Wild Cranes Research Articles

Breeding records and the detection of nesting predators of wild-release red-crowned cranes into non-breeding areas of the Yancheng National Nature Reserve, China.

The western population of the red-crowned crane Grus japonensis in mainland China has been decreasing in the past few decades and wild population enhancement programmes have been launched in this country. First, 14 captive-bred red-crowned cranes were released into the core area of Yancheng National Nature Reserve for Rare Birds (YNNR), one of the most important wintering areas of this species, in 2013 (seven individuals) and 2015 (seven individuals) and then 8 more captive-bred cranes were released into YNNR from February 2022 to February 2023. We used satellite positioning and drone monitoring to study the status of released cranes. The results showed that two individuals (No. BJZ001 and BJZ008) from the first group of released cranes were found breeding in 6 of 7 years in the YNNR from 2017 to 2023. Three individuals (No. WNNR022, WNNR025 and WNNR026) from the second group of released cranes were recorded breeding in YNNR in 2023. All released cranes lived in the YNNR year round and did not migrate with wild cranes. Raccoon dogs, Nyctereutes procyonoides, were first recorded as red-crowned crane nest predators in the YNNR. Although these released cranes breed successfully in the YNNR, nestlings might face the threat of predators in non-traditional breeding areas. Further research is needed to determine whether offsprings of released individuals migrate with wild cranes and if breeding in their original wintering grounds is truly beneficial for population growth.

Characteristics of cross transmission of gut fungal pathogens between wintering Hooded Cranes and sympatric Domestic Geese

Migratory birds travel long distance and link various pathogens. Due to habitat degradation, wintering waterfowls forage together with poultry, increasing the risk of pathogen transmission between hosts. We investigated the fungal communities between wintering Hooded Cranes and Domestic Geese by high-throughput sequencing, and inferred the potential gut pathogens for both hosts at different wintering stages. The fungal community compositions were significantly different between seasons and between the hosts. The negative correlation was found between fungal diversity and pathogenic diversity, with higher fungal diversity and less pathogenic diversity in early stage and less fungal diversity and higher pathogenic diversity in late stage for both hosts. The dissimilarity of pathogenic community compositions decreased from early to late stage, with the quantity of overlapping potential pathogenic OTUs increasing along wintering periods between the two hosts, demonstrating the existence of pathogen cross transmission between the two hosts. Furthermore, the transmission pathway of avian pathogens was mainly from Hooded Cranes to Domestic Geese while the transmission direction of human pathogens was primarily from Domestic Geese to wild cranes. Based on above results, we argued that pathogen cross transmission and underlying outbreak risk of disease should be closely monitored in migratory birds and domestic poultry.

Comparative analysis of intestinal flora between rare wild red-crowned crane and white-naped crane.

Animal intestines are extremely rich in microbial ecosystems. Numerous studies in different fields, such as epidemiology and histology, have revealed that gut microorganisms considerably mediate the survival and reproduction of animals. However, gut microbiology studies of homogeneously distributed wild cranes are still rare. This study aimed to understand the structural composition of the gut microbial community of wild cranes and elucidate the potential roles of the microorganisms. We used high-throughput sequencing to analyze the gut microbial community structure of wild cranes in the Zhalong Nature Reserve. A total of 1,965,683 valid tags and 5248 OTUs were obtained from 32 fecal samples. Twenty-six bacteria phyla and 523 genera were annotated from the intestinal tract of the red-crowned crane. Twenty-five bacteria phyla and 625 genera were annotated from the intestine of the white-naped crane. Firmicutes, Proteobacteria, and Bacteroidetes are the dominant bacterial phyla in the intestinal tract of red-crowned cranes, while Catellicoccus, Lactobacillus, Neisseria, and Streptococcus were the dominant genera. The dominant bacterial phyla in the intestinal tract of white-naped cranes were Firmicutes, Proteobacteria, Bacteroidetes, Epsilonbacteraeota, Actinobacteria, and Fusobacteria. However, the dominant genera were Catellicoccus, Lactobacillus, Neisseria, Campylobacter, Streptococcus, Anaerobiospirillum, Romboutsia, Turicibacter, Haemophilus, and Lautropia. Firmicutes had significantly higher relative abundance in the intestine of the red-crowned than white-naped cranes (P < 0.05). However, the relative abundance of Actinobacteria and Bacteroidetes was significantly higher (P < 0.05) in the intestines of white-naped than red-crowned cranes. The diversity of the intestinal flora between the two crane species was significantly different (P < 0.05). Besides, the alpha diversity of the intestinal flora was higher for white-naped than red-crowned cranes. Eight of the 41 functional pathways differed in the gut of both crane species (P < 0.05). Both species live in the same area and have similar feeding and behavioral characteristics. Therefore, host differences are possibly the main factors influencing the structural and functional differences in the composition of the gut microbial community. This study provides important reference data for constructing a crane gut microbial assessment system. The findings have implications for studying deeper relationships between crane gut microbes and genetics, nutrition, immunity, and disease.

