scholarly journals An event of underground predation on a wintering caudate amphibian by a carabid beetle

2014 ◽  
Vol 25 (3) ◽  
pp. 157-160 ◽  
Author(s):  
Rafal Bernard ◽  
Juliusz Samoląg
Keyword(s):  
Carabid Beetles ◽  
Generalist Predator ◽  
Large Species ◽  
Complete Darkness ◽  
Natural Conditions ◽  
Ambient Temperatures ◽  
Lissotriton Vulgaris ◽  
Autumn And Winter ◽  
Typical Prey ◽  
Nw Poland

Pterostichus niger (Coleoptera: Carabidae) preying on Lissotriton vulgaris (Caudata: Salamandridae) in complete darkness and fairly low ambient temperatures was recorded in mid-winter in the underground fortifications near Strzaliny, NW Poland, confirming the occurrence of the predation on small caudate amphibians by carabid beetles in natural conditions. The long but successful predatory event, being a result of sharing the same shelter, revealed the opportunistic predispositions of that generalist predator in a situation in which its typical prey was absent. This suggested that small amphibians may be a source of food for carabids, even for only moderately large species, in late autumn and winter shelters.

Behavioral Energetics of Overwintering in the Rifleman, Acanthisitta-Chloris

1991 ◽  
Vol 39 (6) ◽  
pp. 643 ◽  
Author(s):  
A Lill
Keyword(s):  
Population Density ◽  
Prey Capture ◽  
Activity Rhythm ◽  
Capture Rate ◽  
Microhabitat Use ◽  
Lowland Forest ◽  
Time Activity ◽  
Ambient Temperatures ◽  
Prey Capture Rate ◽  
Autumn And Winter

The role of behavioural adjustments in meeting increased daily energy requirements in winter was investigated in rifleman, Acanthisitta chloris, inhabiting lowland forest in South I., New Zealand, by comparing their population density, time-activity budget and foraging behaviour in autumn and winter. Rifleman foraged for 83% of daytime in both seasons. The combined effects on the birds' winter energy budget of increased thermoregulation costs and the shorter daylength for foraging were at least partly offset by an estimated 23-29% decrease in the amount of energy expended daily on activity and a 78% increment in prey caught per day. The reduced energy expenditure on activity resulted from rifleman spending less time on expensive flying and more time roosting. The increase in prey capture rate may have stemmed from a 35% seasonal reduction in the birds' population density and reduced prey mobility at lower ambient temperatures. Marked sexual size dimorphism was not reflected in gender differences in activity budgeting or prey capture rate, but the sexes differed in their relative use of foraging substrates. Rifleman showed few seasonal changes in daily activity rhythm or microhabitat use. The behavioural energetic overwintering tactics of rifleman are compared with those of other Australasian and north temperate zone land-birds.

An inexpensive portable freezer for in situ freezing in the field

2002 ◽  
Vol 32 (12) ◽  
pp. 2160-2168 ◽  
Author(s):  
Yves Dubuc ◽  
Jean Dubuc ◽  
Francine J Bigras
Keyword(s):  
Picea Glauca ◽  
White Spruce ◽  
Field Conditions ◽  
Natural Conditions ◽  
Dry Ice ◽  
Ambient Temperatures ◽  
Programmable Controller ◽  
Controlled Conditions ◽  
Large Trees

A portable freezer was developed to apply frost to branches of large trees to study their growth and recuperation after frost application under natural conditions. The freezer measures 37.5 × 63.5 × 31.5 cm and weighs approximately 3 kg. It consists of two compartments, a freezing compartment and a dry ice compartment. The portable freezer provides a ramp-and-soak freezing pattern using a programmable controller. The nonfreezing temperature plateaus can be set from 1 to 6°C and maintained for 0 to 12 h. The cooling and warming rates can be programmed from 1 to 12°C·h–1. Test temperatures can be maintained for a period of time ranging from 0 to 12 h at set temperatures. Freezers were tested without samples under controlled conditions at ambient temperatures of 0, –5, –10, 5, 15, 20, and 25°C. Under these conditions, the cooling and warming rates showed a deviation of less than ±1°C·h–1 at a set rate of 2°C·h–1. The freezer provides test temperatures as low as –38°C and –47°C at ambient temperatures of 20 and –10°C, respectively. Freezers were also tested under field conditions on attached branches in mature white spruce (Picea glauca (Moench) Voss) trees under hardening conditions.

