How does nest box temperature affect nestling growth rate and breeding success in a parrot?

Climate change is predicted to affect many species by reducing range, habitat suitability and breeding success. Cavity-nesting species, already threatened by deforestation and declining natural hollows, may be particularly at risk because they are limited in nest-site location, and climatic alterations may further reduce usability of natural cavities. It is therefore essential to determine how cavity-users may be affected. We recorded internal nest box temperatures and modelled the relationships of four temperature parameters (relating to mean temperature, variability in temperature, low temperature extremes and high temperature extremes) with breeding success and nestling growth in an Australian cavity-nesting parrot, the Crimson Rosella (Platycercus elegans). We found that less extreme low temperatures resulted in heavier nestlings; however, higher mean temperatures tended to result in lighter nestlings. Greater temperature variability tended to reduce fledging success; however, no temperature variables had a clear effect on clutch size or hatching success. Our findings indicate that there may be a complex relationship between nestling growth and temperature, and although less extreme cold temperatures may benefit nestlings, continued increases in mean temperature and variability may have negative consequences.

Fathers with highly demanding partners and offspring in a semidesert environment: energetic aspects of the breeding system of Monteiro's Hornbills (Tockus monteiri) in Namibia

Molting females of Monteiro's Hornbills (Tockus monteiri) seal themselves in nest cavities to breed until chicks are about half grown. To gain insight into the chronology of energy requirements of the Monteiro's Hornbill family unit in relation to this peculiar breeding strategy, we measured a number of ecological, physiological, and environmental variables during the Monteiro's Hornbill's breeding season. Those measurements included rates of energy expenditure of female Monteiro's Hornbills while in the nest cavity, characterizing their thermal environment, timing of egg laying, molt, hatching and fledging of chicks, as well as measuring clutch size and chick growth. Temperatures within the nest box varied between 12 and 39°C and did not affect the female energy expenditure. Female body mass and energy expenditure averaged 319 g and 5 W, respectively, at the start of concealment and decreased by on average 1.1 g day -1 and 0.05 W day -1 during at least the first 30 days of the 52-58 day concealment period. Clutch size varied between 1 and 8 and averaged 4.1 eggs, with eggs averaging only 66% of the mass predicted for a bird of this size. Over the range of chick ages at which the female might leave the nest, the predicted energy requirements for maintenance and tissue growth for a Monteiro's Hornbill chick increase sharply from 1.2 W at age 8 to 3.0 W at age 25. Reduction of the female energy requirement with time, the relatively low growth rate and therewith low energy requirements of Monteiro's Hornbill chicks, and an appropriate timing of the female's exodus from the nest cavity all aid in containing peak energy demands to levels that are sustainable for the food provisioning male.

Climate change and sea turtles : a 150-year reconstruction of incubation temperatures at a major marine turtle rookery

Sea turtles show temperature dependent sex determination. Using an empirical relationship between sand and air temperature, we reconstructed the nest temperatures since 1855 at Ascension Island, a major green turtle (Chelonia mydas) rookery. Our results show that inter-beach thermal variations, previously ascribed to the albedo of the sand, which varies hugely from one beach to another, have persisted for the last century. Reconstructed nest temperatures varied by only 0.5 °C on individual beaches over the course of the nesting season, while the temperature difference between two key nesting beaches was always around 3 °C. Hence inter-beach thermal variations are the main factor causing a large range of incubation temperatures at this rookery. There was a general warming trend for nests, with a mean increase in reconstructed nest temperatures for different months of between 0.36 and 0.49 °C for the last 100 years.

Prenatal acoustic communication programs offspring for high posthatching temperatures in a songbird.

In many species, embryos can perceive and learn external sounds. Yet, the possibility that parents may use these embryonic capacities to alter their offspring's developmental trajectories has not been considered. Here, we demonstrate that zebra finch parents acoustically signal high ambient temperatures (above 26°C) to their embryos. We show that exposure of embryos to these acoustic cues alone adaptively alters subsequent nestling begging and growth in response to nest temperature and influences individuals' reproductive success and thermal preferences as adults. These findings have implications for our understanding of maternal effects, phenotypic plasticity, developmental programming, and the adaptation of endothermic species to a warming world.

