During in vitro fertilization, human embryos are incubated without light, and these conditions do not ensure embryo survival. This study explored whether environmental conditions can influence the embryo viability rat...During in vitro fertilization, human embryos are incubated without light, and these conditions do not ensure embryo survival. This study explored whether environmental conditions can influence the embryo viability rates of the house cricket, Acheta domesticus. In particular, the experiment tested what colors of visible light provide the best incubation conditions to ensure cricket embryo viability. The concept was to use house cricket embryos to represent human embryos. Cricket embryos were chosen as their eggs have soft outer membrane casings and resemble human embryos during the first few days after fertilization. During the experiment, the adult crickets laid their eggs into one of six soil-filled boxes called substrates. Each substrate was placed into one of six storage containers filled with adult crickets and lit with a different colored visible light (red, yellow, green, blue, white, or no light). After two days of breeding, the egg-filled substrates were removed from the adult crickets and placed in another storage container of the same color light. After incubation under heat-emitting lamps and under one of six light colors, nymphs were counted after hatching to determine embryo viability. After three trials, the red light provided the significantly highest viability rate, with yellow and no light being comparable seconds. The green, blue, and white lights showed significantly lower viability rates than no visible light. My results raise the speculation that exposing fertilized mammal eggs to visible light colors might have the same effects during the in vitro fertilization process.展开更多
DEAR EDITOR, In this study, we sequenced the complete mitochondrial DNA genome （mitogenome） of the Zhengyang Yellow chicken （Gallus gallus domesticus） by next-generation sequencing technology. Samples were taken f...DEAR EDITOR, In this study, we sequenced the complete mitochondrial DNA genome （mitogenome） of the Zhengyang Yellow chicken （Gallus gallus domesticus） by next-generation sequencing technology. Samples were taken from Zhumadian city, Henan Province, China. The complete mitogenome was 16 785 bp in size, and had a nucleotide composition of 30.3% （A）, 23.7% （T） 32.5% （C）, and 13.5% （G）, with a high AT content of 54.0%. The assembled mitogenome exhibited typical mitochondrial DNA （mtDNA） structure, including a non-coding control region, two rRNA genes, 13 protein-coding genes, and 22 tRNA genes. Phylogenetic analysis indicated that this mitogenome defined a novel sub-haplogroup B3 within haplogroup B. These results should provide essential information for chicken domestication and insiqht into the evolution of genomes.展开更多
Traceability based on DNA analysis is attracting increasing interest due to the crisis of confidence that consumers show towards the products of animal origin. The present work discusses a genetic traceability system ...Traceability based on DNA analysis is attracting increasing interest due to the crisis of confidence that consumers show towards the products of animal origin. The present work discusses a genetic traceability system of meat and processed products from an historical Tuscan native pig breed, the Cinta Senese. The study is based on a panel of 8 ISAG (International Society for Animal Genetics) DNA microsatellite markers usage done both on pigs and derived products. The SSRs panel allowed us to obtain a unique fingerprint of the individuals to be used as a tracer “downstream” in the processed products. The molecular method used proved that the hams, analyzed just before commercialization, were obtained from Cinta Senese pigs and that the analyzed meat products derived from the Cinta Senese were produced at least with 95% of Cinta Senese meat. In perspective, the molecular testing could be introduced as a voluntarily adopted method for proving intrinsic quality of many regional food products.展开更多
Following an introduction, non-native species are exposed to environments that differ from those found in their native range; further, as these non-native species expand beyond the site of introduction, they must cons...Following an introduction, non-native species are exposed to environments that differ from those found in their native range; further, as these non-native species expand beyond the site of introduction, they must constantly adapt to novel environ- ments. Although introduced species are present across most ecosystems, few species have successfully established themselves on a truly global scale. One such species, the house sparrow Passer domesticus, is now one of the world＇s most broadly distributed vertebrate species and has been introduced to a great part of its current range. To date, work on four continents suggests both ge- netic and phenotypic variation exists between native and introduced ranges. As such, house sparrows represent an excellent op- portunity to study adaptations to novel environments and how these adaptations are derived. The global distribution of this spe- cies and the multiple independent introductions to geographically isolated sites allow researchers to ask questions regarding ge- netic variation and adaptation on a global scale. Here, we summarize the molecular studies of invasive house sparrows from the earliest work using allozymes through more recent work on epigenetics; using these studies, we discuss patterns of dispersal of this species. We then discuss future directions in techniques （e.g. next generation sequencing） and how they will provide new in- sight into questions that are fundamental to invasion biology. Finally, we discuss how continued research on the house sparrow in light of these genetic changes and adaptations will elucidate answers of adaptation, invasion biology, range expansion, and resi- lience in vertebrate systems generally展开更多
