Spurs, sexual dimorphism and reproductive maturity in Tasmanian echidnas (Tachyglossus aculeatus setosus)

2019 ◽  
Vol 41 (2) ◽  
pp. 161 ◽  
Author(s):  
Stewart C. Nicol ◽  
Niels A. Andersen ◽  
Gemma E. Morrow ◽  
Rachel L. Harris
Keyword(s):  
Sexual Dimorphism ◽  
Wild Population ◽  
Reliable Indicator ◽  
Mass Ratio ◽  
Reproductive Maturity ◽  
In The Wild ◽  
Minimum Age ◽  
Age At First Breeding ◽  
Basic Biology ◽  
Male To Female

We present data from an 18-year study of a wild population of Tasmanian echidnas, which show that the presence of spurs in an adult are a reliable indicator of sex, and that there is a slight but significant sexual dimorphism in size, with a male to female mass ratio of 1.1. Minimum age at first breeding in the wild for Tasmanian echidnas was 5 years, as has been found on Kangaroo Island, compared with 3 years in captive echidnas. It is often assumed that although the echidna is distributed throughout Australia, New Guinea and off-shore islands that all aspects of its basic biology are the same in all populations, but comparisons of our results with data from other populations suggest that there may be differences in size and sexual dimorphism.

scholarly journals A Genome Scan for Quantitative Trait Loci in a Wild Population of Red Deer (Cervus elaphus)

Genetics ◽  
2002 ◽  
Vol 162 (4) ◽  
pp. 1863-1873 ◽  
Author(s):  
J Slate ◽  
P M Visscher ◽  
S MacGregor ◽  
D Stevens ◽  
M L Tate ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Cervus Elaphus ◽  
Quantitative Trait ◽  
Red Deer ◽  
Wild Population ◽  
Additive Genetic Variance ◽  
Model Organisms ◽  
A Genome ◽  
Trait Loci ◽  
In The Wild

Abstract Recent empirical evidence indicates that although fitness and fitness components tend to have low heritability in natural populations, they may nonetheless have relatively large components of additive genetic variance. The molecular basis of additive genetic variation has been investigated in model organisms but never in the wild. In this article we describe an attempt to map quantitative trait loci (QTL) for birth weight (a trait positively associated with overall fitness) in an unmanipulated, wild population of red deer (Cervus elaphus). Two approaches were used: interval mapping by linear regression within half-sib families and a variance components analysis of a six-generation pedigree of >350 animals. Evidence for segregating QTL was found on three linkage groups, one of which was significant at the genome-wide suggestive linkage threshold. To our knowledge this is the first time that a QTL for any trait has been mapped in a wild mammal population. It is hoped that this study will stimulate further investigations of the genetic architecture of fitness traits in the wild.

scholarly journals Sexual dimorphism in the squirrel monkey, Saimiri sciureus (Linnaeus, 1758) and Saimiri ustus (I. Geoffroy, 1844) (Primates, Cebidae)

2009 ◽  
Vol 69 (1) ◽  
pp. 171-174 ◽  
Author(s):  
B. Goldschmidt ◽  
A. Mota-Marinho ◽  
C. Araújo-Lopes ◽  
MA. Brück-Gonçalves ◽  
D. Matos-Fasano ◽  
...  
Keyword(s):  
Body Weight ◽  
Sexual Dimorphism ◽  
Squirrel Monkey ◽  
Coat Color ◽  
Morphological Characters ◽  
Saimiri Sciureus ◽  
External Ear ◽  
Adult Females ◽  
In The Wild ◽  
Capture Techniques

Causes and implications of sexual dimorphism have been studied in several different primates using a variety of morphological characters such as body weight, canine length, coat color and ornamentation. Here we describe a peculiar coat color characteristic in the squirrel monkey that is present only in adult females over five years old and which increases with age. Neither males nor young animals manifest this phenomenon, which is characterized by a spot of black hairs located anteriorly to the external ear (pinna). This characteristic could be used to discriminate adult females of Saimiri sciureus in the wild without the need of capture techniques.

scholarly journals Ngwevu intloko: a new early sauropodomorph dinosaur from the Lower Jurassic Elliot Formation of South Africa and comments on cranial ontogeny in Massospondylus carinatus

