scholarly journals Long-Term Effects of Woody Vegetation Management on Seasonal Body Condition of Northern Bobwhites

1993 ◽  
Vol 46 (6) ◽  
pp. 520
Author(s):  
Jon C. Boren ◽  
Robert L. Lochmiller ◽  
David M. Leslie ◽  
David M. Engle
Keyword(s):  
Body Condition ◽  
Vegetation Management ◽  
Woody Vegetation ◽  
Long Term Effects ◽  
Northern Bobwhites

Do researchers impact their study populations? Assessing the effect of field procedures in a long term population monitoring of sea kraits

2012 ◽  
Vol 33 (3-4) ◽  
pp. 365-372 ◽  
Author(s):  
Thomas Fauvel ◽  
François Brischoux ◽  
Marine Jeanne Briand ◽  
Xavier Bonnet
Keyword(s):  
Body Condition ◽  
New Caledonia ◽  
Stress Hormones ◽  
Population Level ◽  
Population Monitoring ◽  
Long Term Effects ◽  
Negative Effects ◽  
Short Term ◽  
Head Morphology

Long term population monitoring is essential to ecological studies; however, field procedures may disturb individuals. Assessing this topic is important in worldwide declining taxa such as reptiles. Previous studies focussed on animal welfare issues and examined short-term effects (e.g. increase of stress hormones due to handling). Long-term effects with possible consequences at the population level remain poorly investigated. In the present study, we evaluated the effects of widely used field procedures (e.g. handling, marking, forced regurgitation) both on short-term (hormonal stress response) and on long-term (changes in body condition, survival) scales in two intensively monitored populations of sea kraits (Laticauda spp.) in New Caledonia. Focusing on the most intensively monitored sites, from 2002 to 2012, we gathered approximately 11 200 captures/recaptures on 4500 individuals. Each snake was individually marked (scale clipping + branding) and subjected to various measurements (e.g. body size, head morphology, palpation). In addition, a subsample of more than 500 snakes was forced to regurgitate their prey for dietary analyses. Handling caused a significant stress hormonal response, however we found no detrimental long-term effect on body condition. Forced regurgitation did not cause any significant effect on both body condition one year later and survival. These results suggest that the strong short-term stress provoked by field procedures did not translate into negative effects on the population. Although similar analyses are required to test the validity of our conclusions in other species, our results suggest distinguishing welfare and population issues to evaluate the potential impact of population surveys.

Effects of capturing and collaring on polar bears: findings from long-term research on the southern Beaufort Sea population

2014 ◽  
Vol 41 (4) ◽  
pp. 311 ◽  
Author(s):  
Karyn D. Rode ◽  
Anthony M. Pagano ◽  
Jeffrey F. Bromaghin ◽  
Todd C. Atwood ◽  
George M. Durner ◽  
...  
Keyword(s):  
Research Methods ◽  
Body Mass ◽  
Body Condition ◽  
Polar Bear ◽  
Beaufort Sea ◽  
Polar Bears ◽  
Long Term Effects ◽  
Movement Rates ◽  
Related Mortality

Context The potential for research methods to affect wildlife is an increasing concern among both scientists and the public. This topic has a particular urgency for polar bears because additional research is needed to monitor and understand population responses to rapid loss of sea ice habitat. Aims This study used data collected from polar bears sampled in the Alaska portion of the southern Beaufort Sea to investigate the potential for capture to adversely affect behaviour and vital rates. We evaluated the extent to which capture, collaring and handling may influence activity and movement days to weeks post-capture, and body mass, body condition, reproduction and survival over 6 months or more. Methods We compared post-capture activity and movement rates, and relationships between prior capture history and body mass, body condition and reproductive success. We also summarised data on capture-related mortality. Key results Individual-based estimates of activity and movement rates reached near-normal levels within 2–3 days and fully normal levels within 5 days post-capture. Models of activity and movement rates among all bears had poor fit, but suggested potential for prolonged, lower-level rate reductions. Repeated captures was not related to negative effects on body condition, reproduction or cub growth or survival. Capture-related mortality was substantially reduced after 1986, when immobilisation drugs were changed, with only 3 mortalities in 2517 captures from 1987–2013. Conclusions Polar bears in the southern Beaufort Sea exhibited the greatest reductions in activity and movement rates 3.5 days post-capture. These shorter-term, post-capture effects do not appear to have translated into any long-term effects on body condition, reproduction, or cub survival. Additionally, collaring had no effect on polar bear recovery rates, body condition, reproduction or cub survival. Implications This study provides empirical evidence that current capture-based research methods do not have long-term implications, and are not contributing to observed changes in body condition, reproduction or survival in the southern Beaufort Sea. Continued refinement of capture protocols, such as the use of low-impact dart rifles and reversible drug combinations, might improve polar bear response to capture and abate short-term reductions in activity and movement post-capture.

