Impact of a large dam on reproduction of a non-migratory teleost species, Acestrorhynchus lacustris (Characiformes: Acestrorhynchidae)

The release of water from the reservoir hypolimnion, lower concentration of oxygen and the anthropogenic regulation of the river flow, could affect the reproduction of fish, especially migratory species. However, little is known about the effects of these changes in water on non-migratory species. In this sense, the reproduction of Acestrohynchus lacustris was evaluated in two sections of São Francisco River, Minas Gerais, Brazil. Section 1, located immediately downstream from Três Marias Dam (18°09’31.65”S and 45°13’36.00”W) and section 2, located at the confluence of the São Francisco and the Abaeté Rivers (18°02’47.78”S and 45°10’57.95”W). For this, we obtained the physico-chemical parameters of water of each study section. Additionally, biometric data and biological indices of all specimens were measured. Fecundity and follicles diameters were measured in females. Temperature, dissolved oxygen and flow showed lower values in section 1. Fish captured in this section, had lower values of GSI in both sexes, and females presented decreased values of fecundity and follicles diameter. This species showed reproductive activity in the two sections analyzed, however, in section 1 where the temperature and dissolved oxygen presented significant lower values, the reproductive capacity of A. lacustris, was negatively affected.

Stock identification of Kawakawa Euthynnus affinis (Cantor, 1849) from Peninsular Malaysia using discriminant analysis

Small epipelagic and migratory, Eutynnus affinis (kawakawa) is one of the commercially significant tunas of Indo-Pacific’s tropical and subtropical waters. Consequently, successful management must ensure its sustainability. Unfortunately, the management and stock structure of certain migratory species in the area are not clear. The current study aimed to discriminate the E. affinis through body shape variations and to evaluate the variations among seven populations of E. affinis. A total of 114 individuals of E. affinis collected from two main geographic area, Straits of Malacca and South China Sea. Multivariate analyses, such as discriminant function analyses (DFA) of 12 morphometric characters was carried out to discriminate seven populations of E. affinis. The results revealed there is a significant variation among the body shape and seven populations of E. affinis. The average shapes of populations from Terengganu, Kelantan, and Johor were approximately similar to each other. In contrast, the average shapes of populations from Selangor were separated. This present study is the first report using morphometric method conducted on E. affinis from Peninsular Malaysian waters.

Effectiveness of Adaptive Real-Time Closures for Managing Migratory Species in Data-Limited Multispecies Fisheries

Fixed closure (FC) is a standard fisheries management tool for protecting sensitive species or species requiring conservation. However, an FC might not effectively manage migratory species because of the large uncertainties of their migration. Adaptive real-time closure (ARTC) is a tool that updates closure areas according to the latest information. This study aimed to evaluate the effectiveness of ARTC to conserve sensitive species for data-limited fisheries by a series of simulations using migration models with hotspots. In the single species simulation, the conservation ratio for the sensitive species in FC varies widely at greater migration uncertainty. In ARTC, a longer duration of a hotspot resulted in a higher conservation ratio. When the mean duration of hotspots was medium or long, the conservation ratio for the sensitive species was more than 50 % in more than 99 % of the simulation trials. In multispecies fisheries, a clear trade-off was observed between the conservation ratio of sensitive species and other species. ARTC was more effective than whole closure when the proportion of sensitive species was high or without closure when the proportion was low. Conditions in which ARTC was most appropriate were described for hotspot duration, increased numbers of individuals in a hotspot, and the relative value of conservation, representing the ratio of the value of conserving sensitive species to one of catching other species.

Response of an Afro-Palearctic bird migrant to glaciation cycles

Migration allows animals to exploit spatially separated and seasonally available resources at a continental to global scale. However, responding to global climatic changes might prove challenging, especially for long-distance intercontinental migrants. During glacial periods, when conditions became too harsh for breeding in the north, avian migrants have been hypothesized to retract their distribution to reside within small refugial areas. Here, we present data showing that an Afro-Palearctic migrant continued seasonal migration, largely within Africa, during previous glacial–interglacial cycles with no obvious impact on population size. Using individual migratory track data to hindcast monthly bioclimatic habitat availability maps through the last 120,000 y, we show altered seasonal use of suitable areas through time. Independently derived effective population sizes indicate a growing population through the last 40,000 y. We conclude that the migratory lifestyle enabled adaptation to shifting climate conditions. This indicates that populations of resource-tracking, long-distance migratory species could expand successfully during warming periods in the past, which could also be the case under future climate scenarios.

