scholarly journals Predicting the hatching date of Malleefowl Leipoa ocellata eggs without excavating the mound

2021 ◽  
Vol 38 ◽  
pp. 78-86
Keyword(s):  
Western Australia ◽  
Egg Production ◽  
Hatching Success ◽  
Cost Effective ◽  
Breeding Population ◽  
Egg Laying ◽  
The North ◽  
Remote Cameras ◽  
Invasive Method ◽  
Conservation Concern

The Malleefowl Leipoa ocellata (Family Megapodiidae) has suffered a major contraction in its distribution across Australia and is considered vulnerable to extinction. It incubates its eggs in a mound. A key conservation concern for this species is the level of recruitment of young into the breeding population. One approach for measuring recruitment success is to mark chicks as they emerge from the mound. Traditional methods have involved excavating the mound in order to determine the rate of egg production, hatching success and to predict the timing of hatching. This is laborious, involves significant disturbance and may pose a risk to the eggs or chicks. A less invasive method, using remote cameras to determine the date of egg-laying and hatching, and length of incubation, was tested to help predict when chicks emerge from their mound. In the mound studied at Matuwa in central Western Australia, 19 eggs were laid from 26 August 2017 to 27 January 2018, with eggs being laid earlier in the day as temperature increased and as time progressed. An average incubation period of 61.25 days was observed for four chicks that were recorded emerging from the mound. This study has provided evidence that remote cameras can be used to help determine the number of eggs laid and their hatching success and to predict emergence times of Malleefowl chicks without needing to excavate mounds. Further development of this technique as a more cost-effective and passive alternative for providing information on chick recruitment is recommended to help facilitate the recovery of the species. It was also of interest to record details of the mound observed here as the study site was located on the north-eastern limit ofthe known Malleefowl range in Western Australia, where there are few detailed records.

scholarly journals Recreational Harvest of Sharks and Rays in Western Australia Is Only a Minor Component of the Total Harvest

2021 ◽  
Vol 13 (11) ◽  
pp. 6215
Author(s):  
Matias Braccini ◽  
Eva Lai ◽  
Karina Ryan ◽  
Stephen Taylor
Keyword(s):  
Western Australia ◽  
Minor Component ◽  
The North ◽  
Commercial Harvest ◽  
Unknown Status ◽  
Reef Sharks ◽  
Conservation Concern ◽  
Taxonomic Groups ◽  
A Minor ◽  
Port Jackson

Sharks and rays are a global conservation concern with an increasing number of species considered at risk of extinction, mostly due to overfishing. Although the recreational harvest of sharks and rays is poorly documented and generally minimal, it can be comparable to the commercial harvest. In this study, we quantified the recreational harvest of sharks and rays in Western Australia, a region with a marine coastline greater than 20,000 km. A total of 33 species/taxonomic groups were identified, with the harvest dominated by dusky and bronze whalers, blacktip reef sharks, gummy sharks, Port Jackson sharks, wobbegongs, and rays and skates. Eighty-five percent of individuals were released with an unknown status (alive or dead). We found a latitudinal gradient of species composition, with tropical and subtropical species of the genus Carcharhinus dominating in the north and temperate species from a range of families dominating in the south. Overall, our findings showed that the recreational harvest was negligible when compared with commercial landings.

Reproduction in the nest building vizcacheras frog Leptodactylus bufonius in central Argentina

2003 ◽  
Vol 24 (4) ◽  
pp. 415-427 ◽  
Author(s):  
G.M. Jofré ◽  
C.J. Reading
Keyword(s):  
Sex Ratio ◽  
Sexual Maturity ◽  
Egg Production ◽  
Breeding Population ◽  
Nest Building ◽  
Central Argentina ◽  
The North ◽  
Maximum Temperatures

