Enterococcus faecalis provides protection during scavenging in carrion crow (Corvus corone)

The gut microbiota significantly influences host physiology and provides essential ecosystem services.While diet can affect the composition of the gut microbiota,the gut microbiota can also help the host adapt to specific dietary habits.The carrion crow(Corvus corone),an urban facultative scavenger bird,hosts an abundance of pathogens due to its scavenging behavior.Despite this,carrion crows infrequently exhibit illness,a phenomenon related to their unique physiological adaptability.At present,however,the role of the gut microbiota remains incompletely understood.In this study,we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing,China.Our findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria(75.51%)and Firmicutes(22.37%).Significant differences were observed in the relative abundance of Enterococcus faecalis among groups,highlighting its potential as a biomarker of facultative scavenging behavior in carrion crows.Subsequently,E.faecalis isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against Salmonella enterica infection.Results showed that E.faecalis down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha(TNF-α),interferon gamma(IFN-γ),and interleukin 6(IL-6),prevented S.enterica colonization,and regulated the composition of gut microbiota in mice,thereby modulating the host’s immune regulatory capacity.Therefore,E.faecalis exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior,offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.

The breeding biology of endemic Spectacled Parrotbill(Sinosuthora conspicillatus) in Lianhuashan National Nature Reserve, Gansu Province, China

Background: Life history traits play critical roles in population survival and evolution.Breeding information should be particularly detailed in order to provide significant insights into the population status and the evolution of other traits.To our knowledge, there is still no information about the breeding biology of Spectacled Parrotbill(Sinosuthora conspicillatus), an endemic parrotbill in China.Methods: We searched the nests, checked all nests found and recorded the information of eggs, nestlings and nest sites of the Spectacled Parrotbill from 2013 to 2015 at Lianhuashan National Nature Reserve in Gansu Province, China.Results: A total of 16 nests were found.Nest trees were artificial young spruces and honeysuckles.Mean nest height was 0.89 ± 0.47 m(n = 16) above the ground level.All nests were cup-shaped and constructed using leaves, fine strips of barks and grasses by both parents.The mean clutch size was 4.42 ± 0.79(n = 12).The eggs were oval in pale blue without speckles, and the mean egg mass was 1.25 ± 0.07 g(n = 27).The egg length was 15.56 ± 0.46 mm(n = 27) and the width was 12.46 ± 0.29 mm(n = 27).Incubation period was 13 days and nestling period was 13–14 days.The breeding success rate was 46%, and among those failed nest, 71% were depredated and 29% were deserted.Conclusion: Detailed life history information about parrotbill is still limited.The breeding biology of Spectacled Parrotbill reported in the present study should be helpful for further research about population, breeding behavior and conservation of this bird.

Population and conservation status of a transboundary group of black snub-nosed monkeys(Rhinopithecus strykeri)between China and Myanmar

DEAR EDITOR,We examined the distribution,population,and conservation status of the critically endangered Myanmar or black snub-nosed monkey(Rhinopithecus strykeri)via field surveys over 26 months(2019-2021)in the Pianma region of the China-Myanmar border.Contrary to previous reports,we only identified one group in the region,which was a cross-border group occupying a multi-year home range of 51.50-57.02 km^(2).The current group size was much larger(155-160 individuals)than that in 2012-2014(ca 100 individuals),and the group appeared to be growing.However,confirmed poaching,mining,and transboundary forest fires on the Myanmar side of the border threaten their survival.

Climate change challenge, extinction risk, and successful conservation experiences for a threatened primate species in China: Golden snub-nosed monkey(Rhinopithecus roxellana)

DEAR EDITOR, Despite the vulnerability of primates to the negative impacts of human activities and climate change, there is still room for optimism. Notably, years of conservation efforts may have paid off for the golden snub-nosed monkey(Rhinopithecus roxellana). Our field surveys confirmed the existence of 188 to 220 wild multilevel societies(MLS) of R. roxellana, with an estimated 22 710 to 26 130 individuals in 2019。

Thermal Biology of Cold-climate Distributed Heilongjiang Grass Lizard,Takydromus amurensis

