Long-term declines in multiple waterbird species in a tidal embayment, south-east Australia

2015 ◽  
Vol 40 (5) ◽  
pp. 515-527 ◽  
Author(s):  
Birgita D. Hansen ◽  
Peter Menkhorst ◽  
Paul Moloney ◽  
Richard H. Loyn
2017 ◽  
Vol 45 (2) ◽  
pp. 147-154 ◽  
Author(s):  
EVAN J. PICKETT ◽  
MELANIE CHAN ◽  
WENDA CHENG ◽  
JOHN ALLCOCK ◽  
SIMBA CHAN ◽  
...  

SUMMARYThe East Asian–Australasian flyway contains some of the most threatened habitats in the world, with at least 155 waterbird species reliant on the tidal habitats it comprises. The black-faced spoonbill (Platalea minor) is an iconic endangered species distributed across the coast of East Asia. Its population suffered a severe decline into the 1990s, but extensive monitoring and conservation interventions have aided a substantial recovery of the species. We used a population viability analysis based on data collected over the past two decades in conjunction with species distribution models to project spatially explicit models of population change for the next 35 years. Over nearly all scenarios of habitat loss and climate change, the global spoonbill population was projected to increase in the short-term due to low population numbers likely well below current population carrying capacities. However, climate change and habitat loss together threaten the recovery of the spoonbill population such that, by 2050, population declines are apparent as a consequence of these cumulative impacts. These threats are also cryptic and represent a challenge to the conservation of species recovering from anthropogenic impacts; observed population increases can hide large reductions in habitat suitability that threaten the long-term viability of species.


2021 ◽  
Vol 9 ◽  
Author(s):  
Yik-Hei Sung ◽  
Chun-chiu Pang ◽  
Tom Chung-hoi Li ◽  
Paulina Pui Yun Wong ◽  
Yat-tung Yu

Along the East Asian-Australasian flyway (EAAF), waterbirds are threatened by a wide range of human activities. Studies have shown that wintering populations of many species have declined in Australia and Japan; however, long term data along China’s coast are limited. In this study, we analyzed data collected from monthly bird surveys to quantify population trends of wintering waterbirds from 1998 to 2017 in the Deep Bay area, South China. Of the 42 species studied, 12 declined, while nine increased significantly. Phylogenetic comparative analysis revealed that population trends were negatively correlated to reliance on the Yellow Sea and body size. Further, waterbird species breeding in Southern Siberia declined more than those breeding in East Asia. These findings, coupled with a relatively high number of increasing species, support the continual preservation of wetlands in the Deep Bay area. This study provides another case study showing that data collected from wintering sites provide insights on the threats along migratory pathway and inform conservation actions. As such, we encourage population surveys in the EAAF to continue, particularly along the coast of China.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Evan J. Buck ◽  
Jeffery D. Sullivan ◽  
Cody M. Kent ◽  
Jennifer M. Mullinax ◽  
Diann J. Prosser

Abstract Background While the period from fledging through first breeding for waterbird species such as terns (e.g., genus Sterna, Sternula) is of great interest to researchers and conservationists, this period remains understudied due in large part to the difficulty of marking growing juveniles with radio transmitters that remain attached for extended periods. Methods In an effort to facilitate such research, we examined the impact of various combinations of harness types (backpack, leg-loop, and 3D-printed harnesses), harness materials (Automotive ribbon, Elastic cord, and PFTE ribbon), and transmitter types (center-weighted and rear-weighted) on a surrogate for juvenile terns, 28-day-old Japanese quail (Coturnix japonica; selected due to similarities in adult mass and downy feathering of juveniles), in a 30-day experiment. We monitored for abrasion at points of contact and tag gap issues via daily exams while also recording mass and wing cord as indices of growth. This study was designed to serve as an initial examination of the impacts of marking on the growth and development of young birds and does not account for any impacts of tags on movement or behavior. Results While we found that treatment (the specific combination of the transmitter type, harness type, and harness material) had no impact on bird growth relative to unmarked control birds (P ≥ 0.05), we did observe differences in abrasion and tag gap between treatments (P ≤ 0.05). Our results suggest that leg-loop harnesses constructed from elastic cord and backpack harnesses from PFTE ribbon are suitable options for long-term attachment to growing juveniles. Conversely, we found that automotive ribbon led to extensive abrasion with these small-bodied birds, and that elastic cord induced blisters when used to make a backpack harness. Conclusions While these results indicate that long-term tagging of juvenile birds is possible with limited impacts on growth, this work does not preclude the need for small-scale studies with individual species. Instead, we hope this provides an informed starting point for further exploration of this topic.