AbstractA population of vizcacheras frogs Leptodactylus bufonius was studied at a man-made pond in the north of Córdoba Province in central Argentina during December 2000 and 2001. Breeding females were larger than breeding males with both sexes attaining sexual maturity at two years of age and most living to a maximum age of four years. The sex ratio of the breeding population was approximately 1.2♂ : 1♀. Although the numbers of eggs and tadpoles found in sealed nests was the same as the number of eggs found in the ovaries of unspawned females, between-year differences in egg production per female were found. Nests were constructed by males, at night, and then abandoned for at least 24 hours. Amplexus and spawning occurred within the nest. The nest was then vacated and the female sealed the nest aperture with wet mud. The minimum and maximum temperatures recorded inside sealed nests were less extreme than those recorded outside the nest.

scholarly journals Recreational Harvest of Sharks and Rays in Western Australia is only a Minor Component of the Total Harvest

2021 ◽  
Author(s):  
Matias Braccini ◽  
Eva Lai ◽  
Karina Ryan ◽  
Stephen Taylor
Keyword(s):  
Western Australia ◽  
Time Series Data ◽  
Minor Component ◽  
Series Data ◽  
Commercial Fishing ◽  
The North ◽  
Commercial Harvest ◽  
Conservation Concern ◽  
Taxonomic Groups ◽  
A Minor

Abstract Sharks and rays are of global conservation concern with an increasing number of species at risk of extinction, mostly attributed to overfishing by commercial fishing. Their recreational harvest is poorly known but it can be of similar magnitude to the commercial harvest in some regions. We quantified the recreational harvest of sharks and rays in Western Australia, a region with a marine coastline of > 20,000 km. We recorded 33 species/taxonomic groups but the harvest was dominated by dusky and bronze whalers, blacktip reef shark, gummy shark, Port Jackson shark, wobbegongs, and rays and skates. Most species caught were released (85% of all individuals), although gummy and whiskery sharks were typically retained. There was a clear latitudinal gradient of species composition with tropical and subtropical species of the genus Carcharhinus dominating in the north and temperate species of the families Triakidae, Carcharhinidae, Heterodontidae and Rajidae dominating in the south. The recreational harvest was negligible compared with commercial landings. The newly available time series data can be incorporated into stock assessments to allow the quantification of recreational fishing mortality of shark and ray species and therefore comply with state, national and international initiatives for their conservation and sustainable management.

Double-crested Cormorants of the Great Lakes: egg-laying parameters, reproductive failure, and contaminant residues in eggs, Lake Huron 1972–1973

1983 ◽  
Vol 61 (2) ◽  
pp. 427-436 ◽  
Author(s):  
D. Vaughn Weseloh ◽  
Stanley M. Teeple ◽  
Michael Gilbertson
Keyword(s):  
Egg Production ◽  
Demographic Data ◽  
Residue Analysis ◽  
Reproductive Failure ◽  
Egg Laying ◽  
Lake Huron ◽  
The North ◽  
The Status ◽  
Wet Weight ◽  
The 1960S

During the 1960s Double-crested Cormorants breeding on Lake Huron experienced a decline in numbers and an elevation in body and egg contaminant burdens. In 1972 and 1973 the Canadian Wildlife Service visited their colonies to collect demographic data and eggs for residue analysis. In 1972, colonies were small. They suffered high egg breakage and loss (95%) and nearly total reproductive failure (0.06–0.11 young per nest). Eggshells were 23.9% thinner than normal. Clutch size (2.0 ± 1.2 eggs) was low but egg production (4.1 ± 1.9 eggs) appeared normal. Subsequent clutches appeared in 45% of the nests. Levels of DDE (14.5 ± 5.6 ppm, wet weight) and PCBs (23.8 ± 9.6 ppm) in the eggs were higher than in other cormorant populations in Canada. Levels of DDT, DDD, dieldrin, heptachlor epoxide, hexachlorobenzene, and mercury were less than 1 ppm. Organochlorine levels in eggs from Georgian Bay were similar to those from the North Channel, but mercury levels were higher. Colony size continued to decline in 1973, although reproductive success improved (0.3 young per nest). These data may be used to assess subsequent changes in the status of Lake Huron cormorants which unpublished observations indicate are now recovering rapidly.

