Environmental factors have little influence on the reproductive activity of the Iberian hare (Lepus granatensis)

2003 ◽  
Vol 30 (6) ◽  
pp. 639 ◽  
Author(s):  
P. C. Alves ◽  
A. Rocha
Keyword(s):  
Environmental Factors ◽  
Seasonal Pattern ◽  
Reproductive Activity ◽  
Lepus Europaeus ◽  
Climatic Data ◽  
Regression Equations ◽  
Wild Rabbit ◽  
European Hare ◽  
Pregnant Females ◽  
Iberian Hare

The two European hare species with the largest ranges, the brown hare (Lepus europaeus) and the mountain hare (L. timidus), have a marked seasonal pattern of reproduction, probably reflecting strong environmental influences during the year. In this work, we evaluate the role of some environmental factors on the reproductive activity of another European hare species, the Iberian hare (L. granatensis). The study was carried out in Pancas, southern Portugal, from mid-1997 through December 1999. Climatic data (mean monthly values of minimum and maximum air temperature, daylength and total monthly rainfall) were recorded at the nearest meteorological station. To assess abundance and quality of food, samples of the herbaceous vegetation were collected every two months and analysed for water, fibre and crude protein content. Iberian hares were collected every two months and live or post mortem analyses were performed. The proportion of males with external testes and of pregnant females as well as the weight of the gonads were recorded. While environmental variables had marked seasonal variations, the Iberian hare nevertheless showed continuous reproductive activity. In all sampled periods, males with external testes and pregnant females were observed. However, a slight decrease of sexual activity appears to occur, mainly in males, during autumn. Only the variation of male reproductive characteristics was significantly explained by multiple regression equations. Maximum regression coefficients were obtained with the climatic variables (minimum, maximum temperatures and daylength) and vegetation biomass of the preceding two months. Our data indicate that environmental factors have little effect on reproduction in the Iberian hare. The results are compared with those obtained for other phylogenetically and geographically close hare species, and with another leporid, the wild rabbit (Oryctolagus cuniculus algirus), which occurs sympatrically with L. granatensis.

Biology of the Wild Rabbit, Oryctolagus cuniculus (L.), in the Southern Tablelands of New South Wales

1991 ◽  
Vol 18 (3) ◽  
pp. 327 ◽  
Author(s):  
I Parer ◽  
JA Libke
Keyword(s):  
Age Structure ◽  
New South ◽  
Seasonal Pattern ◽  
New South Wales ◽  
Wild Rabbit ◽  
Timing Of Reproduction ◽  
Pregnant Females ◽  
South Wales ◽  
Lactating Females ◽  
Semi Arid

Shot samples of rabbits were taken every eight weeks for two years at four sites in the Southern Tablelands of New South Wales. Age structure differed between sites. The two sites at which rabbits were controlled by poisoning had the youngest age structures; the site where rabbits were not controlled had the the oldest age structure, the lowest density, the least myxomatosis and the highest production of young per female. The seasonal percentages of males in the samples were inversely proportional to the percentages of lactating females. Rabbits that were recovering from myxomatosis had higher infestations of Graphidium strigosum than rabbits that had active myxomatosis or no symptoms. At one of the sites, rabbits with myxomatosis were shot on every sampling occasion. Differences between sites, in duration and timing of reproduction, were very small compared with differences between rabbit populations from climatically different regions of Australasia; annual production of young per female older than six months varied between sites from 23.7 to 26.5 compared with the range of 15-53 for Australasia. The percentage of pregnant females and fertile males was highest in late spring and fell to zero for 1-2 months in summer. This seasonal pattern of reproduction is intermediate between the pattern found in some high-rainfall Australasian environments, where more than 30% of the females are pregnant in all months, and the patterns in arid, semi-arid and subalpine environments, where no females are pregnant for 3-6 months of the year.

Seasonal variation in the reproductive activity of the wild rabbit (Oryctolagus cuniculus algirus) in a Mediterranean ecosystem

2002 ◽  
Vol 29 (2) ◽  
pp. 165 ◽  
Author(s):  
H. Gonçalves ◽  
P. C. Alves ◽  
A. Rocha
Keyword(s):  
Oryctolagus Cuniculus ◽  
Seasonal Pattern ◽  
Reproductive Activity ◽  
Mediterranean Ecosystem ◽  
Seminiferous Tubules ◽  
Corpora Lutea ◽  
Clear Understanding ◽  
Wild Rabbit ◽  
Sperm Production ◽  
Daily Sperm Production

