Research advances of Galliformes since 1990 and future prospects

Background: Galliformes are widely distributed throughout the world and economically important to humans as domesticated animals or gamebirds. They are at a unique position for advancing knowledge and techniques of wildlife conservation as the barometer of the status of applied ecology. Populations of many galliform species have declined mainly due to habitat loss and over-hunting. An assessment of knowledge of Galliformes could help to provide guidelines for future research and conservation strategies.Methods: Using the Web of Science search engine, we conducted a literature review of galliform-related articles published from 1990 to 2016. We used the "research area" option to filter articles focused on the zoology, environmental sciences ecology, biodiversity conservation, forestry, behavioral sciences, reproductive biology, biochemistry and molecular biology, cell biology, genetics and heredity, evolutionary biology, physiology and developmental biology. We then checked duplication based on the title, abstract and full text. In addition, we examined the reference lists of selected studies to include the publications that were missed by above searching.Results: We retained 1874 articles related to the Galliformes from the initial 243,128 publications that were found. About 91.4% focused on one or two species, and 85.0% were conducted within a short duration, typically 1–2 years. The majority of the articles concentrated on macroscopic ecology(55.5%), mainly focusing on habitat selection or habitat use. With recent advances of molecular biology, the studies of taxonomy and phylogenetics rose quickly in last two decades. The study of physiology and biochemistry was no longer limited to simple description but expanded to the mechanisms of phenotype and micro-evolutionary potential. An additional area receiving increasing attention is the conservation of Galliformes, with the assessment of the conservation status and conservation management effectiveness of Galliformes(e.g. species diversity and genetic diversity) becoming the focus.Conclusions: The studies on Galliformes have made great achievements since 1990, but there are still gaps, particularly in macroscopic ecology, molecular genetics, and conservation. There is an urgent need to enhance long-term monitoring and analysis of population dynamics, and applying different disciplines to galliform conservation. Moreover, life history information of many galliform species is still lacking, which has hindered conservation efforts and effectiveness. In addition, multidiscipline studies and new technologies are not common for galliform studies, and should be encouraged.

Two Field Techniques for Estimating Relative Abundance of Galliformes

Galliformes are often difficult to count adequately in their natural habitats due to low detectability of them. In the present study, we confirm availability of feather-count and feces-count as two useful field techniques to estimate the relative abundance of eared-pheasants (Crossoptilon spp.). The former is suitable to forest environments during the post-incubation period, whereas the latter is best in areas with dry climate conditions during the fall-winter season. With the advantages of reduced survey effort and high repeatability, the two techniques are potentially applicable to other Galliform species in habitat selection studies and long-term population monitoring.

The evolution of courtship displays in Galliformes

Species in Galliformes have elaborate ritual courtship displays,often including strutting,fluffing of tail or head feathers,and vocal sounds that serve as excellent examples of sexual selection.According to the male orientation to the female while either posturing or moving,these courtship displays of gallinaceous species can be classified into three categories:1)‘frontal displays’,2)‘lateral displays’,and 3)‘both frontal and lateral displays’.Questions regarding which category of displays is the ancestral state and the evolutionary history of courtship displays in Galliformes remain unanswered.We collected and classified 131 species in terms of their courtship displays into the three categories listed above and carried out a large-scale comparative analysis to reveal the evolutionary trajectory of this trait.We found that the ancestral state of courtship displays of Galliformes involves both relatively short and straightforward frontal and lateral elements(i.e.,the category of‘both frontal and lateral displays’).Furthermore,ancestral trait reconstructions suggest that transitions from‘lateral displays’to‘frontal displays’occurred more frequently than the other way around(i.e.,from‘frontal displays’to‘lateral displays’).In addition,some transitions occurred from‘both frontal and lateral displays’to‘lateral displays’but not from‘both frontal and lateral displays’to‘frontal displays’.Ancestral state reconstruction of courtship displays at the root of the Galliformes phylogeny supports the‘both frontal and lateral displays’first scenario.This original state then evolved towards two extremes,either‘frontal displays’or‘lateral displays’,with more complicated and elaborate display components.Moreover,subsequent transitions occurred from‘lateral displays’to‘frontal displays’much more frequently than the other way around during the evolutionary history,indicating positive selection of‘frontal displays’.

