Phenotypic assortative mating and within-pair sexual dimorphism and its influence on breeding success and offspring quality in Magellanic penguins

2001 ◽  
Vol 79 (8) ◽  
pp. 1414-1422 ◽  
Author(s):  
M G Forero ◽  
J L Tella ◽  
J A Donázar ◽  
G Blanco ◽  
M Bertellotti ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Assortative Mating ◽  
Body Mass ◽  
Body Condition ◽  
Relative Difference ◽  
The Body ◽  
Phenotypic Traits ◽  
Magellanic Penguins ◽  
Patagonian Coast ◽  
Potential Factors

We examined within-pair sexual dimorphism and phenotypic assortative mating in Magellanic penguins (Spheniscus magellanicus) breeding in six colonies located on the Patagonian coast (Argentina). All measured phenotypic traits except the number of pectoral spots differed between the sexes; bill depth and flipper length were the most and least dimorphic traits, respectively. We found assortative mating by bill depth and body mass. The similarity in body condition within pairs was close to significant. When we performed separate correlations for birds that bred successfully, i.e., raised one or two offsprings, and birds that did not attempt to breed or bred unsuccessfully, only the successful breeders showed assortative mating by body mass. In addition, we attempted to relate the body size of each member of the pair and the degree of sexual dimorphism within pairs to the breeding performance of individuals, which was measured as brood size, and body condition and immunocompetence of offspring. We found that pairs that were less dimorphic in flipper length raised more offspring. This effect was due to female flipper length per se and not to the relative difference in flipper length between members of the pair. Females with larger flippers had a higher probability of raising two chicks. No effects of body measurements or degree of sexual dimorphism on body condition or T-cell-mediated immune response of offspring were found. We discuss these results in the context of potential factors responsible for the maintenance of sexual size dimorphism in this species.

Phenotypical characterization of Kababich breed in peri-urban zone of N’Djamena-Chad

2021 ◽  
Vol 2 (2) ◽  
pp. 041-049
Author(s):  
Djalal Ardjoun Khalil ◽  
Mahamat Ibrahim Souleymane ◽  
Issa Youssouf ◽  
Madjina Tellah ◽  
Mopate Logtene Youssouf ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Genetic Improvement ◽  
The Body ◽  
Phenotypic Characterization ◽  
Phenotypic Traits ◽  
Phenotypic Characteristics ◽  
Young Males ◽  
Urban Zone ◽  
One Year

This work was carried out on the phenotypic characteristics of the Kababich sheep exploited in the peri-urban zone of N'Djamena (Chad). This phenotypic characterization of Kababich sheep should be continued on local breeds for genetic improvement and objective optimization of productivity. The objective of this study is the characterization of phenotypically Kababich sheep exploited in the peri-urban area of ​​N'Djamena-Chad. It was conducted in 39 farms and involved 1035 sheep aged less than one year old. Phenotypic traits were measured according to the guideline defined by FAO. A total of 12 variables were measured including five qualitative and seven quantitative. The results obtained show a positively significant correlation (p> 0.001) between the age of the sheep estimated by the breeder and the dentition (0.83). The ears are drooping and measure 17.90 ± 2.77 cm. The color of the brown dress (fawn) and the smooth and short coat are dominant. The females are matte and the rams of brown dress have horns in the forms of the vestiges. The Kababich is large with a height at the withers of 81.50 ± 9.40 cm, a rump height of 83.24 ± 9.42 cm and a chest circumference of 88.29 ± 9.22 cm. The body is 72.82 ± 9.63 cm long, has a basin width of 19.89 ± 2.53 cm and a chest depth of 40.68 ± 5.16 cm. These measurements show that Kababich is a meat breed by excellence. In addition, the sexual dimorphism very accentuated in this race orients towards a valorization of the young males in the fattening workshops.

scholarly journals Dentition and body condition: tooth wear as a correlate of weight loss in roe deer

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Roberta Chirichella ◽  
Anna Maria De Marinis ◽  
Boštjan Pokorny ◽  
Marco Apollonio
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Physical Condition ◽  
Roe Deer ◽  
Tooth Wear ◽  
The Body ◽  
Permanent Teeth ◽  
Tooth Surface ◽  
Mandible Length