The main aims of this research were to study possible differences in objective morphometric sperm characteristics, establish normative sperm morphometry standards, and evaluate the presumed different subpopulation dis...The main aims of this research were to study possible differences in objective morphometric sperm characteristics, establish normative sperm morphometry standards, and evaluate the presumed different subpopulation distribution of avian spermatozoa from the rooster （Gallus domesticus） and Guinea fowl （Numida meleagris） as model avian species. Seventy-two ejaculates （36 per species studied） were obtained manually, following a training period involving gently combined dorso-abdominal and lumbo.sacral massage of the birds. Ejaculates were processed for volume, sperm concentration, viability, motility, and morphology. Moreover, samples were submitted for sperm morphometric assessment using objective Computer-Assisted Semen Analysis for Morphometry （CASA-Morph） methods, with sperm morphometric descriptors evaluated by Principal Component Analysis （PCA） and multivariate clustering analyses. There were several differences observed between the avian species in values obtained for ejaculate volume and sperm concentration （P 〈 0.001）. Irrespective of species, PCA revealed two Principal Components （PCs） explaining more than 80% of the variance. In addition, the number of subpopulations differed with species （three and five subpopulations for rooster and Guinea fowl, respectively）. Moreover, the distribution of the sperm subpopulations was found to be structurally different between species. In conclusion, our findings from using CASA-Morph methods indicate pronounced sperm morphometric variation between these two avian species. Because of the strong differences observed in morphometric parameter values and their subpopulation distribution, these results suggest that application of objective analytical methods such as CASA-Morph could substantially improve the reliability of comparative studies and help establish valid normative sperm morphological values for avian species.展开更多
A large-scale outbreak of the house mouse populations occurs in grain growing in Australia on average once every four years.High densities of mice cause major yield losses to cereal crops,and low to moderate densities...A large-scale outbreak of the house mouse populations occurs in grain growing in Australia on average once every four years.High densities of mice cause major yield losses to cereal crops,and low to moderate densities of mice also cause some losses.Several predictive models based on rainfall patterns have been developed to forecast mouse density.These models carry some uncertainty and the economic value of basing management actions on these models is not clear.Baiting is the most commonly used method and zinc phosphide and other rodenticide bait are effective in reducing up to 90%of mouse populations.Ecologically-based best farming practice for controlling mice has recently been developed on the basis of long-term field studies of mouse populations.No effective biological control method has been developed for mice.However,grain growers still cannot make economically rational decisions to implement control because they do not know the pest threshold density(D_(T))above which the economic benefits of control exceed the economic costs of control.Applied predator-prey theory suggests that understanding the relationship between mouse density and damage is the basis for determining D_(T).Understanding this relationship is the first research priority for managing mouse damage.The other research priority is to develop a reliable method to estimate unbiased mouse density.展开更多
We examined theta activity in the temporal hippocampus of ure-thane-chloralose-anesthetized pigs by stimulation with two chemical odors, beta-phenyl ethyl alcohol (PEA;rose-like odor) and n-amyl acetate (banana-like o...We examined theta activity in the temporal hippocampus of ure-thane-chloralose-anesthetized pigs by stimulation with two chemical odors, beta-phenyl ethyl alcohol (PEA;rose-like odor) and n-amyl acetate (banana-like odor). Neural activity was recorded in the neural cell layer nearby fimbria of the temporal hippocampus in three of six animals. Odor stimulation with PEA at a low concentration (10-4 w/w;100 ppm) significantly increased power of the low-frequency theta band (type-2;4 - 6 Hz) for the middle 10 s (w (3, 6, 2.5%) >2.56). The PEA odor at a higher concentration (10-3 w/w;1000 ppm), however, showed a tendency for gradual increase in?the low-frequency theta but the response was insignificant compared with the control. On the other hand, odor stimulation with n-amyl acetate (10-4 w/w;100 ppm) caused no apparent increase or a tendency for decrease in power of the low-frequency theta. Thus, the type-2 theta response in the temporal hippocampus to the PEA odor contrasted strikingly with that to the n-amylacetate in the ure-thane-chloralose-anesthetized pigs. The response of the type-2 theta rhythm in the temporal hippocampus may underlie the difference in emotional sensation and cognition of PEA from n-amyl acetate in the pig.展开更多
