scholarly journals Life history of the Rio Grande leopard frog (Lithobates berlandieri) in Texas

2018 ◽  
Author(s):  
Daniel F. Hughes ◽  
Walter E. Meshaka
Keyword(s):  
Life History ◽  
Body Size ◽  
Rio Grande ◽  
Leopard Frog ◽  
Minimum Size ◽  
Late Winter ◽  
Adult Males ◽  
Adult Females ◽  
Body Sizes ◽  
Gravid Females

ABSTRACTWe ascertained various life-history traits from an examination of 310 museum specimens of the Rio Grande leopard frog (Lithobates berlandieriBaird, 1859) collected during 1907–2016 from Texas, USA.Lithobates berlandieriwas captured during every month of the year except November, and adults were most frequently encountered during January–September with a distinct peak in May. Mean body size of adult males (69.5 mm) was smaller than that of adult females (77.5 mm), and both sexes were larger in mean body sizes than those of New Mexico populations (M = 64.4 mm; F = 73.5 mm). Females were gravid during January–September, and most gravid females were captured from late-winter to early-summer. Gonadal enlargement in males was generally high throughout January–September with no detectable seasonal increase. Feeding became widespread in both sexes during May–June shortly after a spring breeding bout. Spent females were common in July and lipid deposition increased in June/July, signaling oogenesis for breeding in the fall. From 15 gravid females, we estimated a mean clutch size of 3,107 eggs which was correlated with female body size, yet egg diameter was not related to clutch or body size. Age to metamorphosis was likely 2 to 4 months depending upon whether eggs were laid in the winter/spring or late fall. If metamorphosis occurred in May/June, the minimum size at sexual maturity in adult males (50.1 mm) could have been reached in 3–4 months and in 6–7 months for adult females (57.2 mm). Mean adult body sizes, however, may have taken 12 to 17 months to reach. A synthesis across Texas populations suggests that the breeding season extends almost continuously from the fall through the winter and spring until mid-summer and is interrupted by winter and summer peaks in seasonal temperatures.

The Hidden Costs of Sociality: Intra-Group Variation in Feeding Strategies in Sumatran Long-Tailed Macaques (Macaca Fascicularis)

Behaviour ◽  
1986 ◽  
Vol 99 (3-4) ◽  
pp. 296-314 ◽  
Author(s):  
Maria A. VAN NOORDWIJK ◽  
Carel P. VAN SCHAIK
Keyword(s):  
Body Size ◽  
Travel Time ◽  
Macaca Fascicularis ◽  
Fruit Trees ◽  
Feeding Competition ◽  
Feeding Strategies ◽  
Adult Males ◽  
Adult Females ◽  
Hidden Cost ◽  
Group Variation

AbstractGroups of long-tailed macaques (Macaca fascicularis) are often fissioned into a large main party and one or more small parties. We studied the size and composition of the main party in relation to fruit supply and the ecology of the various age-sex categories in order to establish the cause of this fissioning. The size of the main party varied not only because the size of available fruit trees varied but also because the various age-sex categories were so different in their feeding strategies that they sometimes went separate ways. Our observations suggest that body size and sex profoundly affected food requirements and the risks attached to leaving the main party. We concluded that adult females left the main party mainly to escape from feeding competition and attempted to reduce travel time when they had infants so as to minimise the costs of carrying infants. Males, by contrast, left above all because of their different food requirements; subadult males left to eat more fruit than the others, adult males mainly to eat bigger fruit than the others. This intra-group variation in feeding strategies constitutes a usually hidden cost to sociality.