The effect of nutrition during early life on voluntary food intake by lambs between weaning and 2 years of age

1998 ◽  
Vol 66 (3) ◽  
pp. 697-703 ◽  
Author(s):  
A. M. Sibbald ◽  
G. C. Davidson
Keyword(s):  
Body Condition ◽  
Live Weight ◽  
Late Pregnancy ◽  
Metabolizable Energy ◽  
Long Term Effects ◽  
Fat Depots ◽  
Pregnancy And Lactation ◽  
Grazed Swards ◽  
Body Condition Scores

AbstractTwo experiments were carried out with Scottish Blackface lambs to investigate the effects of restricted nutrition during pregnancy and lactation on voluntary food intakes (VFI) between weaning and 2 years of age. Ewes were given diets providing 0·7 (LP) or 10 (HP) of their estimated metabolizable energy requirements during the last 6 weeks of pregnancy and subsequently grazed swards with mean sward surface heights of approximately 3 cm (LL) or 6 cm (HL) during lactation. All lambs were weaned at 17 weeks of age. In experiment 1, four treatment combinations (LP-LL, LP-HL, HP-LL and HP-HL) were applied and female lambs were studied. In experiment 2, two treatment combinations (LP-LL and HP-HL) were applied and male lambs were studied. In both experiments the lambs received a common level of nutrition between weaning and 2 years of age.In both experiments, mean live weights were proportionately 0·2 higher for HP-HL than for LP-LL lambs at weaning (P < 0·001) and in experiment 2 mean live weights and body condition scores were still higher in HP-HL than in LP-LL lambs at 2 years of age (P < 0·05). Abomasum weights were higher in HP than in LP lambs at birth and higher in HP-HL than in LP-LL lambs at weaning in experiment 1 and the weights of the rumen and dimensions of the rumen villi were greater in HP-HL than in LP-LL lambs at weaning in both experiments (P < 0·05). The treatments had no effect on lipid content or mean adipocyte diameter in the main fat depots at birth or weaning. There were no treatment effects on VFI in either experiment. It was concluded that restricted nutrition during late pregnancy and early lactation does not affect VFI between weaning and 2 years of age in sheep, even though there are differences in live weight and the development of the gastrointestinal tract at weaning and there may be long-term effects on live weight and body condition, particularly in male animals.

Pasture condition and milk production by grazing dairy cows as affected by daily herbage-allowance restriction

2019 ◽  
Vol 59 (8) ◽  
pp. 1510 ◽  
Author(s):  
V. M. Merino ◽  
O. A. Balocchi ◽  
R. G. Pulido
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Body Condition ◽  
Soil Compaction ◽  
Body Condition Score ◽  
Main Tool ◽  
Milk Composition ◽  
Unaffected Individual ◽  
Long Term Effects

Daily herbage allowance is recognised as the main tool to control pasture utilisation and milk production per cow. The aim of the present study was to evaluate the long-term effects of daily herbage allowance (DHA) on pasture characteristics and milk production of dairy cows. Forty-four dairy cows were randomly assigned to one of four treatments in a 2 × 2 factorial design by considering two levels of DHA (20 and 30 kg DM/cow.day) and two types of supplements (high-moisture maize and maize silage) over a 77-day period. Pre- and post-grazing herbage masses, vertical distribution of herbage mass, species density, botanical and chemical composition, sward depletion and changes in morphological components of the pasture were measured. The effect of DHA on soil compaction was evaluated on the basis of the penetration resistance. Milk production and composition levels, bodyweights and body condition scores were recorded. Post-grazing residual declined as the level of DHA decreased, while grazing efficiency increased from 39.8% to 44.8%. We found no effects of DHA on any pasture characteristics, pasture regrowth or soil compaction. Low-DHA conditions induced a faster sward-height reduction, while the herbage mass remained unaffected. Individual milk production decreased with DHA. However, milk outputs per hectare increased by 2772 L/ha. Milk composition, bodyweight and body condition score were not affected by DHA. The results showed that DHA restriction decreases milk production per cow while increasing both herbage utilisation and milk production per hectare, without affecting long-term pasture condition.