Background: The evolution of sexual signals is not only determined by immediate sexual selection but also by selection arising from the environment and the interaction with developmental effects.In this study we aimed...Background: The evolution of sexual signals is not only determined by immediate sexual selection but also by selection arising from the environment and the interaction with developmental effects.In this study we aimed to investigate how the badge size of male house sparrows(Passer domesticus) is correlated to avian malaria infections as well as to prenatal testosterone exposure,measured as the 2D:4D digit ratio.The rationale behind this study is that the immunosuppressive effect of maternal testosterone deposition combined with the fitness cost imposed by parasites may cause important trade-offs to the development of secondary sexual signals.Methods: Assuming that vector abundance is a key variable associated with infection risk by avian malaria,we caught adult male sparrows from eight different populations in the Camargue,France,four of which were located in a vector-controlled area,and the other four in an untreated area.For each bird we measured its badge size,digit ratio and took blood to determine its infections status.We used PCR to identify the malaria parasite species and strain that caused the infection.Results: Contrary to our expectation,prevalence of disease did not differ across the vector-treatment regions,with around 80 % of birds being infected in both areas,and those infections were caused largely by a single strain,Plasmodium relictum SGS1.Although infected birds had a badge size not significantly different from uninfected males,there was a condition-dependent association between badge size,infection status and maternal testosterone deposition.Conclusions: This study illustrates that the complexity of temporal and ecological dimensions makes the relationships between disease,testosterone-related traits and secondary sexual signals that have been previously reported less general than thought.展开更多
Background: The House Sparrow(Passer domesticus) has undergone dramatic population declines in many parts of Europe.It has been widely hypothesised that a lack of cavity nest sites has contributed to this decline.Howe...Background: The House Sparrow(Passer domesticus) has undergone dramatic population declines in many parts of Europe.It has been widely hypothesised that a lack of cavity nest sites has contributed to this decline.However the idea of the House Sparrow being nest site limited is somewhat incompatible with the long history of nest site plasticity in the species.Methods: The nest-site selection in a population of non-native House Sparrows introduced to Australia from Europe just over 150 years ago was characterised.The prevalence of non-cavity nesting was quantified,and nest-site selection in terms of landscape and nesting structure were described.Results: Flexible nesting behaviors were reported over a range of different landscapes and a surprisingly high rate of nesting in vegetation(43%) was documented.Most nests found in vegetation were not in cavities,but were woven into the foliage and supported by branches and stems.Conclusion: The high rate of vegetation nesting indicates that in this introduced population,the House Sparrow is unlikely to be constrained by cavity-nest site availability.The high degree of nest site plasticity in the Australian population may suggest that European House Sparrows have the potential to shift away from their proclivity for cavity nests.Future work in Europe should examine the incidence of non-cavity nesting in House Sparrows more closely,and perhaps reconsider the idea that House Sparrows are nest-site constrained.展开更多
Parasites are known to be a key driving force in mate choice and are important for the expression and evolution of ornaments and behavioral traits being used.However,there is little experimental evidence on how the pa...Parasites are known to be a key driving force in mate choice and are important for the expression and evolution of ornaments and behavioral traits being used.However,there is little experimental evidence on how the parasite’s burden of the choosing individual is integrated into the mate-choice process and how it affects decision-making,especially in relation to parasite infestation of potential mates.Thus,the aim of our study was to determine whether female house sparrows Passer domesticus adjust their mate preference according to their own as well as the parasite load of prospective partners.To do this,we experimentally manipulated female parasite load and determined their mate preferences prior to and after parasite treatment.We manipulated the chronic coccidian parasite burden of females either by initiating the acute infection phase via re-infecting them with coccidian or by temporally reducing the parasite load of coccidia.We then measured the effect of this manipulation on mate preference by presenting females with a choice of four stimuli:three males with similar ornaments,but unmanipulated,naturally varying chronic coccidiosis levels,and an unmanipulated control female.Additionally,we recorded some males’behavior in relation to their infection status pointing toward an increased or reduced interest in mating.We found that females preferred highly infested males prior to manipulation,regardless of their own infestation level.However,after manipulation,infested females avoided highly infested males probably in response to the deterioration of their health condition by parasites.Our study suggests that mate-choice decisions are more complex when they are mediated by parasites.The implications of parasites for evolutionary theories of sexual signaling and mate choice are discussed.展开更多
