial gland and plumage brightness. These findings provide evidence consistent with a role of uropygial secretions in signaling plumage brightness.展开更多
Parasites are globally widespread pathogenic organisms,which impose im portant selective forces upon their hosts.Thus,in accordance with the A djustm ent to parasite pressure hypothesis,it is expected that defenses am...Parasites are globally widespread pathogenic organisms,which impose im portant selective forces upon their hosts.Thus,in accordance with the A djustm ent to parasite pressure hypothesis,it is expected that defenses among hosts vary relative to the selective pressure imposed by parasites.According to the latitudinal gradient in diversity,species richness and abundance of parasites peak near the equator.The uropygial gland is an im portant defensive exocrine gland against pathogens in birds.Size of the uropygial gland has been proposed to vary among species of birds because of divergent selection by pathogens on their hosts.Therefore,we should expect that bird species from the tropics should have relatively larger uropygial glands for their body size than species from higher latitudes.However,this hypothesis has not yet been explored.Here,we analyze the size of the uropygial gland of 1719 individual birds belonging to 36 bird species from 3 Neotropical(Peru)and 3 temperate areas(Spain).Relative uropygial gland volum e was 12.52%larger in bird species from the tropics than from temperate areas.This finding is consistent w ith the relative size of this defensive organ being driven by selective pressures imposed by parasites.We also explored the potential role of this gland as a means of avoiding haemosporidian infection,showing that species with large uropygial glands for their body size tend to have lower mean prevalence of haemosporidian infection,regardless o f their geographical origin.This result provides additional support for the assum ption that secretions from the uropygial gland reduce the likelihood of becoming infected with haemosporidians.展开更多
基金supported by grants from Chinese NSF(No.30870297to J.X.ZNo.30370196to M.X.Z.)International Partnership Project of CAS(CXTD2005-4to L.S and J.X.Z)
文摘Over-shadowed by eye-catching vocal and visual signals, chemical communication has long been overlooked in birds. This study aimed at exploring whether volatile composition of the uropygial gland secretion （UGS） of birds was associated with the information about sex, individual and species. By using dichloromethane extraction and gas chromatography-mass spectrometry （GC-MS）, we analyzed the UGS volatiles of domesticated Bengalese finches （ Lonchura striata, Estrildiea） which is also known as white-rumped munias. We characterized 16 volatile molecules from the UGS, including eight n-alkanols, five diesters, an ester, an aldehyde and a fatty acid, and quantified them in terms of GC peak area percentages （relative abundances） . Among these compounds, hexadecanol and octadecanol were major components in both sexes. The former was richer in males than in females and the latter richer in females than in males, suggesting that they might be male and female pheromone candidates, respectively. The high inter-individual variations, in relative abundance, of the UGS volatiles implied that these compounds might carry information about individuality. The similarity between GC profiles of the UGS and wing feather from same individuals indicates that the birds might preen the secretion to their feathers to transmit chemical cues. Additionally, by comparing with three sympatric passerine species, i. e., zebra finches Taeniopygia guttata, yellow-bowed buntings Emberiza chrysophrys and rooks Corvus frugilegus, we found that the composition of C13 - C18 alkanols in the UGS might code for information about species. Our study also showed that quantitative differences （degree） of same UGS volatiles might be the key for the Bengalese finch to code for information about sex and individuality whereas both the kind and degree of UGS constituents could be utilized to code for information about species [ Current Zoology 55 （5）： 357-365, 2009].
基金supported by institutional funding from the Universitàdegli Studi di Milano(to D.R.),Universitàdegli Studi di Padova(to C.S.),and the Istituto Nazionale per la Protezione e la Ricerca Ambientale(ISPRA)(to J.G.C.).Nest-boxes were installed with support from the European Commission through the LIFE Project“Rapaci Lucani”(LIFE05NAT/IT/00009)and were designed by G.Ceccolini.
文摘Costs and benefits of brain lateralization may depend on environmental conditions.Growing evidence indicates that the development of brain functional asymmetries is adaptively shaped by the environmental conditions experienced during early life.Food availability early in life could act as a proxy of the environmental conditions encountered during adulthood,but its potential modulatory effect on lateralization has received little attention.We increased food supply from egg laying to early nestling rearing in a wild population of lesser kestrels Falco naumanni,a sexually dimorphic raptor,and quantified the lateralization of preening behavior(head turning direction).As more lateralized individuals may perform better in highly competitive contexts,we expected that extra food provisioning,by reducing the level of intra-brood competition for food,would reduce the strength of lateralization.We found that extra food provisioning improved nestling growth,but it did not significantly affect the strength or direction of nestling lateralization.In addition,maternal body condition did not explain variation in nestling lateralization.Independently of extra food provisioning,the direction of lateralization differed between the sexes,with female nestlings turning more often toward their right.Our findings indicate that early food availability does not modulate behavioral lateralization in a motor task,suggesting limited phenotypic plasticity in this trait.
文摘The uropygial gland has been hypothesized to play a role in sexual signaling through a "make-up" function derived from the effects of secretions from the gland on the appearanee of the plumage and bare parts of the body. Here we show that plumage brightness of dorsal feathers of individual barn swallows Hirundo rustica was greater in mated than in unmated individuals. In addition, plumage brightness in creased with colony size. Furthermore, plumage bright ness was positively correlated with the amount of wax in the uropygial gland, negatively correlated with time of sampling of uropygial wax (perhaps because more wax is present early in the morning after an entire night of wax production without any preening), and negatively correlated with the number of chewing lice that degrade the plumage. Experimentally preventing barn swallows from access to the uropygial gland reduced plumage brightness, showing a causal link between secretions from the uropygial gland and plumage brightness. These findings provide evidence consistent with a role of uropygial secretions in signaling plumage brightness.
基金This work was supported by the Spanish Ministry of Economy and Competitiveness research projects[grant CGL2015-64650P]Junta de Extremadura[grant IB16121]S.M.and A.M.were supported by a Ph.D.grant from the Ministry of Economy and Competition of Spain and a mobility grant of Junta de Extremadura(129/2015),respectively.L.G.-L.was supported by the Junta de Extremadura[PO17024,Post-Doc grant].
文摘Parasites are globally widespread pathogenic organisms,which impose im portant selective forces upon their hosts.Thus,in accordance with the A djustm ent to parasite pressure hypothesis,it is expected that defenses among hosts vary relative to the selective pressure imposed by parasites.According to the latitudinal gradient in diversity,species richness and abundance of parasites peak near the equator.The uropygial gland is an im portant defensive exocrine gland against pathogens in birds.Size of the uropygial gland has been proposed to vary among species of birds because of divergent selection by pathogens on their hosts.Therefore,we should expect that bird species from the tropics should have relatively larger uropygial glands for their body size than species from higher latitudes.However,this hypothesis has not yet been explored.Here,we analyze the size of the uropygial gland of 1719 individual birds belonging to 36 bird species from 3 Neotropical(Peru)and 3 temperate areas(Spain).Relative uropygial gland volum e was 12.52%larger in bird species from the tropics than from temperate areas.This finding is consistent w ith the relative size of this defensive organ being driven by selective pressures imposed by parasites.We also explored the potential role of this gland as a means of avoiding haemosporidian infection,showing that species with large uropygial glands for their body size tend to have lower mean prevalence of haemosporidian infection,regardless o f their geographical origin.This result provides additional support for the assum ption that secretions from the uropygial gland reduce the likelihood of becoming infected with haemosporidians.