To establish a successful strategy for managing wild rabbit (Oryctolagus cuniculus algirus) populations it is essential to have a clear understanding of reproductive biology. In Portugal, previous work suggested a seasonal pattern of reproductive activity for this species. In this study we present additional information on the seasonal reproductive activity of the wild rabbit as well as data on the influence that environmental factors have on the onset and length of the breeding season. The study was carried out in Pancas, southern Portugal, from October 1997 to September 1998. Rabbits were collected every two months and post mortem analyses were performed. In the males, circulating concentration of testosterone, gonadal weight, daily sperm production, diameter of the seminiferous tubules and the thickness of epithelial cells were measured. The numbers of corpora lutea, embryos and placental scars were recorded in the females. To assess abundance and quality of food, samples of herbaceous vegetation were collected and analysed for water, fibre and crude protein content. The reproductive season extended from November to June with a peak in March/April, with both sexes showing an annual cycle of gonadal development and subsequent regression. All analysed females were pregnant and/or lactating between March and June. The mean litter size estimated by counting the embryos in the uteri was 3.90 ± 0.50. Daily sperm production was highest between November and April. Testicular function was strongly correlated with environmental temperature and the water content of the vegetation, and both testicular and ovarian development were correlated with vegetation biomass.

scholarly journals Regional environmental controllers influence continental scale soil carbon stocks and future carbon dynamics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel Ruiz Potma Gonçalves ◽  
Umakant Mishra ◽  
Skye Wills ◽  
Sagar Gautam
Keyword(s):  
Environmental Factors ◽  
Land Cover ◽  
Environmental Conditions ◽  
Climate Feedback ◽  
Soil Types ◽  
Climatic Data ◽  
Earth System ◽  
Land Cover Types ◽  
Continental Scale ◽  
Soc Stocks

AbstractUnderstanding the influence of environmental factors on soil organic carbon (SOC) is critical for quantifying and reducing the uncertainty in carbon climate feedback projections under changing environmental conditions. We explored the effect of climatic variables, land cover types, topographic attributes, soil types and bedrock geology on SOC stocks of top 1 m depth across conterminous United States (US) ecoregions. Using 4559 soil profile observations and high-resolution data of environmental factors, we identified dominant environmental controllers of SOC stocks in 21 US ecoregions using geographically weighted regression. We used projected climatic data of SSP126 and SSP585 scenarios from GFDL-ESM 4 Earth System Model of Coupled Model Intercomparison Project phase 6 to predict SOC stock changes across continental US between 2030 and 2100. Both baseline and predicted changes in SOC stocks were compared with SOC stocks represented in GFDL-ESM4 projections. Among 56 environmental predictors, we found 12 as dominant controllers across all ecoregions. The adjusted geospatial model with the 12 environmental controllers showed an R2 of 0.48 in testing dataset. Higher precipitation and lower temperatures were associated with higher levels of SOC stocks in majority of ecoregions. Changes in land cover types (vegetation properties) was important in drier ecosystem as North American deserts, whereas soil types and topography were more important in American prairies. Wetlands of the Everglades was highly sensitive to projected temperature changes. The SOC stocks did not change under SSP126 until 2100, however SOC stocks decreased up to 21% under SSP585. Our results, based on environmental controllers of SOC stocks, help to predict impacts of changing environmental conditions on SOC stocks more reliably and may reduce uncertainties found in both, geospatial and Earth System Models. In addition, the description of different environmental controllers for US ecoregions can help to describe the scope and importance of global and local models.

scholarly journals Myxomatosis in farmland rabbit populations in England and Wales

1989 ◽  
Vol 103 (2) ◽  
pp. 333-357 ◽  
Author(s):  
J. Ross ◽  
A. M. Tittensor ◽  
A. P. Fox ◽  
M. F. Sanders
Keyword(s):  
Breeding Season ◽  
Annual Cycle ◽  
Seasonal Pattern ◽  
Mortality Factor ◽  
Mass Movements ◽  
Wild Rabbit ◽  
Regulatory Effect ◽  
Methods Of Calculation ◽  
Attenuated Virus ◽  
Virus Strains

SUMMARYThe overall pattern and consequences of myxomatosis in wild rabbit populations were studied at three farmland sites in lowland southern England and upland central Wales between 1971 and 1978. When results from all years were combined, the disease showed a clear two-peaked annual cycle, with a main autumn peak between August and January, and a subsidiary spring peak during February to April.Rabbit fleas, the main vectors of myxomatosis in Britain, were present on full-grown rabbits in sufficient numbers for transmission to occur throughout the year, but the observed seasonal pattern of the disease appeared to be influenced by seasonal mass movements of these fleas. However other factors were also important including the timing and success of the main rabbit breeding season, the proportion of rabbits which had recovered from the disease and the timing and extent of autumn rabbit mortality from other causes.Significantly more males than females, and more adults and immatures than juveniles, were observed to be infected by myxomatosis. Only 25–27% of the total populations were seen to be infected during outbreaks. Using two independent methods of calculation, it was estimated that between 47 and 69% of infected rabbits died from the disease (much lower than the expected 90–95% for fully susceptible rabbits with the partly attenuated virus strains that predominated). Thus it was estimated that 12–19% of the total rabbit populations were known to have died directly or indirectly from myxomatosis.Although the effects of myxomatosis were much less than during the 1950s and 1960s, it continued to be an important mortality factor. It may still have a regulatory effect on rabbit numbers, with autumn/winter peaks of disease reducing the numbers of rabbits present at the start of the breeding season.

