Excretion patterns of coccidian oocysts and nematode eggs during the reproductive season in Northern Bald Ibis (Geronticus eremita)

Worldwide Dispersion of Coccidia from Migratory Birds: First Report of Eimeria bazi Chauhan et Bhatia, 1970 (Eimeriidae) Outside Asia from Buff-Necked Ibises Theristicus caudatus (Boddaert, 1783) (Threskiornithidae) in South America

BACKGROUND

Eimeria spp. are coccidian protozoan parasites of domestic and wild animals. Pelecaniform birds are hosts of some Eimeria spp., however, from the family Threskiornithidae only one eimerian species is recorded, Eimeria bazi Chauhan et Bhatia, 1970 which was described from red-naped ibises Pseudibis papillosa (Temminck, 1824) in India. In this study, in turn, this species is morphologically and molecularly identified from buff-necked ibises Theristicus caudatus (Boddaert, 1783) in Brazil.

PURPOSE

This study aimed to report E. bazi from buff-necked ibises T. caudatus in southeastern Brazil, revealing the worldwide distribution of this coccidian species, in addition to providing preliminary genotypic identification via sequencing of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene.

METHODS

A total of 73 fecal samples were collected from a flock of buff-necked ibises, which remained on the campus of the Federal Rural University of Rio de Janeiro (Universidade Federal Rural do Rio de Janeiro-UFRRJ) from March 2019 to August 2020. Fecal samples were processed by the Sheather's method to recover oocysts. The morphological and morphometrical studies of the oocysts were performed using an optical microscope and graphic editing software. Molecular analysis was performed by sequencing of the COI gene, and the phylogenetic analysis was based in the neighbor-joining and maximum likelihood estimates.

RESULTS

Forty-five fecal samples were positive for oocysts identified as E. bazi. This oocysts are ovoidal, 26.2 × 18.9 μm, with smooth to slightly rough wall, c.1.7 μm thick. Micropyle robust and protruding, sometimes with a polar body attached. Oocyst residuum absent, but one or two small polar granules are present. Sporocysts ovoidal to lemon-shaped, 14.2 × 8.7 μm. The Stieda body is knob-like to rounded and sub-Stieda body is absent or vestigial. Sporocyst residuum is composed of granules often membrane-bound. Sporozoites are vermiform, with refractile bodies. This morphology was consistent with the original description of E. bazi from P. papillosa in India. Molecular analysis at the COI gene exhibited low similarity with coccidians sequenced for the same genic region deposited in GenBank, sitting E. bazi separately on the cladogram.

CONCLUSIONS

The morphological and molecular studies support the identification of E. bazi from T. caudatus in South America, thus revealing the wide distribution of this eimerian species in the world provided by migratory birds and/or with intercontinental distribution.

Infectious Wildlife Diseases in Austria-A Literature Review From 1980 Until 2017

This literature review examines infectious wildlife disease research in Austria. We analyzed 226 research papers, published between 1980 and 2017. We determined that wildlife disease papers increased significantly from 0.8 ± 0.8 publications per year in the first decade (1980–1989) when compared to 2008–2017 with an average of 12.9 ± 4.1 publications per year. We illustrate information about the most investigated diseases and highlight the lack of research into certain wildlife pathogens. A special emphasis was given to diseases with zoonotic potential. The review showed that research focused on a few select species like the red fox (Vulpes vulpes), red deer (Cervus elaphus), and wild boar (Sus scrofa), all game species. Moreover, diseases affecting livestock and human health were seen more often. The review also found that only a low number of publications actually stated disease prevalence and confidence interval data. The reported diseases identified were classified according to their notifiable status and the distribution at the wildlife–human and wildlife–livestock interface. Furthermore, we try to argue why research into some diseases is prioritized, and why other diseases are underrepresented in current Austrian research. While spatiotemporal indicators could not be assessed due to the variability in methodologies and objectives of various studies, the information provided by this review offers the first comprehensive evaluation of the status of infectious wildlife disease research in Austria. Therefore, this study could assist investigators to identify further areas of priorities for research and conservation efforts and for wildlife management professionals to inform policy and funding strategies. With this review, we want to encourage research in the field of wildlife diseases in Austria to enhance current knowledge in the prevention of further loss in biodiversity and to find new measures to promote “One Health” on a global scale.

