Clutch Size and Productivity in 3 Sympatric Species of Cockatoo (Psittaciformes) in the Southwest of Western-Australia

1986 ◽  
Vol 13 (2) ◽  
pp. 275 ◽  
Author(s):  
GT Smith ◽  
DA Saunders
Keyword(s):  
Body Size ◽  
Incubation Period ◽  
Clutch Size ◽  
Western Australia ◽  
Hatching Success ◽  
Sympatric Species ◽  
Nestling Period ◽  
Time Of Year ◽  
Study Sites ◽  
Nestling Mortality

The galah, long-billed corella and red-tailed black cockatoo coexist throughout much of the northern wheatbelt of Western Australia. Various aspects of the breeding biology of these species were studied at Burakin and Three Springs in 1979. Laying began at the same time of year in all three, although the peak was later and the length of the laying period longer for the red-tailed black cockatoo. Data are given on clutch size, hatching success, nestling mortality, nestling period, fledging weight and productivity for each species at both study sites. The only significant differences between study areas were that the fledging weight and productivity of the galah were greater at Burakin than at Three Springs. Productivity was severely reduced in the galah by an unidentified nestling disease, and in the red-tailed black cockatoo by high infertility and nestling mortality of unknown cause. Between the species, incubation period and fledging period increased with body size but clutch size decreased with body size.

scholarly journals Temperature-sex determination in Podocnemis expansa (Testudines, Podocnemididae)

2011 ◽  
Vol 101 (3) ◽  
pp. 151-155 ◽  
Author(s):  
Kelly Bonach ◽  
Adriana Malvasio ◽  
Eliana R. Matushima ◽  
Luciano M. Verdade
Keyword(s):  
Sex Determination ◽  
Success Rate ◽  
Incubation Period ◽  
Clutch Size ◽  
Hatching Success ◽  
Incubation Temperature ◽  
Small Sample ◽  
Mato Grosso ◽  
Araguaia River ◽  
Podocnemis Expansa

This study has been carried out at the central region of the Araguaia river on the border between the states of Goiás and Mato Grosso in the Brazilian Amazon Basin from September to December 2000. We recorded temperature fluctuation, clutch-size, incubation period and hatching success rate and hatchlings' sex ratio of five nests of Podocnemis expansa (Schweigger, 1812). Despite the relatively small sample size we infer that: a) nests of P. expansa in the central Araguaia river have a lower incubation temperature than nests located further south; however, incubation period is shorter, hatching success rate is lower and clutch-size is larger; b) Podocnemis expansa may present a female-male-female (FMF) pattern of temperature sex-determination (TSD); c) thermosensitive period of sex determination apparently occur at the last third of the incubation period; and, d) future studies should prioritize the relationship between temperature variation (i.e., range and cycle) and embryos development, survivorship and sex determination.

The effect of drought on body size, growth and abundance of wild brush-tailed phascogales (Phascogale tapoatafa) in south-western Australia

2002 ◽  
Vol 29 (3) ◽  
pp. 235 ◽  
Author(s):  
S. G. Rhind ◽  
J. S. Bradley
Keyword(s):  
Body Size ◽  
Western Australia ◽  
Population Decline ◽  
Adult Males ◽  
Growth Data ◽  
The South ◽  
Nest Boxes ◽  
South West ◽  
Size Growth ◽  
Time Of Year

Body size and growth data were gathered on 387 wild brush-tailed phascogales captured between 1992–1997 in south-western Australia. This marsupial has not previously been studied in Western Australia. Compared with Victorian phascogales, those in the south-west (single region) are typically 20–30% smaller in mass, smaller in skeletal measurements, and sexual size dimorphism is less. Habitat quality was correlated with body size and the largest phascogales were found in swamp/gully systems. These findings suggest food is a normally limiting resource for this species in the south-west environment. Additionally, a significant decrease in growth and size occurred during a drought year (1994), and growth of young seemed restricted during dependency. Maternal mortality appeared high during late lactation as orphaned, unweaned young were encountered in nest boxes. In 1995 adult males were 25% less in mass than usual; females 15% less. Population decline followed and by 1996 capture rates were 1/3 of that typically found for the time of year. Recovery was not apparent until two years after drought (early 1997). In this food-limited environment phascogale populations appear particularly vulnerable to annual fluctuations in rainfall.

