Signaling, Agonistic Behavior, and Life-History Traits of Steppe Agama (Trapelus sanguinolentus) in Prague Zoo

2020 ◽  
Vol 27 (6) ◽  
pp. 334-340
Author(s):  
Karel Novák ◽  
Petr Velenský ◽  
Oldrich Kopecký
Keyword(s):  
Life History ◽  
Life Expectancy ◽  
Sex Ratio ◽  
Body Condition ◽  
Agonistic Behavior ◽  
Life History Traits ◽  
Morphological Characteristics ◽  
Agonistic Interactions ◽  
Aggressive Interactions ◽  
Signal Type

Life history traits are influenced by many factors, such as social structure, social displays and aggressive interactions. We investigated signalling and agonistic behavior in relation to body condition and lifespan in Trapelus sanguinolentus, a small, semi-arboreal, oviparous agamid lizard from the Central Asia. We individually examined basic morphological characteristics, number of performed signal displays and relative success in agonistic interactions (via Clutton-Brock index). Life expectancy of males did not differ from life expectancy of females. Overall variability of signals was low and simple push-up display was prevalent signal type for both sexes. Frequency of performed signals differed between sexes with males signalling more. For both sexes number of signals was not associated with life expectancy. Interaction of life expectancy and sex was also not significant. In females — body condition influenced number of performed signals when individuals in better body condition signalled more. Most of agonistic interactions was solved by means of signal displays and did not lead to a direct physical combat. While in males association between CBI and number of signals was not significant, in females higher value of CBI means more performed signals. Conditions of our study (sex ratio 4:1 in favor of females, 20 individuals on 16.5 m2 of terrarium) means that agonistic signals have greater importance for females. The agonistic interactions in females led to direct physical combat more frequently could reflect more competitive intra-sexual environment. Females in better body condition probably used higher signalling activity and better performance in direct combat for access to mates and to places for sunbathing and oviposition.

scholarly journals Spatiotemporal variation in the adult sex ratio, male aggregation, and movement of two tropical cloud forest dung beetles

2021 ◽  
Author(s):  
Julliana Barretto ◽  
Martha L Baena ◽  
Israel Huesca Domínguez ◽  
Federico Escobar
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Life History Traits ◽  
Cloud Forest ◽  
Habitat Preferences ◽  
Habitat Type ◽  
Dung Beetle ◽  
Adult Sex Ratio ◽  
The Face ◽  
Male Aggregation

Abstract While theory suggests that at conception the sex ratio should be balanced (1:1), this can be variable across space and time in wild populations. Currently, studies of the environmental factors that regulate adult sex ratio (ASR) in species with different life-history traits are scarce. Using capture-recapture over a year, we analyzed the influence of habitat type (forest and non-forest) and season (rainy and dry) on variation in ASR, male aggregation and the trajectory movement of two dung beetle species with different life-history traits: Deltochilum mexicanum (a hornless roller species) and Dichotomius satanas (a tunneler species with horns on its head and thorax). We found opposite tendencies. The D. mexicanum population tends to be female-biased, but the population of D. satanas tends to be predominantly male, and observed values were not related to habitat type or season. However, the 95% confidence intervals estimated were highly variable between seasons depending on habitat. On examining the monthly variation in ASR for both habitats, we found that it depends on the species. In addition, male aggregation differed between species depending on habitat type and season, and species movement patterns were closely related to their habitat preferences. Based on our results, we argue that comparative population studies of species with different life-history traits are necessary to understand the variation in demographic parameters as well as its ecological and evolutionary implications in the face of spatial and climatic environmental variation.

scholarly journals Body reserves mediate trade-offs between life-history traits: new insights from small pelagic fish reproduction

2016 ◽  
Vol 3 (10) ◽  
pp. 160202 ◽  
Author(s):  
Pablo Brosset ◽  
Josep Lloret ◽  
Marta Muñoz ◽  
Christian Fauvel ◽  
Elisabeth Van Beveren ◽  
...  
Keyword(s):  
Life History ◽  
Maternal Effects ◽  
Body Condition ◽  
Life History Traits ◽  
Pelagic Fish ◽  
Small Pelagic Fish ◽  
Gulf Of Lions ◽  
Fish Size ◽  
Trade Offs ◽  
The Cost