Edible insects are advocated as sustainable and healthy food and feed.However,commercially produced insects are often low in n‐3 fatty acids and have suboptimal n‐6/n‐3 ratios.A certain amount and proportion of the...Edible insects are advocated as sustainable and healthy food and feed.However,commercially produced insects are often low in n‐3 fatty acids and have suboptimal n‐6/n‐3 ratios.A certain amount and proportion of these FAs is required to optimize human health.Flaxseed oil consists primarily(57%)out of alpha‐linolenic acid.An experiment was conducted to quantify the effect of flaxseed oil provision on fatty acid composition and to determine the quantity needed to attain a beneficial n‐6/n‐3 ratio.Three species were used in the experiment:house crickets(Acheta domesticus[L.]),lesser mealworms(Alphitobius diaperinus[Pfanzer])and black soldier flies(Hermetia illucens[L.]).These were provided with either a control diet or a diet enriched with 1%,2%,or 4%flaxseed oil during their larval/nymphal stage.Fatty acid profiles of diets and insects were determined via GC‐MS.The three species had distinct fatty acid profiles on all four diets,but responded similarly to flaxseed oil addition.For each percent added to the diet,the alpha‐linolenic acid content of the insects increased by 2.3%–2.7%.Four percent addition increased the n‐3 fatty acid content 10–20 fold in the three species and thereby strongly decreased n‐6/n‐3 ratios from 18–36 to 0.8–2.4.A ratio below 5 is considered optimal for human health and was achieved by 2%flaxseed oil inclusion for house crickets and lesser mealworms,and at 1%inclusion for black soldier flies.Adding a source of n‐3 fatty acids to insect diets can thus improve the nutritional quality of insects.展开更多
In the last decades, higher attention has been paid to olfactory perception in birds. As a consequence, a handful of avian species have been discovered to use olfaction in different contexts. Nevertheless, we still ha...In the last decades, higher attention has been paid to olfactory perception in birds. As a consequence, a handful of avian species have been discovered to use olfaction in different contexts. Nevertheless, we still have a very limited knowledge about the use of odor cues in avian social life, particularly, in the case of songbirds. Here, we investigate if female house sparrows Passer domesticus show any preference for the odor of kin and nonkin conspecifics and we also test a possible role of familiarity based on male see nt in female choice. We performed the experiment with captive birds twice, duri ng the non breeding and breedi ng seas ons. Our results show that female house sparrows strongly avoided the odor of unrelated familiar (UF) males, both in the breeding and nonbreeding seasons. Our results suggest recognition for olfactory stimuli related to familiarity and kin ship. We suggest that avoidance for UF males is associated with previous experie nee in this species. Also, we provided further evidenee to the use of olfaction in passerine species by using a new experimental setup.展开更多
Contrary to the nestling phase, the post-fledging phase has been less studied probably because it is challenging to follow the chicks after they fledge. However, this phase is crucial to consider when focusing on the ...Contrary to the nestling phase, the post-fledging phase has been less studied probably because it is challenging to follow the chicks after they fledge. However, this phase is crucial to consider when focusing on the life cycle of individuals because it is associated with new demands： After leaving the nest, individuals have to find their own food and cope with a new set of previously unknown stressors. In this study, we aimed at better understanding how energetically demanding the post-ftedging period is in house sparrows Passer domesticus by measuring several indices of a fledgling＇s state （body condition, fat and muscle scores and plumage quality）. If the energetic demands of the post-fledging period are greater than those of the adult life, we predicted that fledglings should be in lower condition and should have a plumage of lower quality relative to adults. Supporting this prediction, the condition and the plumage of fledglings differed dramatically from those of adults. Interestingly, this difference disappeared in autumn. Overall, our results suggest that the post-fledging period is probably one of the most energetically demanding of the life cycle in this species. Supporting this idea, the resighting probability of fledglings was lower relative to adults. However, resighting probability depends on many factors （mortality, dispersal, habitat use and behaviours） and future studies are necessary to tease apart their relative importance in determining resighting probability [Current Zoology 60 （4）： 449-459, 2014].展开更多