퇴직한 교육행정직 공무원의 생애사 연구

Objectives This study is to understand what the personal and professional life course of education administrative officials who retired after working for decades in an organization called school, how those life course affect life after retirement, and how they prepare for life after retirement. Through this, the purpose is to provide an opportunity to recognize educational administrative officials as partners to achieve educational purposes, and to obtain theoretical and practical implications for our lives living in the age of 100.&#x0D; Methods To this end, a life history research method was used. The life history research method is a good research method to understand the life transition and adaptation course in the continuity of time by examining the internal dynamics and life changes in an individual's life course on the axis of time of the past, present, and future. In this study, we listened to Administration manager Kim's oral speech, who retired on June 30, 2019, and interpreted the meaning of specific experiences, events, and adaptations by connecting his life experiences in the course of life with socio-cultural and historical contexts.&#x0D; Results Administration manager Kim has lived his whole life to keep his promises to his mother and wife, and since he faithfully fulfilled his personal and professional life, he has no regrets in his life, and is very grateful that he can receive a pension, although he has left office without receiving a retirement medal due to unexpected events. Kim wants to return to the “Mountain with Ancestors' Tomb” and grow trees and live a free life like “Wandering Clouds and Wild Cranes,” but his lack of prior knowledge, declining body, and bad news of “COVID-19” forced him to put his dream on hold. He is living his second life by finding a job for the elderly as a way to spend a long time without being bored.&#x0D; Conclusions In order for a life after retirement to be satisfactory life, you must first have a healthy body, find yourself a work that will not tire you out no matter how hard you work, and the organization needs to open up a yard that collects various careers after retirement so that those who are scheduled to retire can find the work.

Blood Mercury in Three Populations of Endangered Whooping Crane (Grus americana).

We investigated concentrations of blood total mercury (THg) in three extant populations of endangered Whooping Crane (Grus americana). Blood THg was greater in cranes reintroduced during 2001-2008 that range in the eastern US (median = 0.31 ug/g ww) than both wild cranes in central North America (median = 0.11 ug/g ww) and from captivity (median = 0.01 ug/g ww). The median THg blood concentrations in the two free-ranging populations of Whooping Cranes were low compared to reproductive toxic thresholds suggested for other large bird species (> 4.3 ug/g ww), but a singular elevated concentration was observed in one crane (1.04 ug/g ww; 6% of samples from the reintroduced population). These results likely reflect variable dietary Hg exposure among these populations, but should prompt additional biomonitoring to discern risk of greater Hg exposure nearer to the time of breeding and potential effects on productivity.

