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 experimental analysis of prey availability for sanderlings (Aves: Scolopacidae) feeding on sandy beach crustaceans

1980 ◽  
Vol 58 (9) ◽  
pp. 1564-1574 ◽  
Author(s):  
J. P. Myers ◽  
S. L. Williams ◽  
F. A. Pitelka
Keyword(s):  
Prey Density ◽  
Prey Capture ◽  
Prey Size ◽  
Prey Availability ◽  
Capture Rate ◽  
Search Time ◽  
Beach Sand ◽  
Sand Surface ◽  
Prey Capture Rate ◽  
Bodega Bay

We investigated the role of prey size, prey depth, prey microdistribution, and substrate penetrability in affecting prey availability to sanderlings (Calidris alba Pallas). Five experiments were performed in the laboratory manipulating these availability factors and prey density in beach sand. The effects on prey risk and sanderling prey capture rate were measured.Prey risk increased linearly with prey size. Prey within 10 mm of the surface were vulnerable to predation but their risk decreased sharply below that depth. Substrate penetrability affected prey risk by controlling how deeply a sanderling could probe beneath the sand surface while searching for prey.Prey capture rates varied between 0.01 and 0.84 captures per second of search time over a range of prey density between 60 and 1200 prey per square metre. Prey size and substrate penetrability affected capture rate through their effect on prey risk, and substrate penetrability also influenced capture rate directly. Prey density had the strongest effect on prey capture rate. Measurements in the field around Bodega Bay, California, indicate that prey density, prey size, prey depth, and substrate penetrability can have significant impact on sanderling foraging under field conditions.

scholarly journals Captive culture of two sea snake species Hydrophis curtus and Hydrophis cyanocinctus

2021 ◽  
Vol 20 (4A) ◽  
pp. 105-114
Author(s):  
Nguyen Trung Kien ◽  
Hua Thai An ◽  
Huynh Minh Sang ◽  
Do Huu Hoang ◽  
Cao Van Nguyen ◽  
...  
Keyword(s):  
Body Weight ◽  
Survival Rate ◽  
Prey Capture ◽  
Prey Selection ◽  
Capture Rate ◽  
The Body ◽  
Sea Snake ◽  
Snake Species ◽  
Prey Capture Rate

Acclimation culture and trial culture of two sea snake species Hydrophis curtus and H. cyanocinctus in composite tanks were conducted to determine growth, survival rate, predation behavior and prey selection. The results showed that adults of H. curtus and H. cyanocinctus did not capture any prey such as anchovy, eel and shrimp in a period of 30 days of acclimation culture. The body weight of two these species reduced gradually from 783.3 ± 76.4 g and 360.0 ± 60.0 g to 660.0 ± 135.2 g and 315.0 ± 77.8 g, respectively. Survival rate was 100% in H. curtus and 80% in H. cyanocinctus. Meanwhile, the results of acclimation culture of sea snake juvenile revealed that frozen anchovy was preferred prey in both of two species. The body weight of H. curtus increased from 49.8 ± 0.5 g to 70.0 ± 8.2 g and that of H. cyanocinctus was 44.3 ± 3.1 g to 47.1 ± 5.2 g. The prey capture rate of H. curtus and H. cyanocinctus was 100% and 60%, respectively. Survival rate of the juvenile of two species was 100% after 30 days of acclimation culture. In 60 days of trial culture, similar results as acclimation culture were observed in adults of two sea snake species, they still did not capture any prey and the body weight reduced gradually. The result of 60-day culture of sea snake juvenile showed that the prey capture rate was 100% in both of two species. The body weight of H. curtus and H. cyanocinctus increased from 70.0 ± 8.2 g and 57.5 ± 5.8 g to 78.3 ± 15.3 g and 65.0 ± 14.1, respectively. SGR of H. curtus was 0.16 ± 0.32 %/day and that of H. cyanocinctus was 0.52 ± 0.36%/day. The survival rate of H. curtus and H. cyanocinctus was 60% and 40% in period of 60 day trial.