Allometry and Paleoecology of Medial Miocene Dwarf Rhinoceroses from the Texas Gulf Coastal Plain

Paleobiology ◽  
1982 ◽  
Vol 8 (1) ◽  
pp. 16-30 ◽  
Author(s):  
Donald R. Prothero ◽  
Paul C. Sereno
Keyword(s):  
Body Size ◽  
Coastal Plain ◽  
Sympatric Species ◽  
High Plains ◽  
Gulf Coastal Plain ◽  
Canine Tooth ◽  
Positive Allometry ◽  
Mammalian Faunas ◽  
The Common ◽  
Limb Proportions

Barstovian (medial Miocene) mammalian faunas from the Texas Gulf Coastal Plain contained four apparently sympatric species of rhinoceroses: the common forms Aphelops megalodus and Teleoceras medicornutus, a dwarf Teleoceras, and a dwarf Peraceras. Previous work has suggested positive allometry in tooth area with respect to body size in several groups of mammals, i.e., larger mammals have relatively more tooth area. However, dwarfing lineages were shown to have relatively more tooth area for their body size. Our data show no significant allometry in post-canine tooth area of either artiodactyls or ceratomorphs. Similarly, dwarf rhinoceroses and hippopotami show no more tooth area than would be predicted for their size. Limbs are proportionately longer and more robust in larger living ceratomorphs (rhinos and tapirs) than predicted by previous authors. Limb proportions of both dwarf rhinoceroses and dwarf hippopotami are even more robust than in their living relatives.The high rhinoceros diversity reflects the overall high diversity of Barstovian faunas from the Texas Gulf Coastal Plain. The first appearance of several High Plains mammals in these faunas indicates “ecotone”-like conditions as faunal composition changed. Study of living continental dwarfs shows that there is commonly an ecological separation between browsing forest dwarfs and their larger forebears, which are frequently savannah grazers. This suggests that the dwarf rhinoceroses might have been forest browsers which were sympatric with the larger grazing rhinos of the High Plains during the Barstovian invasion. The continental dwarf model also suggests that insular dwarfism may be explained by the browsing food resources that predominate on islands.

scholarly journals The isotopic niche of Atlantic, biting marine mammals and its relationship to skull morphology and body size

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Massimiliano Drago ◽  
Marco Signaroli ◽  
Meica Valdivia ◽  
Enrique M. González ◽  
Asunción Borrell ◽  
...  
Keyword(s):  
Body Size ◽  
Atlantic Ocean ◽  
Fisheries Management ◽  
Marine Mammals ◽  
Trophic Position ◽  
Sympatric Species ◽  
Isotopic Niche ◽  
Apex Predators ◽  
Skull Morphology ◽  
Ecosystem Based Fisheries Management

AbstractUnderstanding the trophic niches of marine apex predators is necessary to understand interactions between species and to achieve sustainable, ecosystem-based fisheries management. Here, we review the stable carbon and nitrogen isotope ratios for biting marine mammals inhabiting the Atlantic Ocean to test the hypothesis that the relative position of each species within the isospace is rather invariant and that common and predictable patterns of resource partitioning exists because of constrains imposed by body size and skull morphology. Furthermore, we analyze in detail two species-rich communities to test the hypotheses that marine mammals are gape limited and that trophic position increases with gape size. The isotopic niches of species were highly consistent across regions and the topology of the community within the isospace was well conserved across the Atlantic Ocean. Furthermore, pinnipeds exhibited a much lower diversity of isotopic niches than odontocetes. Results also revealed body size as a poor predictor of the isotopic niche, a modest role of skull morphology in determining it, no evidence of gape limitation and little overlap in the isotopic niche of sympatric species. The overall evidence suggests limited trophic flexibility for most species and low ecological redundancy, which should be considered for ecosystem-based fisheries management.

scholarly journals Glucocorticoids, state-dependent reproductive investment and success in the face of danger in a long-lived bird

2020 ◽  
Author(s):  
Kristina Noreikienė ◽  
Kim Jaatinen ◽  
Benjamin B. Steele ◽  
Markus Öst
Keyword(s):  
Predation Risk ◽  
Telomere Length ◽  
Clutch Size ◽  
Body Condition ◽  
Nest Predation ◽  
Hatching Success ◽  
Reproductive Investment ◽  
Trade Off ◽  
Relative Telomere Length ◽  
Future Reproduction

AbstractGlucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.