Abstract Background In many mammalian species, once the permanent teeth have erupted, the only change to dentition is a gradual loss of tooth surface/height through wear. The crown of the teeth cannot be repaired once worn. When dental crown tissue has been depleted due to wear, the animal is expected to have a suboptimal body condition. We evaluated the role of tooth wear in causing a reduction of physical condition in adult roe deer females (Capreolus capreolus). Results The progressive wearing of the lower cheek teeth was assessed in a Northern Apennines (Italy) population with a new scoring scheme based on objectively described tooth characteristics (morphotypes) being either present or absent. Eviscerated body mass and mandible length, which is a good proxy for body size in roe deer, were related to the tooth wear score by the use of linear regressions. The sum of wear scores for molariform teeth correlated most strongly with body condition (i.e., eviscerated body mass/mandible length), showing the importance of the entire chewing surface for acquiring energy by food comminution, chewing, and digestion. In comparison with individuals of comparable size experiencing minor tooth wear, the body mass of those with the most advanced stage of tooth wear was decreased by 33.7%. This method was compared to the height and the hypsodonty index of the first molar, the most commonly used indices of tooth wear. The sum of molariform wear scoring scheme resulted in a more suitable index to describe the variation in body condition of roe deer. Conclusions Describing tooth wear patterns in hunted populations and monitoring at which tooth wear level (and therefore dental morphotype) an animal is no longer able to sustain its physical condition (i.e. when it begins to lose body mass) can be a useful tool for improving the management of the most widespread and abundant deer species in Europe. At the same time, such an approach can clarify the role of tooth wear as a proximate cause of senescence in ungulates.

scholarly journals Body mass index and glucose variations during the night in free-ranging Artibeus planirostris (Chiroptera: Phyllostomidae)

2019 ◽  
Vol 36 ◽  
pp. 1-8 ◽  
Author(s):  
Luane Maria Melo Azeredo ◽  
Monique Silva Ximenes ◽  
Kleytone Alves Pereira ◽  
Maria Paula Aguiar Fracasso ◽  
Luiz Carlos Serramo Lopez
Keyword(s):  
Blood Glucose ◽  
Body Mass ◽  
Body Condition ◽  
The Body ◽  
Energy Reserve ◽  
Glucose Levels ◽  
Reproductive Phase ◽  
Condition Indices ◽  
Positive Correlations ◽  
Free Ranging

Body condition is an important measure to estimate the energy reserve of an organism. Scientists frequently use body condition indices (BCIs) with morphometric measures but direct measurements, such as blood glucose, seem to be more reliable. We observed oscillations in the body condition and glucose indexes of individuals of Artibeusplanirostris (Spix, 1823) during 13 nights in the field. We assume that if glucose levels are proportional to feeding state and body condition is a measure of energy reserve, blood glucose and BCI should be positively correlated and both are expected to increase during the night as the bats leave their diurnal roost to feed. To test this, we examined the relationship between blood glucose levels, BCI and reproductive phase of free flying male bats (n = 70) for 12 hours after sunset for 13 nights. Bats were captured in Reserva Biológica de Guaribas (Paraíba, Brazil) using mist nets. Blood glucose was analyzed with a portable glucometer. Supporting our assumptions, the number of hours after sunset and BCI presented significant positive correlations with glucose levels in A.planirostris. Reproductive phase did not present a significant correlation with any other variables. As we predicted, glucose level can be used as proxy for morphometric BCI and it can be measured with a simple portable glucometer. The increase both in glucose and BCI around the night can be explained by the efficient assimilation of nutrients present in fruits ingested by bats and the quick metabolism that increases the levels of glucose (an other nutrients) in blood, increasing the body mass.

scholarly journals Seasonal and temporal variation in scaled mass index of Black-capped Chickadees (Poecile atricapillus)

