scholarly journals Age-dependent shifts and spatial variation in the diet of endangered Black-faced Spoonbill (Platalea minor) chicks

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253469
Author(s):  
Min-Su Jeong ◽  
Chang-Young Choi ◽  
Woo-Shin Lee ◽  
Ki-Sup Lee

The endangered Black-faced Spoonbill (Platalea minor) strictly breeds in marine environments and is threatened by the rapid loss of coastal wetlands within its breeding range. Adults with chicks are thought to gradually switch feeding sites from freshwater wetlands to coastal mudflats as the chicks’ osmoregulatory system develops. We investigated age-dependent shifts in the diet of Black-faced Spoonbill chicks at four breeding colonies with varying freshwater habitat availability by examining stable isotopes (δ13C, δ15N) between the tip (grown at the age of 10 days) and middle (grown at the age of 22 days) portions of their primary feathers. The δ13C value of the middle portions was significantly higher than that of the tips, which suggested that the ratio of marine resources increased with the growth and development of chicks. A Bayesian isotope mixing model revealed that the diet proportion of marine prey in the early-chick rearing season was slightly higher than in the late-chick rearing season at three colonies in inshore areas, although this proportion was approximately 60% even in the early chick-rearing period. In contrast, isotopic values and reconstructed diet composition suggested that chicks in an offshore colony with limited freshwater wetlands relied more heavily on freshwater diets for both chick-rearing periods (>80%). Our results suggest that the shifts in feeding sites seen in previous studies might be related to the age-dependent dietary shift of chicks, highlighting the importance of freshwater wetlands for spoonbills on offshore islands without an inflow of freshwater in nearby intertidal mudflats. These findings emphasize the importance of freshwater prey and wetlands even for the endangered marine-breeding spoonbills, even though the negative impact of salt stress remains inconclusive.

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4091
Author(s):  
Zorana Kovačević ◽  
Ana Sutlović ◽  
Ana Matin ◽  
Sandra Bischof

In this study, the natural dye was extracted from Spartium junceum L. (SJL) flowers and applied on cellulose (cotton) and protein (wool) fabric. Fabrics were pre-mordant with alum prior to the dyeing process. Considering the global requirements on zero waste and green policy, the dyeing process was intended to be as much as possible environmentally friendly but still effective. Therefore, mordant concentration was optimized due to the reduction of the negative impact. The efficiency of the dyeing process was investigated by examination of fabrics’ color characteristics and colorfastness to washing properties. In this paper, we have proved that the extracted dye from Spartium junceum L. is an acidic dye (mordant dye) which is more applicable for the treatment of wool fabrics. In this paper, it was proved that phytochemicals responsible for coloring are part of the flavonoids group. The UV absorption spectra of extracted dye show 4 bands in the region of λmax 224, 268, 308 and 346 nm which are ascribed to bands characteristic for flavonoids. Wool fabric pre-mordant with 3% alum and dyed shows great chromatic (C*) properties where C* value is in a range from 47.76 for unwashed samples to 47.50 for samples after 5 washing cycles and color hue (h°) is in a range 82.13 for unwashed samples to 81.52 for samples after 5 washing cycles. The best result regarding the colorfastness properties is shown by the wool sample treated with 3% alum after 5 washing cycles (total difference in color (Delta E*) = 0.87). These results confirm that metal (Al) from alum mordant make strong chemical bonds with wool substrate and dye since Delta E* values decrease in comparison to Delta E* values of the cotton samples treated the same way. The results revealed it is possible to reduce the concentration of mordant up to 3% and obtain satisfactory results regarding the colorfastness. Nevertheless, future research will go in the direction of replacing synthetic mordant with a more environmentally friendly one.


2021 ◽  
Vol 48 (3) ◽  
pp. 33-40
Author(s):  
L. S. Yaqub ◽  
A. E. Ezekiel ◽  
A. Umar ◽  
B. Habibu ◽  
H. Aliyu ◽  
...  