An Experimental Analysis of Macrophyte Growth Forms as Fish Foraging Habitat

1991 ◽  
Vol 48 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Michele Dionne ◽  
Carol L. Folt
Keyword(s):  
Plant Growth ◽  
Growth Form ◽  
Plant Density ◽  
Prey Capture ◽  
Capture Rate ◽  
Habitat Associations ◽  
Growth Forms ◽  
Plant Growth Form ◽  
Macrophyte Growth ◽  
Capture Rates

In this laboratory study we measured the independent effects of macrophyte growth form, plant density, and prey abundance on the foraging rate of the pumpkinseed sunfish (Lepomis gibbosus). We demonstrate that macrophyte growth forms are not all similar in their effects on fish foraging. Prey capture rates of pumpkinseeds foraging among Scirpus validus (cylindrical stems) were 53 and 365% times greater than for Potamogeton amplifolius (leafy stems) for cladoceran (Sida crystallina) and larval damselfly (Coenagrionidae) prey, respectively. Plant growth form influenced prey capture rates more than charges in natural plant density. Plant density effects ranged from none on damselfly capture rates to a 29% decline in cladoceran capture rate over a twofold increase in plant density. Our results indicate that in plant-structured habitats, variation in plant growth form can be an important determinant of fish foraging and habitat associations.

scholarly journals 1605. Temperature Modulates the Rate of Increase of Antibiotic Resistance Across Europe

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S585-S586
Author(s):  
Sarah McGough ◽  
Derek MacFadden ◽  
Mohammad Hattab ◽  
Kare Molbak ◽  
Mauricio Santillana
Keyword(s):  
Public Health ◽  
Antibiotic Resistance ◽  
Population Density ◽  
Antibiotic Consumption ◽  
Human Populations ◽  
Ambient Temperatures ◽  
E Coli ◽  
Factors Influencing ◽  
Rate Of Increase ◽  
Public Health Threat

Abstract Background Widely recognized as a major public health threat globally, the rapid increase of antibiotic resistance in bacteria could soon render our most effective method to combat infections obsolete. Factors influencing the burden of resistance in human populations remain poorly described, though temperature is known to play an important role in mechanisms of bacterial growth and transmission. Methods Here, we present the first evidence that ambient temperatures may modulate the rate of increase of antibiotic resistance across Europe. Using a comprehensive dataset containing information across 28 countries, for 17 years (2000–2016), 3 common bacterial pathogens, and 4 antibiotic classes collectively representing over 4 million tested isolates, we show that antibiotic resistance has increased more rapidly in warmer regions over a period of nearly 2 decades. Results Specifically, we show that European countries with 10°C warmer ambient temperatures have experienced more rapid increases in antibiotic resistance to E. coli and K. pneumoniae over the 17-year period, ranging between 0.33%/year (95% CI 0.2, 0.5) and 1.2%/year (0.4, 1.9), even after accounting for recognized drivers of resistance including antibiotic consumption and population density. We found a decreasing relationship for S. aureus and methicillin of -0.4%/year (95% CI −0.7, 0.0), reflecting widespread declines in MRSA across Europe over the study period. Conclusion Our findings suggest that rising temperatures globally may hasten the spread of resistance and complicate efforts to mitigate it. Disclosures All authors: No reported disclosures.

Methods and ethical considerations of pitfall trapping for the western pygmy possum (Cercartetus concinnus Gould) (Marsupialia:Burramyidae), with observations on capture patterns and nest sites

2007 ◽  
Vol 34 (4) ◽  
pp. 296 ◽  
Author(s):  
Angela J. L. Pestell ◽  
Sophie Petit
Keyword(s):  
Capture Rate ◽  
South Australia ◽  
Trap Depth ◽  
Pitfall Trap ◽  
House Mice ◽  
Pitfall Trapping ◽  
Ethical Considerations ◽  
Ethical Implications ◽  
Nest Sites ◽  
Autumn And Winter

