Feeding Ecology of the Whiskered Tern, Chlidonias-Hybrida, in the Alligator Rivers Region, Northern-Territory

1989 ◽  
Vol 16 (5) ◽  
pp. 549 ◽  
Author(s):  
PL Dostine ◽  
SR Morton
Keyword(s):  
Feeding Ecology ◽  
Dry Weight ◽  
Northern Territory ◽  
Sexual Differences ◽  
Small Fish ◽  
Important Prey ◽  
Whiskered Tern ◽  
Invertebrate Animals ◽  
Chlidonias Hybrida

Prey from stomachs of 55 whiskered terns collected on a freshwater floodplain in the monsoonal Northern Territory were identified and counted. The terns ate a wide variety of invertebrate animals, most of them aquatic or with aquatic affinities. The most important prey in terms of dry weight were small fish, particularly Eleotridae, and insects, particularly Coleoptera, Odonata and Hemiptera. Vertebrates constituted 51% by dry weight of the diet. Numerically, dominant groups were Coleoptera, Odonata and small fish. Sexual differences were evident in morphology and diet. Males were heavier, had longer bills and wider gapes, and consumed more fish; females ate more invertebrates.

Accumulation of microelements by different invertebrate trophic groups on wasted lands

2017 ◽  
Vol 7 (4) ◽  
pp. 30-34 ◽  
Author(s):  
O. A. Didur ◽  
Yu. L. Kulbachko ◽  
V. Y. Gasso
Keyword(s):  
Active Agent ◽  
Dry Weight ◽  
Nature Management ◽  
Habitat Transformation ◽  
Natural Landscapes ◽  
Invertebrate Animals ◽  
Risk Of Disease ◽  
Ore Dressing ◽  
Processing Enterprise

<p>The problem of transformation of natural landscapes resulted from the negative technogenic impact is highlighted. It is shown that mining enterprises are powerful anthropo-technical sources of organic and inorganic toxicants entering the environment. Their wastes pollute all components of the ecosystems and negatively influence human health by increasing a risk of disease. The nature of the accumulation of trace elements (Fe, Cu, Zn, Ni, Cd, and Pb) by invertebrate animals of various functional groups under conditions of anthropo-technogenic pressure was studied. The sample plots were located on self-overgrowing sites with ruderal vegetation located in the immediate vicinity of the Mangan ore-dressing and processing enterprise (Dnipropetrovsk region). It is quite naturally that among the studied biogenic microelements (Fe, Cu, Zn and Ni), the phyto-, zoo-, and saprophages in the investigated zone of technogenic pollution most actively accumulate Fe:<em> </em>22758, 17516 and 18884 mg/kg dry weight on average, respectively. There are significant differences (p ≤ 0.05) in the content of studied microelements between saprophages and phytophages. The saprophages accumulate such trace metals as Mn, Cu, Zn and Cd in high quantities, but Ni and Pb – in smaller ones. The saprophagous functional group of invertebrates is an active agent of detritogenesis, in the conditions of modern nature management it acts as a powerful element of ecosystem engineering (habitat transformation), the main ecological role of which is to modify the habitat of other soil biota. In addition, the saprophages fulfil their concentrating geochemical function. They actively participate in the most important soil biochemical process: the formation of humus, the migration of microelements along trophic chains, the biological cycle in general, and provide such supporting ecosystem services as increasing soil fertility and nutrient cycling.</p>

Indirect evidence of conspecific nest parasitism in the colonial whiskered tern (Chlidonias hybrida)

2008 ◽  
Vol 331 (7) ◽  
pp. 559-567 ◽  
Author(s):  
Jean-Marc Paillisson ◽  
Franck Latraube ◽  
Loïc Marion ◽  
Vincent Bretagnolle
Keyword(s):  
Indirect Evidence ◽  
Nest Parasitism ◽  
Whiskered Tern ◽  
Chlidonias Hybrida

Reproductive parameters in relation to food supply in the whiskered tern (Chlidonias hybrida)

2006 ◽  
Vol 148 (1) ◽  
pp. 69-77 ◽  
Author(s):  
Jean-Marc Paillisson ◽  
Sébastien Reeber ◽  
Alexandre Carpentier ◽  
Loïc Marion
Keyword(s):  
Food Supply ◽  
Reproductive Parameters ◽  
Whiskered Tern ◽  
Chlidonias Hybrida

Herbicides for weed control in grain sorghum crops in the Northern Territory

1970 ◽  
Vol 10 (46) ◽  
pp. 588
Author(s):  
IMW Wood
Keyword(s):  
Good Control ◽  
Dry Weight ◽  
Grain Sorghum ◽  
Northern Territory ◽  
Research Station ◽  
Wet Season ◽  
Grain Yields ◽  
Stylosanthes Humilis ◽  
Townsville Stylo ◽  
Grass Weed

