Towards accurate and simple morphometric sex differentiation in Bonelli’s Eagle Aquila fasciata nestlings: Interpopulation variations and influence of growth conditions

2021 ◽  
pp. 175815592110631
Author(s):  
Daniel Redondo-Gómez ◽  
Jesús Bautista ◽  
José María Gil-Sánchez ◽  
Francesc Parés ◽  
Antonio Hernández-Matías ◽  
...  

Morphometric methods of sex differentiation may be cheap, simple, quick, and reliable alternatives to molecular approaches. However, there are still important uncertainties regarding the use of morphometric methods in birds, particularly regarding their applicability to different populations and environmental conditions. Between 2004 and 2019, we sampled 245 Bonelli´s Eagle Aquila fasciata nestlings, 197 from nests in Catalonia (northeastern Spain) and Andalusia (southeastern Spain) and 56 that were partially or totally raised in captivity. Our objective was to develop morphometry-based sexing methods for Bonelli’s Eagle nestlings that can be applied in situ to different subpopulations and growth conditions. We recorded up to nine measures related to nestling body mass, bill, tarsus, and claw length. Tail and wing length were used to control for the age of nestlings, and all individuals were sexed genetically. We found important morphometric differences between the two natural subpopulations. According to our discriminant analyses, body mass and claw length were the most discriminant variables, both in wild and captivity conditions. Differences between sexes were more prominent during the flight feathers’ growing period. Feeding ad libitum in captivity conditions led to larger nestlings and reduced between-sexes differences. We provide different models for sexing Bonelli’s Eagle nestlings that can be applied according to the studied geographic location, growth conditions (wild versus captive), and balance between accuracy and simplicity. Overall, our findings highlight that extrapolating sex discriminant functions to different subpopulations and growth conditions may be risky.

2020 ◽  
Vol 77 (6) ◽  
pp. 1000-1009
Author(s):  
Barry A. Berejikian ◽  
Christopher P. Tatara ◽  
Donald M. Van Doornik ◽  
Michael A. Humling ◽  
Matt R. Cooper ◽  
...  

Female steelhead trout (Oncorhynchus mykiss) reared for 1 year (traditional, “S1”) and 2 years (experimental, “S2”) in captivity in the Methow River Basin, Washington, produced very similar numbers of offspring in replicate spawning channels over 3 consecutive years. In contrast, S1 anadromous males outcompeted S2 males for access to nesting females and, as a result, produced significantly more offspring. Male dominance was positively associated with body mass, but body mass did not account for differences between S1 and S2 males. Much smaller precocious S2 males that matured during rearing in hatchery raceways sired offspring in all six breeding groups. Contributions from precocious males were nearly always the result of sneak spawning events, although on rare occasions, precocious males were able to stimulate females to spawn in the absence of an anadromous male. Similarities in female breeding success suggest that S1 and S2 hatchery steelhead should exhibit similar productivity under natural conditions, but S1 male steelhead may result in greater rates of gene flow from hatchery to natural populations.


The Condor ◽  
2003 ◽  
Vol 105 (4) ◽  
pp. 696-706 ◽  
Author(s):  
Brian E. Washburn ◽  
Joshua J. Millspaugh ◽  
John H. Schulz ◽  
Susan B. Jones ◽  
Tony Mong