A new species of the Pristimantis orestes group (Amphibia: Strabomantidae) from the high Andes of Ecuador, Reserva Mazar

Zootaxa ◽  
2013 ◽  
Vol 3616 (4) ◽  
pp. 345-356 ◽  
Author(s):  
JUAN M. GUAYASAMIN ◽  
ALEJANDRO F. ARTEAGA
Keyword(s):  
New Species ◽  
Body Size ◽  
Molecular Phylogeny ◽  
Mitochondrial Gene ◽  
Small Body ◽  
Dominant Frequency ◽  
Small Body Size ◽  
Adult Males ◽  
Adult Females ◽  
A New Species

We describe a new Pristimantis from La Libertad and Rumiloma, Reserva Mazar, Andes of Southeastern Ecuador, at elevations between 2895–3415 m. This species is assigned to the P. orestes group, from whose members it differs by its small body size (adult males ≤ 18.1 mm; adult females ≤ 23.7 mm), usually reticulated ventral pattern, and visible tympanum. The vocalization of the new species consists of a series of calls; each call is composed by a pulsed, non-modulated note in frequency, and with a dominant frequency of 3122–3171 Hz. A molecular phylogeny based on a fragment of the mitochondrial gene 12S shows that the new species is sister to Pristimantis simonbolivari.

scholarly journals Social and Behavioural Factors in Cetacean Responses to Overexploitation: Are Odontocetes Less “Resilient” Than Mysticetes?

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Paul R. Wade ◽  
Randall R. Reeves ◽  
Sarah L. Mesnick
Keyword(s):  
Life History ◽  
Mating Systems ◽  
Alloparental Care ◽  
Transfer Of Knowledge ◽  
Older Individuals ◽  
Adult Males ◽  
Baleen Whales ◽  
Social Nature ◽  
Adult Females ◽  
Behavioural Factors

Many severely depleted populations of baleen whales (Mysticeti) have exhibited clear signs of recovery whereas there are few examples in toothed whales (Odontoceti). We hypothesize that this difference is due, at least in part, to social and behavioural factors. Clearly, a part of the lack of resilience to exploitation is explained by odontocete life history. However, an additional factor may be the highly social nature of many odontocetes in which survival and reproductive success may depend on: (a) social cohesion and organization, (b) mutual defence against predators and possible alloparental care, (c) inter-generational transfer of “knowledge”, and (d) leadership by older individuals. We found little evidence of strong recovery in any of the depleted populations examined. Their relatively low potential rates of increase mean that odontocete populations can be over-exploited with take rates of only a few percent per year. Exploitation can have effects beyond the dynamics of individual removals. Four species showed evidence of a decrease in birth rates following exploitation; potential mechanisms include a deficit of adult females, a deficit of adult males, and disruption of mating systems. The evidence for a lack of strong recovery in heavily exploited odontocete populations indicates that management should be more precautionary.

scholarly journals Fishing-induced life-history changes degrade and destabilize harvested ecosystems

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Anna Kuparinen ◽  
Alice Boit ◽  
Fernanda S. Valdovinos ◽  
Hélène Lassaux ◽  
Neo D. Martinez
Keyword(s):  
Life History ◽  
Body Size ◽  
Network Model ◽  
Temporal Variability ◽  
Lake Ecosystem ◽  
Ecosystem Impacts ◽  
Body Sizes ◽  
Environmental Variations ◽  
Mechanistic Basis ◽  
Fish Abundances

Abstract Fishing is widely known to magnify fluctuations in targeted populations. These fluctuations are correlated with population shifts towards young, small, and more quickly maturing individuals. However, the existence and nature of the mechanistic basis for these correlations and their potential ecosystem impacts remain highly uncertain. Here, we elucidate this basis and associated impacts by showing how fishing can increase fluctuations in fishes and their ecosystem, particularly when coupled with decreasing body sizes and advancing maturation characteristic of the life-history changes induced by fishing. More specifically, using an empirically parameterized network model of a well-studied lake ecosystem, we show how fishing may both increase fluctuations in fish abundances and also, when accompanied by decreasing body size of adults, further decrease fish abundance and increase temporal variability of fishes’ food resources and their ecosystem. In contrast, advanced maturation has relatively little effect except to increase variability in juvenile populations. Our findings illustrate how different mechanisms underlying life-history changes that may arise as evolutionary responses to intensive, size-selective fishing can rapidly and continuously destabilize and degrade ecosystems even after fishing has ceased. This research helps better predict how life-history changes may reduce fishes’ resilience to fishing and ecosystems’ resistance to environmental variations.