2021 ◽  
Vol 9 ◽  
Author(s):  
Lucas Mander ◽  
Luca Scapin ◽  
Chris B. Thaxter ◽  
Rodney M. Forster ◽  
Niall H. K. Burton

Estuaries have historically been subject to considerable habitat loss, and continue to be subjected to such in areas where the natural landward migration of intertidal habitats is constrained by hard coastal defences. Thus, in estuaries where direct (e.g., port development) or indirect (e.g., sea level rise) processes are predicted to threaten intertidal habitats and associated waterbird species, there is a regulatory requirement to produce compensatory intertidal habitats. Managed realignment (MR) is a shoreline management practise that is undertaken to build sustainable coastal defences and create intertidal habitats in estuaries. This nature-based solution brings multiple benefits in the form of carbon storage, increased resilience to flooding, and, potentially, the formation of new habitats, which is the topic of this study. A 75-ha site at the Paull Holme Strays (Humber Estuary, United Kingdom) was monitored over a 10-year period following MR to examine the change in the abundance of waterbirds in the chosen site in response to the physical processes occurring there. Using digital terrain models (DTMs) collected via light detection and ranging (LiDAR), we examined how four compensatory target species responded to changes in elevation after the creation of the site. It was shown that the very rapid accretion of estuarine sediment occurred in the first decade of the new re-created intertidal, which, over time, led to changes in the numbers of benthic foraging birds supported. Furthermore, elevation change was also driven by this sediment accretion, the rate of which depended on the initial bed elevation of the sectors within the site. Ten years after the recreation of the habitat, the spatial heterogeneity in the bed elevation remained high; however, the sectors with the lowest elevations accreted the most over the 10-year period. The foraging number of the four waterbird species that colonised the MR site significantly declined above a certain elevation, with this effect being most pronounced for the Eurasian curlew (Numenius arquata). The number of common shelducks (Tadorna tadorna), dunlins (Calidris alpina), and common redshanks (Tringa totanus) declined significantly after initial peaks 5–7 years after the creation of the site, reflecting the ongoing elevation changes. Thus, this study highlighted the need for long-term studies to understand how species respond to large-scale habitat construction. It can also aid in predicting the suitability of an MR site for waterbirds in the medium and long term.


2021 ◽  
Vol 23 (1) ◽  
pp. 95-112
Author(s):  
Dan-Traian Ionescu ◽  
Călin Vasile Hodor

Abstract Waterbird species from the category of rare or irregular migratory, can have faunistical and conservative value, especially locally, but also regionally or nationally. This paper presents the results of long-term avifauna inventories (25 years) from two wetlands of importance for waterbirds, located in southeastern Transylvania, central Romania. 44 species of waterbirds from these phenological categories have been identified, some for the first time at national or regional level (Transylvania), others with a high number of individuals for the reference area or even records for Transylvania. Moreover, at least one of the species has bred sporadically here, as the only place inside the country and the second in Romania (Ichthyaetus melanocephalus), another is possibly breeding for several years (Grus grus).


2018 ◽  
Vol 29 (1) ◽  
pp. 83-99 ◽  
Author(s):  
LARS DINESEN ◽  
ALAN CHAMORRO ◽  
JON FJELDSÅ ◽  
CONSTANTINO AUCCA

SummaryLake Junín is famous for the abundance and diversity of breeding, staging and wintering waterbirds. The lake supports the entire world population of three species or subspecies: Junín Grebe Podiceps taczanowskii, Junín Rail Laterallus tuerosi and the endemic subspecies of the White-tufted Grebe Rollandia rolland morrisoni. Surveys undertaken in the 1930s, 1960s, 1970s and 1980s confirmed the lake’s importance in the Andes, however there has been no recent assessment of its waterbird community. We undertook waterbird counts between 6 and 20 February 2014 from the lakeshore and by boat. Despite using differing survey methods, we nevertheless conclude that the relative abundance of waterbird species has changed dramatically compared to earlier counts. Most notably, the Junín Grebe has experienced a major decline since the 1930s when the species was considered extremely abundant and another native fish-eating species the White-tufted Grebe also appears to have declined. In contrast the Northern Silvery Grebe Podiceps juninensis, classified as ‘Near Threatened’, has apparently become more abundant. Numbers of Puna Teal Spatula puna and Common Gallinule Gallinula galeata seem to have crashed, presumably reflecting the general loss of submerged vegetation. In spite of a major decline in waterbirds overall, the Junín area holds numbers of migratory shorebirds, perhaps as a consequence of local hunting restrictions and awareness campaigns. Lake Junín is a candidate for listing on the Montreux Record under the Ramsar Convention as a wetland showing serious change in ecological character. Management planning should proceed to balance conflicting interests at the lake. Actions to re-establish a clear water column by reducing eutrophication (from settlements in the catchment) as well as sedimentation and heavy metals (from upstream mining) will contribute to improving ecological functions and to secure waterbirds including the endemics.


2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.


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