Limited resources in the environment prevent individuals from simultaneously maximizing all life-history traits, resulting in trade-offs. In particular, the cost of reproduction is well known to negatively affect energy investment in growth and maintenance. Here, we investigated these trade-offs during contrasting periods of high versus low fish size and body condition (before/after 2008) in the Gulf of Lions. Female reproductive allocation and performance in anchovy ( Engraulis encrasicolus ) and sardine ( Sardina pilchardus ) were examined based on morphometric historical data from the 1970s and from 2003 to 2015. Additionally, potential maternal effects on egg quantity and quality were examined in 2014/2015. After 2008, the gonadosomatic index increased for sardine and remained steady for anchovy, while a strong decline in mean length at first maturity indicated earlier maturation for both species. Regarding maternal effects, for both species egg quantity was positively linked to fish size but not to fish lipid reserves, while the egg quality was positively related to lipid reserves. Atresia prevalence and intensity were rather low regardless of fish condition and size. Finally, estimations of total annual numbers of eggs spawned indicated a sharp decrease for sardine since 2008 but a slight increase for anchovy during the last 5 years. This study revealed a biased allocation towards reproduction in small pelagic fish when confronted with a really low body condition. This highlights that fish can maintain high reproductive investment potentially at the cost of other traits which might explain the present disappearance of old and large individuals in the Gulf of Lions.

scholarly journals Dispersal as a source of variation in age-specific reproductive strategies in a wild population of lizards

2015 ◽  
Vol 282 (1820) ◽  
pp. 20151741 ◽  
Author(s):  
Olivier Cotto ◽  
Manuel Massot ◽  
Ophélie Ronce ◽  
Jean Clobert
Keyword(s):  
Life History ◽  
Body Condition ◽  
Life History Traits ◽  
Reproductive Effort ◽  
Wild Population ◽  
Recent Theory ◽  
Offspring Sex Ratio ◽  
Dispersal Syndromes ◽  
Common Lizard ◽  
High Investment

Dispersal syndromes describe the patterns of covariation of morphological, behavioural, and life-history traits associated with dispersal. Studying dispersal syndromes is critical to understanding the demographic and genetic consequences of movements. Among studies describing the association of life-history traits with dispersal, there is anecdotal evidence suggesting that dispersal syndromes can vary with age. Recent theory also suggests that dispersive and philopatric individuals might have different age-specific reproductive efforts. In a wild population of the common lizard ( Zootoca vivipara ), we investigated whether dispersive and philopatric individuals have different age-specific reproductive effort, survival, offspring body condition, and offspring sex ratio. Consistent with theoretical predictions, we found that young dispersive females have a higher reproductive effort than young philopatric females. Our results also suggest that the early high investment in reproduction of dispersive females trades-off with an earlier onset of senescence than in philopatric females. We further found that young dispersive females produce smaller offspring in lower body condition than do young philopatric females. Overall, our results provide empirical evidence that dispersive and philopatric individuals have different age-specific life-history traits.

Reproductive biology of Orchestia gammarellus (Crustacea: Amphipoda) living in a sewage treatment works

1993 ◽  
Vol 73 (2) ◽  
pp. 405-416 ◽  
Author(s):  
M. B. Jones ◽  
G. D. Wigham
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Embryonic Development ◽  
Body Length ◽  
Life History Traits ◽  
Ovigerous Female ◽  
Seasonal Pattern ◽  
Sewage Treatment ◽  
Female Size ◽  
Egg Volume

A population of the supralittoral Orchestia gammarellus (Pallas) (Amphipoda: Talitridae), living in a percolating filter of a sewage treatment works has been studied over 12 months. The population showed a seasonal pattern of occurrence, few animals being collected during the winter. The sex ratio was biased significantly to females except during the breeding season when it did not deviate significantly from 1:1. Ovigerous females, never collected in high numbers (1–14 per month), were found from April to August, with peak occurrence in May/June. Juveniles were present throughout the year, but peak recruitment occurred in summer, following the period of reproduction by females. The smallest ovigerous female had a body length of 12.6 mm and the largest measured 20.0 mm. Egg numbers (5–31 per brood) increased with increasing female size and egg volume more than doubled during embryonic development. These findings are discussed in relation to the possible methods of colonization of this unique habitat and the influence of sewage on crustacean life-history traits.

