scholarly journals Breeding phenology in Rana temporaria . Local variation is due to pond temperature and population size

2016 ◽  
Vol 6 (17) ◽  
pp. 6202-6209 ◽  
Author(s):  
Jon Loman
Keyword(s):  
Population Size ◽  
Rana Temporaria ◽  
Local Variation ◽  
Breeding Phenology

scholarly journals Breeding biology and population increase of the Endangered Bermuda Petrel Pterodroma cahow

2012 ◽  
Vol 22 (1) ◽  
pp. 35-45 ◽  
Author(s):  
JEREMY MADEIROS ◽  
NICHOLAS CARLILE ◽  
DAVID PRIDDEL
Keyword(s):  
Climate Change ◽  
Population Size ◽  
Breeding Success ◽  
Reproductive Output ◽  
Small Population ◽  
Population Increase ◽  
Storm Damage ◽  
Breeding Phenology ◽  
North East ◽  
Rate Of Increase

SummaryThe Bermuda Petrel Pterodroma cahow was thought to have become extinct early in the 17th century due to a combination of hunting by human colonists and predation by introduced rats, cats, dogs and pigs. However, single individuals were found on four occasions during the first half of the 20th century, and in 1951 a small population was discovered breeding on several rocky islets in north-east Bermuda. Recovery actions began in 1962 when the population numbered just 18 pairs, dispersed among five small islets. Although rats extirpated one of these five colonies in 1967, the population has grown steadily to 56 breeding pairs in 2000. We investigated the breeding phenology, productivity and population size of the Bermuda Petrel between 2000/2001 and 2007/2008. Each year, the birds began arriving in Bermuda around mid-October. They departed on a pre-breeding exodus between 19 November and 14 December, returning after 32–56 days to lay a single egg between 31 December and 31 January. Eggs hatched from 16 February to 26 March after a mean (± SD) incubation period of 53 ± 2 days, and young fledged from 15 May to 25 June after a mean fledging period of 91 ± 5 days. Between 2000/2001 and 2007/2008, reproductive output ranged from 29 to 40 fledglings per annum. Mean annual breeding success (62%) was reasonably high relative to other Procellariiformes, largely due to the provision of artificial (concrete) nesting burrows. In 2008, the population numbered 85 breeding pairs. Monitoring since 1961 indicates the population has been increasing exponentially, doubling approximately every 22 years. This rate of increase, together with the increased incidence of storm damage, is making it progressively more impracticable to construct sufficient concrete burrows on the current nesting islets to accommodate all breeding pairs. The vulnerability of these sites to accelerating storm damage and erosion as a result of anthropomorphic climate change is now the greatest threat to the Bermuda Petrel.

Long-Term United Kingdom Trends in The Breeding Phenology of The Common Frog, Rana Temporaria

2008 ◽  
Vol 42 (1) ◽  
pp. 89-96 ◽  
Author(s):  
W. Andrew Scott ◽  
David Pithart ◽  
John K. Adamson
Keyword(s):  
United Kingdom ◽  
Rana Temporaria ◽  
Common Frog ◽  
Breeding Phenology ◽  
Frog Rana Temporaria ◽  
The Common

scholarly journals Earlier Snowmelt Advances Breeding Phenology of the Common Frog (Rana temporaria) but Increases the Risk of Frost Exposure and Wetland Drying

2021 ◽  
Vol 9 ◽  
Author(s):  
Marjorie Bison ◽  
Nigel G. Yoccoz ◽  
Bradley Z. Carlson ◽  
Geoffrey Klein ◽  
Idaline Laigle ◽  
...  
Keyword(s):  
Climate Change ◽  
Rana Temporaria ◽  
Larval Mortality ◽  
High Elevation ◽  
Common Frog ◽  
Breeding Phenology ◽  
Mountain Environments ◽  
The Future ◽  
Drying Up ◽  
The Common