High atmospheric temperatures and 'ambient incubation' drive embryonic development and lead to earlier hatching in a passerine bird

Tropical and subtropical species typically experience relatively high atmospheric temperatures during reproduction, and are subject to climate-related challenges that are largely unexplored, relative to more extensive work conducted in temperate regions. We studied the effects of high atmospheric and nest temperatures during reproduction in the zebra finch. We characterized the temperature within nests in a subtropical population of this species in relation to atmospheric temperature. Temperatures within nests frequently exceeded the level at which embryo's develop optimally, even in the absence of parental incubation. We experimentally manipulated internal nest temperature to demonstrate that an average difference of 6°C in the nest temperature during the laying period reduced hatching time by an average of 3% of the total incubation time, owing to 'ambient incubation'. Given the avian constraint of laying a single egg per day, the first eggs of a clutch are subject to prolonged effects of nest temperature relative to later laid eggs, potentially increasing hatching asynchrony. While birds may ameliorate the negative effects of ambient incubation on embryonic development by varying the location and design of their nests, high atmospheric temperatures are likely to constitute an important selective force on avian reproductive behaviour and physiology in subtropical and tropical regions, particularly in the light of predicted climate change that in many areas is leading to a higher frequency of hot days during the periods when birds breed.

Sand temperatures for nesting sea turtles in the Caribbean: Implications for hatchling sex ratios in the face of climate change

A 200-year time series of incubation temperatures and primary sex ratios for green (Chelonia mydas), hawksbill (Eretmochelys imbricata) and leatherback (Dermochelys coriacea) sea turtles nesting in St. Eustatius (North East Caribbean) was created by combining sand temperature measurements with historical and current environmental data and climate projections. Rainfall and spring tides were important because they cooled the sand and lowered incubation temperatures. Mean annual sand temperatures are currently 31.0. °C (SD. =. 1.6) at the nesting beach but show seasonality, with lower temperatures (29.1-29.6. °C) during January-March and warmer temperatures (31.9-33.3. °C) in June-August. Results suggest that all three species have had female-biased hatchling production for the past decades with less than 15.5%, 36.0%, and 23.7% males produced every year for greens, hawksbills and leatherbacks respectively since the late nineteenth century. Global warming will exacerbate this female-skew. For example, projections indicate that only 2.4% of green turtle hatchlings will be males by 2030, 1.0% by 2060, and 0.4% by 2090. On the other hand, future changes to nesting phenology have the potential to mitigate the extent of feminisation. In the absence of such phenological changes, management strategies to artificially lower incubation temperatures by shading nests or relocating nest clutches to deeper depths may be the only way to prevent the localised extinction of these turtle populations.

Pandora`s box : academic perceptions of student plagiarism in writing

Plagiarism is viewed by many academics as a kind of Pandora's box—the elements contained inside are too frightening to allow escape for fear of the havoc that may result. Reluctance by academic members of staff to discuss student plagiarism openly may contribute to the often untenable situations we, as teachers, face when dealing with student plagiarism issues. In this article, I examine the dilemmas English for Academic Purposes (EAP) staff face when dealing with student plagiarism in the tertiary classroom. The perceptions of all 11 teachers involved in teaching a first year EAP writing subject at South-Coast University are detailed in light of the university's policy on plagiarism. My research indicates that not only is an agreed definition of plagiarism difficult to reach by members of staff teaching the same subject, but plagiarism is a multi-layered phenomenon encompassing a spectrum of human intention. Evaluating the spectrum can lead to differences in the implementation of university plagiarism policy, the result of which embodies issues of equity. The aim of the article is to encourage policy-makers and academic staff to acknowledge the concerns about implementation of plagiarism policy. Collaborative, cross-disciplinary re-thinking of plagiarism is needed to reach workable solutions.

Australia`s box - ironbark forests and woodlands : saving the fragments of a threatened ecosystem

Australia's box-ironbark forests and woodlands once covered about 14 per cent of the State of Victoria on the riverine plains and foothills of the Great Dividing Range. But approximately 83 per cent of the total original habitat has been destroyed and what remains of this significant ecosystem is now highly fragmented and vulnerable to further degradation. Moreover, only 14 per cent of the area remaining is on public land. A 10 year campaign on the part of the environmental movement eventually succeeded in forcing the State government to conduct an independent inquiry into this ecosystem and make recommendations on future management. This paper outlines the innovative public participation process adopted by the Victorian State government and the outcomes of the inquiry. A subsequent compensation package for commercial operations disadvantaged by the proclamation of a series of new national parks is also discussed, as are the shortcomings of a process that can have little or no impact on what happens on private land.