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7240 ◽  
Author(s):  
Kimberley E.J. Chapelle ◽  
Paul M. Barrett ◽  
Jennifer Botha ◽  
Jonah N. Choiniere
Keyword(s):  
South Africa ◽  
New Species ◽  
Sexual Dimorphism ◽  
New Genus ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Adult Size ◽  
Minimum Age ◽  
Cranial Ontogeny ◽  
Morphological Differences

Our knowledge of Early Jurassic palaeobiodiversity in the upper Elliot Formation of South Africa has increased markedly in recent years with the discovery of new fossils, re-assessments of previously collected material and a better understanding of Stormberg Group stratigraphy. Here, Ngwevu intloko, a new genus of upper Elliot basal sauropodomorph is named on the basis of a complete skull and partial skeleton (BP/1/4779) previously assigned to Massospondylus carinatus. It can be distinguished from all other basal sauropodomorphs by a combination of 16 cranial and six postcranial characters. The new species is compared to a small ontogenetic series of M. carinatus as well as to a range of closely related taxa. Taphonomic deformation, sexual dimorphism and ontogeny are rejected as possible explanations for the morphological differences present between BP/1/4779 and other taxa. Osteohistological examination reveals that BP/1/4779 had nearly reached adult size at the time of its death at a minimum age of 10 years.

scholarly journals Individual tracking reveals first breeding of Oriental Storks at age 2 years in the wild

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anton Sasin ◽  
Anna Serdyuk ◽  
Baoguang Zhu ◽  
Qingshan Zhao
Keyword(s):  
River Basin ◽  
Wild Population ◽  
Sex Identification ◽  
Amur River Basin ◽  
Amur River ◽  
Field Verification ◽  
Successful Reproduction ◽  
In The Wild ◽  
Individual Tracking

AbstractIn this study, we report the first ever documented instances of attempted and successful reproduction (rearing two offspring) of Oriental Storks (Ciconia boyciana) at age 2 years in a wild population in the middle Heilongjiang-Amur River Basin in Russia, using a combination of GPS-GSM tracking, DNA sex identification and field verification.

scholarly journals Cognitive Abilities in the Wild: Population-scale game-based cognitive assessment

2021 ◽  
Author(s):  
Mads Kock Pedersen ◽  
Carlos Mauricio Castaño Díaz ◽  
Mario Alejandro Alba-Marrugo ◽  
Ali Amidi ◽  
Rajiv Vaid Basaiwmoit ◽  
...  
Keyword(s):  
Cognitive Abilities ◽  
Wild Population ◽  
Full Range ◽  
Large Population ◽  
Population Sample ◽  
The Social ◽  
In The Wild ◽  
Large Population Sample ◽  
Key Questions ◽  
Unique Dataset

Psychology and the social sciences are undergoing a revolution: It has become increasingly clear that traditional lab-based experiments fail to capture the full range of differences in cognitive abilities and behaviours across the general population. Some progress has been made toward devising measures that can be applied at scale across individuals and populations. What has been missing is a broad battery of validated tasks that can be easily deployed, used across different age ranges and social backgrounds, and employed in practical, clinical, and research contexts. Here, we present Skill Lab, a game-based approach allowing the efficient assessment of a suite of cognitive abilities. Skill Lab has been validated outside the lab in a crowdsourced population-size sample recruited in collaboration with the Danish Broadcast Company (Danmarks Radio, DR). Our game-based measures are five times faster to complete than the equivalent traditional measures and replicate previous findings on the decline of cognitive abilities with age in a large population sample. Furthermore, by combining the game data with an in-game survey, we demonstrate that this unique dataset has implication for key questions in social science, challenging the Jack-of-all-Trades theory of entrepreneurship and provide evidence for risk preference being independent of executive functioning.

scholarly journals Sex influence on genetic expressions of early growth in Afshari lambs

2016 ◽  
Vol 59 (1) ◽  
pp. 9-17 ◽  
Author(s):  
F. Ghafouri-Kesbi ◽  
D. R. Notter
Keyword(s):  
Sexual Dimorphism ◽  
Fixed Effects ◽  
Early Growth ◽  
Domestic Sheep ◽  
Environmental Correlations ◽  
Male And Female ◽  
Selection Strategies ◽  
Genetic Components ◽  
Low Levels ◽  
Male To Female