Barriers for conservation: mitigating the impact on amphibians and reptiles by water cisterns in arid environments

2017 ◽  
Vol 38 (1) ◽  
pp. 113-118 ◽  
Author(s):  
Juan M. Pleguezuelos ◽  
Luis García-Cardenete ◽  
Jesús Caro ◽  
Mónica Feriche ◽  
María T. Pérez-García ◽  
...  
Keyword(s):  
Mixed Models ◽  
Cost Effective ◽  
Wire Mesh ◽  
Arid Environments ◽  
Western Sahara ◽  
The North ◽  
Management Condition ◽  
Conservation Concern ◽  
The Impact ◽  
North Western

Anthropogenic infrastructures are one of the major threats to biodiversity. In the north-western Sahara shepherds are increasingly building water cisterns of reinforced concrete for watering livestock. These infrastructures attract desert fauna and act as indiscriminate death traps for the amphibians and reptiles (herps) in the surrounding habitats. Here we propose an on-site, cost-effective management measure. We selected two groups of 36 cisterns, managed a group by covering the lateral openings with wire mesh (managed cistern), leaving the other group unmanaged (control cistern). Managed cisterns trapped fewer species, fewer individuals (one third), and individuals of smaller body size and of less conservation concern than did control cisterns. In a multivariate approach by Generalized Mixed Models, the best models explaining the number of species and individuals of herps trapped within cisterns included as the predictor only the management condition, with a trend for higher values in control cisterns.

Multiple clutches, egg mortality and mate choice in the mid-wife toad, Alytes obstetricans

1988 ◽  
Vol 9 (4) ◽  
pp. 357-364 ◽  
Author(s):  
R.T. Clarke ◽  
C.J. Reading
Keyword(s):  
Mate Choice ◽  
Egg Production ◽  
Hatching Success ◽  
Egg Laying ◽  
Central Spain ◽  
Egg Survival ◽  
Small Reservoir ◽  
Egg Mortality ◽  
Alytes Obstetricans

AbstractEgg laying, clutch brooding, egg survival and mate choice were investigated in the mid-wife toad, Alytes obstetricans (Lataste) at a small reservoir in central Spain during 1986 and 1987. Females divided their total egg production into at least three separate clutches. The majority of males brooded between one and three clutches of eggs, though one may have brooded four. First clutches received by males were 24-34% larger than subsequent clutches. No significant differences were found in egg fertilisation, survival and hatching success between individual clutches. The results show that females prefer to spawn with non-brooding males rather than brooding males but that they will spawn with brooding males. When spawning with brooding males they lay smaller clutches than with non-brooding males.

Probiotics in the diets of laying quails

2020 ◽  
pp. 60-66
Author(s):  
O. Merzlyakova ◽  
V. Rogachyev ◽  
V. Chegodaev
Keyword(s):  
Bacillus Subtilis ◽  
Bacillus Licheniformis ◽  
Egg Production ◽  
Positive Impact ◽  
Hematological Parameters ◽  
Economic Effect ◽  
Egg Laying ◽  
Control Group ◽  
Egg Mass ◽  
The Cost

The efficiency of introducing probiotics based on strains of Bacillus subtilis, Bacillus licheniformis and their consortium in the amount of 150 g/t of feed into the diets of laying quails has been studied. The experiment lasting 182 days has been carried out on four groups of quails with 30 heads in each. The quails have been housed in the broiler battery in compliance with the required microclimate conditions. Quails of all groups have been received the main diet (compound feed) developed taking into account their age and physiological characteristics. The quails of the 1st, 2nd and 3rd experimental groups in addition to the main diet received probiotics (150 g/t compound feed) based on strains Bacillus subtilis, Bacillus licheniformis and their consortium, respectively. It has been found that feeding the laying quails of the consortium of strains Bacillus subtilis and Bacillus licheniformis had the most significant positive impact on their productive performance, it allowed to increase egg production by 7,81 %, egg laying intensity by 5,0 %, egg mass yield by 9,77 %, while reducing feed expenditures for 10 eggs by 13,35 %. The yield of hatching eggs has been increased by 7,03 %, hatchability of chickens from laid and fertilized eggs by 8,33 and 8,35 %, brooding waste decreased by 21,74 %. Hematological parameters of quails during the whole experiment were within the physiological norm. The economic effect calculated on the basis of data on the cost of compound feed, probiotics and the cost of sold eggs of quail laying was 14,56 % in the 3rd experimental group (in relation to the control group).

