Effects of ultraviolet radiation on life-history stages of anurans from Ontario, Canada

1995 ◽  
Vol 73 (12) ◽  
pp. 2292-2301 ◽  
Author(s):  
Karen P. Grant ◽  
Lawrence E. Licht
Keyword(s):  
Life History ◽  
High Intensity ◽  
Rana Sylvatica ◽  
Ultraviolet B ◽  
Egg Mass ◽  
Hyla Versicolor ◽  
Population Declines ◽  
Life History Stages ◽  
Embryo Stage

We tested the effects of ultraviolet-a (uv-a) and ultraviolet-b (uv-b) radiation on life-history stages of the anurans Bufo americanus, Hyla versicolor, Rana clamitans, and Rana sylvatica. No effect of uv-a was found on eggs or larvae even at exposures twice the intensity of normal outdoor levels. Only R. sylvatica was tested in the embryo stage. All embryos exposed to 30 min or more of artificially high intensity uv-b died. After exposure to artificially high intensity uv-b of 15 min or less, or at ecologically relevant levels, there was no effect on hatching success. The proportion of abnormal embryos after exposure to 10 or 15 min of artificially high intensity treatment was higher at 12 °C than at 20 °C. The jelly surrounding the ova can effectively reduce uv-b transmission through the egg mass. Of the four species tested, only larval R. clamitans showed some tolerance of artificially high uv-b levels, but development of the survivors was arrested and metamorphosis was not initiated. Ecologically relevant doses of uv-b had no effect on developmental period, duration of metamorphic climax, or mass at metamorphosis in B. americanus, H. versicolor, or R. sylvatica. Whereas all metamorphosed juvenile R. clamitans and R. sylvatica died after exposure to high-intensity uv-b, some B. americanus survived. Older B. americanus exposed for the same length of time had higher survivorship than younger animals. The role of uv radiation in presumed amphibian population declines is discussed.

scholarly journals Early exposure to UV radiation causes telomere shortening and poorer condition later in life

2021 ◽  
Author(s):  
Niclas U Lundsgaard ◽  
Rebecca L. Cramp ◽  
Craig E Franklin
Keyword(s):  
Life History ◽  
Early Life ◽  
Later Life ◽  
Ultraviolet B ◽  
Tree Frog ◽  
Population Declines ◽  
Carryover Effects ◽  
Telomere Shortening ◽  
Life History Stages ◽  
Trade Offs

Determining the contribution of elevated ultraviolet–B radiation (UVBR; 280 — 315 nm) to amphibian population declines is being hindered by a lack of knowledge about how different acute UVBR exposure regimes during early life history stages might affect post–metamorphic stages via long–term carryover effects. We acutely exposed tadpoles of the Australian green tree frog (Litoria caerulea) to a combination of different UVBR irradiances and doses in a multi–factorial experiment, and then reared them to metamorphosis in the absence of UVBR to assess carryover effects in subsequent juvenile frogs. Dose and irradiance of acute UVBR exposure influenced carryover effects into metamorphosis in somewhat opposing manners. Higher doses of UVBR exposure in larvae yielded improved rates of metamorphosis. However, exposure at a high irradiance resulted in frogs metamorphosing smaller in size and in poorer condition than frogs exposed to low and medium irradiance UVBR as larvae. We also demonstrate some of the first empirical evidence of UVBR-induced telomere shortening in vivo, which is one possible mechanism for life–history trade–offs impacting condition post-metamorphosis. These findings contribute to our understanding of how acute UVBR exposure regimes in early life affect later life–history stages, which has implications for how this stressor may shape population dynamics.

scholarly journals Life-history trade-offs and limitations associated with phenotypic adaptation under future ocean warming and elevated salinity

2019 ◽  
Vol 374 (1768) ◽  
pp. 20180428 ◽  
Author(s):  
Michael D. Jarrold ◽  
Leela J. Chakravarti ◽  
Emma M. Gibbin ◽  
Felix Christen ◽  
Gloria Massamba-N'Siala ◽  
...  
Keyword(s):  
Life History ◽  
Elevated Temperature ◽  
Egg Mass ◽  
Physiological Mechanisms ◽  
Trade Offs ◽  
Elevated Salinity ◽  
Metabolism Enzymes ◽  
Marine Polychaete ◽  
Ocean Conditions