Maximum and minimum metabolic rates in birds are flexible traits and such flexibility can be advantageous in variable climates.The climatic variability hypothesis(CVH)posits that more variable climates should result i...Maximum and minimum metabolic rates in birds are flexible traits and such flexibility can be advantageous in variable climates.The climatic variability hypothesis(CVH)posits that more variable climates should result in greater metabolic flexibility for geographically distinct populations.Whether the CVH applies to sympatric species occupying microclimates differing in variability is unknown.Microclimates of open habitats are likely more variable than those of sheltered habitats.If the CVH extends to microclimates,we expect birds from open habitats to show greater flexibility than those from sheltered habitats.To test this extension of the CVH,we compared seasonal variation in microclimates and metabolic rates for sympatric horned larks Eremophila alpestris,which occupy open habitats,and house sparrows Passer domesticus,which occupy sheltered habitats.We measured operative temperature(T_(e′) an integrative measure of the thermal environment),summit metabolic rate(M_(sum′) maximal cold-induced metabolic rate),and basal metabolic rate(BMR,minimal maintenance metabolic rate)in summer and winter.For both winter and summer,daily minimum Te was similar between open and sheltered habitats but maximum Te was higher for open habitats.Winter microclimates,however,were colder for open than for sheltered habitats after accounting for convective differences.Both species increased M_(sum) in winter,but seasonal M_(sum) flexibility was greater for larks(43%)than for sparrows(31%).Winter increases in BMR were 92.5% and 11% for larks and sparrows,respectively,with only the former attaining statistical significance.Moreover,species*season interactions in general linear models for whole-organism metabolic rates were significant for BMR and showed a similar,although not significant,pattern for M_(sum),with greater seasonal metabolic flexibility in horned larks than in house sparrows.These results suggest that extending the CVH to sympatric bird species occupying different microclimates may be valid.展开更多
文摘During in vitro fertilization, human embryos are incubated without light, and these conditions do not ensure embryo survival. This study explored whether environmental conditions can influence the embryo viability rates of the house cricket, Acheta domesticus. In particular, the experiment tested what colors of visible light provide the best incubation conditions to ensure cricket embryo viability. The concept was to use house cricket embryos to represent human embryos. Cricket embryos were chosen as their eggs have soft outer membrane casings and resemble human embryos during the first few days after fertilization. During the experiment, the adult crickets laid their eggs into one of six soil-filled boxes called substrates. Each substrate was placed into one of six storage containers filled with adult crickets and lit with a different colored visible light (red, yellow, green, blue, white, or no light). After two days of breeding, the egg-filled substrates were removed from the adult crickets and placed in another storage container of the same color light. After incubation under heat-emitting lamps and under one of six light colors, nymphs were counted after hatching to determine embryo viability. After three trials, the red light provided the significantly highest viability rate, with yellow and no light being comparable seconds. The green, blue, and white lights showed significantly lower viability rates than no visible light. My results raise the speculation that exposing fertilized mammal eggs to visible light colors might have the same effects during the in vitro fertilization process.
基金supported by the Guangdong Natural Science Foundation(2014A030307018)Science and Technology Planning Project of Guangdong Province(2016A030303068)Animal Branch of the Germplasm Bank of Wild Species(GBOWS)
文摘DEAR EDITOR, In this study, we sequenced the complete mitochondrial DNA genome （mitogenome） of the Zhengyang Yellow chicken （Gallus gallus domesticus） by next-generation sequencing technology. Samples were taken from Zhumadian city, Henan Province, China. The complete mitogenome was 16 785 bp in size, and had a nucleotide composition of 30.3% （A）, 23.7% （T） 32.5% （C）, and 13.5% （G）, with a high AT content of 54.0%. The assembled mitogenome exhibited typical mitochondrial DNA （mtDNA） structure, including a non-coding control region, two rRNA genes, 13 protein-coding genes, and 22 tRNA genes. Phylogenetic analysis indicated that this mitogenome defined a novel sub-haplogroup B3 within haplogroup B. These results should provide essential information for chicken domestication and insiqht into the evolution of genomes.
文摘Traceability based on DNA analysis is attracting increasing interest due to the crisis of confidence that consumers show towards the products of animal origin. The present work discusses a genetic traceability system of meat and processed products from an historical Tuscan native pig breed, the Cinta Senese. The study is based on a panel of 8 ISAG (International Society for Animal Genetics) DNA microsatellite markers usage done both on pigs and derived products. The SSRs panel allowed us to obtain a unique fingerprint of the individuals to be used as a tracer “downstream” in the processed products. The molecular method used proved that the hams, analyzed just before commercialization, were obtained from Cinta Senese pigs and that the analyzed meat products derived from the Cinta Senese were produced at least with 95% of Cinta Senese meat. In perspective, the molecular testing could be introduced as a voluntarily adopted method for proving intrinsic quality of many regional food products.