2019 ◽  
Vol 132 (4) ◽  
pp. 368-377 ◽  
Author(s):  
Emma J. Nip ◽  
Barbara Frei ◽  
Kyle H. Elliott
Keyword(s):  
Ambient Temperature ◽  
Body Mass ◽  
Body Condition ◽  
Seasonal Variability ◽  
Time Of Day ◽  
The Body ◽  
Food Sources ◽  
Poecile Atricapillus ◽  
Evolutionary Response ◽  
Scaled Mass Index

Avian body mass reflects a trade-off between risk of starvation and predation, and may vary with ambient temperature, age, and time of day. Seasonal variability in body mass is a common occurrence in northern temperate regions, including adaptive fattening. Previous evidence suggests that seasonal variability is less pronounced in tree-feeding bird species, as their food sources during winter are less limited and variable compared to ground-foraging species. We determined fat scores of tree-feeding Black-capped Chickadees (Poecile atricapillus) captured year-round between 2004 and 2015 (n = 4248) in southern Quebec, to test the relative strength of possible drivers of variability in chickadee body mass, including time, date, and year of capture, age, and temperature. First, we demonstrated that scaled mass index (SMI) was the body condition index, out of four possible indices tested, which most strongly correlated with fat scores measured in the field. We used SMI subsequently as our estimator of body condition to avoid observer effects associated with fat scores. Similar to other studies, time of capture significantly affected SMI, in which birds captured later were heavier, indicating that chickadees experience overnight weight loss and subsequent weight gain from foraging throughout the day. SMI was constant from April to November, then peaked in late winter, but was not influenced by daily temperature after accounting for month and year. SMI was not significantly affected by age. We concluded that adaptive fattening is an evolutionary response to risk of starvation in winter, rather than a proximal response to immediate ambient temperature.

scholarly journals Measuring body condition of lizards: a comparison between non-invasive dual-energy X-ray absorptiometry, chemical fat extraction and calculated indices

2020 ◽  
Author(s):  
Guy Sion ◽  
Maggie J. Watson ◽  
Amos Bouskila
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Fat Mass ◽  
Dual Energy ◽  
The Body ◽  
Ecological Studies ◽  
Fat Percentage ◽  
X Ray ◽  
Non Invasive ◽  
Fat Extraction

Abstract Background Condition indices (CIs) are used in ecological studies as a way of measuring an individual animal’s health and fitness. Noninvasive CIs are estimations of a relative score of fat content or rely on a ratio of body mass compared to some measure of size, usually a linear dimension such as tarsus or snout-vent length. CIs are generally measured invasively by lethal fat extraction as in a seasonal sample of individuals in a population. Many alternatives to lethal fat extraction are costly or time consuming. As an alternative, dual-energy X-ray absorptiometry (DXA) allows for non-destructive analysis of body composition and enables multiple measurements during an animal's life time. DXA has never been used for ecological studies in a small, free-ranging lizard before, therefore we calibrated this method against a chemical extraction of fat from a sample of 6 geckos (Israeli fan toed gecko Ptyodactylus guttatus) ranging in body mass between 4.2–11.5 g. Results We found that fat mass measured with DXA was significantly correlated with the mass of chemically extracted fat for specimens more than 4.8 g (N = 5, R2 = 0.995, P < 0.001). Fat percentage regressed with body mass significantly predicted the DXA fat percentage (N = 30, R2adj.=0.875, P < 0.001). Live wet mass was significantly correlated with calculated fat mass (N = 30, R2 = 0.984, P < 0.001) for specimens more than 4.8 g. Among the other calculated non-invasive CIs that we tested, the best was mass/SVL (provide N, correlation coeff and p value). Conclusions We recommend that in situations where DXA cannot be used, that the most accurate of the body condition estimators for both males and females in this species is mass/SVL (snout-vent length) for both sexes.

