A standardized dataset for conservation prioritization of songbirds to support CITES

In this article we present a standardized dataset on 6659 songbirds (Passeriformes) highlighting information relevant to species conservation prioritization with a main focus to support the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Data were collected from both scientific and grey literature as well as several online databases. The data are structured into six knowledge categories: Conventions and Treaties, Human Use, Extinction Risk, Management Opportunities, Biological Information, and Intrinsic Values. The Conventions and Treaties category includes the listings for two international conventions, CITES and the Convention on the Conservation of Migratory Species of Wild Animals (CMS), as well as EU listings for the EU Wildlife Trade Regulations and the EU Birds Directive. The Human Use category contains information on both regulated trade collected from the CITES Trade Database and the United States' Law Enforcement Management Information System (LEMIS), and highly aggregated data on seizures which we obtained from TRAFFIC, the United Nations Office on Drugs and Crime (UNODC) and two data sources on traditional medicine. We also present, for the first time, the complete Songbirds in Trade Database (SiTDB), a trade database curated by taxon expert S. Bruslund based on expert knowledge, literature review, market surveys and sale announcements. Data on the types of human use, including traditional medicine are also provided. The knowledge area on Extinction Risk contains data on the species' IUCN Red List status, the Alliance for Zero Extinction Trigger Species status, site and population at the site, the species' IUCN Climate Change Vulnerability Assessment, and the listing of priority species at the Asian Songbird Crisis Summit. In the Management Opportunities category, we gathered data on ex-situ management from Species360 zoo holdings as well as species management plans from the European and North American Zoo Associations (EAZA and AZA, respectively). Biological Information includes data on body mass, clutch size, diet, availability of data from the IUCN Red List on habitat systems, extent of occurrence, generation length, migration pattern, distribution, and biological data from the Demographic Species Knowledge Index, number of occurrences recorded by the Global Biodiversity Information Facility (GBIF) as well as genomic data from the Bird 10 000K Genomes (B10K) project, Vertebrate Genome Project (VGP) and GenBank. Information on invasive species is also part of this knowledge area. The Intrinsic Value category refers to two measures of the species' intrinsic value, namely Ecological and Evolutionary Distinctiveness. In order to make these knowledge areas comparable, we standardized data following the taxonomy of the Handbook of the Birds of the World and Birdlife (Version 4, 2019). The data enable a broad spectrum of analyses and will be useful to scientists for further research and to policymakers, zoos and other conservation stakeholders for future prioritization decisions.

Phylogeographic analyses of a migratory freshwater fish (Megalobrama terminalis) reveal a shallow genetic structure and pronounced effects of sea-level changes

Different types of fish taxa generally seem to present diverse phylogeographic structures and show different responses to environmental changes. In southern China, however, a large number of phylogeographic studies have been employed for small and/or benthic fish species, while phylogeographic patterns of larger and migratory species are not well understood. In this study, we chose Megalobrama terminalis, an endemic cyprinid from Southern China with a median size and relatively high migratory potential as a candidate to explore the phylogeographic structure and to seek the relevant driving forces using a multilocus approach (two mitochondrial markers and three nuclear markers). Our results show that M. terminalis exhibits three mtDNA genetic groups, each presenting genetic structure to the local geography, but the differentiation level was much weaker than that of small and/or benthic fish species reported in earlier studies. Nuclear loci did not observe pronounced genetic group subdivision, but did examine noteworthy genetic differentiation between the Hainan Island population and the mainland populations. Divergence time estimation and demographic analyses suggest that sea-level changes associated with the Late Pleistocene glacial cycles have exerted pronounced effects on the divergence of the three groups and the expansion of M. terminalis populations. Above all, our study provides important knowledge that can be used to improve monitoring programs and develop a conservation strategy for this endemic organism.

Reconstructing long-term trajectories of fish assemblages using historical data: the Seine River basin (France) during the last two centuries

We used historical sources from the end of the nineteenth to the mid-twentieth century and current data to retrace fish assemblage trajectories for the past 150 years on 29 river stretches distributed throughout the Seine River basin. We based our analyses on species presence/absence, occurrence of amphidromous and non-native species, and species ecological traits related to habitat preference, oxygen and temperature requirements, and diet. In accordance with general trends observed for Western Europe, we detected a general decline of amphidromous species and an increase in non-native species, even if, at some sites, several non-native species were extirpated. These changes affecting amphidromous and non-native species led to a weak increase in beta-diversity in fish assemblages. Independently of amphidromous and non-native species, for a reduced set of sites, we noted that changes in the balance of ecological traits over time, trace, in a consistent way, the major steps that affected watercourses like waterway development, increasing pollution, dam construction, or, locally, the recent wastewater treatment improvement. Despite local variations, we found contrasted trends between, on one hand, large rivers and/or catchments which had experienced strong expansion in human population, where fish assemblages had deteriorated, and, on the other hand, upstream catchments, with a declining human population, where fish assemblages showed signs of improvement. Because our results suggested that long-term changes affecting fish assemblages cannot be summarized as an unequivocal gradual degradation, we questioned the use of historical data to define ecological reference conditions for river assessment and management purposes.