scholarly journals Reproduction and growth of the Southern Leopard Frog, Lithobates sphenocephalus utricularius (Harlan, 1825), in Virginia: implications for seasonal shifts in response to global climate change

2017 ◽  
Author(s):  
Daniel Frederick Hughes ◽  
Walter Meshaka Jr. ◽  
Pablo R. Delis
Keyword(s):  
Climate Change ◽  
Sexual Size Dimorphism ◽  
Global Climate ◽  
Leopard Frog ◽  
Late Winter ◽  
Testis Size ◽  
Larval Metamorphosis ◽  
Life History Data ◽  
Gravid Females ◽  
Increased Activity

An examination of 750 museum specimens of the Southern Leopard Frog (Lithobates sphenocephalus) collected during 1938‐1989 from eastern Virginia (USA) provided comparative life‐history data from the northeastern portion of this species geographic range. Individuals were collected in all months except December. Testis size was largest and incidence of gravid females was highest during fall and spring. In both sexes, fat storage was lowest during late‐winter‐spring, which is indicative of increased activity and commencement of breeding. Incidence of food in stomachs was lowest in late winter and relatively high thereafter, especially in males. Geographic trends in five lifehistory traits were corroborated for the Southern Leopard Frog in this study, including breeding season, egg size, mean adult body size, sexual size dimorphism, and larval metamorphosis season. In response to hotter summers and milder winters, as predicted to occur with climate change, the reproductive characteristics for this species in Virginia will likely shift to resemble contemporary reproductive patterns of southern populations.

Relative forelimb–hindlimb investment is associated with flight style, foraging strategy, and nestling period, but not nest type

The Auk ◽  
2022 ◽  
Author(s):  
Jess Kotnour ◽  
Sarah J McPeek ◽  
Hannah Wedig ◽  
Jonah Dominguez ◽  
Natalie A Wright
Keyword(s):  
Life History ◽  
Body Size ◽  
Foraging Strategy ◽  
Long Bones ◽  
Nestling Period ◽  
Body Sizes ◽  
Soaring Birds ◽  
Selection For ◽  
Foraging Method ◽  
Nest Type

Abstract We investigated Dial’s 2003 hypothesis that birds that rely more heavily on flight as their primary mode of locomotion and thus invest more in their forelimbs than hindlimbs will experience selection for smaller body sizes, greater altriciality, and more complex nests. To test this hypothesis, we examined the skeletons of over 2,000 individuals from 313 species representing the majority of avian families and all major branches of the avian tree. We used the lengths of the sternal keel and long bones of the wing relative to the lengths of the leg long bones as an index of relative locomotor investment. We found that locomotor investment was predicted by flight style, foraging method, and length of nestling period, supporting Dial’s hypothesis. Soaring birds and birds with more acrobatic flight styles, birds whose foraging methods were heavily reliant upon flight, and birds whose young spent more time in the nest tended to invest more in their forelimbs relative to hindlimbs. Nest type and body size were not significant predictors of relative forelimb–hindlimb investment, however, suggesting that the relationships among flight style, locomotor investment, and life history are not as tightly intertwined as Dial originally hypothesized.

Growth, maturity, and sexual dimorphism in the wood turtle, Clemmys insculpta

1990 ◽  
Vol 68 (4) ◽  
pp. 672-677 ◽  
Author(s):  
Jeffrey E. Lovich ◽  
Carl H. Ernst ◽  
John F. McBreen
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Carapace Length ◽  
Sexual Size Dimorphism ◽  
Von Bertalanffy ◽  
Size Dimorphism ◽  
Adult Females ◽  
Body Sizes ◽  
Von Bertalanffy Growth Model ◽  
Wood Turtle