RESEARCH ON LACTIC DEHYDROGENASES (LDH) ISOENZYMES OF FOUR SPECIES IN GALLIFORMES

Low-ion-density discontinuous polyacrylamide electrophoresis (pH 8.0) of LDH from different tissuse of four species (Tetrastes bonasia,Chrysolophus pictus, Phasians colchicus, Gallus gallus domesticus) in Galliformes showed that this electrophoresis system was suitable for analysing avian LDH. Thermostabilty to heat and nonsusceptibility to urea inhibition of low-density urea of the four liver LDHs were in such order as LDH1> LDH2> LDH3> LDH4> LDH5. And it appeared. by comparing relative movable ratio of A and B subunits of LDHs, that difference exists between Phasianidae and Tetraonidae and in Phasianidae Phasianus was closer to Chrysolophus than to Gallus.

Climate change induced range shifts of Galliformes in China

Climate change will cause range shifts of many species in the future.Galliformes might be particularly vulnerable to climate change,as they have low dispersal ability.Little is known about their possible responses to the future climate.We used a generalized additive model to predict the current and future ranges of all 63 Galliformes in China,based on a comprehensive species occurrence database and a combination of climate variables.Other environmental variables(e.g.elevation and human footprint index)were also considered,as well as the latitude and longitude of the occurrences.Principal component analysis was conducted to illustrate the association between environmental variables and Galliformes distributions.Using the Special Report on Emissions Scenarios(SRES)A2 climate change scenario for 2071–2100,we projected that 29 species would have range shifts over 50%,including 13 endemic species.Galliformes at higher elevation face greater range shifts.Northward shifts are greater than those in other directions.We suggest conservationists pay special attention to the 29 Galliformes that face extensive range shifts,especially the endemic species among them.

Whole genome phylogeny of Gallus: introgression and data-type effects

Background: Previous phylogenetic studies that include the four recognized species of Gallus have resulted in a number of distinct topologies, with little agreement. Several factors could lead to the failure to converge on a consistent topology, including introgression, incomplete lineage sorting, different data types, or insufficient data.Methods: We generated three novel whole genome assemblies for Gallus species, which we combined with data from the published genomes of Gallus gallus and Bambusicola thoracicus(a member of the sister genus to Gallus). To determine why previous studies have failed to converge on a single topology, we extracted large numbers of orthologous exons, introns, ultra-conserved elements, and conserved non-exonic elements from the genome assemblies. This provided more than 32 million base pairs of data that we used for concatenated maximum likelihood and multispecies coalescent analyses of Gallus.Results: All of our analyses, regardless of data type, yielded a single, well-supported topology. We found some evidence for ancient introgression involving specific Gallus lineages as well as modest data type effects that had an impact on support and branch length estimates in specific analyses. However, the estimated gene tree spectra for all data types had a relatively good fit to their expectation given the multispecies coalescent.Conclusions: Overall, our data suggest that conflicts among previous studies probably reflect the use of smaller datasets(both in terms of number of sites and of loci) in those analyses. Our results demonstrate the importance of sampling large numbers of loci, each of which has a sufficient number of sites to provide robust estimates of gene trees. Low-coverage whole genome sequencing, as we did here, represents a cost-effective means to generate the very large data sets that include multiple data types that enabled us to obtain a robust estimate of Gallus phylogeny.

First evidence of heteroplasmy in Grey Partridge(Perdix perdix)

We report for the first time the occurrence of heteroplasmy in Grey Partridge(Perdix perdix)revealed by means of two mitochondrial fragments.The possible serious biological and management implications of this exception to unilateral inheritance of mtDNA were underlined.