Thermal biology traits reflect thermal adaptations to an environment and can be used to infer responses to climate warming in animal species.Within a widespread genus or species,assessing the latitudinal or altitudinal gradient of thermal physiological traits is essential to reveal thermal adaptations and determine future vulnerability to climate warming geographically.We determined the thermal biology traits of a cold-climate distributed lizard,Takydromus amurensis,and integrated published thermal biology traits within the genus Takydromus to reveal a preliminary geographical pattern in thermal adaptation.The mean selected body temperature(cloaca temperature;T_(sel)),critical thermal maximum(CT_(max)),critical thermal minimum(CT_(min)),and optimal temperature for locomotion(i.e.,sprint speed;T_(opt)) of T.amurensis were 32.6,45.1,3.1,and 33.4℃,respectively.The resting metabolic rates of T.amurensis were po sitively related to temperature from 18℃ to 38℃.We compared the traits of tropical T.sexlineatus,subtropical T.septentrionalis,and T.wolteri with T.amurensis and found that the CT_(max) and thermal tolerance range(the difference between CT_(max) and CT_(min);TTR) increased toward high latitudes,whereas CT_(min) increased toward low latitudes in these four Takydromus lizards.According to this preliminary pattern,we speculate the species at medium and low latitudes would be more vulnerable to extreme heat events caused by ongoing climate warming.We highlight the importance of integrating thermal biology traits along geographical clues,and its potential contribution to evaluate the vulnerabilities of species in the context of climate warming.

Conservation genomics of sibling grouse in boreal forests reveals introgression and adaptive population differentiation in genes controlling epigenetic variation

The Chinese Grouse(Tetrastes sewerzowi) and Hazel Grouse(T. bonasia) are sibling species that are well-adapted to harsh high-altitude and latitude habitats. In the current study, we sampled and sequenced 29 Chinese Grouse(n=16) and Hazel Grouse(n=13) from eight locations in China, Sweden,Germany, and northeast Poland to analyze population genetic diversity and structure, introgression, and local adaptation.

Global view on virus infection in non-human primates and implications for public health and wildlife conservation

Viruses can be transmitted from animals to humans(and vice versa)and across animal species.As such,host-virus interactions and transmission have attracted considerable attention.Non-human primates(NHPs),our closest evolutionary relatives,are susceptible to human viruses and certain pathogens are known to circulate between humans and NHPs.Here,we generated global statistics on virus infections in NHPs(VI-NHPs)based on a literature search and public data mining.In total,140 NHP species from 12 families are reported to be infected by 186 DNA and RNA virus species,68.8%of which are also found in humans,indicating high potential for crossing species boundaries.

Stable seasonal migration patterns in giant pandas

A critical function of animal movement is to maximize access to essential resources in temporally fluctuating and spatially heterogeneous environments.Seasonally mediated resource fluctuations may influence animal movements,enabling them to track changing resource distributions,resulting in annual migration patterns.The conservation-dependent giant panda(Ailuropoda melanoleuca) displays seasonal movement patterns;however,the key factor driving these seasonal migration patterns remains poorly understood.Here,we used GPS tracking collars to monitor the movements of six giant pandas over a 12-year period across different elevations,and performed statistical analysis of seasonal migration directions,routes,habitat revisitation,home range overlap,first arrival events,and stability.Our results revealed a compelling pattern of seasonal migrations that facilitated the ability of the pandas to forage at the appropriate time and place to maximize nutritional intake.Our results indicated that pandas utilize spatial memory to locate reliable food resources,as evidenced by their annual return to the same or similar winter and summer home ranges and the consistently maintained percentage of home range overlap.These novel insights into giant panda foraging and movement ecology not only enhance our understanding of its ability to adapt to nutritionally poor dietary resources but also provide important information for the development of resource utilization-based protection and management strategies.