文摘Following an introduction, non-native species are exposed to environments that differ from those found in their native range; further, as these non-native species expand beyond the site of introduction, they must constantly adapt to novel environ- ments. Although introduced species are present across most ecosystems, few species have successfully established themselves on a truly global scale. One such species, the house sparrow Passer domesticus, is now one of the world＇s most broadly distributed vertebrate species and has been introduced to a great part of its current range. To date, work on four continents suggests both ge- netic and phenotypic variation exists between native and introduced ranges. As such, house sparrows represent an excellent op- portunity to study adaptations to novel environments and how these adaptations are derived. The global distribution of this spe- cies and the multiple independent introductions to geographically isolated sites allow researchers to ask questions regarding ge- netic variation and adaptation on a global scale. Here, we summarize the molecular studies of invasive house sparrows from the earliest work using allozymes through more recent work on epigenetics; using these studies, we discuss patterns of dispersal of this species. We then discuss future directions in techniques （e.g. next generation sequencing） and how they will provide new in- sight into questions that are fundamental to invasion biology. Finally, we discuss how continued research on the house sparrow in light of these genetic changes and adaptations will elucidate answers of adaptation, invasion biology, range expansion, and resi- lience in vertebrate systems generally
文摘The main aims of this research were to study possible differences in objective morphometric sperm characteristics, establish normative sperm morphometry standards, and evaluate the presumed different subpopulation distribution of avian spermatozoa from the rooster （Gallus domesticus） and Guinea fowl （Numida meleagris） as model avian species. Seventy-two ejaculates （36 per species studied） were obtained manually, following a training period involving gently combined dorso-abdominal and lumbo.sacral massage of the birds. Ejaculates were processed for volume, sperm concentration, viability, motility, and morphology. Moreover, samples were submitted for sperm morphometric assessment using objective Computer-Assisted Semen Analysis for Morphometry （CASA-Morph） methods, with sperm morphometric descriptors evaluated by Principal Component Analysis （PCA） and multivariate clustering analyses. There were several differences observed between the avian species in values obtained for ejaculate volume and sperm concentration （P 〈 0.001）. Irrespective of species, PCA revealed two Principal Components （PCs） explaining more than 80% of the variance. In addition, the number of subpopulations differed with species （three and five subpopulations for rooster and Guinea fowl, respectively）. Moreover, the distribution of the sperm subpopulations was found to be structurally different between species. In conclusion, our findings from using CASA-Morph methods indicate pronounced sperm morphometric variation between these two avian species. Because of the strong differences observed in morphometric parameter values and their subpopulation distribution, these results suggest that application of objective analytical methods such as CASA-Morph could substantially improve the reliability of comparative studies and help establish valid normative sperm morphological values for avian species.
文摘A large-scale outbreak of the house mouse populations occurs in grain growing in Australia on average once every four years.High densities of mice cause major yield losses to cereal crops,and low to moderate densities of mice also cause some losses.Several predictive models based on rainfall patterns have been developed to forecast mouse density.These models carry some uncertainty and the economic value of basing management actions on these models is not clear.Baiting is the most commonly used method and zinc phosphide and other rodenticide bait are effective in reducing up to 90%of mouse populations.Ecologically-based best farming practice for controlling mice has recently been developed on the basis of long-term field studies of mouse populations.No effective biological control method has been developed for mice.However,grain growers still cannot make economically rational decisions to implement control because they do not know the pest threshold density(D_(T))above which the economic benefits of control exceed the economic costs of control.Applied predator-prey theory suggests that understanding the relationship between mouse density and damage is the basis for determining D_(T).Understanding this relationship is the first research priority for managing mouse damage.The other research priority is to develop a reliable method to estimate unbiased mouse density.
文摘We examined theta activity in the temporal hippocampus of ure-thane-chloralose-anesthetized pigs by stimulation with two chemical odors, beta-phenyl ethyl alcohol (PEA;rose-like odor) and n-amyl acetate (banana-like odor). Neural activity was recorded in the neural cell layer nearby fimbria of the temporal hippocampus in three of six animals. Odor stimulation with PEA at a low concentration (10-4 w/w;100 ppm) significantly increased power of the low-frequency theta band (type-2;4 - 6 Hz) for the middle 10 s (w (3, 6, 2.5%) >2.56). The PEA odor at a higher concentration (10-3 w/w;1000 ppm), however, showed a tendency for gradual increase in?the low-frequency theta but the response was insignificant compared with the control. On the other hand, odor stimulation with n-amyl acetate (10-4 w/w;100 ppm) caused no apparent increase or a tendency for decrease in power of the low-frequency theta. Thus, the type-2 theta response in the temporal hippocampus to the PEA odor contrasted strikingly with that to the n-amylacetate in the ure-thane-chloralose-anesthetized pigs. The response of the type-2 theta rhythm in the temporal hippocampus may underlie the difference in emotional sensation and cognition of PEA from n-amyl acetate in the pig.