Developing a census method based on sight counts to estimate rabbit (Oryctolagus cuniculus) numbers

2003 ◽  
Vol 30 (5) ◽  
pp. 487 ◽  
Author(s):  
Dylan W. Poole ◽  
Dave P. Cowan ◽  
Graham C. Smith
Keyword(s):  
Population Size ◽  
Field Trials ◽  
Population Estimates ◽  
Economic Costs ◽  
Natural Conditions ◽  
Commercial Farms ◽  
The Mean ◽  
The Difference ◽  
Study Sites ◽  
Autumn And Winter

A rabbit-census method, based on systematic counts conducted at night or at dawn and dusk, was developed and validated in terms of estimating the total number of rabbits present in a given area. Initially, models were developed under semi-natural conditions to describe the relationships between the numbers of rabbits counted and population size. Confidence limits were also calculated. The models were developed by comparing rabbit counts with the actual number of rabbits present, from a known population of animals. Only spotlight counts at night were considered reliable enough to estimate rabbit population size. During the autumn and winter months these represented ~60% of the population present. The model was subsequently validated, in two different exercises, following a series of field trials conducted under a variety of conditions on commercial farms. Initially, population estimates derived from the model were compared with those calculated using an alternative census technique. Population estimates, using the two techniques, were very similar at nine of the ten study sites. A second validation exercise was also conducted whereby the number of rabbits removed at each of the sites was compared with the difference between the mean pre- and post-removal spotlight counts. The results further supported the proposition that spotlight counts represent ~60% of the population present, with the difference between the two mean spotlight counts representing 61.2% (± 11.0, s.d.) of the number of rabbits removed. The census method therefore shows considerable promise as a means to estimate rabbit numbers under a range of agricultural conditions and therefore has the potential to predict accurately the economic costs of rabbit damage and also to gauge the effectiveness of various methods of rabbit control.

Energy metabolism of oiled muskrats

1974 ◽  
Vol 52 (8) ◽  
pp. 1057-1062 ◽  
Author(s):  
E. H. McEwan ◽  
N. Aitchison ◽  
P. E. Whitehead
Keyword(s):  
Thermal Conductivity ◽  
Energy Metabolism ◽  
Heat Production ◽  
Thermal Conduction ◽  
Dry Matter ◽  
Fold Increase ◽  
Dry Matter Intake ◽  
Natural Conditions ◽  
Ambient Temperatures ◽  
Feeding Activities

The heat production of muskrats (Ondatra zibethica), oiled with varying quantities of crude oil, was measured at three ambient temperatures, −5, 5, and 10C on days 0, 1, and 3 after oiling. On day 0, the heat production of muskrats oiled with 1.9 to 42.3 g of oil was from 14 to 119% higher, respectively, than the non-oiled muskrats. Three days after oiling, the metabolic rate of oiled muskrats was about the same as the control values. A similar trend was determined for ambient temperatures of 5 and 10C. Heavy oiling increased the thermal conduction of muskrats by as much as 122%. To compensate for the loss of insulation and increased thermal conductivity of the fur, there was a 2.5-fold increase in dry-matter intake. In view of their dependence on water, both for feeding activities and a place for refuge, it is doubtful if muskrats exposed to moderate quantities of oil could survive under natural conditions.

scholarly journals Forming egg shape index as influenced by ambient temperatures and age of hens

2006 ◽  
Vol 22 (1-2) ◽  
pp. 119-125 ◽  
Author(s):  
Nedeljka Nikolova ◽  
Dragoslav Kocevski
Keyword(s):  
Winter Season ◽  
Shape Index ◽  
Poultry Farm ◽  
High Significance ◽  
Ambient Temperatures ◽  
Average Temperature ◽  
Autumn Season ◽  
Average Shape ◽  
Index Value ◽  
Autumn And Winter