Improved mammalian family phylogeny using gap-rare multiple sequence alignment:A timetree of extant placentals and marsupials

The timing of mammalian diversification in relation to the Cretaceous-Paleogene(KPg)mass extinction continues to be a subject of substantial debate.Previous studies have either focused on limited taxonomic samples with available whole-genome data or relied on short sequence alignments coupled with extensive species samples.In the present study,we improved an existing dataset from the landmark study of Meredith et al.(2011)by filling in missing fragments and further generated another dataset containing 120 taxa and 98 exonic markers.Using these two datasets,we then constructed phylogenies for extant mammalian families,providing improved resolution of many conflicting relationships.Moreover,the timetrees generated,which were calibrated using appropriate molecular clock models and multiple fossil records,indicated that the interordinal diversification of placental mammals initiated before the Late Cretaceous period.Additionally,intraordinal diversification of both extant placental and marsupial lineages accelerated after the KPg boundary,supporting the hypothesis that the availability of numerous vacant ecological niches subsequent to the mass extinction event facilitated rapid diversification.Thus,our results support a scenario of placental radiation characterized by both basal cladogenesis and active interordinal divergences spanning from the Late Cretaceous into the Paleogene.

Unique characteristics of gut microbiota in black snub-nosed monkeys(Rhinopithecus strykeri) reveal an enzymatic mechanism of adaptation to dietary vegetation

DEAR EDITOR,The Myanmar or black snub-nosed monkey(Rhinopithecus strykeri) is a recently discovered and critically endangered colobus primate with an unknown gut microbiota. Here, we characterized and compared the gut microbiota of R. strykeri with those of two closely related snub-nosed monkey species.

Oxygen Availability Affects Behavioural Thermoregulation of Turtle Embryos

Extending recent findings that reptile embryos seek optimal temperatures inside eggs for thermoregulation,our study demonstrates that this thermoregulatory behaviour can be affected by the amount of oxygen available to an embryo.We exposed embryos of a freshwater turtle(Mauremys reevesii)to two heat sources(an optimal temperature of 30°C and a high temperature of 33°C)under three different oxygen levels–hypoxia(12%O2),normoxia(21%O2)and hyperoxia(30%O2)–and quantified the interactive effects of temperature and oxygen availability on embryonic thermoregulatory behaviour.Our results demonstrated that,in both thermal treatments,embryos exposed to hypoxia did not move as close to the heat source and therefore selected lower temperatures than those exposed to normoxia or hyperoxia.Embryos may select low temperatures under hypoxic conditions to decrease oxygen consumption and therefore alleviate the negative impact of hypoxic stress.

Unraveling the macroevolution of horseshoe bats(Chiroptera: Rhinolophidae: Rhinolophus)

Unraveling the diversification mechanisms of organisms is a fundamental and important macroevolutionary question regarding the diversity,ecological niche, and morphological divergence of life. However, many studies have only explored diversification mechanisms via isolated factors. Here,based on comparative phylogenetic analysis, we performed a macroevolutionary examination of horseshoe bats(Chiroptera: Rhinolophidae:Rhinolophus), to reveal the inter-relationships among diversification, intrinsic/extrinsic factors, and climatic ecological niche characteristics. Results showed a general slowing trajectory during diversification, with two dispersal events from Asia into Southeast Asia and Africa playing key roles in shaping regional heterogeneous diversity. Morphospace expansions of the investigated traits(e.g., body size,echolocation, and climate niche) revealed a decoupled pattern between diversification trajectory and trait divergence, suggesting that other factors(e.g., biotic interactions) potentially played a key role in recent diversification. Based on ancestral traits and pathway analyses, most Rhinolophus lineages belonging to the same region overlapped with each other geographically and were positively associated with the diversification rate, implying a competitive prelude to speciation. Overall, our study showed that multiple approaches need to be integrated to address diversification history. Rather than a single factor, the joint effects of multiple factors(biogeography, environmental drivers, and competition) are responsible for the current diversity patterns in horseshoe bats, and a corresponding multifaceted strategy is recommended to study these patterns in the future.

A high level of extra-pair paternity in the Chestnut Thrush(Turdus rubrocanus)