基金jointly funded by the Td V, the EGI and Jesus College, Oxford
文摘Background: The evolution of sexual signals is not only determined by immediate sexual selection but also by selection arising from the environment and the interaction with developmental effects.In this study we aimed to investigate how the badge size of male house sparrows(Passer domesticus) is correlated to avian malaria infections as well as to prenatal testosterone exposure,measured as the 2D:4D digit ratio.The rationale behind this study is that the immunosuppressive effect of maternal testosterone deposition combined with the fitness cost imposed by parasites may cause important trade-offs to the development of secondary sexual signals.Methods: Assuming that vector abundance is a key variable associated with infection risk by avian malaria,we caught adult male sparrows from eight different populations in the Camargue,France,four of which were located in a vector-controlled area,and the other four in an untreated area.For each bird we measured its badge size,digit ratio and took blood to determine its infections status.We used PCR to identify the malaria parasite species and strain that caused the infection.Results: Contrary to our expectation,prevalence of disease did not differ across the vector-treatment regions,with around 80 % of birds being infected in both areas,and those infections were caused largely by a single strain,Plasmodium relictum SGS1.Although infected birds had a badge size not significantly different from uninfected males,there was a condition-dependent association between badge size,infection status and maternal testosterone deposition.Conclusions: This study illustrates that the complexity of temporal and ecological dimensions makes the relationships between disease,testosterone-related traits and secondary sexual signals that have been previously reported less general than thought.
基金supported by Australian Research Council funding to SCG(FT130101253)an MQRES Ph.D scholarship to ELS from Macquarie University
文摘Background: The House Sparrow(Passer domesticus) has undergone dramatic population declines in many parts of Europe.It has been widely hypothesised that a lack of cavity nest sites has contributed to this decline.However the idea of the House Sparrow being nest site limited is somewhat incompatible with the long history of nest site plasticity in the species.Methods: The nest-site selection in a population of non-native House Sparrows introduced to Australia from Europe just over 150 years ago was characterised.The prevalence of non-cavity nesting was quantified,and nest-site selection in terms of landscape and nesting structure were described.Results: Flexible nesting behaviors were reported over a range of different landscapes and a surprisingly high rate of nesting in vegetation(43%) was documented.Most nests found in vegetation were not in cavities,but were woven into the foliage and supported by branches and stems.Conclusion: The high rate of vegetation nesting indicates that in this introduced population,the House Sparrow is unlikely to be constrained by cavity-nest site availability.The high degree of nest site plasticity in the Australian population may suggest that European House Sparrows have the potential to shift away from their proclivity for cavity nests.Future work in Europe should examine the incidence of non-cavity nesting in House Sparrows more closely,and perhaps reconsider the idea that House Sparrows are nest-site constrained.
文摘Parasites are known to be a key driving force in mate choice and are important for the expression and evolution of ornaments and behavioral traits being used.However,there is little experimental evidence on how the parasite’s burden of the choosing individual is integrated into the mate-choice process and how it affects decision-making,especially in relation to parasite infestation of potential mates.Thus,the aim of our study was to determine whether female house sparrows Passer domesticus adjust their mate preference according to their own as well as the parasite load of prospective partners.To do this,we experimentally manipulated female parasite load and determined their mate preferences prior to and after parasite treatment.We manipulated the chronic coccidian parasite burden of females either by initiating the acute infection phase via re-infecting them with coccidian or by temporally reducing the parasite load of coccidia.We then measured the effect of this manipulation on mate preference by presenting females with a choice of four stimuli:three males with similar ornaments,but unmanipulated,naturally varying chronic coccidiosis levels,and an unmanipulated control female.Additionally,we recorded some males’behavior in relation to their infection status pointing toward an increased or reduced interest in mating.We found that females preferred highly infested males prior to manipulation,regardless of their own infestation level.However,after manipulation,infested females avoided highly infested males probably in response to the deterioration of their health condition by parasites.Our study suggests that mate-choice decisions are more complex when they are mediated by parasites.The implications of parasites for evolutionary theories of sexual signaling and mate choice are discussed.