Little is known about the life-history trade-offs and limitations, and the physiological mechanisms that are associated with phenotypic adaptation to future ocean conditions. To address this knowledge gap, we investigated the within- and trans-generation life-history responses and aerobic capacity of a marine polychaete, Ophryotrocha labronica, to elevated temperature and elevated temperature combined with elevated salinity for its entire lifespan. In addition, transplants between treatments were carried out at both the egg mass and juvenile stage to identify the potential influence of developmental effects. Within-generation, life-history trade-offs caused by the timing of transplant were only detected under elevated temperature combined with elevated salinity conditions. Polychaetes transplanted at the egg mass stage grew slower and had lower activities of energy metabolism enzymes but reached a larger maximum body size and lived longer when compared with those transplanted as juveniles. Trans-generation exposure to both elevated temperature and elevated temperature and salinity conditions restored 20 and 21% of lifespan fecundity, respectively. Trans-generation exposure to elevated temperature conditions also resulted in a trade-off between juvenile growth rates and lifespan fecundity, with slower growers showing greater fecundity. Overall, our results suggest that future ocean conditions may select for slower growers. Furthermore, our results indicate that life-history trade-offs and limitations will be more prevalent with the shift of multiple global change drivers, and thus there will be greater constraints on adaptive potential. This article is part of the theme issue ‘The role of plasticity in phenotypic adaptation to rapid environmental change’.

Migratory behaviour of captive white-crowned sparrows, Zonotrichia leucophrys gambelii, differs during autumn and spring migration

Behaviour ◽  
2006 ◽  
Vol 143 (10) ◽  
pp. 1219-1240 ◽  
Author(s):  
Marilyn Ramenofsky ◽  
Renée Agatsuma
Keyword(s):  
Life History ◽  
High Intensity ◽  
Primary Source ◽  
Migratory Restlessness ◽  
Long Distance ◽  
Free Living ◽  
Zonotrichia Leucophrys ◽  
Life History Stages ◽  
In Captivity ◽  
Zonotrichia Leucophrys Gambelii

AbstractGambel's white-crown sparrow (Zonotorichia leucophrys gambelii) is a long-distance, over-land migrant. In captivity birds display many characteristics of the autumn and spring migratory life history stages that include hyperphagia, fattening and high intensity nocturnal activity termed migratory restlessness or Zugunruhe. We recorded the behaviour of captive birds while simultaneously collecting 24 h locomotor activity. These data were used to define the behaviour displayed by captive birds during autumn and spring in order to compare the two migratory stages and to draw inferences for free-living birds. The predominant behaviour during day and nighttime was rest. Feeding occurred only during daylight hours but at a greater frequency in autumn than spring. Birds generally used their feet as the primary source of locomotion during the day termed 'jump'. During the night, two distinct behaviours, 'beak-up flight' and 'beak-up' involving high intensity wing motions were observed and considered components of migratory restlessness. The frequency of the 'beak-up flight' was greatest during spring and associated with the enhanced tempo of vernal migration. In both stages, migratory restlessness was preceded by a quiescent phase, the occurrence of which differed and related to time available for foraging and length of the night. Given these findings, we hypothesize that diel behaviours displayed by autumn and spring migrants in captivity highlight distinctions between the two life history stages.

Community Structure and Biomass of Euphausiids in the Bay of Fundy

1982 ◽  
Vol 39 (2) ◽  
pp. 326-334 ◽  
Author(s):  
D. W. Kulka ◽  
S. Corey ◽  
T. D. Iles
Keyword(s):  
Life History ◽  
Community Structure ◽  
Vertical Migration ◽  
High Intensity ◽  
Sampling Scheme ◽  
Bay Of Fundy ◽  
Migration Patterns ◽  
Life History Stages ◽  
Diurnal Vertical Migration ◽  
Meganyctiphanes Norvegica