Abstract Fecal glucocorticoid assays provide a potentially useful, noninvasive means to study physiological responses of wildlife to various stressors. The objective of our study was to validate a method for measuring glucocorticoid metabolites in Mourning Dove (Zenaida macroura) feces. We validated the assay using standard procedures (e.g., parallelism, recovery of exogenous corticosterone) to demonstrate that the assay accurately and precisely measured glucocorticoid metabolites in Mourning Dove fecal extracts. We conducted adrenocorticotropin (ACTH) challenge experiments to validate the assay's ability to determine biologically important changes in fecal glucocorticoids. Fecal glucocorticoid levels increased significantly approximately 2–3 hr after administration of ACTH at 50 IU per kg body mass to wild Mourning Doves held in captivity. In contrast, fecal glucocorticoid metabolites did not increase in control birds, birds that received saline injections, or a lower dose of ACTH (1 IU per kg body mass). Variation in overall fecal glucocorticoid metabolite levels may have been influenced by season and the length of time birds were held in captivity. Noninvasive fecal glucocorticoid metabolite analyses, in combination with demographic information, may have considerable utility for monitoring the effects of natural and anthropogenic disturbances on Mourning Dove populations. Uso de Glucocorticoides Fecales Para Evaluar el Estrés en Zenaida macroura Resumen. Las evaluaciones de glucocorticoides fecales representan un medio no invasor potencialmente útil para estudiar las respuestas fisiológicas de los animales silvestres ante agentes causantes de estrés. El objetivo de nuestro estudio fue validar un método para medir metabolitos glucocorticoides en heces de palomas Zenaida macroura. Validamos el método mediante procedimientos estándar (e.g., paralelismo, recuperación de corticosterona exógena) para demostrar que éste mide con exactitud y precisión los metabolitos glucocorticoides en extractos fecales de Z. macroura. Realizamos experimentos de desafío con adrenocorticotropina (ACTH) para validar la habilidad que tenía el método para determinar cambios biológicamente importantes en los glucocorticoides fecales. Los niveles de glucocorticoides fecales aumentaron de forma significativa aproximadamente 2–3 hr después de la administración de ACTH a 50 IU por kg de peso corporal a palomas silvestres mantenidas en cautiverio. En contraste, los metabolitos glucocorticoides fecales no aumentaron en aves control, ni en aves que recibieron inyecciones salinas o una menor dosis de ACTH (1 IU por kg de peso corporal). La variación en los niveles generales de metabolitos glucocorticoides fecales podría haber sido influenciada por la estación y la longitud del período de tiempo en que las aves fueron mantenidas en cautiverio. Los análisis no invasores de metabolitos glucocorticoides, en combinación con información demográfica, podrían ser de considerable utilidad para monitorear los efectos de los disturbios naturales y antropogénicos sobre las poblaciones de Z. macroura.


2015 ◽  
Vol 49 (1) ◽  
pp. 103-105 ◽  
Author(s):  
Massimiliano Di Vittorio ◽  
Salvatore Grenci ◽  
Giovanni La Grua ◽  
Carmelo Bucalo ◽  
Angelo Scuderi ◽  
...  

2016 ◽  
Vol 50 (1) ◽  
pp. 125-128 ◽  
Author(s):  
Antonio Hernández-Matías ◽  
Joan Real ◽  
Francesc Parés ◽  
Santiago Llacuna

1993 ◽  
Vol 71 (7) ◽  
pp. 1397-1404 ◽  
Author(s):  
Katherine L. Parker ◽  
Michael P. Gillingham ◽  
Thomas A. Hanley ◽  
Charles T. Robbins

Body mass, body composition, and water transfer rates were determined over a continuous 2-year period in nine free-ranging Sitka black-tailed deer (Odocoileus hemionus sitkensis). Body masses showed a cyclical pattern, declined 14 – 31% between October and March, and were best described by a five-parameter, biologically based regression model. The amount of mass lost by black-tailed deer over winter depended on the peak body mass attained during fall. During winter, animals used 70 – 82% of their body fat and 10 – 15% of their protein reserves. Body fat was preferentially mobilized at rates 2.3 – 11.6 times higher than protein. Because of the higher energy content of fat, fat accounted for 83 – 92% of the catabolized energy. Water transfer rates varied seasonally with average summer values approximately four times those of winter; lactating deer had significantly higher rates of water transfer than nonlactating animals. Seasonal changes in all of the above parameters for wild deer were greater than those for eight deer of the same age in captivity.


Biologia ◽  
2011 ◽  
Vol 66 (6) ◽  
Author(s):  
Pablo Grenat ◽  
Lucio Zavala Gallo ◽  
Nancy Salas ◽  
Adolfo Martino

AbstractWe provide the first description of development for a species belonging to Odontophrynus genus by describing all external changes of embryonic and larval stages for Odontophrynus cordobae. External morphological changes through development were analyzed on specimens bred in captivity. Embryonic and larval development, from fertilization to metamorphosis, was completed in 62 days and 46 stages were defined. We split the staging series into ten developmental groups: fertilization (stages 1 and 2); segmentation (stages 3–9); gastrulation (stages 10–12); neurulation (stages 13–16); elongation (stages 17–19); external gill larva (stages 20–24); internal gill larva (stage 25); pre-metamorphosis (stages 26–41); pro-metamorphosis (stage 42); metamorphic climax (stages 43–46). Marked increases in total length were evidenced during elongation and during stage 25, when the tadpole begins to feed. Stage 25 was the longest one (8 days) and it was related to organs rearrangement, morphological progression and body mass increment typical of free life larval form. Similar studies on related species are needed to compare different developmental stages at different taxonomic levels.