Frequency distribution of TATA box and extension sequences on human promoters

TATA box is one of the most important transcription factor binding sites. But the exact sequences of TATA box are still not very clear yet. In this study, we conducted a dedicated analysis on the frequency distribution of TATA Box and its extension sequences on human promoters. Sixteen TATA elements derived from TATA Box motif, TATAWAWN, were classified into three distribution patterns: peak, bottom-peak and bottom. Fourteen TATA extension sequences (up to two base extensions) were predicted to be the new TATA Box elements because of their high motif factors, which indicate their statistical significance. Statistical analysis on the promoters of mouse, zebrafish and drosophila melanogaster verified seven of these elements. It was also observed that the distribution of TATA elements on the promoters of housekeeping genes are very similar with their distribution on the promoters of tissue specific genes in human.

Nest-tree selection by the threatened brush-tailed phascogale (phascogale tapoatafa) (marsupialia: dasyuridae) in a highly fragmented agricultural landscape

The conservation of roosting and nesting resources is of critical concern for many hollow-dependent species around the world. We investigated the nest-tree requirements of the threatened brush-tailed phascogale (Phascogale tapoatafa) in a highly cleared agricultural landscape in south-eastern Australia. We documented the physical characteristics of selected nest trees and describe the spatial and temporal patterns of nest-tree use as revealed by radio-tracking. Nine phascogales (seven females, two males) were radio-tracked between March and July 1999 in an area where most woodland habitat is confined to linear strips along roads and streams or small patches and scattered trees in cleared farmland. Female phascogales were monitored for 13–35 days over periods of 5–15 weeks and two males were monitored for 2 and 9 days respectively. A total of 185 nest-tree fixes was collected and all nests occupied by phascogales were in standing trees. Eighty-three nest trees were identified, ranging in diameter at breast height (dbh) from 25 to 171 cm, with a mean dbh for the trees used by each individual phascogale of >80 cm. Phascogales did not discriminate between canopy tree species in selecting nest trees, but showed highly significant selection for trees in the largest size class. All individuals used multiple nest trees, with the seven females occupying an average of 11.4 nest trees from a mean of 25 diurnal locations. The number of nest trees continued to increase throughout the study, suggesting that more would be identified during a longer or more intensive study. Occupied nest trees were located throughout each individual’s home range, highlighting the importance of a continuous spatial distribution of suitable nest trees across the landscape. Nest trees were also located in adjacent farmland up to 225 m from roadside vegetation, demonstrating the value that scattered clumps and even single trees in farmland can have for wildlife conservation.

A comparison of pilling results tested with the ICI pill box and a new perspex™ pill box

Identical single jersey wool knit fabrics produced inconsistent results when tested on the same type of ICI pill box in 4 independence testing laboratories.  The hypothesis formulated to investigate this event was that continued pilling testing in the ICI pill box changes the frictional properties of the cork liners, resulting in the difference pilling ratings.  The aim of this study was to decrease the inconsistencies in the pilling results by replacing the conventional cork lined pill box with a Perspex^TM pill box.  The smae or similar pilling results found for several of the knit facots tested in the two difference pill boxes, while for others there were some significant differences found.  In addition, while using the Perspex^TM pill box observations of the movement of the pilling tubes during testing provided evidence of greater fabric-to-fabric abrasion, rather the expected high degree of fabric-to-cork abrasion (or fabric-to-Perspex^TM) during pilling testing.

The diet of a Southern Boobook Ninox novaeseelandiae in Box-ironbark country, central Victoria

The diet of a Southern Boobook Ninox novaeseelandiae in a Box-Ironbark woodland remnant in central Victoria was studied. An analysis of 42.5 pellets found invertebrates to represent 82% of the total prey items, but vertebrates, in the form of the House Mouse Mus domesticus, to represent 88% of the biomass. The proportion of spiders as prey items in the diet in this instance (43%) was significantly higher than in other studies on mainland Australia.