The effects of ambient temperatures and hen?s age were investigated on poultry farm on the south of R. Macedonia, where annually average temperature was higher then other regions. In nine-month period of testing were included summer, autumn and winter season. Two groups of hens (ISA-BROWN) were used; the first one was younger (to 45-week age) and second was older (above 45-weeks). Once a month, about 100 eggs were examined, so the final number of tested eggs was 877. Average shape index was 75.19% for all eggs. High significance (p<0.01) showed both factors: age and season. Eggs from younger hens had index value of 76.16%, which is pointed on eggs with rounded shape, while older hen's eggs had index 74.20% with elongated shape. In summer and autumn season, most of eggs were with elongated shape while rounded shape had eggs in winter season.

scholarly journals Competition and Intraguild Predation Between Beetles, Pterostichus stygicus (Coleoptera: Carabidae) and Centipedes, Scolopocryptops sexspinosus (Scolopemdromorpha: Scolopocryptopidae)

2019 ◽  
Vol 112 (5) ◽  
pp. 473-481
Author(s):  
Michele E Julian ◽  
Cari-Ann M Hickerson ◽  
Carl D Anthony
Keyword(s):  
Intraguild Predation ◽  
Forest Floor ◽  
Deciduous Forest ◽  
Field Studies ◽  
Trophic Levels ◽  
Carabid Beetles ◽  
Generalist Predators ◽  
Generalist Predator ◽  
Trophic Morphology ◽  
Predator Interactions

Abstract Studying interactions between distantly related species is necessary to understand the complexity of food webs. Generalist predator interactions, such as intraguild predation (IGP) and competition, can alleviate predation pressure and weaken top–down control that predators have on lower trophic levels. Centipedes (Chilopoda) and carabid beetles (Coleoptera) are common deciduous forest floor generalist predators that may interact by competing for resources beneath rocks and logs on the forest floor, especially during dry periods when prey become confined to such microhabitats. We used laboratory and field studies to determine whether the carabid beetle, Pterostichus stygicus (Say), and the centipede, Scolopocryptops sexspinosus (Say) co-occur under artificial cover. Additionally, a laboratory mesocosm experiment was used to examine competitive interactions in intra- and interspecific trials. There was significant negative co-occurrence of beetles and centipedes beneath cover objects in the field and laboratory. Pairings of S. sexspinosus and P. stygicus within mesocosms resulted in high mortality of P. stygicus, and reciprocal but asymmetric IGP. Centipedes maintained weight within solitary, intra- and interspecific mesocosm treatments, however, beetles lost mass in all treatments. Scolopocryptops sexspinosus responded more favorably to intra- and interspecific competition than did P. stygicus. Analysis of the leaf litter mesofauna indicated that these predators consumed similar prey in laboratory mesocosms. Our results suggest that species with very different trophic morphology have the potential to compete for shared microhabitat and prey.

THE WINTER BIOENERGETICS OF A BEAVER POPULATION IN NORTHERN LATITUDES

1967 ◽  
Vol 45 (6) ◽  
pp. 1107-1118 ◽  
Author(s):  
N. S. Novakowski
Keyword(s):  
National Park ◽  
Castor Canadensis ◽  
Deciduous Trees ◽  
Ambient Temperatures ◽  
Fat Reserves ◽  
Northern Latitudes ◽  
Unlimited Supply ◽  
Wood Buffalo National Park ◽  
Autumn And Winter ◽  
Reduced Activity

The winter bioenergetics of a beaver population were studied in au area of Wood Buffalo National Park; which is located partly in Alberta and partly in the Northwest Territories. In these latitudes the beaver (Castor canadensis canadensis) are confined to subnivean existence for approximately 150 days each year. Although there is an unlimited supply of deciduous trees, which are cached by the colonies for this period, the caches were not sufficient for the energy requirements of the colonies, as calculated from the number and weight of animals in each colony. This indicates that energy deficits are a product of the winter behavior of the animals and that methods of energy conservation, such as reduced activity, periods of dormancy, huddling, insulation from ambient temperatures by lodge construction, and an increase in fur insulation and fat deposition provide the necessary mechanisms for survival. Based on a comparison of autumn and winter weights of beaver, the younger animals (kits and yearlings) increased their weight during the winter while the older animals, who presumably use fat reserves for survival, did not.