Identification of diverse novel genomoviruses in gut of wild birds

Genomoviridae is a virus family belonging to circular replication associated protein encoding ssDNA (CRESS-DNA) viruses, which have diverse genomic architecture and are widely distributed among different ecosystems. In this study, we characterized 39 novel genomovirus genomes including 3 from wild egrets, 9 from wild cranes, as well as 27 from wild finches in three different types of cloacal swabs of wild bird sampled in the station of Xinqing bird ringing, Maoershan Nature Reserve in Heilongjiang Province, Changbai Mountain in Jilin Province, and Hangzhou Wetland Park in Zhejiang Province, China. Here, using a Rep sequence phylogeny-based analysis, we divided the 39 genomoviruses into 8 genera within the family Genomoviridae, including Gemycircularvirus (n=20), Gemykibivirus (n=3), Gemygorvirus (n=2), Gemyvongvirus (n=2), Gemykolovirus (n=3), Gemykrogvirus (n=6), Gemytondvirus (n=1), Gemyduguivirus (n=1) and one unclassified genomovirus. The 39 genomovirus genomes belong to 36 species (27 of which are new) based on the currently accepted genomovirus pairwise nucleotide sequence identity species demarcation threshold of 78%. Overall, the research enriches our knowledge of CRESS-DNA viral diversity in China and emphasizes the prevalence of genomoviruses in nature.

Home Range and Habitat Use of Breeding Black-Necked Cranes.

Simple SummaryThe Black-necked Crane is the only crane that breeds on the Qinghai–Tibetan Plateau, and it is currently classified as a vulnerable species. Habitat destruction and loss are the main threats for the Black-necked Crane. However, the breeding needs of Black-necked Cranes with regard to their preferred habitat remain unknown. To find the driving factors of their habitat selection, we studied the utilization rate of three habitats within the home range of Black-necked Cranes during four consecutive breeding stages. Black-necked Cranes mainly utilize meadows in the whole breeding season, followed by marsh meadows and marshes. Compared with other stages, the utilization of marsh habitat slightly increased in the postfledging stage. Since this stage is a very vulnerable period for young cranes, we suggest that grazing needs to be managed during this stage, that is, from late May to early September.To effectively protect a species, understanding its habitat needs and threats across its life-history stages is necessary. The Black-necked Crane (Grus nigricollis) is an endangered wetland bird species of the Qinghai–Tibetan Plateau, which is an important grazing area in China. To overcome the conflict between increasing grazing activities and the protection of wild cranes, we investigated the variation of habitat utilization within the home range of cranes at different stages (preincubation, incubation, postfledging, and fully fledged stages). We manually tracked 13 pairs of cranes in the Zoige international wetland, used the fixed-kernel-polygon (FKP) method to determine home-range size, and used satellite images to identify different habitat types. The average home-range size was 143.38 ± 34.46 ha. Cranes were most often located in meadow habitats followed by marsh meadows and marshes. During the postfledging stage, home-range size was significantly decreased, with the proportion of marsh habitat slightly increased. Since this stage is crucial for young-crane survival, research on the importance of marshes and effective protection measures should be further strengthened.

Genetic diversity of wild wintering red-crowned crane (Grus japonensis) by microsatellite markers and mitochondrial Cyt B gene sequence in the Yancheng reserve

The red-crowned crane (Grus japonensis) is one of the most endangered cranes in the world, and its wild population is still declining. To characterize the genetic resources of East Asian migratory populations, we studied the genetic variation in wild red-crowned cranes at the Yancheng reserve. Based on a partial Cyt b gene sequence, 32 wild red-crowned crane samples were screened from 100 feathers with unknown sample information. Twelve haplotypes were detected using 32 wild red-crowned crane samples. Six pairs of published microsatellite primers were selected for genotyping. A total of 47 alleles were obtained, with an average of 7.8 alleles per locus. All microsatellite loci were highly polymorphic; the average polymorphic information content and expected heterozygosity were 0.721 ± 0.080 and 0.768 ± 0.071, respectively. These results show that the East Asian migratory population of wild red-crowned cranes exhibits high polymorphism. These data are useful for informing reintroduction efforts. The study results provide a basis for understanding the population genetic properties of an endangered crane.

Surveillance of antibiotic resistance in Escherichia coli isolated from wild cranes on the Izumi plain in Kagoshima prefecture, Japan.