Diversity of waterbirds in mudflat and fishpond habitats in coastal Wetlands of East Lampung, Indonesia

Coastal wetlands provide habitat for waterbirds. However, changes in land use in coastal wetlands in East Lampung, Lampung Province, might affect the use of habitats by waterbirds. The study objective was to identify waterbird species using wetland habitat in coastal areas of East Lampung. Field surveys were conducted in November 2020 in two habitat types, i.e., mudflats and fishponds, employing a concentration method from several vantage points, then calculating Shannon-Wienner diversity indices (H’). A total of 23 species from 9 families of waterbirds were recorded. Mudflat had a higher diversity (H’½2.21) than fishpond (H’=1.74). Sixteen species were found on mudflats, dominated by shorebirds from the families of Scolopacidae and Charadriidae, which are primarily migratory species. Fishponds were used by 12 species, dominated by the Little Egret (Egretta garzetta) and Glossy Ibis (Plegadis falcinellus). Two endangered species, i.e., Far Eastern Curlew (Numenius madagascariensis) and Milky Stork (Mycteria cinerea), and one vulnerable species, Lesser Adjutant (Leptoptilos javanicus), were observed using mudflats. This study showed that mudflat in coastal wetlands of East Lampung provides essential habitats for conserving threatened waterbirds and migratory shorebirds.

Linking migratory performance to breeding phenology and productivity in an Afro-Palearctic long-distance migrant

Understanding the relationship between migratory performance and fitness is crucial for predicting population dynamics of migratory species. In this study, we used geolocators to explore migration performance (speed and duration of migratory movements, migratory timings) and its association with breeding phenology and productivity in an Afro-Palearctic insectivore, the European bee-eater (Merops apiaster), breeding in Iberian Peninsula. Bee-eaters migrated at higher travel speeds and had shorter travel duration in spring compared to autumn. Individuals that departed earlier or spent fewer days in-flight arrived earlier to the breeding areas. Our results show overall positive, but year-specific, linkages between arrival and laying dates. In one year, laying was earlier and productivity was higher, remaining constant throughout the season, while in the subsequent year productivity was lower and, importantly, declined with laying date. These results suggest that arriving earlier can be advantageous for bee-eaters, as in years when breeding conditions are favourable, early and late breeders produce high and similar number of fledglings, but when conditions are unfavourable only early breeders experience high productivity levels.

Language as an Impediment to Immigrants’ welfares and Development: A Case Study

Language is a vector of development. “Considered like privileged vehicle of transfer of knowledge and ideas, the language plays an irreplaceable role (…) in all the process of scientific and technological development” (Diki-Kidiri, 2004: 27). It is the means of expressing or communicating ideas which provide the capacity to communicate, thus making it a tool crucial to social organization and technological development. Indeed, language and development are intimately and incontestably linked that no country in the world could develop under using a language other than that of the concerned population. On the other hand, migration is not a new phenomenon: humans are migratory species. For economic or security reasons, people migrate. They moved to new location and new language ecologies where they come in contact with speakers of a specific set of other languages. These changes in the linguistic environment are not without consequences. At this juncture, it is worth noting that to reach their own objectives, immigrants as well as the developers: partners, animators, sensitisers, NGOs agents are in need of language of communication as the development constitutes a process in the center of which the language is. This paper focuses on the utility of language in action in order to understand how can language blocs, impedes immigrants in their daily interaction as it is inconceivable for man to do almost any activity that he does without the use of language. The research utilizes qualitative research methodology by incorporating structured interviews. Another research instrument I use is obtrusive observation to find out which of the second language acquisition, code switching, code mixing or even translation can help immigrants overcome language barriers and experience successful economic and social integration in the host country.

Does the expansion of the species' breeding range also involve the establishment of new migratory routes and new wintering ranges? The case of the citrine wagtail Motacilla citreola (Pallas, 1776)

From the second half of the 20th century, some Asian or Eastern European species expanded their breeding range westward. These include red-flanked bluetail Tarsiger cyanurus, black-headed bunting Emberiza melanocephala, common rosefinch Carpodacus erythrinus, and citrine wagtail Motacilla citreola. All of these species are long-range migratory species that historically have their own wintering ranges concentrated in Southern Asia. Although migratory behavior is mainly controlled by genetic factors, there is evidence of a high degree of flexibility and adaptability. Therefore, in the event of specific environmental changes, the genetic basis for a rapid and diverse micro-evolutionary development that affects the future migration patterns of birds is already in place. Possible adaptations also include changes to migratory directions and the choice of new and closer winter quarters. It is therefore prudent to ask whether the long-range migratory species that have expanded their breeding range westward in Europe have also established new migration routes and wintering ranges. This research shows that over the last few decades, the wintering area of Motacilla citreola has expanded westwards, including significantly the Middle East and, to a lesser extent, Africa and Europe. Especially in the activation of the most western routes, a fundamental role was played by the phenomenon of post-fledging dispersal, manifested by young who, as also observed in other Asian passerines (e.g., Pallas's warbler Phylloscopus proregulus, yellow-browed warbler Phylloscopus inornatus, pine bunting Emberiza leucocephalos), in autumn moved in different directions than the typical migratory route of their species. The Middle East and the neighboring Horn of Africa are progressively increasing in relevance as an additional area for the wintering of the species as a whole. Similarly, if in Europe the expansion of the breeding range towards the west continues in the future, West Africa, reached through Gibraltar, could become important as additional wintering ranges. In analogy with what is being observed for the western yellow wagtail Motacilla flava, Europe itself is also becoming part of the wintering range of the species. In fact, there is an increase in cases of wintering not only in the south of the continent, but there is also a progression towards the north.