scholarly journals Proteomic Analysis Identifies Potential Markers for Chicken Primary Follicle Development

Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1108
Author(s):  
Armughan Ahmed Wadood ◽  
Jingyuan Wang ◽  
Liping Pu ◽  
Qaisar Shahzad ◽  
Muhammad Waqas ◽  
...  
Keyword(s):  
Proteomic Analysis ◽  
Egg Production ◽  
Potential Role ◽  
Protein Localization ◽  
Follicular Development ◽  
Egg Laying ◽  
Follicle Development ◽  
Phosphate Binding ◽  
Primary Follicle ◽  
Mannose Metabolism

Follicles’ development in chicken imparts a major impact on egg production. To enhance the egg-laying efficiency, comprehensive knowledge of different phases of follicular development is a prerequisite. Therefore, we used the tandem mass tag (TMT) based proteomic approach to find the genes involved in the primary follicular development of chicken. The primary follicles were divided into two groups—small primary follicles (81–150 μm) and developed primary follicles (300–500 μm). Differential expression analysis (fold change > 1.2, p-value < 0.05) revealed a total of 70 differentially expressed proteins (DEPs), of which 38 were upregulated and 32 were downregulated. Gene ontology (GO) enrichment analysis disclosed that DEPs were intricate with cellular protein localization, the establishment of protein localization, and nucleoside phosphate-binding activities. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment pathway indicated the involvement of DEPs in different metabolic pathways such as glycolysis, pyruvate metabolism, galactose metabolism, and fructose and mannose metabolism. The current proteomic analysis suggested suitable markers such as Anxa2, Pdia3, and Capzb, which may serve as a potential role for primary follicle development. The present study provides the first insight into the proteome dynamics of primary follicle development and would play a potential role for further studies in chicken to improve egg productivity.

scholarly journals Dual-Purpose Poultry in Organic Egg Production and Effects on Egg Quality Parameters

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 897
Author(s):  
Marianne Hammershøj ◽  
Gitte Hald Kristiansen ◽  
Sanna Steenfeldt
Keyword(s):  
Egg Production ◽  
Egg Quality ◽  
Quality Parameters ◽  
Egg Laying ◽  
High Yield ◽  
Meat Production ◽  
Dual Purpose ◽  
Shell Quality ◽  
Egg Shell ◽  
Genotype A

Egg laying genotypes have been selected for generations due to their high yield and egg quality, resulting in efficient feed utilization and low body weight; hence, they are not suitable for meat production. This imposes an issue for the male layer chicks, which are killed at one day old. Because of ethical and food waste concerns, the search for suitable dual-purpose genotypes in order to avoid euthanasia of male day-old chicks has intensified. The aim of the present study is to evaluate potential dual-purpose genotypes for their egg quality compared to a representative egg laying genotype. Three dual-purpose genotypes with divergent characteristics were evaluated: genotype A represented an experimental crossbreed based on a broiler type male and an egg layer female, genotype B was a pure breed, and genotype C was a crossbreed of a layer type. These were compared to a control genotype D, which was an egg layer. Eggs were collected six times during the period of 21–54 weeks of hen age, i.e., a total of 1080 shell eggs were analyzed. Examined parameters were weights of egg, shell, yolk, and albumen, by calculating their relative proportions. Shell quality was assessed by shell strength, shell stiffness, and shell thickness. Yolk quality was determined as yolk color and inclusions of blood and meat spots, and albumen quality was evaluated in terms of pH and dry matter (DM) content. The egg layer genotype produced the smallest eggs with least blood and meat spot inclusions compared to that produced by the three dual-purpose genotypes. Shell quality was superior for the layer genotype. However, the experimental genotype A laid eggs of comparable shell quality, albumen DM, and yolk weight, but also with the darkest and most red-yellow colored yolk. The two other dual-purpose genotypes produced eggs of low-medium quality. In conclusion, the genotype A could serve as dual-purpose genotype from an egg quality perspective.

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