High relative humidity and ambient temperature are one of the constrains to efficient thermoregulatory responses of rabbits in the tropics during the early-rainy season. The study investigated the effect of age on diurnal thermoregulatory responses in rectal (RT), ear (ET) and skin temperatures (ST) of rabbits during the early-rainy season. Seventeen apparently healthy rabbits were divided into three groups of 5 weaners, 6 growers and 6 adults. Physiologic parameters of RT, ET and ST of the rabbits were recorded concurrently with thermal environmental parameters of dry-bulb (DBT) and wet-bulb readings, at 07:00, 10:00, 13:00, 16:00 and 19:00 h, once per week for three weeks. Result revealed that RT, ET and ST were higher in adult compared to weaner or grower rabbits. The RT and ST were higher in adult than weaner rabbits at 13:00, 16:00 and 19:00 h. The ET was higher in adult than the weaner rabbits at 07:00 h. However, there was no significant (P > 0.05) difference in physiological parameters between the weaner and grower rabbits. The DBT positively correlated with ET in all age groups (Weaners r = 0.960, P < 0.01; Growers r = 0.975, P < 0.01; Adult r = 0.942, P < 0.05). The ST of weaner (r = 0.904; P < 0.05) and grower (r = 0.997; P < 0.01) rabbits positively correlated with DBT. It was concluded that there was age- dependent effect on diurnal thermoregulatory responses and RH negatively impacted on heat dissipation ability of the rabbits. It is recommended that adequate ventilation should be provided in rabbit house to reduce the negative impact of high RH on heat dissipation ability of rabbits during the early-rainy season.     L'humidité relative élevée et la température ambiante sont l'une des contraintes aux réponses thermorégulatrices efficaces des lapins sous les tropiques pendant la saison des pluies. L'étude a étudié l'effet de l'âge sur les réponses thermorégulatrices diurnes dans les températures rectales (RT), de l'oreille (ET) et de la peau (ST) des lapins pendant la saison des pluies précoces. Dix-sept lapins apparemment en bonne santé ont été divisés en trois groupes de 5 sevrés, 6 cultivateurs et 6 adultes. Les paramètres physiologiques de RT, ET et ST des lapins ont été enregistrés en même temps que les paramètres environnementaux thermiques des lectures de bulbe sec (DBT) et d'ampoule humide, à 07:00, 10:00, 13:00, 16:00 et 19:00 h, une fois par semaine pendant trois semaines. Le résultat a révélé que rt, ET et ST étaient plus élevés chez les adultes par rapport aux lapins sevrés ou de producteur. Le RT et le ST étaient plus élevés chez les lapins adultes que chez les lapins sevrés à 13 h, 16 h et 19 h. L'ET était plus élevé chez les adultes que chez les lapins sevrés à 7 h. Cependant, il n'yavait aucune différence significative (P > 0.05) dans les paramètres physiologiques entre le sevreur et les lapins de producteur. Le DBT était en corrélation positive avec l'ET dans tous les groupes d'âge (Sevreurs r = 0.960, P < 0.01; Producteurs r = 0.975, P < 0.01; Adulte r = 0.942, P < 0.05). Le ST du sevreur (r = 0.904; P < 0.05) et producteur (r = 0.997; P < 0.01) lapins positivement corrélés avec DBT. On a conclu qu'il y avait un effet dépendant de l'âge sur les réponses thermorégulatrices diurnes et que l'HR avait un impact négatif sur la capacité de dissipation thermique des lapins. Il est recommandé d'assurer une ventilation adéquate dans la maison du lapin afin de réduire l'impact négatif d'une HR élevée sur la capacité de dissipation thermique des lapins pendant la saison des pluies


2021 ◽  
Vol 91 (1) ◽  
pp. 51-54
Author(s):  
Francesco Scarton ◽  
Alvise Luchetta ◽  
Emiliano Molin ◽  
Alessandro Sartori ◽  
Roberto G. Valle