Extra-pair copulation(EPC)can potentially maximize individual reproductive fitness,and this process may involve sexual selection of male and female traits that reflect individual quality.Previous studies have implied that adult characteristics are associated with the probability of extra-pair paternity(EPP),but it differs between species.Moreover,there are relatively few examples of the adaptive rationale for females’engagement in EPCs based on an examination of these more traditionally recorded traits,in combination with female flight-mediated traits such as wing length.We investigated whether EPP existed in the wild Chestnut Thrush(Turdus rubrocanus)population during three breeding seasons(2019–2021),and whether paternity was related to morphological traits of males and females.Eight highly variable microsatellite loci were used to identify paternity,and generalized linear mixed models were used to analyze the relationship between paternity and morphological traits.We found that EPP existed in the Chestnut Thrush.53.3%(N=41/77)of the broods contained at least one extra-pair offspring(EPO),and 34.6%(N=72/208)of the nestlings were EPO.We also found that male wing length was negatively associated with the probability of EPP and the proportion of EPO.Female body length was positively related to the probability of EPP.Both female body condition and mass were negatively associated with the proportion of EPO.While other traits of male and female did not relate to the probability of EPP or the proportion of EPO.Extra-pair males had better body condition compared to the males they cuckolded.EPO did not differ from their half-siblings in terms of body size or body condition.The results suggest that body size and body condition were associated with EPP in the Chestnut Thrush.This study provides fundamental information for further studies on the evolution and maintenance of EPP in the Chestnut Thrush,and it is also useful for the comparison of EPP among Turdus species.

Comparisons of thermogenic features in four coexisting songbirds:Is the northward colonized White-browed Laughingthrush different?

Thermogenic features are often invoked to illustrate animal’s colonization,distribution,and response to climate change.To understand why the White-browed Laughingthrush(Pterorhinus sannio)has expanded its distribution to temperate zones in recent years,we compared its thermogenic features with three species of songbirds that cooccur in its newly colonized areas.Thermogenic parameters of these four species were measured under different ambient temperatures,ranging from 0 to 40℃.The results showed that basal metabolic rate(BMR)was 44.5±3.9 mL O2/h in P.sannio,which is lower than predicted value by its body weight.This is also lower than the BMR of both its temperate congener the Plain Laughingthrush(P.davidi)and the montane,similar species Elliot’s Laughingthrush(Trochalopteron elliotii).The thermal neutral zone(TNZ)in P.sannio was 15-35℃,as compared to 10-27.5℃in P.davidi,25-30℃in T.elliotii,and 7.5-32.5℃in the Green-capped Greenfinch(Chloris sinica).Thermal conductance was lowest in P.sannio,with the minimum value lower than the predicted value based on its body weight.Our results showed that the northward-colonizing P.sannio exhibited different thermogenic characteristics compared with its coexisting species in the new habitat,even its congener P.davidi,which shared similar microhabitats to P.sannio.We suggest that researchers further explore the physiological mechanisms of birds’northward expansion.

Lower risk of male infanticide in multilevel primate societies

DEAR EDITOR,Male infanticide is considered a severe manifestation of sexual conflict in non-human primates during male takeover or male dominance changes. Males engaging in infanticide may obtain fitness benefits, but at the cost of female reproductive outcomes. Consequently, females have developed various anti-infanticide counterstrategies, such as coalitions, dispersal.

Dihydroergotamine ameliorates liver fibrosis by targeting transforming growth factor β type Ⅱ receptor

BACKGROUND The transforming growth factor β(TGFβ) signaling pathway plays a crucial role in the development of liver fibrosis by activating TGFβ type Ⅱ receptor(TGFβR2), followed by the recruitment of TGFβR1 finally triggering downstream signaling pathway.AIM To find drugs targeting TGFβR2 that inhibit TGFβR1/TGFβR2 complex formation, theoretically inhibit TGFβ signaling pathway, and thereby ameliorate liver fibrosis.METHODS Food and Drug Administration-approved drugs were screened for binding affinity with TGFβR2 by virtual molecular docking. We identified 6 candidates and further explored their potential by Cell Counting Kit-8(CCK-8) cell cytotoxic experiment to validate toxicity and titrated the best cellular working concentrations. Next, we further demonstrated the detailed molecular working mechanisms using mutagenesis analysis. Finally, we used a mouse model to investigate its potential anti-liver fibrosis effect.RESULTS We identified 6 drug candidates. Among these 6 drugs, dihydroergotamine(DHE) shows great ability in reducing fibrotic gene expressions such as collagen, p-SMAD3, and α-SMA in TGFβ induced cellular model of liver fibrosis in LX-2 cells. Furthermore, we demonstrated that DHE binds to TGFβR2. Moreover, mutation of Leu27, Phe30, Thr51, Ser52, Ile53, and Glu55 of TGFβR2 disrupted the binding of TGFβR2 with DHE. In addition, DHE significantly improved liver fibrosis, as evidenced by Masson’s trichrome staining of liver sections. This is further supported by the width and the velocity of the portal vein, and serum markers of liver function. In line with those observations, DHE also decreased macrophages infiltration and extracellular matrix deposition in the liver.CONCLUSION DHE alleviates liver fibrosis by binding to TGFβR2 thereby suppressing TGFβ signaling pathway. We show here that as far as drug repurposing, DHE has great potential to treat liver fibrosis.

