Assessing alternative anthropogenic habitats for conserving waterbirds: salinas as buffer areas against the impact of natural habitat loss for shorebirds

Because many natural waterbird habitats are threatened by human disturbance and sea level rise, it is vitally important to identify alternative wetlands that may supplement declining natural habitats. Coastal salinas are anthropogenic habitats used for obtaining salt by evaporation of sea water. These habitats support important numbers of waterbirds around the world, but their importance as feeding habitats is poorly understood. I evaluated salinas as feeding habitats relative to natural intertidal habitats by comparing time spent foraging, prey-size selection, and net energy intake rate of four overwintering small-sized shorebird species on intertidal mudflats and on adjacent salinas. In winter, Dunlin Calidris alpina, Curlew Sandpiper C. ferruginea and Sanderling C. alba predominantly used the mudflats, whereas Little Stint C. minuta fed mainly on the salina. In the pre-migration fattening period, all species preferred to feed on the salina, significantly increasing the time they spent feeding in the supratidal pans. Net energy intake rates (kJ min^–1) were significantly higher on the salina than on the intertidal mudflats in 60% of all comparisons. On average, salina contributed 25.2 ± 24.2% (range: 4–54%) of the daily consumption in winter and 78.7 ± 16.4% (range: 63–100%) of the daily consumption in the pre-migration period. I recommend that modern active salinas maintain flooding conditions in the evaporation pans throughout winter, thus increasing the available surface for foraging waterbirds. I conclude that the conservation of salinas at coastal wetlands is a viable approach for shorebird conservation.     

The costs of migration: Injuries in migratory waterbirds along the west coast of India

The long distant, transcontinental migration of shorebirds entails many well identified costs in terms of time, energy, and direct mortality risk. Injuries from debris or from human structures and activities were observed as the major reasons for the direct mortality of shorebirds during migration worldwide. We recorded injured birds in major coastal wetlands of Kerala, for a period of 15 years from 2005 to 2019. The injured birds were observed in 9 different sites in various districts of Kerala. The highest instances of injuries were observed in Kadalundi-Vallikunnu Community Reserve, the major wintering and stop over site of migrant shorebirds in the west coast of India. During the study period, fifty-eight individuals of shorebirds belonging to four families were found to be injured. The highest proportion of injuries was recorded among the families Scolopacidae and Charadriidae comprising long distance migrant shorebird species and the lowest among Laridae and Ardeidae. We recommend that environmental authorities pay special attention to minimize anthropogenic debris along the flyways used by migratory birds thereby reducing the risk of injuries to some of these species. Proactive measures such as removal of discarded fishing gear or plastic debris from wintering areas as well as stopover areas could greatly reduce injuries in migratory birds arising from anthropogenic sources.     

Determining high value areas for steppe birds in Spain: hot spots,complementarity and the efficiency of protected areas

We have examined the distribution of 26 species of steppe birds in the Iberian Peninsula and the Balearic Islands within a grid of 5,070 10 × 10 km grid cells. The most valuable areas for steppe birds have been identified by selecting the upper 5% of the 10 × 10 km grid cells after a simple ranking based on the following criteria: species-richness, richness of rare species, rarity index, species vulnerability at Spanish, European and Global levels, and using an index combining the previous criteria. We have also used a heuristic algorithm to select those areas which offered most complementarity. The results have been analysed on a national scale and have been compared with those obtained by species assessments in previous status summaries. Finally, we have performed an analysis of the coverage afforded to locations which are valuable for steppe species by Natural Protected Areas (NPAs) and Special Protected Areas (SPAs), and an evaluation of the potential effects of temporal changes in species’ threat-status. The combined index was the most reliable criterion for defining hotspots, encompassing 15% of the species’ distributions within 5% of the total area considered. This index showed a high level of geographical concordance with the other criteria (nearly 70% of the selected grid cells coincided). Analysis of complementarity delivered poorer results than simple rank-scoring. The analysis of the efficiency of NPA network showed a very low coverage (less than 2%) of the hotspots selected according to the Combined Index. Coverage of the SPA network was higher (nearly 45%), although it diminished (to <35%) when only steppe-defined SPAs were included. The geographical concordance between high-value areas selected using current status summaries and those chosen using earlier ones was low for European threat status (53.4%), intermediate (63.2%) for Spanish threat status and high for SPEC status (78.1%). The Combined Index showed a high level of geographical concordance between the old and new data (76.6%). We conclude that automatic scoring methods (identifying hotspots) are useful for selecting valuable areas and for analysing the efficiency of the network of protected natural spaces, as well as for examining the potential effects of status changes on hotspot definition. Furthermore, the Spanish SPA network does not cover the most important areas for steppe birds adequately.     

Peripherally administered non-peptide oxytocin antagonist, L368,899, accumulates in limbic brain areas: a new pharmacological tool for the study of social motivation in non-human primates

Central administration of oxytocin (OT) antagonists inhibits maternal and sexual behavior in non-primates, providing the strongest experimental evidence that endogenous OT facilitates these behaviors. While there have been a few reports that ICV administration of OT increases social behaviors in monkeys, no studies to date have assessed the effects of OT antagonists. Therefore, we studied in rhesus monkeys whether L368,899, a non-peptide antagonist produced by Merck that selectively blocks the human uterine OT receptor, penetrates the CNS after peripheral administration and alters female maternal and sexual behavior. In two studies in four male monkeys, L368,899 was injected iv (1 mg/kg) after which (1) CSF samples were collected at intervals over 4 h and (2) brains were collected at 60 min. Assay of samples confirmed that iv-administered L368,899 entered CSF and accumulated in the hypothalamus, septum, orbitofrontal cortex, amygdala and hippocampus, but not other areas. An adult female monkey was tested for interest in either an infant or sexual behavior, receiving a different iv treatment prior to each test (1 or 3 mg/kg of L368,899 or saline). OT antagonist treatment reduced or eliminated interest in the infant and sexual behavior. These results, although preliminary, are the first to directly implicate endogenous OT in activation of primate maternal interest and sexual behavior. While it remains to be empirically demonstrated that peripherally administered L368,899 blocks central OT receptors, our behavioral findings suggest that this non-peptide antagonist may facilitate testing OT involvement in a variety of social and other behaviors in primates.