Long-Term Effects of Electrofishing on Growth and Body Condition of Brown Trout and Rainbow Trout

1997 ◽  
Vol 17 (1) ◽  
pp. 154-159 ◽  
Author(s):  
Kevin G. Thompson ◽  
Eric P. Bergersen ◽  
R. Barry Nehring ◽  
David C. Bowden
Keyword(s):  
Rainbow Trout ◽  
Body Condition ◽  
Brown Trout ◽  
Long Term Effects

scholarly journals Long-term capture and handling effects on body condition, reproduction and survival in a semi-aquatic mammal

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rasmus M. Mortensen ◽  
Frank Rosell
Keyword(s):  
Body Condition ◽  
Ecological Factors ◽  
Field Studies ◽  
Older Individuals ◽  
Long Term Effects ◽  
Aquatic Mammal ◽  
Animal Populations ◽  
Capture Stress ◽  
In The Beginning

Abstract In long-term individual-based field studies, several parameters need to be assessed repeatedly to fully understand the potential fitness effects on individuals. Often studies only evaluate capture stress that appears in the immediate weeks or breeding season and even long-term studies fail to evaluate the long-term effects of their capture procedures. We investigated effects of long-term repeated capture and handling of individuals in a large semi-aquatic rodent using more than 20 years of monitoring data from a beaver population in Norway. To investigate the effects, we corrected for ecological factors and analysed the importance of total capture and handling events, years of monitoring and deployment of telemetry devices on measures related to body condition, reproduction and survival of individual beavers. Body mass of dominant individuals decreased considerably with number of capture events (107 g per capture), but we found no statistically clear short or long-term effects of capture and handling on survival or other body condition indices. Annual litter size decreased with increasing number of captures among older individuals. Number of captures furthermore negatively affected reproduction in the beginning of the monitoring, but the effect decreased over the years, indicating habituation to repeated capture and handling. By assessing potential impacts on several fitness-related parameters at multiple times, we can secure the welfare of wild animal populations when planning and executing future conservation studies as well as ensure ecologically reliable research data.

scholarly journals Long term effects of fire frequency and season on the woody vegetation dynamics of the Sclerocarya birrea/Acacia nigrescens savanna of the Kruger National Park

Koedoe ◽  
2000 ◽  
Vol 43 (1) ◽  
Author(s):  
B.W. Enslin ◽  
A.L.F. Potgieter ◽  
H.C. Biggs ◽  
R. Biggs
Keyword(s):  
National Park ◽  
Structural Changes ◽  
Environmental Parameters ◽  
Woody Species ◽  
Fire Frequency ◽  
Kruger National Park ◽  
Woody Vegetation ◽  
Long Term Effects ◽  
Season Of Burn

A lack of knowledge together with vacillating fire management approaches in the Kruger National Park until the mid 1950s, gave rise to a long term fire research experiment aimed at shedding light on savanna responses to various combinations of fire fre- quencies and seasons. This trial was laid out in 1954 in four of the six major vegetation zones of the park. With the future of the experiment now being reconsidered, full scale vegetation surveys have been conducted on all the plots and compared to the surveys done in 1954. This paper examines the woody vegetation responses to fourteen fire treatments in the Knobthorn/Marula savanna. Parameters of interest were woody species composition responses, together with tree & shrub density and structural changes. The results indicate that no significant changes in woody species had occurred for the peri- od 1954 vs 1998, while density decreased on biennial and increased on triennial treatments. The proportion of single stemmed plants increased over the period. Season of burn has a marked effect on structure, with April and August burns giving rise to the largest basal areas but the lowest heights. Environmental parameters such as climate, varying herbivory and differing soils, and their respective interactions on vegetation morphology, together with fire behaviour, further influenced results.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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