Seven species of euphausiids were found in the Bay of Fundy: Meganyctiphanes norvegica, Thysanoessa inermis, T. longicaudata, T. raschii, T. gregaria, Euphausia krohnii, and Nematoscelis megalops (listed in descending order of abundance). A high-intensity sampling scheme during November and March facilitated detailed distributional studies which revealed that M. norvegica, T. inermis, and T. longicaudata each had a specific stationary center of abundance in the study area, and each species performed a different pattern of diurnal vertical migration. Meganyctiphanes norvegica formed 90% (constituting 70 kt) of the euphausiids. The last four species were occasional immigrants from areas south of the Bay of Fundy. From the relationships between life history stages, vertical migration patterns, distribution, and currents in the Fundy Region, we suggest that these euphausiid species form stocks.Key words: euphausiids, Meganyctiphanes norvegica, Thysanoessa inermis, Thysanoessa longicaudata, biomass, community structure, stock, Bay of Fundy

Factors influencing ultraviolet radiation dose to developing frogs in northern vernal pools

2013 ◽  
Vol 70 (10) ◽  
pp. 1531-1541 ◽  
Author(s):  
Jennifer H. Olker ◽  
Lucinda B. Johnson ◽  
Richard P. Axler ◽  
Catherine M. Johnson
Keyword(s):  
Water Column ◽  
Rana Sylvatica ◽  
Vernal Pool ◽  
Vernal Pools ◽  
Temporal Variations ◽  
Forest Harvesting ◽  
Ultraviolet B ◽  
Atmospheric Conditions ◽  
Population Declines ◽  
Vegetative Cover

Ultraviolet-B (UV-B) radiation exposure is one hypothesized mechanism explaining amphibian population declines and malformations, but it is rarely quantified in amphibian habitats. We measured spatial and temporal variations in northern vernal pools with UV-B attenuation through the water column, incident UV-B across pool surfaces and seasons, and cumulative UV-B dose. Atmospheric, local, and landscape effects were compared with variances across spatial and temporal scales, plus influence on exposure risk. Risk was evaluated using published reports on detrimental levels for amphibian survival and health, with life history and behavior of vernal pool breeding Rana sylvatica L. (wood frog). Pools were exposed to sufficiently high UV-B at or near the surface for developing amphibians to be at risk of reduced survival, altered growth, and malformation. Atmospheric conditions, vegetative cover, and water column properties significantly influenced UV-B levels, with oviposition and larval behavior controlling actual embryonic and larval exposure. UV-B risk to vernal pool species is greater than predicted in previous studies. Given changes in light regimes, climate change, and forest harvesting, amphibian UV-B exposure could reach levels of great concern.

Apes, humans, and M. C. Escher: Uniqueness and continuity in the evolution of language

2006 ◽  
Vol 29 (3) ◽  
pp. 289-290
Author(s):  
Barbara J. King
Keyword(s):  
Life History ◽  
Childhood And Adolescence ◽  
Evolution Of Language ◽  
High Quality ◽  
Life History Stages ◽  
Human Family

Ontogeny, specifically the role of language in the human family now and in prehistory, is central to Locke & Bogin's (L&B's) thesis in a compelling way. The unique life-history stages of childhood and adolescence, however, must be interpreted not only against an exceptionally “high quality” human infancy but also in light of the evolution of co-constructed, emotionally based communication in ape, hominid, and human infancy.

scholarly journals CONDITION-SPECIFIC COMPETITION IN CONTAINER MOSQUITOES: THE ROLE OF NONCOMPETING LIFE-HISTORY STAGES

Ecology ◽  
2005 ◽  
Vol 86 (12) ◽  
pp. 3289-3295 ◽  
Author(s):  
Katie S. Costanzo ◽  
Banugopan Kesavaraju ◽  
Steven A. Juliano
Keyword(s):  
Life History ◽  
Life History Stages ◽  
Container Mosquitoes

Ecological Time

2019 ◽  
pp. 43-66
Author(s):  
Eric Post
Keyword(s):  
Life History ◽  
Individual Organism ◽  
Life History Stages ◽  
Use Of Time ◽  
The Individual

This chapter explores the role of time in ecology as a resource. In this framework, the established terms timing, rate, acceleration, and duration accrue more nuanced importance. Here, timing, rate, and duration refer to the onset of, progression through, and hence use of time in linked series of associated phenophases that comprise an individual organism's life history cycle. As with other resources, time available for allocation to such phenophases or life history stages is limited in supply, and it is in demand by conspecific and heterospecific competitors alike. The chapter then argues that time, much like space, varies in its scales of availability for use by the individual organism, and in its forms available for use by the individual organism.

Sign in / Sign up

Export Citation Format

Share Document