In experiments conducted in the 1968-69 wet season at the Katherine Research Station, Northern Territory, a number of herbicides gave good control of the grass weed Pennisetum polystachyon in grain sorghum crops. Linuron at 3 lb a.i. an acre and PCP at 20 lb a.i. an acre as pre-emergence applications effectively controlled grasses with no apparent adverse affects on the crop. With both there were significantly higher grain yields than on unweeded control plots containing an average of 1378 lb dry weight of P. polystachyon an acre. Fluometuron at 3 lb a.i. an acre late pre-emergence and early post-emergence and chlorthal at 7 lb a.i. an acre pre-emergence controlled grasses but did not increase grain yields. Further investigations are warranted with these herbicides, as banded applications to the interrow may overcome the apparent problem of crop phytotoxicity. Chlorthal at rates that gave good grass control had no adverse effect on Townsville stylo (Stylosanthes humilis). This could be an important advantage when sorghum is sown in rotation with Townsville stylo pasture or where the crop is undersown with Townsville stylo.

Patterns of Variation in The Prosome Length of Overwintering Stage V Copepodites of Calanus Finmarchicus in The Firth of Clyde

1981 ◽  
Vol 61 (4) ◽  
pp. 885-899 ◽  
Author(s):  
H. Grigg ◽  
S. J. Bardwell ◽  
S. Tyzack
Keyword(s):  
Respiration Rate ◽  
Biochemical Composition ◽  
Biological Response ◽  
Dry Weight ◽  
Sexual Differences ◽  
Calanus Finmarchicus ◽  
Calanoid Copepods ◽  
Prosome Length ◽  
Environmental Fluctuations ◽  
Males And Females

In attributing variations in growth and metabolism within a population to environmental fluctuations, and in interpreting the biological response to environmental fluctuations, it is important to recognize the variations that are intrinsic to the population or species. Consequently, it is common practice in studies on the growth and metabolism of calanoid copepods to separate instars and, in the case of adults, males and females when analysing measurements. Although studies on calanoids, in particular species of Calanus and Euchaeta, have demonstrated the existence of pronounced sexual differences in parameters such as dry weight, biochemical composition and respiration rate (e.g. Comita, Marshall & Orr, 1966; Marshall, 1973; Bamstedt, 1975, 1979; Gatten et al. 1979, 1980), the possibility that similar differences might occur in pre-adult instars has not been examined, this despite the fact that in many species in this group it is possible to distinguish the sex of copepodites IV and V, the two instars preceding the adult.

Behaviour, Energetics, and Associated Mortality of Young-of-the-Year White Perch (Morone americana) and Yellow Perch (Perca flavescens) under Simulated Winter Conditions

1991 ◽  
Vol 48 (4) ◽  
pp. 672-680 ◽  
Author(s):  
Timothy B. Johnson ◽  
David O. Evans
Keyword(s):  
Yellow Perch ◽  
White Perch ◽  
Perca Flavescens ◽  
Direct Consequence ◽  
Dry Weight ◽  
Routine Metabolic Rate ◽  
Winter Period ◽  
Small Fish ◽  
Morone Americana ◽  
Winter Conditions

After 150 d of simulated winter conditions, 71.2% of the white perch (Morone americana) had died at 2.5 °C, while only 11.1% had died at 4.0 °C. For yellow perch (Perca flavescens), 0.8% had died at 2.5 °C, while 17.7% had died at 4.0 °C. For both species, small fish died first. Multiple regression models relating overwinter mortality versus fall total length and winter duration predict 3.3 times greater mortality for white perch versus similar sized yellow perch at winter temperature regimes typical of the Great Lakes region. In laboratory tanks, white perch remained active throughout the winter period, while yellow perch sought cover and rested on or near the bottom of the experimental tanks. As a direct consequence, yellow perch had a lower routine metabolic rate and consumed body energy more gradually than white perch. During their inactive wintering period at 4.0 °C, yellow perch consumed 25.8% less oxygen than white perch. Actual measurements of dry weight loss indicated that yellow perch in the experimental tanks at 2.5 °C consumed 24.6% less dry weight than similar sized white perch. These differences in overwinter behaviour, metabolism, and survival appear to be adequate to account for observed differences in survival of these species in the wild.

Diet of the Feral Cat (Felis catus) in Central Australia

1997 ◽  
Vol 24 (1) ◽  
pp. 67 ◽  
Author(s):  
Rachel Paltridge ◽  
David Gibson ◽  
Glenn Edwards
Keyword(s):  
Body Mass ◽  
Stomach Contents ◽  
Northern Territory ◽  
Felis Catus ◽  
Feral Cat ◽  
Feral Cats ◽  
Important Prey ◽  
Southern Half ◽  
Central Australia

Feral cats (Felis catus) occur throughout central Australia. In this study, we analysed the stomach contents of 390 feral cats collected between 1990 and 1994 from the southern half of the Northern Territory. Cats fed on a wide variety of invertebrates, reptiles, birds and mammals, including animals up to their own body mass in size. Mammals were the most important prey but reptiles were regularly eaten in summer and birds were important in winter. Invertebrates were present in the diet in all seasons. Carrion appeared in stomach samples during dry winters only and this has implications for future control of feral cats.

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