The prevalence of antibiotic resistance in 376 Escherichia coli (E. coli) isolates from fecal samples of Hooded and White-naped cranes was investigated on the Izumi plain in Kagoshima prefecture, Japan, during winter 2016 and 2017. Resistance to oxytetracycline, ampicillin, and nalidixic acid were observed in 10.9%, 3.1–4.4%, and 2.1–7.7% of isolates, respectively. Since the previous surveillance in 2007, isolation rates of antibiotic-resistant E. coli recovered from wild cranes have remained at significantly low levels compared with those in Japanese livestock. Our results indicate that surveillance of antibiotic-resistant E. coli from wild cranes wintering in the Izumi plain could be a useful strategy to indicate natural environmental pollution by antibiotic-resistant bacteria in the environment.

Characterization of gizzards and grits of wild cranes found dead at Izumi Plain in Japan.

We analyzed the gizzards, and grits retained in the gizzards of 41 cranes that migrated to the Izumi Plain during the winter of 2015/2016 and died there, either due to accident or disease. These included 31 Hooded Cranes (Grus monacha) and 10 White-naped Cranes (G. vipio). We determined body weight, gizzard weight, total grit weight and number per gizzard, and size, shape, and surface roundness of the grits. Average gizzard weights were 92.4 g for Hooded Cranes and 97.1 g for White-naped Cranes, and gizzard weight positively correlated with body weight in both species. Average total grit weights per gizzard were 19.7 g in Hooded Cranes and 25.7 g in White-naped Cranes, and were significantly higher in the latter. Average percentages of body weight to grit weight were 0.8% in Hooded Cranes and 0.5% in White-naped Cranes. Average grit number per gizzard was 693.5 in Hooded Cranes and 924.2 in White-naped Cranes, and were significantly higher in the latter. The average grit size was 2.8 mm in both species. No differences were found in the shape and surface roundness of grits between the two species. To the best of our knowledge, this is the first study on the grits retained in the gizzards of Hooded and White-naped Cranes.

Effects of captivity and artificial breeding on microbiota in feces of the red-crowned crane (Grus japonensis).

Reintroduction of the threatened red-crowned crane has been unsuccessful. Although gut microbiota correlates with host health, there is little information on gut microbiota of cranes under different conservation strategies. The study examined effects of captivity, artificial breeding and life stage on gut microbiota of red-crown cranes. The gut microbiotas of wild, captive adolescent, captive adult, artificially bred adolescent and artificially bred adult cranes were characterized by next-generation sequencing of 16S rRNA gene amplicons. The gut microbiotas were dominated by three phyla: Firmicutes (62.9%), Proteobacteria (29.9%) and Fusobacteria (9.6%). Bacilli dominated the ‘core’ community consisting of 198 operational taxonomic units (OTUs). Both captivity and artificial breeding influenced the structures and diversities microbiota of the gut. Especially, wild cranes had distinct compositions of gut microbiota from captive and artificially bred cranes. The greatest alpha diversity was found in captive cranes, while wild cranes had the least. According to the results of ordination analysis, influences of captivity and artificial breeding were greater than that of life stage. Overall, captivity and artificial breeding influenced the gut microbiota, potentially due to changes in diet, vaccination, antibiotics and living conditions. Metagenomics can serve as a supplementary non-invasive screening tool for disease control.

釧路市動物園への傷病タンチョウの受け入れとその後について

釧路市動物園では，北海道道東を中心に生息している野生タンチョウのレスキューを行っている。生息数および保護収容数の増加に伴い，限られた施設と人員配置のため，受け入れ制限（同時に2羽まで）を行いながら，先着順で，できるだけの治療を行うスタイルをとっている。保護収容を実施する環境省でも，野外で自活可能な傷病個体はできる限り収容しない方針としている。3羽目以降は，環境省の判断で野外経過観察もしくは釧路湿原野生生物保護センター（WLC）へ受け入れが検討される。治療を行った後，特に大きな損傷もない回復個体は，環境省リングを付けて放鳥される。人馴れの大きい人工育雛個体や飛翔不能個体は，飼育下繁殖群へ編入となり繁殖を目指す。ただし，肩関節や上腕近位での断翼個体は，ペアリング対象となりづらい。義足装着個体は，室内のある隔離ケージにて生涯単独飼育となる。起立不能個体・下半身麻痺個体は，ハンモック保定・強制給餌による長期介護飼育を実施する。釧路市動物園は多くの飼育ケージを持つとはいえ，特にペアリングに不向きな継続飼育個体の増加は，教育普及に活用する道を模索するとしても，問題となる。生息数増加や生息地拡大，生活スタイルの変化から，今後更に保護数増加と保護地域拡大が予測される。なんらかの根本的な改革を必要としているだろう。