Abstract. Very little is known about the genetic aspects of sexual dimorphism of body weight in domestic sheep, and therefore this study was conducted to quantify the genetic basis of sexual dimorphism for early-growth-related traits in Afshari lambs. Traits evaluated included birth weight (BW), weaning weight (WW), and growth rate (GR) in male and female lambs. Male lambs were 6.6 % heavier at birth, had 14.4 % higher preweaning growth rates and were 16.0 % heavier at weaning compared to female lambs. Levels of sexual-size dimorphism (SSD), expressed as the ratio of male to female means, for BW, WW and GR were 1.07, 1.14 and 1.15, respectively, which indicated low levels of SSD in the traits studied. Fixed effects of year of birth and type of birth interacted with sex effects, with greater variability in birth and weaning weights among years and birth types in male lambs, suggesting greater environmental sensitivity in the males. Bivariate animal models and restricted maximum likelihood (REML) procedures were used to estimate phenotypic variances and their genetic and non-genetic components in male and female lambs. Estimates of the direct heritability (h2) and additive coefficient of variation (CVA) for BW were higher in males. However, for WW and GR, heritability estimates were higher in females. In contrast, whereas the contribution of maternal permanent environmental effects (c2) to variation of BW was higher in females, for WW and GR higher estimates of c2 were observed in males. Respective genetic and maternal permanent environmental correlations between records on males and females were 0.986 and 0.723 for BW, 0.995 and 0.983 for WW, and 0.995 and 0.966 for GR, indicating possible sexual dimorphism only for maternal effects on BW. Based on an approximate 95 % confidence interval, none of the observed differences in variance components between sexes differed from zero and none of the observed genetic or maternal correlations differed from 1.0, indicating no need or opportunity for sex-specific selection strategies.

scholarly journals Evaluating the Sensitivities and Efficacies of Fungicides with Different Modes of Action Against Phomopsis asparagi

Plant Disease ◽  
2020 ◽  
Vol 104 (2) ◽  
pp. 448-454 ◽  
Author(s):  
Niuniu Shi ◽  
Hongchun Ruan ◽  
Lin Gan ◽  
Yuli Dai ◽  
Xiujuan Yang ◽  
...  
Keyword(s):  
Wild Population ◽  
Good Control ◽  
Field Trials ◽  
Growth Inhibition Assay ◽  
Frequency Distributions ◽  
Stem Blight ◽  
Development Of Resistance ◽  
In The Wild ◽  
The Mean ◽  
Phomopsis Asparagi

Asparagus stem blight caused by Phomopsis asparagi is a major hindrance to asparagus production worldwide. Currently, fungicides are used to manage the disease in commercial production, but resistance to common fungicides has emerged in the wild population. In the present study, 132 isolates of P. asparagi collected from different provinces in China were tested for sensitivities to pyraclostrobin, tebuconazole, and fluazinam. We also determined the efficacies of six fungicides against P. asparagi. The frequency distributions of EC50 values of the isolates tested were unimodal, but the curves for pyraclostrobin and tebuconazole had long right-hand tails. The mean EC50 values for pyraclostrobin, tebuconazole, and fluazinam were 0.0426 ± 0.0029, 0.6041 ± 0.0416, and 0.0314 ± 0.0013 μg/ml, respectively. In addition, the EC50 values for pyraclostrobin were very similar with or without salicylhydroxamic acid (SHAM), 20 μg/ml, indicating that SHAM is not needed to determine the sensitivity of P. asparagi to pyraclostrobin when using the mycelial growth inhibition assay. In greenhouse assays, Merivon (42.4% fluxapyroxad plus pyraclostrobin SC), Frown-cide (500 g/liter fluazinam SC), Cabrio (250 g/liter pyraclostrobin EC), and Nativo (75% trifloxystrobin plus tebuconazole WG) showed excellent preventive efficacy against P. asparagi. And these fungicides were more effective before inoculation than when they were applied after inoculation (P < 0.05). Therefore, these fungicides should be applied prior to infection to control stem blight. In field trials, Frown-cide, Merivon, Nativo, and Cabrio also performed good control effects, ranging from 75.2 to 86.0% in 2017 and 75.4 to 87.1% in 2018. We demonstrated that Frown-cide, Merivon, Nativo, and Cabrio had considerable potential to manage asparagus stem blight. In addition, rotations of these fungicides are essential for precluding or delaying the development of resistance and for controlling the disease.