Extremely low fecundity and highly female-biased sex ratio in nest-living spider mite Schizotetranychus brevisetosus (Acari: Tetranychidae)

2017 ◽  
Vol 22 (2) ◽  
pp. 170 ◽  
Author(s):  
Kaori Tamura ◽  
Katsura Ito
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Life Histories ◽  
Life History Traits ◽  
Defense Mechanism ◽  
Intrinsic Rate ◽  
Spider Mites ◽  
Natural Increase ◽  
Blue Oak ◽  
Life Type

Spider mites show various life types characterized by spinning behavior, web structure, and sociality. Individuals of the woven-nest (WN) species construct silken nests on the undersurface of host leaves, inside which they develop and reproduce. This nesting behavior may be related with the defense mechanism and life history traits of mites in the stable habitat (e.g., evergreen trees). If the WN life type affects the life-history traits, these traits may be similar within WN species. The WN species are known to be fragmentarily distributed in diverse genera, Stigmaeopsis, Schizotetranychus, Eotetranychus, and Oligonychus, and their life types are suspected to have secondarily converged. However, their life histories have not been elucidated except for several species in specific genera. To supply the information in Schizotetranychus, we investigated the demographic traits and the sex ratio of Schizotetranychus brevisetosus, which shows the WN life type and lives on the evergreen Japanese blue oak Quercus glauca. We estimated the development time of females as 22.6 ± 3.1 days (mean ± SD, n = 22) and the fecundity of fertilized females as 13.7 ± 5.9 (n = 37) at 25°C. The sex ratio of males to the total number of adults at emergence was low (0.072). The intrinsic rate of natural increase (rm) was estimated as 0.060 day-1, one of the lowest ever reported for spider mites at the same temperature. The present results were similar to other WN species in that fecundity and male ratio were low. 

scholarly journals Changes in Life History Traits of Small Pelagic Fish in the Western Mediterranean Sea

2021 ◽  
Vol 8 ◽  
Author(s):  
Marta Albo-Puigserver ◽  
Maria Grazia Pennino ◽  
Jose María Bellido ◽  
Ana Isabel Colmenero ◽  
Ana Giráldez ◽  
...  
Keyword(s):  
Life History ◽  
Mediterranean Sea ◽  
Body Condition ◽  
Life History Traits ◽  
Seawater Temperature ◽  
Western Mediterranean ◽  
Pelagic Fish ◽  
Additive Models ◽  
Small Pelagic Fish ◽  
Western Mediterranean Sea

Small pelagic fish (SPF) in the western Mediterranean Sea are key elements of the marine food web and are important in terms of biomass and fisheries catches. Significant declines in biomass, landings, and changes in the age/size structure of sardine Sardina pilchardus and anchovy Engraulis encrasicolus have been observed in recent decades, particularly in the northern area of the western Mediterranean Sea. To understand the different patterns observed in SPF populations, we analyzed key life history traits [total length at age, length at maturity, gonadosomatic index (GSI), and body condition (Kn)] of sardine and anchovy collected between 2003 and 2017, from different fishing harbors distributed along a latitudinal gradient from northern to southern Spain. We used Generalized Linear Models (GLM) to estimate the length at maturity and Generalized Additive Models (GAMs) to test the relationship with environmental variables (seawater temperature, water currents, and net primary productivity). The life history traits of both species presented seasonal, interannual and latitudinal differences with a clear decline in length at age, length at first maturity, and body condition, for both species in the northern part of the study area. In the southern part, on the contrary, life history traits did not present a clear temporal trend. The environmental conditions partially explained the long-term changes in life history traits, but the selected variables differed between areas, highlighting the importance of regional oceanographic conditions to understand the dynamics of small pelagic fish. The truncated length-at-age pattern for both species with the disappearance of the larger individuals of the population could have contributed to the poor condition of small pelagic fish populations in the northern part of the western Mediterranean Sea in recent years. In the south area, recent declines in body condition for sardine and anchovy were observed and could be a possible first sign for future population declines. This study highlights the importance of understanding the trade-off between the energy invested in reproduction, maintenance and growth at seasonal and interannual level to advance our knowledge on how environmental and human pressures influence population dynamics of small pelagic fish at local and regional scales.

scholarly journals Telomere length covaries with age across an elevational gradient in a Mediterranean lizard

2019 ◽  
Author(s):  
Pablo Burraco ◽  
Mar Comas ◽  
Senda Reguera ◽  
Francisco Javier Zamora-Camacho ◽  
Gregorio Moreno-Rueda
Keyword(s):  
Life History ◽  
Body Size ◽  
Telomere Length ◽  
Body Condition ◽  
Life History Traits ◽  
Elevational Gradient ◽  
Habitat Characteristics ◽  
Tail Autotomy ◽  
Non Linear