Physical Body Parameters of Red-Crowned Cranes &lt;i&gt;Grus japonensis&lt;/i&gt; by Sex and Life Stage in Eastern Hokkaido, Japan

Red-crowned (or Japanese) cranes Grus japonensis are native to eastern Hokkaido, Japan--the island population, and mainland Asia--the continental population that migrates from breeding grounds along the Amur River Basin to winter in east China and the Korean Peninsula. The island population was reduced to about 50-60 birds in early part of the 20th century. Since 1950s, the population has increased to more than 1,300 as a consequence of human-provided food in winter, resulted in change of their habitats and food resource. From the carcasses of 284 wild cranes from the island population, collected in Hokkaido since 1976 until 2010, we measured six physical parameters (body weight and lengths of body, wing, tarsus, tail and exposed culmen) and divided into groups by sex and three developmental stages (juvenile, yearling and adult). All parameters of males were larger than those of females at the same stage. Total body length of females tends to grow up earlier than males, in contrast to body weight. Obvious time trends were not observed in these all parameters during 34 years for these six categories measured, except total length of male juveniles, which showed a significant increasing trend. These results provide the first extensive data on body size and mass in the wild red-crowned cranes.

Antimicrobial Susceptibility of &lt;i&gt;Escherichia coli&lt;/i&gt; Isolated from Feces of Wild Cranes Migrating to Kagoshima, Japan

Susceptibility to 13 antimicrobial agents was examined for 138 Escherichia coli isolates obtained from 192 fecal samples of wild cranes that migrated for wintering to the Izumi plain, Kagoshima prefecture in Japan. The numbers of isolates that were resistant to the antimicrobials used in this study are as follows: oxytetracycline (OTC), 22 isolates; minocycline, 7 isolates; ampicillin (ABPC), 4 isolates; nalidixic acid, 4 isolates; enrofloxacin, 2 isolates; kanamycin, one isolate. Multidrug resistant isolates exhibiting 2-4 drug resistances were obtained. All of the OTC-resistant isolates carried either the tet (A) or tet(B) gene. The bla(TEM) gene was found in all of the ABPC-resistant isolates.

Accurate analysis of prevalence of coccidiosis in individually identified wild cranes in inhabiting and migrating populations in Japan

Eimeria gruis and E. reichenowi cause coccidiosis, a major parasitic disease of cranes. By non-invasive molecular approaches, we investigated the prevalence and genetic characterization of pathogens in two Japanese crane habitats; one is Hokkaido inhabited by the endangered red-crowned crane, and the other is Izumi in Kyushu where populations that consist mainly of vulnerable hooded and white-naped cranes migrate in winter. The non-invasively collected faecal samples from each wintering population were first subjected to host genomic DNA-targeted analyses to determine the sample origin and avoid sample redundancy. Extremely high prevalence was observed in the Izumi populations (> 90%) compared with the Hokkaido population (18-30%) by examining 470 specimens by microscopy and PCR-based capillary electrophoresis (PCR-CE), using genetic markers in the second internal transcribed spacer (ITS2). Correspondence analysis of PCR-CE data revealed differences in community composition of coccidia between hooded and white-naped cranes. 18S rRNA and ITS2 sequences were determined from single oocysts excreted by red-crowned and hooded cranes. Phylogenetic analysis of 18S rRNA suggested that E. reichenowi was polyphyletic while E. gruis was monophyletic. Together with PCR-CE data, these results indicate different host specificity among the E. reichenowi type. Our data suggest that E. reichenowi comprises multiple species.