Genetic structure analyses of different populations of grass carp (Ctenopharyngodon idella) using the TRAP technique

2007 ◽  
Vol 4 (1) ◽  
pp. 27-32
Author(s):  
Zhang Zhi-Wei ◽  
Cao Zhe-Ming ◽  
Zhou Jing-Song ◽  
Wu Ting-Ting
Keyword(s):  
Genetic Structure ◽  
Grass Carp ◽  
Wild Population ◽  
Electrophoretic Pattern ◽  
Scientific Basis ◽  
Genetic Distances ◽  
Ctenopharyngodon Idella ◽  
Grass Carp Ctenopharyngodon Idella ◽  
In The Wild ◽  
Genetic Structures

AbstractTarget region amplified polymorphism (TRAP) was used to compare genetic structures among three populations of grass carp (Ctenopharyngodon idella) – one wild and two cultured populations. Seven out of 15 primer combinations produced good amplification patterns and provided 103 amplified loci from the three populations. Numbers of polymorphic loci in the wild population were higher, indicating a decrease in genetic polymorphism in the two cultured populations. Compared with the wild population, only 39.98% loci gene frequency remained unchanged in the cultured samples, showing a genetic structure change in cultured populations. The genetic distances between wild and cultured populations were 0.0421 and 0.0809. With primer combination Ga5-800-E5, we detected a region in the electrophoretic pattern in which the number of amplified loci apparently decreased in cultured populations. These results establish a good scientific basis for developing molecular markers that can help in distinguishing wild from cultured populations.

scholarly journals Arabian oryx reintroduction in Oman: successes and setbacks

Oryx ◽  
1999 ◽  
Vol 33 (2) ◽  
pp. 168-175 ◽  
Author(s):  
J. A. Spalton ◽  
M. W. Lawerence ◽  
S. A. Brend
Keyword(s):  
Wild Population ◽  
Species Conservation ◽  
Population Based ◽  
Monitoring Programme ◽  
New Approach ◽  
The World ◽  
In The Wild ◽  
Arabian Oryx ◽  
Supplementary Feed

AbstractThe return of the Arabian oryx Oryx leucoryx to Oman symbolized the success of a new approach to species conservation and established reintroduction as a conservation tool. Ten years after the species had been exterminated in the wild by poaching, the first 10 founder oryx, descendants of the ′World Herd′, were reintroduced to the desert in central Oman in January 1982. A second release followed in 1984 and the population grew slowly through a 3-year drought that was broken by rain in June 1986. Further years of good rainfall and more founders meant that by April 1990 there were over 100 oryx in the wild, independent of supplementary feed and water, and using a range of over 11,000 sq km. At that time a new monitoring programme was implemented that allowed the transition from individual- to population-based monitoring and management. The population continued to grow and by October 1995 numbered approximately 280 in the wild (of which 22 were surviving founders) and used over 16,000 sq km of the Arabian Oryx Sanctuary. However, in February 1996 poaching resumed and oryx were captured for sale as live animals outside the country. Despite the poaching the population continued to increase and by October 1996 was estimated to be just over 400. However, poaching intensified and continued through late 1996 and 1997. By September 1998 it had reduced the wild population to an estimated 138 animals, of which just 28 were females. The wild population was no longer considered viable and action was taken to rescue some of the remaining animals from the wild to form a captive herd.

Effects of age and gender on immune function of dragonflies (Odonata, Lestidae) from a wild population

2001 ◽  
Vol 79 (12) ◽  
pp. 2176-2180 ◽  
Author(s):  
Jens Rolff
Keyword(s):  
Gender Differences ◽  
Immune Function ◽  
Wild Population ◽  
Age And Gender ◽  
Mature Adults ◽  
Immune Parameters ◽  
In The Wild ◽  
Insect Populations ◽  
And Gender ◽  
Sexually Mature

Immunity is a crucial determinant of fitness. Despite this, very few studies have addressed the expression of immune function in insect populations in the wild. I present data on two immune parameters, hemocyte load and expression of phenoloxidase, in adult damselflies (Lestes viridis) from a wild population. In a comparison of newly emerged with sexually mature adults, it was found that the latter had higher hemocyte loads but lower phenoloxidase expression. Mature females showed significantly higher phenoloxidase expression than mature males. The sexual differences might be explained by gender differences in life history.

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