AbstractThe timing of organisms’ senescence is developmentally programmed but also shaped by the interaction between environmental inputs and life-history traits. In ectotherms, ageing dynamics are still poorly understood despite their particularities concerning thermoregulation, regeneration capacity, or growth trajectory. Here, we investigate the role of life-history traits such as age, sex, body size, body condition, and tail autotomy (i.e self-amputation) in shaping telomere length of six populations of the Algerian sand lizard (Psammodromus algirus) distributed across an elevational gradient from 300 to 2500 meters above the sea level. Additionally, we show in a review table the available information on reptiles’ telomere length. We found that telomeres elongated with lizards’ age. We also observed that body size and age class showed a positive relationship, suggesting that cell replication did not shorten lizards’ telomeres by itself. Elevation affected telomere length in a non-linear way, a pattern that mirrored the variation in age structure across elevation. Telomere length was unaffected by tail autotomy, and was sex-independent, but positively correlated with body condition. Our results show that telomeres elongate throughout the first four years of lizards’ lifetime, a process that stress the role of telomerase in maintaining ectothermic telomeres, and, likely, in extending lifespan in organisms with indeterminate growth. Regarding the non-linear impact that elevation had on telomere length of lizards, our results suggest that habitat (mainly temperature) and organisms’ condition might play a key role in regulation ageing rate. Our findings emphasize the relevance of understanding species’ life histories (e.g. age and body condition) and habitat characteristics for fully disentangling the causes and consequences of lifespan trajectory.

scholarly journals Life history traits of Characidium pterostictum (Characiformes, Crenuchidae) along the longitudinal gradient of a Neotropical river in southern Brazil

2017 ◽  
Vol 107 (0) ◽  
Author(s):  
Raquel C. Fitz ◽  
◽  
Cesar A. Rodenbusch ◽  
Renato B. Dala-Corte ◽  
Marco A. Azevedo ◽  
...  
Keyword(s):  
Life History ◽  
Body Size ◽  
Sex Ratio ◽  
Standard Length ◽  
Reproductive Strategy ◽  
Life History Traits ◽  
Southern Brazil ◽  
Longitudinal Gradient ◽  
Female Total ◽  
Size Standard

ABSTRACT Life history traits of Characidium pterostictum Gomes, 1947 (Characiformes, Crenuchidae) from three different reaches of the upper Sinos river, southern Brazil, were described and comparatively analyzed according to the longitudinal gradient. For all reaches, results indicated a seasonal reproductive strategy with a higher intensity during warmer months of higher photoperiod (November to February). Only females were found in the upstream reach and they were more numerous than males in all the sampled reaches. Mean absolute fecundity ranged from 5189 (±2131 SD) to 7394 (±3807 SD), whereas mean relative fecundity (oocytes per mg of female total weight) ranged from 1.08 (±0.40 SD) to 1.12 (±0.29 SD). Oocyte development was characterized as synchronic in two groups, typical of total spawning. Longitudinal gradient comparison suggests that body size (standard length) of C. pterostictum individuals and sex ratio were the only characteristics that differed between sampled reaches. Larger individuals and thus females tended to be more frequently found in upstream reaches of the Sinos river, with a decrease in body size and in the proportional number of females towards downstream.

Age Structure and Life Expectancy in a Stellagama stellio (Linnaeus, 1758) Population from Kütahya, Turkey

2021 ◽  
Vol 28 (6) ◽  
pp. 327-332
Author(s):  
Muge Gidis ◽  
Eyup Baskale
Keyword(s):  
Life History ◽  
Standard Deviation ◽  
Sexual Dimorphism ◽  
Life Expectancy ◽  
Age Structure ◽  
Life History Traits ◽  
Age At Maturity ◽  
Males And Females ◽  
The Mean ◽  
The Difference

The life history traits of the rough-tailed agama, Stellagama stellio (Linnaeus, 1758) in a population from Kütahya, Turkey were described by the skeletochronological method. From a total of 54 individuals, the mean ages ± standard deviation (SD) of males and females were calculated as 5.03 ± 2.076 years and 4.79 ± 1.584 years, respectively, and age distributions were not significantly different between sexes. The age at maturity was 2 years for both sexes. The longevity of females was 8 years, whereas for males it was 9 years. Mean snout-vent length (SVL) ± SD was 101.7 ± 9.6 mm in females and 104.9 ± 14.4 mm in males and did not significantly differ between the two sexes. We examined the sexual dimorphism of S. stellio in relation to the difference in population age structure between the sexes using the skeletochronological method. Male individuals were slightly larger than female individuals at the same age, but this difference was not statistically significant. We also estimated the maximum ages for S. stellio, which agree with other populations in Turkey.

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