Social facilitation is a better predictor of frog reproductive activity than environmental factors

Biotropica ◽  
2017 ◽  
Vol 49 (3) ◽  
pp. 372-381 ◽  
Author(s):  
Gerlinde Höbel
Keyword(s):  
Environmental Factors ◽  
Social Facilitation ◽  
Reproductive Activity

scholarly journals Lepus europaeus (Lagomorpha: Leporidae)

2020 ◽  
Vol 52 (997) ◽  
pp. 125-142
Author(s):  
Anni Bock
Keyword(s):  
Natural Resources ◽  
Lepus Europaeus ◽  
European Hare ◽  
International Union ◽  
Declining Populations ◽  
The 1960S

Abstract Lepus europaeus Pallas, 1778, commonly called the European hare, is one of 32 species of Lepus. It is widely distributed in Europe and Asia where it was not native but introduced by humans for sport. L. europaeus does not burrow, nor hibernate, and gives birth to precocial young (leverets). It prefers open grassland, fields, agricultural farmland, and pastures with hedgerows and bushes. Declining populations in several countries since the 1960s led to increased research to investigate the reasons; L. europaeus is considered threatened in several countries, but of “Least Concern” by the International Union for Conservation of Nature and Natural Resources.

scholarly journals Impact of Microtus arvalis and Lepus europaeus on apple trees by trunk bark gnawing

2019 ◽  
Vol 55 (No. 2) ◽  
pp. 142-147
Author(s):  
Josef Suchomel ◽  
Jan Šipoš ◽  
Ladislav Čepelka ◽  
Marta Heroldová
Keyword(s):  
Apple Tree ◽  
Common Vole ◽  
Apple Orchard ◽  
Lepus Europaeus ◽  
Microtus Arvalis ◽  
European Hare ◽  
Bark Damage ◽  
Dead Trees ◽  
Apple Cultivars ◽  
Common Voles

A unique evaluation of the apple tree trunk bark damage caused by common vole and European hare was presented. Damage was found in an apple orchard under organic farming, in Central Moravia (Czech Republic), at 700 m a.s.l. There were two cultivated apple cultivars Red Spring and Melodie/Angold. Damage occurred in winter with the snow cover lasting from December to February. In total 1 012 trees and 95.7% of trees were damaged. The cv. Red Spring was damaged more than cv. Melodie/Angold. Almost 90% of the dead trees were killed by common voles. While hares damaged both cultivars equally, voles damaged the cv. Red Spring to a significantly greater extent (P = 0.04). The study confirms the need of further research on the development of methodologies for orchard protection from damage caused by small mammals.

scholarly journals Genetic and Environmental Factors Associated to Glutenin Polymer Characteristics of Wheat

Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 683 ◽  
Author(s):  
Gérard Branlard ◽  
Annie Faye ◽  
Larbi Rhazi ◽  
Ayesha Tahir ◽  
Véronique Lesage ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Grain Protein Content ◽  
Gyration Radius ◽  
Molecular Characteristics ◽  
Climatic Data ◽  
Field Flow Fractionation ◽  
Factors Associated ◽  
Average Temperature ◽  
Genetic And Environmental Factors ◽  
Glutenin Polymer

The polymers of wheat glutenins are studied here using asymmetric flow field flow fractionation (A4F). Molecular mass (Mw), gyration radius (Rw), and the polydispersity index (PI) of polymers were measured over a four-year, multi-local wheat trial in France. The experiment, involving 11 locations and 192 cultivars, offered the opportunity to approach the genetic and environmental factors associated with the phenotypic values of the polymer characteristics. These characteristics, which were all highly influenced by environmental factors, exhibited low broad-sense heritability coefficients and were not influenced by grain protein content and grain hardness. The 31 alleles encoding the glutenin subunits explained only 17.1, 25.4, and 16.8% of the phenotypic values of Mw, Rw, and PI, respectively. The climatic data revealed that a 3.5 °C increase between locations of the daily average temperature, during the last month of the grain development, caused an increase of more than 189%, 242%, and 434% of the Mw, Rw, and PI, respectively. These findings have to be considered in regard to possible consequences of global warming and health concerns assigned to gluten. It is suggested that the molecular characteristics of glutenins be measured today, especially for research addressing non-celiac gluten sensitivity (NCGS).

Sign in / Sign up

Export Citation Format

Share Document