After more than a decade of regular occurrence, the first confirmed breeding of the Sacred Ibis Threskiornis aethiopicus in the lagoon of Venice (Italy) was observed in 2020, in three sites. The ibises nested in colonies with of one or more species of Ardeidae and Phalacrocoracidae. The colonies were on islets < 2 ha in size, covered with thick vegetation. Nests were placed on the top of bushes or trees, at a height of 1.5-5 m. The colony sites seemed not occupied by adults until the end of February - half of March; laying took place from early May, with hatchings occurring from the end of that month until July. Overall, 22-24 pairs nested in 2020. Birds were observed feeding at saltmarshes, freshwater wetlands and arable fields; a public garbage collection site was also used regularly. Given the high number of suitable nesting and feeding sites, a rapid growth of the Sacred Ibis population is expected in the next years.


2016 ◽  
Vol 14 (1) ◽  
pp. 43
Author(s):  
Sudaryono .

The growth of the dairy industry in Indonesia is expected to be an attraction for the local farmers. The increasing number of breeders will have a negative impact on the increase of waste generated.Waste from the farm business can be a solid waste, gas and liquid waste. Animal husbandary waste can be processed to produce biogas as an energy alternative to oil burner and premium drive electricgenerators. From the measurement of CH4 content ranged from (56.67 - 62.8 %), while the CO2 content ranged between (36.36 - 42.64 %). This value is between methane and carbon dioxide content of the theoretical limit. Gasbio volume generated during the 24 hours ranged of 4.218 - 6.198M3, or the average of the gas produced as much: 5,096 M3 per day. Electricity generated = 3.822 kWh. Electricity power genset of 500 watt can burn for 7 hours. The results of laboratory analysis of sludge solids can be seen that the C / N ratio is still relatively high at 42.6, whereas the C / N ratio, which allowed ranged of 15-25. The C value is very high due to the organic composting process is too short, the element N is very low because the nitrogen is still in the complex chain that required the administration of N fastening bacteria such as : Azotobacter, Azotomonas, Pseudomonas.Keywords: cattle manure, biogas, energy listrk, compostAbstrakPertumbuhan industri susu olahan di Indonesia diharapkan akan mampu menjadi daya tarik bagi peternak lokal. Meningkatnya jumlah peternak akan berdampak negatif terhadap meningkatkanlimbah yang dihasilkan. Limbah dari usaha peternakan tersebut dapat berupa limbah padat, gas dan limbah cair. Limbah peternakana dapat diproses untuk menghasilkan biogas sebagai energi alternatif pengganti minyak kompor dan premium menggerakan generator listrik. Dari hasil pengukuran kandungan CH4 berkisar antara (56,67 – 62.8%), sedang kandungan CO2 berkisar antara (36.36 – 42,64%). Nilai tersebut berada diantara kandungan metan dan karbon dioksida pada batas secara teori. Volume gasbio yang dihasilkan selama 24 jam berkisar antara (4,218 - 6,198) M3,atau rata-rata gas yang dihasilkan sebanyak : 5,096 M3 perhari. Listrik yang dihasilkan = 3,822 kWh. Genset dengan daya 500 Watt maka listrik bisa menyala selama 7 jam. Dari hasil analisislaboratorium terhadap padatan sludge dapat diketahui bahwa C/N ratio tergolong masih tinggi yaitu 42,6, padahal C/N ratio yang diizinkan berkisar antara 15 – 25. Hal ini disebabkan karena Corganiknya sangat tinggi akibat proses komposing masih terlalu singkat, unsur N sangat rendah karena nitrogen masih dalam rantai yang kompleks sehingga diperlukan pemberian bakteripenambat N, diantaranya adalah: bakteri Azotobacter, Azotomonas, Pseudomonas. Kata kunci: Kotoran ternak, biogas, energi listrk, kompos


2020 ◽  
Vol 163 (1) ◽  
pp. 161-179
Author(s):  
Rebekah Grieger ◽  
Samantha J. Capon ◽  
Wade L. Hadwen ◽  
Brendan Mackey