文摘Edible insects are advocated as sustainable and healthy food and feed.However,commercially produced insects are often low in n‐3 fatty acids and have suboptimal n‐6/n‐3 ratios.A certain amount and proportion of these FAs is required to optimize human health.Flaxseed oil consists primarily(57%)out of alpha‐linolenic acid.An experiment was conducted to quantify the effect of flaxseed oil provision on fatty acid composition and to determine the quantity needed to attain a beneficial n‐6/n‐3 ratio.Three species were used in the experiment:house crickets(Acheta domesticus[L.]),lesser mealworms(Alphitobius diaperinus[Pfanzer])and black soldier flies(Hermetia illucens[L.]).These were provided with either a control diet or a diet enriched with 1%,2%,or 4%flaxseed oil during their larval/nymphal stage.Fatty acid profiles of diets and insects were determined via GC‐MS.The three species had distinct fatty acid profiles on all four diets,but responded similarly to flaxseed oil addition.For each percent added to the diet,the alpha‐linolenic acid content of the insects increased by 2.3%–2.7%.Four percent addition increased the n‐3 fatty acid content 10–20 fold in the three species and thereby strongly decreased n‐6/n‐3 ratios from 18–36 to 0.8–2.4.A ratio below 5 is considered optimal for human health and was achieved by 2%flaxseed oil inclusion for house crickets and lesser mealworms,and at 1%inclusion for black soldier flies.Adding a source of n‐3 fatty acids to insect diets can thus improve the nutritional quality of insects.
文摘In the last decades, higher attention has been paid to olfactory perception in birds. As a consequence, a handful of avian species have been discovered to use olfaction in different contexts. Nevertheless, we still have a very limited knowledge about the use of odor cues in avian social life, particularly, in the case of songbirds. Here, we investigate if female house sparrows Passer domesticus show any preference for the odor of kin and nonkin conspecifics and we also test a possible role of familiarity based on male see nt in female choice. We performed the experiment with captive birds twice, duri ng the non breeding and breedi ng seas ons. Our results show that female house sparrows strongly avoided the odor of unrelated familiar (UF) males, both in the breeding and nonbreeding seasons. Our results suggest recognition for olfactory stimuli related to familiarity and kin ship. We suggest that avoidance for UF males is associated with previous experie nee in this species. Also, we provided further evidenee to the use of olfaction in passerine species by using a new experimental setup.
文摘Contrary to the nestling phase, the post-fledging phase has been less studied probably because it is challenging to follow the chicks after they fledge. However, this phase is crucial to consider when focusing on the life cycle of individuals because it is associated with new demands： After leaving the nest, individuals have to find their own food and cope with a new set of previously unknown stressors. In this study, we aimed at better understanding how energetically demanding the post-ftedging period is in house sparrows Passer domesticus by measuring several indices of a fledgling＇s state （body condition, fat and muscle scores and plumage quality）. If the energetic demands of the post-fledging period are greater than those of the adult life, we predicted that fledglings should be in lower condition and should have a plumage of lower quality relative to adults. Supporting this prediction, the condition and the plumage of fledglings differed dramatically from those of adults. Interestingly, this difference disappeared in autumn. Overall, our results suggest that the post-fledging period is probably one of the most energetically demanding of the life cycle in this species. Supporting this idea, the resighting probability of fledglings was lower relative to adults. However, resighting probability depends on many factors （mortality, dispersal, habitat use and behaviours） and future studies are necessary to tease apart their relative importance in determining resighting probability [Current Zoology 60 （4）： 449-459, 2014].
文摘Maximum and minimum metabolic rates in birds are flexible traits and such flexibility can be advantageous in variable climates.The climatic variability hypothesis(CVH)posits that more variable climates should result in greater metabolic flexibility for geographically distinct populations.Whether the CVH applies to sympatric species occupying microclimates differing in variability is unknown.Microclimates of open habitats are likely more variable than those of sheltered habitats.If the CVH extends to microclimates,we expect birds from open habitats to show greater flexibility than those from sheltered habitats.To test this extension of the CVH,we compared seasonal variation in microclimates and metabolic rates for sympatric horned larks Eremophila alpestris,which occupy open habitats,and house sparrows Passer domesticus,which occupy sheltered habitats.We measured operative temperature(T_(e′) an integrative measure of the thermal environment),summit metabolic rate(M_(sum′) maximal cold-induced metabolic rate),and basal metabolic rate(BMR,minimal maintenance metabolic rate)in summer and winter.For both winter and summer,daily minimum Te was similar between open and sheltered habitats but maximum Te was higher for open habitats.Winter microclimates,however,were colder for open than for sheltered habitats after accounting for convective differences.Both species increased M_(sum) in winter,but seasonal M_(sum) flexibility was greater for larks(43%)than for sparrows(31%).Winter increases in BMR were 92.5% and 11% for larks and sparrows,respectively,with only the former attaining statistical significance.Moreover,species*season interactions in general linear models for whole-organism metabolic rates were significant for BMR and showed a similar,although not significant,pattern for M_(sum),with greater seasonal metabolic flexibility in horned larks than in house sparrows.These results suggest that extending the CVH to sympatric bird species occupying different microclimates may be valid.