Identifying priority protection areas of key food resources of the giant panda

Animals that live in seasonal environments adjust their reproduction cycle to optimize seasonal forage quality.Giant pandas(Ailuropoda melanoleuca)are seasonal altitudinal migrants that feed on bamboo shoots and leaves with different nutritional quality.However,the importance of bamboo shoots to giant pandas,especially small and isolated populations,is not fully appreciated.Here,we explored whether mating time of giant pandas is shaped by bamboo shoot phenology.We also assessed the intensity of ongoing bamboo shoot harvesting by local communities in 42 giant panda reserves based on questionnaire surveys.Varying intensity and protection levels of bamboo shoot harvesting were found.From these data,we developed a priority ranking scheme of protection areas for this key food resource.Our study showed that pandas time their mating behavior to coincide with bamboo shoot phenology due to the high nutritional demands associated with mating and pregnancy.We also found that bamboo shoots were not well protected in many places.Liangshan,Daxiangling,and Xiaoxiangling,containing the most isolated panda populations,were identified as the areas with the most urgent need of protection.Furthermore,equal attention should be paid to the Qiong L-B population,as this region holds considerable potential to serve as a corridor between the Minshan and Qionglai populations.To address the challenges posed by bamboo shoot harvesting,we recommend establishing more practical bamboo shoot management policies,increasing public awareness of bamboo shoot protection,and providing alternative sources of income for local communities.

Smarter birds, smaller eggs, and less parental care time

DEAR EDITOR,Natural selection favors encephalization(i.e., enlargement of relative brain size) not only because it ultimately enhances the survival of organisms but also because it does not impair reproductive success. However, little is known regarding how encephalization does not impact the reproductive success of organisms. Here, by analyzing a dataset of more than 1 000 modern bird species.

Global freshwater assessment of establishment risk of invasive Alligator gar(Atractosteus spatula) and risks to freshwater ecosystems in China

DEAR EDITOR,The introduction of freshwater fish into areas outside their native range has impacted freshwater ecosystems worldwide.In China,the non-native Alligator gar(Atractosteus spatula)fish has attracted attention due to its widespread occurrence and destructive effects on local fish populations,signaling a high potential of invasiveness.

四川唐家河自然保护区扭角羚冬春季日活动模式研究

根据相机陷阱调查获得照片的时间,研究了2008年12月～2009年5月唐家河自然保护区内野生扭角羚Budorcastaxicolor的日活动模式。通过对24个1km×1km样方的调查,共完成686个相机工作日的取样量,获得有效的扭角羚捕捉次数709次(冬季322次,春季387次),并分别计算出扭角羚冬季和春季在各时间段的相对活动强度指数RAI。结果显示,扭角羚在冬季和春季的日活动模式没有显著差异(χ2检验,P>0.1),每天都有3个活跃时期(凌晨、早上和下午)和3个紧随的不活跃时期。其中,冬季日活动的最高峰出现在下午17:00～18:00(RAI=12.42),最低谷出现在日出前3:00～6:00(RAI=0.00);春季最高峰出现在早上6:00～7:00(RAI=20.16),最低谷出现在日出前2:00～5:00(RAI=0.26)。在春季,扭角羚在上午活跃期的活动强度明显高于下午活跃期,而在冬季则相反。春季与冬季相比,扭角羚上午和下午的两个活跃时间段都有提前,可能是由于不同季节气温和光照差异的影响。研究表明,相机陷阱调查技术是研究野生动物在野外活动模式和活动节律的有效工具,可为今后深入开展扭角羚行为生态学研究和保护区内野生动物的管理提供基础的科学依据。