AbstractCoastal wetlands are significant components of the coastal landscape with important roles in ecosystem service provision and mitigation of climate change. They are also likely to be the system most impacted by climate change, feeling the effects of sea levels rise, temperature increases and rainfall regime changes. Climate change impacts on estuarine coastal wetlands (mangroves, saltmarsh) have been thoroughly investigated; however, the impacts on coastal freshwater wetlands (CFWs) are relatively unknown. To explore the current knowledge of the impacts of climate change on CFWs globally, we undertook a systematic quantitative literature review of peer-reviewed published literature. We found surprisingly little research (110 papers of an initial 678), the majority of which was conducted in the USA, focusing on the effects of sea level rise (SLR) on CFW vegetation or sediment accretion processes. From this research, we know that SLR will lead to reduced productivity, reduced regeneration, and increased mortality in CFW vegetation but little is known regarding the effects of other climate change drivers. Sediment accretion is also not sufficient to keep pace with SLR in many CFWs and again the effects of other climate drivers have not been investigated. The combination of unhealthy vegetation communities and minimal gain in vertical elevation can result in a transition towards a vegetation community of salt-tolerant species but more research is required to understand this process.


2019 ◽  
Vol 99 (8) ◽  
pp. 1869-1877
Author(s):  
Michel Donato Gianeti ◽  
Leandro Yokota ◽  
Rosangela Paula Teixeira Lessa ◽  
June Ferraz Dias

AbstractThis study investigated the diet of longnose stingray Hypanus guttatus in the tropical waters of north-eastern Brazil. Samples were obtained from monthly sampling of artisanal fisheries from August 2007 to July 2008. A total of 258 specimens were examined, 127 females and 131 males, and stomach contents analysis suggested H. guttatus to be a generalist and opportunistic predator feeding on the most available prey in the environment. There was no significant difference in the diet composition of males and females, or between seasons. However, an ontogenetic dietary shift was observed with larger individuals having an increased proportion of molluscs in the diet, whilst smaller individuals predated primarily on small crustaceans.


1998 ◽  
Vol 55 (8) ◽  
pp. 1798-1806 ◽  
Author(s):  
H P Schwarcz ◽  
Y Gao ◽  
S Campana ◽  
D Browne ◽  
M Knyf ◽  
...  

Stable carbon isotope ratios (13C) were measured in annual layers of otoliths of Atlantic cod (Gadus morhua) from the northeastern Scotian Shelf, Atlantic Canada. Layers deposited during the first 4-6 years of otolith growth increased in 13C from minimum values between -5‰ and -2.5‰ to a maximum near 0‰. This pattern of increase was independent of the years in which the fish was collected. Layers formed after reaching the maximum 13C value displayed decreasing or nearly constant isotopic ratios. Early rise in 13C may be a combined result of (i) decrease in the fraction of metabolic oxidized carbon in the fishes' blood as they mature, relative to the proportion of seawater-derived carbon, and (ii) dietary shift to higher trophic-level foods with higher 13C values. Age of maximum in 13C may be indicative of age of maturity of cod. The maximum 13C value attained by otoliths decreased steadily between 1983 and 1993, while cod stocks in Atlantic Canada were declining. Drop in age of attainment of maximum 13C between 1984 and 1985 coincides with changes in population dynamics of the 4Vs stock. This decrease, as well as the post maximum decrease in 13C values of the mature cod otoliths may represent movement of the fish to deeper waters of the shelf, where 13C of dissolved inorganic carbon is lower.


2010 ◽  
Vol 14 (S2) ◽  
pp. 151-175 ◽  
Author(s):  
Ben J. Heijdra ◽  
Jochen O. Mierau

We study labor-income and consumption taxation in an overlapping-generations model featuring endogenous growth due to interfirm investment externalities. Consumption, saving, and labor supply display life-cycle features because mortality and labor productivity are age-dependent and because annuity markets may be imperfect. The government's method of revenue recycling critically affects the growth consequences of taxation. Purely consumptive government spending has a negative impact on growth. Redistribution of tax revenue from dissavers to savers may lead to an increase in growth due to beneficial intergenerational transfer effects.


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