New Nesting Records and Breeding Ecology Observations of Rufous-legged Owls in the Mediterranean Temperate Forest of Central Chile

2021 ◽  
Author(s):  
Martín A. H. Escobar ◽  
M. Angélica Vukasovic ◽  
Jorge A. Tomasevic ◽  
Sandra V. Uribe ◽  
Ana M. Venegas ◽  
...  
Keyword(s):  
Clutch Size ◽  
Temperate Forest ◽  
Breeding Ecology ◽  
Ecological Data ◽  
Central Chile ◽  
Monterey Pine ◽  
Nestling Diet ◽  
Nestling Period ◽  
Nothofagus Forests ◽  
Southern Beech

ABSTRACT The Rufous-legged Owl (Strix rufipes) is the southernmost Strix owl species and its breeding ecology remains little known. We report new observations on the species' breeding ecology, including clutch size, egg size, duration of the incubation and nestling periods, and nestling diet. We conducted our observations on nests found during the summers of 1999 through 2004 in a forestry landscape of central Chile, dominated by Monterey pine (Pinus radiata) plantations with intermixed fragments of native southern beech (Nothofagus) forests. Clutch size was two eggs (n = 2 nests), with one egg larger than the other (mean = 48.8 × 40.1 mm). The incubation period was 30 d and the nestling period 34 d. We analyzed 10 pellets from nestling owls and identified 45 prey items, mostly dominated by large beetles, grasshoppers, and rodents (native and exotic). This information, though based on a limited number of nests, provides baseline ecological data that can inform future studies.

Ecological correlates in Brazilian Amazonian anurans: implications for conservation

2013 ◽  
Vol 34 (2) ◽  
pp. 217-232 ◽  
Author(s):  
Selvino Neckel-Oliveira ◽  
Selvino Neckel-Oliveira ◽  
Ulisses Galatti ◽  
Selvino Neckel-Oliveira ◽  
Ulisses Galatti ◽  
...  
Keyword(s):  
Body Size ◽  
Protected Areas ◽  
Larval Development ◽  
Clutch Size ◽  
Development Stage ◽  
Geographic Range ◽  
Activity Period ◽  
Ecological Groups ◽  
Conservation Units ◽  
Geographic Ranges

The objective of the present study is to identify the ecological characteristics of Amazonian frogs that would make them candidates for endangered species status, and to quantify correlations between body size and geographic distribution. The study included 180 species for which information was available on life history characteristics, including reproductive mode, aquatic larval development, primary larval habitat and adult microhabitat, and activity period. Species with aquatic development were classified in eight ecological groups based on a cluster analysis. Twenty-eight of the aquatic-developing species share a stream-based larval development stage with groups of endangered or vulnerable species from Australia and Central America. The Amazonian species have geographic ranges around five times larger than their Australian and Central American counterparts. The median clutch size and geographic range in aquatic-developing anuran species were 20 percent and 3.3 percent greater, respectively, than those of terrestrial-developing species. For both aquatic- and terrestrial-developing species, body size was positively associated with clutch size. Body size was also correlated with geographic range in aquatic-developing, but not in terrestrial species. Restricted geographic ranges and a lack of populations in protected areas were recorded in both groups. Most of these species occur in the southwestern Brazilian Amazon, which not only has poor coverage of protected areas, but is becoming increasingly threatened by ongoing economic development. The systematic monitoring of the region’s anurans and the creation of new conservation units should thus be of the highest priority.

Clutch Mass, Offspring Mass, and Clutch Size: Body Mass Scaling and Taxonomic and Environmental Variation

2018 ◽  
pp. 68-97
Author(s):  
Douglas S. Glazier
Keyword(s):  
Life History ◽  
Body Size ◽  
Clutch Size ◽  
Body Mass ◽  
Life History Evolution ◽  
Offspring Size ◽  
Egg Mass ◽  
Mass Scaling ◽  
Scaling Relationships ◽  
Clutch Mass

In this chapter, I show how clutch mass, offspring (egg) mass, and clutch size relate to body mass among species of branchiopod, maxillipod, and malacostracan crustaceans, as well as how these important life history traits vary among major taxa and environments independently of body size. Clutch mass relates strongly and nearly isometrically to body mass, probably because of physical volumetric constraints. By contrast, egg mass and clutch size relate more weakly and curvilinearly to body mass and vary in inverse proportion to one another, thus indicating a fundamental trade-off, which occurs within many crustacean taxa as well. In general, offspring (egg) size and number and their relationships to body mass appear to be more ecologically sensitive and evolutionarily malleable than clutch mass. The body mass scaling relationships of egg mass and clutch size show much more taxonomic and ecological variation (log-log scaling slopes varying from near 0 to almost 1 among major taxa) than do those for clutch mass, a pattern also observed in other animal taxa. The curvilinear body mass scaling relationships of egg mass and number also suggest a significant, size-related shift in how natural selection affects offspring versus maternal fitness. As body size increases, selection apparently predominantly favors increases in offspring size and fitness up to an asymptote, beyond which increases in offspring number and thus maternal fitness are preferentially favored. Crustaceans not only offer excellent opportunities for furthering our general understanding of life history evolution, but also their ecological and economic importance warrants further study of the various factors affecting their reproductive success.

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