Male mating success is related to body condition and stress-induced leukocyte response in an anuran with scramble competition

2020 ◽  
Vol 98 (6) ◽  
pp. 391-398
Author(s):  
M.S. Gastón ◽  
M. Vaira
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Condition Index ◽  
Scramble Competition ◽  
The Body ◽  
Male Mating ◽  
Adult Males ◽  
Body Condition Index ◽  
Index Value ◽  
Leukocyte Response

Competition among males can be a decisive factor for successful mating in anuran explosive breeders with a male-biased population sex ratio. The Yungas Red-belly Toad (Melanophryniscus rubriventris (Vellard, 1947)) is an explosive breeder where males exhibit a classic scramble competition. We studied the body size, body condition, and stress-induced leukocyte response of M. rubriventris males under natural scenarios of scramble competition. We hand-captured adult males (categorised as single, in pairs, or in mating balls) and determined their body mass and length, body condition, and their leukocyte profile. We found that males in pairs had significantly higher body mass than single males and those in mating balls. We found the highest percentage of individuals with better body condition within the paired males who showed significantly higher body condition index value than singles or those in mating balls. Amplectant males (those collected in pairs or in mating balls) had a significantly lower proportion of lymphocytes and higher neutrophil–lymphocyte ratios than singles. Amplectant males showed significantly higher proportions of neutrophils or eosinophils than singles. Our results suggest that M. rubriventris males with better body condition can be more successful in acquiring mates, although scramble competition among males can trigger a stress response.

scholarly journals Measuring body condition of lizards: a comparison between non-invasive dual-energy X-ray absorptiometry, chemical fat extraction and calculated indices

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Guy Sion ◽  
Maggie J. Watson ◽  
Amos Bouskila
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Fat Mass ◽  
Dual Energy ◽  
The Body ◽  
Ecological Studies ◽  
Fat Percentage ◽  
X Ray ◽  
Non Invasive ◽  
Fat Extraction

Abstract Background Condition indices (CIs) are used in ecological studies as a way of measuring an individual animal’s health and fitness. Noninvasive CIs are estimations of a relative score of fat content or rely on a ratio of body mass compared to some measure of size, usually a linear dimension such as tarsus or snout-vent length. CIs are generally validated invasively by lethal fat extraction as in a seasonal sample of individuals in a population. Many alternatives to lethal fat extraction are costly or time consuming. As an alternative, dual-energy X-ray absorptiometry (DXA) allows for non-destructive analysis of body composition and enables multiple measurements during an animal’s life time. DXA has never been used for ecological studies in a small, free-ranging lizard before, therefore we calibrated this method against a chemical extraction of fat from a sample of 6 geckos (Israeli fan toed gecko Ptyodactylus guttatus) ranging in body mass between 4.2–11.5 g. We then  used this calibrated  DXA measurements to determine the best linear measurement calculated CI for this species. Results We found that fat mass measured with DXA was significantly correlated with the mass of chemically extracted fat for specimens more than 4.8 g (N = 5, R2 = 0.995, P < 0.001). Fat percentage regressed with body mass significantly predicted the DXA fat percentage (N = 29, R2adj. = 0.862, p < 0.001). Live wet mass was significantly correlated with predicted fat mass (N = 30, R2 = 0.984, P < 0.001) for specimens more than 4.8 g. Among the five calculated non-invasive CIs that we tested, the best was mass/SVL. Conclusions We recommend that in situations where DXA cannot be used, that the most accurate of the body condition estimators for  this species is mass/SVL (snout-vent length) for both sexes.

scholarly journals Sex-specific body mass ageing trajectories in adult Asian elephants

2020 ◽  
Author(s):  
Lucas D. Lalande ◽  
Virpi Lummaa ◽  
Htoo H. Aung ◽  
Win Htut ◽  
U. Kyaw Nyein ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Body Mass ◽  
Life Histories ◽  
The Body ◽  
Captive Population ◽  
Natural Death ◽  
Asian Elephants ◽  
Female Body Mass ◽  
Males And Females ◽  
Longitudinal Dataset

Sex-specific life-histories are thought to shape senescence patterns differently for males and females. In species with marked sexual dimorphism and where one sex is undergoing stronger intrasexual competition, it is expected that this sex ages earlier or quicker. Here, we utilise a unique, longitudinal dataset of a semi-captive population of Asian elephants (Elephas maximus) to describe the body mass ageing trajectories in this species with marked sexual dimorphism in size and lifespan, with males being larger and living shorter. Our results show sex-specific ageing trajectories: males gained weight throughout their life, at a diminishing rate until natural death. In contrast, adult female body mass did not change significantly with age until an abrupt decline during the last year of life. Our study shows that sex-specific life-histories shape ageing patterns contrary to those predicted by classical theory and expands the previously described diversity of ageing dynamics.