野生タンチョウＧｒｕｓ ｊａｐｏｎｅｎｓｉｓにおけるコクシジウム感染

In 2002, young Japanese Cranes Grus japonensis held captive in a facility located next to the winter feeding station in Hokkaido showed symptoms of Disseminated Visceral Coccidiosis (DVC). Screening revealed the presence of oocysts of the coccidia Eimeria gruis and Eimeria reichenowi in the feces of wild cranes, the first record of this infection in wild cranes in Hokkaido. Coccidian oocysts were distributed throughout the entire habitat area, though no serious effects have yet occurred. Given the high density of cranes at winter feeding stations and the decrease of the breeding habitat in Japan, the potential danger posed to the natural crane population by eimerian coccidiosis should be an important concern in the wildlife management practices for this species.

Individual features in the calls of the Grey Crowned Crane, Balearica regulorum gibbericeps

This study investigates if vocal monitoring of the Grey Crowned Crane, Balearica regulorum gibbericeps, is a feasible method to monitor their population. The vocal repertoire of the Grey Crowned Crane was analysed for individual, pair and sexual differences. Wild cranes could not be differentiated by individuals and sexes, and were therefore investigated for identification of pairs. Results were supplemented with data on captive birds for individuals and sexes. The results show that individuals and sex identification are possible in the unison call. Pair identification is feasible in the unison call. Vocal monitoring can, therefore, be used as a possible monitoring tool in Grey Crowned Crane populations.

Use of surrogate parental models and age periods in a successful release of hand‐reared sandhill cranes

AbstractTen sandhill crane chicks were reared in isolation from humans to prepare them for an experimental wild release. They were imprinted on realistic models using crane brooding calls and were fed by crane‐like puppets. Six of the chicks were simultaneously imprinted on a human in a crane costume. The other four chicks were introduced to this surrogate parent at 5–7 days of age. The chicks were fed natural foods by the parent at two wild sites, one of which, the release site, was a staging area for migratory cranes. Observations were made on their behavioral development, including the time spent close to the model or costumed parent and the percentage of time spent foraging. The chicks spent the initial month close to the surrogate parent but moved away more to forage during the second month. The chicks regressed to again spend a great deal of time near the parent during the third and fourth months. They were released during this regressive period by removing the surrogate parent. All five of the released chicks showed increased interest in wild cranes within days of the release and formed a continuous association with wild cranes within 30 days. Four of the five were relocated by telemetry the following spring back in Wisconsin. These young juvenile cranes were excellent candidates for release due to their adaptable nature and their level of social development. The artificial stimuli of the surrogate parent helped the chicks to generalize their attachment to wild cranes. Once with wild cranes they quickly learned additional survival skills.

Survival of Captive, Parent‐Reared Mississippi Sandhill Cranes Released on a Refuge*

Valentine et al. (1976) proposed release of captive, parent-reared Mississippi sandhill cranes (Grus canadensis pulla) to augment the endangered wild population. Field testing of the proposal was first attempted with a nonendangered subspecies, the Florida sandhill crane (G. c. pratensis), in Florida. None of the 17 handreared released cranes survived more than a few months, but a single parent-reared released crane survived at least three years (Nesbitt 1979). Results of a second field test with another nonendangered subspecies in Idaho were more favorable. Seven of 11 captive parentreared greater sandhill cranes (G. c. tabida) integrated successfully with wild cranes and migrated south; one of the seven was later seen on the wintering grounds (Drewien et al. 1981). Longer term postrelease survival studies of captive, parent-reared sandhill cranes have not been reported. We present survival data and mortality causes for captive, parent-reared Mississippi sandhill cranes after six years of annual releases on a refuge.

Salmonella enteritidis and Arizona hinshawii Isolated from Wild Sandhill Cranes

Salmonella enteritidis serotype Rubislaw and Arizona hinshawii were isolated from cloacal swabs of "healthy" live-trapped sandhill cranes (Grus canadensis tabida) in Indiana and Wisconsin. These respective isolations were the first reported from wild sandhill cranes.