Growth in the wood turtle (Clemmys insculpta) is described using the von Bertalanffy growth model and nonlinear regression. Growth in both sexes is similar until about 160 mm plastron length. Males grew at a faster rate after this size. Males appear to mature at a larger size and later age than females, although age-specific body size is highly variable. Sexual size dimorphism, in carapace length, is pronounced, with males attaining mean body sizes significantly larger (1.07–1.10 times) than those of adult females. Plastron length is an inappropriate measure of sexual size dimorphism because of the development of plastral concavity in males. Females tend to predominate in samples, possibly owing to differential maturity of the sexes. The direction of sexual size dimorphism may be maintained by intrasexual competition among males for access to females. Data for several adults captured at intervals of from 9 to 20 years support the concept of indeterminate growth.

scholarly journals Dial behavioral responses of Metamysidopsis elongata atlantica (Crustacea, Mysida) to gradients of salinity and temperature

2011 ◽  
Vol 101 (1-2) ◽  
pp. 103-108 ◽  
Author(s):  
Andréa M. da S Gama ◽  
Danilo Calazans ◽  
Nelson F Fontoura
Keyword(s):  
Surf Zone ◽  
Behavioral Responses ◽  
Rio Grande ◽  
Sandy Beaches ◽  
The State ◽  
Adult Males ◽  
Rio Grande Do Sul ◽  
Adult Females ◽  
Response To Temperature

Metamysidopsis atlantica elongata (Bascescu, 1968) is a common mysid in the surf zone of sandy beaches from the state of Rio Grande do Sul, Brazil, where it is frequently recorded forming dense aggregations. Trough laboratory trials, behavioral responses to salinity (10, 20, 25, 28, 30, 40 e 45), temperature (10, 15, 20, 30±1ºC) and light (yes/no) were tested using adult males, adult females and juveniles. Although there was no response to temperature, the species showed clear response to salinity and light. In the presence of light, organisms remained in the bottom of the aquaria, but moved to surface when bottom salinities were increased. In the absence of light, adults moved to the surface. However, juveniles moved down to or remained on the bottom, maybe as a response to avoid adult predation.

scholarly journals Life history of the Rio Grande leopard frog (Lithobates berlandieri) in Texas

2018 ◽  
Vol 52 (33-34) ◽  
pp. 2221-2242
Author(s):  
Daniel F. Hughes ◽  
Walter E. Meshaka, Jr
Keyword(s):  
Life History ◽  
Rio Grande ◽  
Leopard Frog ◽  
History Of

Interacting effects of latitude, mass, age, and sex on winter survival of Surf Scoters (Melanitta perspicillata): implications for differential migration

2016 ◽  
Vol 94 (3) ◽  
pp. 233-241 ◽  
Author(s):  
Brian D. Uher-Koch ◽  
Daniel Esler ◽  
Samuel A. Iverson ◽  
David H. Ward ◽  
W. Sean Boyd ◽  
...  
Keyword(s):  
Winter Survival ◽  
Late Winter ◽  
Adult Males ◽  
Differential Migration ◽  
Differential Survival ◽  
Melanitta Perspicillata ◽  
Adult Females ◽  
Study Sites ◽  
Range Core ◽  
Age And Sex

We quantified variation in winter survival of Surf Scoters (Melanitta perspicillata (L., 1758)) across nearly 30° of latitude on the Pacific coast of North America to evaluate potential effects on winter distributions, including observed differential distributions of age and sex classes. We monitored fates of 297 radio-marked Surf Scoters at three study sites: (1) near the northern periphery of their wintering range in southeast Alaska, USA, (2) the range core in British Columbia, Canada, and (3) the southern periphery in Baja California, Mexico. We detected 34 mortalities and determined that survival averaged lower at the range peripheries than in the range core, was lower during mid-winter than during late winter at all sites, and was positively correlated with body mass within locations. Although neither age nor sex class had direct effects, mass effects led to differential survival patterns among classes. When simultaneously incorporating these interacting influences, adult males of mean mass for their location had highest survival at the northern range periphery in Alaska, whereas adult females and juveniles had higher survival at the range core and the southern periphery. Our observations help to explain patterns of differential migration and distribution reported for this species and highlight seasonal periods (mid-winter) and locations (range peripheries) of elevated levels of mortality for demographically important age–sex classes (adult females).

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