The alarming decline of amphibians around the world calls for complementary studies to better understand their responses to climate change. In mountain environments, water resources linked to snowmelt play a major role in allowing amphibians to complete tadpole metamorphosis. As snow cover duration has significantly decreased since the 1970s, amphibian populations could be strongly impacted by climate warming, and even more in high elevation sites where air temperatures are increasing at a higher rate than at low elevation. In this context, we investigated common frog (Rana temporaria) breeding phenology at two different elevations and explored the threats that this species faces in a climate change context. Our objectives were to understand how environmental variables influence the timing of breeding phenology of the common frog, and explore the threats that amphibians face in the context of climate change in mountain areas. To address these questions, we collected 11 years (2009–2019) of data on egg-spawning date, tadpole development stages, snowmelt date, air temperature, rainfall and drying up of wetland pools at ∼1,300 and ∼1,900 m a.s.l. in the French Alps. We found an advancement of the egg-spawning date and snowmelt date at low elevation but a delay at high elevations for both variables. Our results demonstrated a strong positive relationship between egg-spawning date and snowmelt date at both elevations. We also observed that the risk of frost exposure increased faster at high elevation as egg-spawning date advanced than at low elevation, and that drying up of wetland pools led to tadpole mortality at the high elevation site. Within the context of climate change, egg-spawning date is expected to happen earlier in the future and eggs and tadpoles of common frogs may face higher risk of frost exposure, while wetland drying may lead to higher larval mortality. However, population dynamics studies are needed to test these hypotheses and to assess impacts at the population level. Our results highlight climate-related threats to common frog populations in mountain environments, but additional research should be conducted to forecast how climate change may benefit or harm amphibian populations, and inform conservation and land management plans in the future.

Shifts in breeding phenology as a response to population size and climatic change: A comparison between short- and long-distance migrant species

The Auk ◽  
2012 ◽  
Vol 129 (4) ◽  
pp. 753-762 ◽  
Author(s):  
Aggeliki Doxa ◽  
Alexandre Robert ◽  
Alain Crivelli ◽  
Giorgos Catsadorakis ◽  
Theodoros Naziridis ◽  
...  
Keyword(s):  
Population Size ◽  
Climatic Change ◽  
Breeding Phenology ◽  
Long Distance

scholarly journals Changes in breeding phenology and population size of birds

2013 ◽  
Vol 83 (3) ◽  
pp. 729-739 ◽  
Author(s):  
Peter O. Dunn ◽  
Anders P. Møller
Keyword(s):  
Population Size ◽  
Breeding Phenology

Reduction of spermatogonia and testosterone in rat testes flown on space lab-3

1986 ◽  
Vol 44 ◽  
pp. 248-249
Author(s):  
Delbert E. Philpott ◽  
W. Sapp ◽  
C. Williams ◽  
T. Fast ◽  
J. Stevenson ◽  
...  
Keyword(s):  
Social Interaction ◽  
Social Status ◽  
Population Size ◽  
Physiological Response ◽  
Social Rank ◽  
Reproductive Function ◽  
Testicular Development ◽  
Organ Weights ◽  
Reproductive Maturation ◽  
Metabolic Activities

Space Lab 3 (SL-3) was flown on Shuttle Challenger providing an opportunity to measure the effect of spaceflight on rat testes. Cannon developed the idea that organisms react to unfavorable conditions with highly integrated metabolic activities. Selye summarized the manifestations of physiological response to nonspecific stress and he pointed out that atrophy of the gonads always occurred. Many papers have been published showing the effects of social interaction, crowding, peck order and confinement. Flickinger showed delayed testicular development in subordinate roosters influenced by group numbers, social rank and social status. Christian reported increasing population size in mice resulted in adrenal hypertrophy, inhibition of reproductive maturation and loss of reproductive function in adults. Sex organ weights also declined. Two male dogs were flown on Cosmos 110 for 22 days. Fedorova reported an increase of 30 to 70% atypical spermatozoa consisting of tail curling and/or the absence of a tail.

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