Influences of age, body condition, and structural size on mate selection by dabbling ducks

1995 ◽  
Vol 73 (12) ◽  
pp. 2251-2258 ◽  
Author(s):  
Mickey E. Heitmeyer
Keyword(s):  
Assortative Mating ◽  
Body Condition ◽  
Mate Selection ◽  
Reproductive Potential ◽  
The Body ◽  
Dabbling Ducks ◽  
Structural Size ◽  
Nutrient Reserve ◽  
Anas Clypeata ◽  
Similar Body

Both members of pairs of mallards (Anas platyrhynchos), northern pintails (Anas acuta), northern shovelers (Anas clypeata), and American wigeon (Anas americana) were collected early in the pairing periods in fall and during spring migration (several months after most birds were paired) to provide insights into whether (i) assortative mating occurs; (ii) body condition changes synchronously among pair members; and (iii) characteristics of selected individuals ultimately confer advantages in survival and recruitment. Both members in 19 of 21 mallard, 16 of 16 pintail, 14 of 14 shoveler, and 14 of 15 wigeon pairs were adults. The predominance of adults in pairs in fall indicates that adults pair earlier than juveniles and suggests at least some assortative mating in relation to age. Generally, body and nutrient reserve masses of males and females within a pair were correlated for all species in both fall and spring, suggesting that individuals tend to form pairs with others of relatively similar body condition, and also that once paired, the body condition of the two members tends to change at the same time. In contrast to body condition, measures of structural size of pair members were not correlated. Field data suggest that older and heavier ducks have greater survival and reproductive potential than young, lighter ducks; consequently, selection of old and heavy mates is probably evolutionarily advantageous.

scholarly journals Measuring Body Condition of Lizards: A Comparison Between Non-Invasive Dual-Energy X-ray Absorptiometry, Chemical Fat Extraction and Calculated Indices

2020 ◽  
Author(s):  
Guy Sion ◽  
Maggie J. Watson ◽  
Amos Bouskila
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Fat Mass ◽  
Dual Energy ◽  
The Body ◽  
Ecological Studies ◽  
Fat Percentage ◽  
X Ray ◽  
Non Invasive ◽  
Fat Extraction

Abstract BackgroundCondition indices (CIs) are used in ecological studies as a way of measuring an individual animal’s health and fitness. Noninvasive CIs are estimations of a relative score of fat content or rely on a ratio of body mass compared to some measure of size, usually a linear dimension such as tarsus or snout-vent length. CIs are generally measured invasively by lethal fat extraction as in a seasonal sample of individuals in a population. Many alternatives to lethal fat extraction are costly or time consuming. As an alternative, dual-energy X-ray absorptiometry (DXA) allows for non-destructive analysis of body composition and enables multiple measurements during an animal's life time. DXA has never been used for ecological studies in a small, free-ranging lizard before, therefore we calibrated this method against a chemical extraction of fat from a sample of 6 geckos (Israeli fan toed gecko Ptyodactylus guttatus) ranging in body mass between 4.2–11.5 g. ResultsWe found that fat mass measured with DXA was significantly correlated with the mass of chemically extracted fat for specimens more than 4.8g (N=5, R2=0.995, P<0.001). Fat percentage regressed with body mass significantly predicted the DXA fat percentage (N=30, R2adj.=0.875, P<0.001). Live wet mass was significantly correlated with calculated fat mass (N=30, R2=0.984, P<0.001) for specimens more than 4.8g. Among the other calculated non-invasive CIs that we tested, the best was mass/SVL (N=30, rMass/SVL= 0.83, PTwo-tailed<0.001). ConclusionsWe recommend that in situations where DXA cannot be used, that the most accurate of the body condition estimators for both males and females in this species is mass/SVL (snout-vent length) for both sexes.

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