Reproductive success of Whiskered Tern Chlidonias hybrida in eastern Spain in relation to water level variation

Background

A study on the Whiskered Tern Chlidonias hybrida was carried out between 2002 and 2009 in wetlands of eastern Spain to evaluate how water level fluctuation affects its reproductive success (hatching, fledgling and breeding success). This species is catalogued as Vulnerable in Spain and has an unfavorable conservation status in Europe.

Methods

Our study includes 18 sampling areas from five wetlands, covering a total of 663 nests, 1,618 eggs, 777 nestlings and 225 fledglings. The colonies were visited at least twice per week in breeding period. The number of eggs and/or nestlings present in each nest were annotated each time the colonies were visited with the aim to compare the evolution of these parameters with time. Hatching success was calculated as the proportion of egg that hatched successfully. Fledgling success and breeding success were calculated as the proportion of chicks that fledged successfully and the proportion of eggs that produced fledglings. We used the Kruskal-Wallis test to analyze the differences in the dependent variables hatching, fledgling and breeding success among the wetlands and the sampling areas. We explored the relationship between the different reproductive success with the average fluctuation rate and the anchoring depth of nests, using statistics of the linear regression.

Results

It was observed that the reproductive success varied significantly in the interaction among the different categories of water level fluctuation and the different areas (using the Kruskal-Wallis test). Our records showed that pronounced variations in water level destroyed several nests, which affected the Whiskered Tern reproductive success. Considering all events that occurred in 18 areas, the mean (±SD) of nests, eggs and nestlings that were lost after water level fluctuations were of 25.60 ± 21.79%, 32.06 ± 27.58% and 31.91 ± 21.28% respectively, also including the effects of rain and predation.

Discussion

Unfavorable climatic events, such as strong wind, rain or hail, also caused the loss of nests, eggs and nestlings, even when wetland water levels remained constant. The influence of the anchorage depth of the nest and the water level fluctuation rate were analyzed and did not provide statistically significant results. It was not possible to establish a clear pattern on these latter variables, so further studies are needed to obtain more significant results. We propose to undertake similar studies in wetlands where the water level can be regulated, with the range of nest anchorage depth on the emergent vegetation being between 30 and 60 cm, which could improve the reproductive success in this kind of habitats. As recommendation, in water level controlled wetlands (that use sluices), it should not vary more than ±6 cm in a short time (1-2 days) once the nests are established since it negatively affects their reproductive success.

Gonadorelin increases semen production and does not affect its quality in Leporinus obtusidens

Use of carp pituitary extract (CPE) as a hormone inducer for Leporinus obtusidens is cost-prohibitive; moreover, CPE contains unknown concentrations of gonadotropins. We evaluated the efficacy of gonadorelin as a substitute by analyzing its effect on sperm characteristics of L. obtusidens and cost-effectiveness (20, 40, 60, 80, and 100μgkg^-1). Untreated and CPE-treated (4mgkg^-1) fish were used as negative and positive controls, respectively. Following a single intramuscular dose of hormones, semen was collected at 200°-h. At doses from 60μgkg^-1, all fish produced higher milt volume (P<0.05) than the negative control (0.2-0.8mLkg^-1), equal (P>0.05) to the positive control (3.52±0.97mLkg^-1). Gonadorelin did not affect sperm concentration (P>0.05). The percentage of morphologically normal spermatozoa was >64% in all treatments. The number of spermatozoa with intact membrane (70%-85%) was equal (P>0.05) to that in the controls. Relative to the negative control, gonadorelin did not affect the motility rate (P>0.05). Curvilinear velocity was equal (P>0.05) to that in both controls. The sperm swimming path was linear (0.9) 10s after activation and was not (P>0.05) dose-dependent. Considering the response rate of gonadorelin-induced fish and the similarity of semen quality compared to controls, the lowest effective dose to produce a higher volume of semen in L. obtusidens is 60μgkg^-1, and the cost to induce 1kg of L. obtusidens is 14.0% lower than that with CPE.