2021 ◽  
Author(s):  
Maria Papadaki ◽  
Manolis Mandalakis ◽  
Thekla I. Anastasiou ◽  
Marina Pouli ◽  
Michalis Asderis ◽  
...  

Abstract The histological process of gonadal differentiation together with the endocrine changes of glucocorticoids and sex steroids was studied in hatchery produced greater amberjack (Seriola dumerili) from 101 until 408 days post-hatching. In the samplings, which were conducted every 50 days, no size dimorphism was observed between the sexes and sex ratio was 1:1, suggesting that there was no influence of early rearing in captivity on sex differentiation. Plasma concentrations of cortisol, cortisone, adrenosterone (Ad), androstenedione (Δ4), 11-ketotestosterone (11ΚΤ), testosterone (Τ), estradiol (Ε2), progesterone (P4) and 17,20β-dihydroxyprogesterone (DHP) were measured in males and females with the use of liquid chromatography tandem mass spectrometry (LC-MS/MS) to examine their role in the sex differentiation process. From the nine hormones, the only one that exhibited differences between the sexes was 11-KT. However, variations were observed in the mean values of cortisol, Ad, Δ4, 11-KT, T, P4 and DHP over time in one or both sexes, indicating their involvement in the sex differentiation process. Moreover, the 11-KT/E2 ratio was found to be a useful diagnostic biomarker for greater amberjack sex, from as early as 150 dph.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Ilya A. Volodin ◽  
Anna V. Klenova ◽  
Olga G. Ilchenko ◽  
Elena V. Volodina

Abstract Objectives This is the first study of the sonic and ultrasonic vocalization in a Dipodidae rodent. For the small-sized quadrupedal northern birch mouse Sicista betulina, phylogenetically related to the bipedal jerboas (Dipodidae), we report null results for ultrasonic vocalization and investigate the acoustic cues to individual identity, sex and body size in the discomfort-related high-frequency tonal sonic calls. Results We used a parallel audio recording in the sonic and ultrasonic ranges during weighting adult northern birch mice before the scheduled hibernation in captivity. The sonic (audible) high-frequency tonal calls (ranging from 6.21 to 9.86 kHz) were presented in all individuals (7 males and 4 females). The ultrasonic calls lacked in the recordings. Two-way nested ANOVA revealed the effects of caller individual identity on all 10 measured acoustic variables and the effects of sex on four out of 10 measured acoustic variables. Discriminant function analyses with 10 acoustic variables included in the analysis showed 85.5% correct assignment of calls to individual and 79.7% correct assignment of calls to sex; both values significantly exceeded the random values (23.1% and 54.3%, respectively) calculated with randomization procedure. Body mass did not differ between sexes and did not correlate significantly with the acoustic variables.


1997 ◽  
Vol 75 (11) ◽  
pp. 1781-1789 ◽  
Author(s):  
Patrice Boily ◽  
David M. Lavigne

Resting metabolic rate (RMR) data obtained from five juvenile and three adult female grey seals (Halichoerus grypus) in captivity over a period of 3.5 years were examined for developmental and seasonal changes. Three juveniles exhibited a significant relationship between log10 RMR and log10 mass, with individual slopes ranging from 0.42 to 1.62. Two of these exhibited a significant relationship between log10 RMR and log10 age. The remaining two juveniles and the three adults exhibited no significant relationship between RMR and body mass. With increasing size and age, RMRs of juveniles approached predicted values for adult mammals, but the large variation made it difficult to establish the precise age at which they achieved an adult-like RMR. RMRs of adults and juveniles exhibited marked seasonal changes. In juveniles, seasonal changes in RMR were limited to the annual moult, when the average RMR was 35% higher than during the rest of the year. In adults, changes in RMR were not limited to the time of the annual moult; rather, RMR was lower (by up to 50%) in the summer than during other seasons.


2020 ◽  
Author(s):  
Jaume Orta ◽  
Guy M. Kirwan ◽  
David Christie ◽  
Peter F. D. Boesman ◽  
Jeffrey S. Marks ◽  
...  

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