In order to enhance future trapping of the western pygmy possum (Cercartetus concinnus) and minimise the capture of non-target species in the context of animal ethics, we examined the effectiveness of several pitfall-trap capture methods and described capture patterns at Innes National Park, South Australia. For 2606 trap-nights, 78 (2.99 per 100 trap-nights) captures were pygmy possums (70 individuals). They represented 69% of the 113 vertebrates captured, followed by house mice (Mus domesticus) (22%). Nocturnal captures of pygmy possums varied with season (5.21 per 100 trap-nights in spring and summer, and 1.02 in autumn and winter). Males were more commonly captured than females. Half of the pygmy possums used the artificial shelters provided in the traps. We alternated 39-cm-deep and 31-cm-deep pitfall traps along trap lines, with and without drift netting. Pitfall depth did not significantly affect the capture rate of pygmy possums, but house mice were captured significantly more often in deep pitfalls. Use of a drift net did not affect the capture of pygmy possums, but increased mouse captures. These results have significant ethical implications because the use of ‘shallow’ traps and the elimination of the drift net minimised the capture of non-target mice. We recommend reporting trapping details precisely, because a difference of only 8 cm in trap depth can have a significant impact on species selected for capture. Our study also showed that pygmy possums are able to use a range of structures for daily shelter and are not dependent on hollows.

Multiple feeding in wolf spiders: the effect of starvation on handling time, ingestion rate, and intercatch intervals in Lycosa lapidosa (Araneae : Lycosidae)

2000 ◽  
Vol 48 (1) ◽  
pp. 59 ◽  
Author(s):  
V. W. Framenau ◽  
L. A. Finley ◽  
K. Allan ◽  
M. Love ◽  
D. Shirley ◽  
...  
Keyword(s):  
Prey Capture ◽  
Ingestion Rate ◽  
Capture Rate ◽  
Wolf Spider ◽  
Handling Time ◽  
Wolf Spiders ◽  
Feeding Regimes ◽  
Acheta Domestica ◽  
Multiple Feeding ◽  
Prey Items

Multiple prey capture, the behaviour of a predator attacking prey whilst handling a previously caught item, occurs in a variety of spiders that do not build webs. The effects of recent feeding history on the frequency of multiple prey attacks, handling time, ingestion rate, and intercatch intervals were examined experimentally in the wolf spider Lycosa lapidosa McKay. Juvenile spiders were subjected to two different feeding regimes (starvation for 14 and 28 days) and then provided with two different prey types (blowflies, Lucilia cuprina, and crickets, Acheta domestica). These two starvation levels or prey types had little effect on the frequency (75%) of multiple prey attacks. Spiders ingested approximately half the weight of any captured prey, regardless of how many prey items they attacked. At the same time, the handling time per prey item decreased with an increasing number of prey attacked. This indicates a more efficient ingestion rate when more prey are consumed. While the attacking time for the first prey was the same for all treatments, the first intercatch interval was longer for spiders that were starved longer. Chronically starved L. lapidosa appear to secure a previously caught item rather than optimise their capture rate by attacking further available prey.

scholarly journals Atmospheric pressure and population density as super-factors influencing the transmission of coronavirus disease 2019 (COVID-19)

2020 ◽  
Author(s):  
Wei Yan ◽  
Muhammad Zohaib Nawaz ◽  
Wenqian Xu ◽  
Zheng Jiang ◽  
Weixiang Sun ◽  
...  
Keyword(s):  
Population Density ◽  
Atmospheric Pressure ◽  
Virus Transmission ◽  
The United States ◽  
Positive Influence ◽  
Etiologic Agent ◽  
The Novel ◽  
Effective Strategies ◽  
Global Pandemic ◽  
Autumn And Winter

Abstract The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of coronavirus disease (COVID-19), recently emerged and led to a global pandemic with enormous consequent losses to global health and economies. To date, more than 30 million cases have been reported globally and have affected almost every with varying degrees. Meteorological and non-meteorological factors such as temperature, relative humidity, atmospheric pressure, population density, and latitude, are considered critical in virus transmission. To explore the correlation of environmental factors with the transmission of SARS-CoV-2 based on parameters including infection rate, effective reproduction number, and compound growth rate, we analyzed data of confirmed cases from 487 counties in the United States. We found a small impact of temperature and humidity on virus transmission, but observed a considerable positive influence of atmospheric pressure and population density on virus transmission. Geographic areas and seasons (autumn and winter), with exposure to higher atmospheric pressure, are more likely at higher risk of an outbreak. Social distancing and other measures could be effective strategies to combat COVID-19 outbreaks in densely populated areas. Additional studies are needed to explore the mechanisms underlying the relationship between meteorological parameters and transmission of SARS-CoV-2.

Sign in / Sign up

Export Citation Format

Share Document