Monitoring public awareness about the endangered northern bald ibis: a case study involving primary school children as citizen scientists

Background

Citizen science has evolved over the past decades by motivating members of the public to interact with scientists and actively participate in scientific research and monitoring. For this purpose, a proficient communication is mandatory in order to efficiently convey messages and reduce the gap of knowledge between scientists and lay people. In the present study, we aimed at evaluating the multiplying effect of children, who were trained to communicate their knowledge on an endangered bird species in order to engage the local community in the long-term ornithological monitoring of the free flying and individually marked colony of northern bald ibis (NBI, Geronticus eremita), which was established at the research station in 1997.

Methods

Pupils of the local primary schools were in regular contact with researchers, enjoyed outdoor encounters with the birds, and were invited to talk about their experience with as many people as possible. Later on, they acted as surveyors to assess the knowledge of the public on (i) the general knowledge about the species, (ii) specific knowledge about the local colony, and (iii) attitudes towards science. In two different years of evaluation (2012 and 2016) a total number of 387 persons were surveyed. The questions were generated together with the pupils and their teachers and the questionnaires were similar for both years of evaluation. All queries were in a closed format.

Results

Our results show an increase in the proportion of correct answers provided by the surveyed persons between the two years of evaluation. Education-based activities may encourage children to effectively act as multipliers of information and attitudes. This has the potential to induce sustainable changes with respect to attitude towards science, at least among local communities. Furthermore, the study suggests caution with the quality of some information reported by citizen scientists, which might be solved by more careful training actions and more specific information about local particularities. Even though the study would have gained more informative power with some additional precautions than in its current form, our findings recommend the empowerment of pupils as multipliers of scientific knowledge.

Investigating individual and social behaviour of the Northern bald ibis (Geronticus eremita): behavioural variety and welfare

The Northern bald ibis (Geronticus eremita) (NBI) is one of the most threatened birds in the world. Intense conservation efforts have been undertaken and several research projects on the species are being done in Morocco and in Europe. Observing animal behaviour has been proved to be an efficient and non-invasive technique to assess the animal welfare, with the performance of a wide array of natural behaviours being one of the mostly used indicators of good mental and physical well-being. The aim of this study was to investigate the behaviour of a flock of 14 zoo-living NBI of different ages. The study focused on the variety of species-specific individual and social behaviours, in the light of reintroduction of the study juveniles in the wild. Per subject, 20 10-min. sessions were done. A continuous focal animal sampling method was used to collect individual and social behaviours. Behavioural data have been compared between adults and juveniles. Moreover, a Behavioural Variety Index (BVI) has been proposed and calculated based on previous literature describing natural ibis behaviours. The BVI might help in the evaluation of the variety of behaviours performed by each individual and the monitoring of the diversity of the behavioural repertoire of zoo animals. Our results showed that the birds performed species-specific behaviours and no abnormal behaviour was reported. Moreover, the BVI highlighted a good behavioural variety as each bird performed approximately 78% of the natural behaviours described in the Northern bald ibis and in close relative species. Our findings seem to suggest the presence of qualitative and quantitative similarities between the behavioural repertoires of the study ibises and those described in wild conspecifics, suggesting a good welfare of the colony. Finally, the BVI proposed in the current study seems to be a useful and practical tool to test behavioural diversity in zoo animals.

Seasonal differences of corticosterone metabolite concentrations and parasite burden in northern bald ibis (Geronticus eremita): The role of affiliative interactions

The reproductive season is energetically costly as revealed by elevated glucocorticoid concentrations, constrained immune functions and an increased risk of infections. Social allies and affiliative interactions may buffer physiological stress responses and thereby alleviate associated effects. In the present study, we investigated the seasonal differences of immune reactive corticosterone metabolite concentrations, endoparasite burden (nematode eggs and coccidian oocysts) and affiliative interactions in northern bald ibis (Geronticus eremita), a critically endangered bird. In total, 43 individually marked focal animals from a free-ranging colony were investigated. The analyses included a description of initiated and received affiliative interactions, pair bond status as well as seasonal patterns of hormone and endoparasite levels. During the reproductive season, droppings contained parasite eggs more often and corticosterone metabolite levels were higher as compared to the period after reproduction. The excretion rate of endoparasite products was lower in paired individuals than in unpaired ones, but paired animals exhibited higher corticosterone metabolite concentrations than unpaired individuals. Furthermore, paired individuals initiated affiliative behaviour more frequently than unpaired ones. This suggests that the reproductive season influences the excretion patterns of endoparasite products and corticosterone metabolites and that affiliative interactions between pair partners may positively affect endoparasite burden during periods of elevated glucocorticoid levels. Being embedded in a pair bond may have a positive impact on individual immune system and parasite resistance.