Energy savings from vocal regulation of ambient temperature by 3-day-old domestic chicks

1996 ◽  
Vol 74 (4) ◽  
pp. 599-605 ◽  
Author(s):  
Anton Espira ◽  
Roger M. Evans
Keyword(s):  
Oxygen Consumption ◽  
Ambient Temperature ◽  
Thermal Gradient ◽  
Energy Savings ◽  
Net Energy ◽  
Natural Conditions ◽  
Ambient Temperatures ◽  
Domestic Chicks ◽  
Important Means ◽  
Cold Challenge

Precocial domestic chicks (Gallus domesticus) become endothermic at or soon after hatching, but when chilled still vocalize to solicit heat from a parent or surrogate. In this study, we examined the potential energy savings resulting from vocal solicitation of heat by comparing the oxygen consumption of 3-day-old chicks facing a cold challenge of 20 °C with and without the option of regulating ambient temperature by vocally soliciting 2-min periods of rewarming at 35 °C from a surrogate parent in the laboratory. Body temperature was unaffected by vocal regulation, but the thermal gradient between body and ambient temperature was reduced by 5.0 ± 0.4 °C (mean ± SE). Mass-specific oxygen consumption [Formula: see text] increased by 62.5% to a near steady state mean of 3.64 mL∙g−1∙h−1 during constant chilling at 20 °C, but increased by only 48.1%, to 3.08 mL∙g−1∙h−1, during vocal regulation. Relative to chilled controls, vocally regulating chicks had a mean net energy saving of 15.4% during the final, stable 15 min of testing. Vocal solicitation of heat from a brooding parent seems likely to be an important means of saving energy expended in thermoregulation in some precocial species when young chicks are exposed to low ambient temperatures under natural conditions.

scholarly journals Assessment of the Biological Control Potential of Common Carabid Beetle Species for Autumn- and Winter-Active Pests (Gastropoda, Lepidoptera, Diptera: Tipulidae) in Annual Ryegrass in Western Oregon

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 722
Author(s):  
Inga Reich ◽  
Casi Jessie ◽  
Seung-Joon Ahn ◽  
Man-Yeon Choi ◽  
Christopher Williams ◽  
...  
Keyword(s):  
Biological Control ◽  
Carabid Beetles ◽  
Crop Damage ◽  
Annual Ryegrass ◽  
Control Potential ◽  
Field Margin ◽  
Molecular Gut Content Analysis ◽  
Biological Control Potential ◽  
Autumn And Winter ◽  
Invertebrate Pests

While carabid beetles have been shown to feed on a variety of crop pests, little is known about their species assemblages in US annual ryegrass crops, where invertebrate pests, particularly slugs, lepidopteran larvae and craneflies, incur major financial costs. This study assesses the biological control potential of carabid beetles for autumn- and winter-active pests in annual ryegrass grown for seed by: (a) investigating the spatial and temporal overlap of carabids with key pests; and (b) molecular gut content analysis using qPCR. Introduced Nebria brevicollis was the only common carabid that was active during pest emergence in autumn, with 18.6% and 8.3% of N. brevicollis collected between September and October testing positive for lepidopteran and cranefly DNA, respectively, but only 1.7% testing positive for slug DNA. While pest DNA was also detected in the guts of the other common carabid species—Agonum muelleri, Calosoma cancellatum and Poecilus laetulus—these were active only during spring and summer, when crop damage by pests is less critical. None of the four carabid species was affected by disk tilling and only N. brevicollis was significantly associated with a vegetated field margin. However, as its impact on native ecosystems is unknown, we do not recommend managing for this species.

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