scholarly journals Feeder density enhances house finch disease transmission in experimental epidemics

2018 ◽  
Vol 373 (1745) ◽  
pp. 20170090 ◽  
Author(s):  
Sahnzi C. Moyers ◽  
James S. Adelman ◽  
Damien R. Farine ◽  
Courtney A. Thomason ◽  
Dana M. Hawley
Keyword(s):  
Radio Frequency Identification ◽  
Disease Transmission ◽  
Bacterial Pathogen ◽  
Pathogen Transmission ◽  
House Finch ◽  
Resource Subsidies ◽  
House Finches ◽  
Bird Feeders ◽  
Group Members ◽  
Radio Frequency Identification Devices

Anthropogenic food provisioning of wildlife can alter the frequency of contacts among hosts and between hosts and environmental sources of pathogens. Despite the popularity of garden bird feeding, few studies have addressed how feeders influence host contact rates and disease dynamics. We experimentally manipulated feeder density in replicate aviaries containing captive, pathogen-naive, groups of house finches ( Haemorhous mexicanus ) and continuously tracked behaviours at feeders using radio-frequency identification devices. We then inoculated one bird per group with Mycoplasma gallisepticum (Mg), a common bacterial pathogen for which feeders are fomites of transmission, and assessed effects of feeder density on house finch behaviour and pathogen transmission. We found that pathogen transmission was significantly higher in groups with the highest density of bird feeders, despite a significantly lower rate of intraspecific aggressive interactions relative to the low feeder density groups. Conversely, among naive group members that never showed signs of disease, we saw significantly higher concentrations of Mg-specific antibodies in low feeder density groups, suggesting that birds in low feeder density treatments had exposure to subclinical doses of Mg. We discuss ways in which the density of garden bird feeders could play an important role in mediating the intensity of Mg epidemics. This article is part of the theme issue ‘Anthropogenic resource subsidies and host–parasite dynamics in wildlife'.

Variation in Seroprevalence of Antibodies against Mycoplasma Gallisepticum and Avipoxvirus in Nine Species of Birds with Differential Access to Feeders

2018 ◽  
Vol 11 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Emily R. Vana ◽  
Elizabeth R. Wrobel ◽  
Travis E. Wilcoxen
Keyword(s):  
Disease Transmission ◽  
Mycoplasma Gallisepticum ◽  
House Finches ◽  
Single Location ◽  
Bird Feeders ◽  
Feeding Activities ◽  
Avian Pox ◽  
Species Specific ◽  
Pathogen Exposure

Congregation of individuals at high densities is known to increase disease transmission and bird-feeding activities are specifically aimed at attracting many birds to a single location. We surveyed nine potential host species for evidence of infection by each Mycoplasma gallisepticum (MG) and Avipoxvirus, or avian pox. We also examined differences in pathogen exposure at sites with bird feeders and sites without bird feeders. Finally, we compared prevalence of birds with antibodies against MG and avian pox to those that showed physical signs of infection. To test for pathogen exposure, we used indirect enzyme-linked immunosorbent assays. We found species-specific disease dynamics, as House Finches Haemorhous mexicanus had a significantly greater likelihood of having antibodies against MG than any other species. Birds at sites with feeders were more likely to have antibodies against MG. Birds at sites with feeders were no more likely to have antibodies against avian pox, but seroprevalence of avian pox did differ significantly among species. Overall, our findings suggest differential exposure and immune responses to each pathogen among species and that feeders increase the exposure of individuals to MG but not to avian pox, offering valuable new insights into the role of bird feeding activities in disease transmission among birds.

scholarly journals Health hazards to wild birds and risk factors associated with anthropogenic food provisioning

2018 ◽  
Vol 373 (1745) ◽  
pp. 20170091 ◽  
Author(s):  
Becki Lawson ◽  
Robert A. Robinson ◽  
Mike P. Toms ◽  
Kate Risely ◽  
Susan MacDonald ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Disease Surveillance ◽  
Large Scale ◽  
Emerging Diseases ◽  
Wild Birds ◽  
Mitigation Strategies ◽  
Health Hazards ◽  
Resource Subsidies ◽  
Supplementary Food ◽  
Bird Feeders

Provision of supplementary food for wild birds at garden feeding stations is a common, large-scale and year-round practice in multiple countries including Great Britain (GB). While these additional dietary resources can benefit wildlife, there is a concomitant risk of disease transmission, particularly when birds repeatedly congregate in the same place at high densities and through interactions of species that would not normally associate in close proximity. Citizen science schemes recording garden birds are popular and can integrate disease surveillance with population monitoring, offering a unique opportunity to explore inter-relationships between supplementary feeding, disease epidemiology and population dynamics. Here, we present findings from a national surveillance programme in GB and note the dynamism of endemic and emerging diseases over a 25-year period, focusing on protozoal (finch trichomonosis), viral (Paridae pox) and bacterial (passerine salmonellosis) diseases with contrasting modes of transmission. We also examine the occurrence of mycotoxin contamination of food residues in bird feeders, which present both a direct and indirect (though immunosuppression) risk to wild bird health. Our results inform evidence-based mitigation strategies to minimize anthropogenically mediated health hazards, while maintaining the benefits of providing supplementary food for wild birds. This article is part of the theme issue ‘Anthropogenic resource subsidies and host–parasite dynamics in wildlife’.

scholarly journals Deposition of pathogenic Mycoplasma gallisepticum onto bird feeders: host pathology is more important than temperature-driven increases in food intake

2013 ◽  
Vol 9 (5) ◽  
pp. 20130594 ◽  
Author(s):  
James S. Adelman ◽  
Amanda W. Carter ◽  
William A. Hopkins ◽  
Dana M. Hawley
Keyword(s):  
Food Intake ◽  
Ambient Temperature ◽  
Disease Transmission ◽  
Population Level ◽  
Mycoplasma Gallisepticum ◽  
Pathogen Transmission ◽  
Disease Dynamics ◽  
Transmission Potential ◽  
Thermoneutral Zone ◽  
Bird Feeders

Although ambient temperature has diverse effects on disease dynamics, few studies have examined how temperature alters pathogen transmission by changing host physiology or behaviour. Here, we test whether reducing ambient temperature alters host foraging, pathology and the potential for fomite transmission of the bacterial pathogen Mycoplasma gallisepticum (MG), which causes seasonal outbreaks of severe conjunctivitis in house finches ( Haemorhous mexicanus ). We housed finches at temperatures within or below the thermoneutral zone to manipulate food intake by altering energetic requirements of thermoregulation. We predicted that pathogen deposition on bird feeders would increase with temperature-driven increases in food intake and with conjunctival pathology. As expected, housing birds below the thermoneutral zone increased food consumption. Despite this difference, pathogen deposition on feeders did not vary across temperature treatments. However, pathogen deposition increased with conjunctival pathology, independently of temperature and pathogen load, suggesting that MG could enhance its transmission by increasing virulence. Our results suggest that in this system, host physiological responses are more important for transmission potential than temperature-dependent alterations in feeding. Understanding such behavioural and physiological contributions to disease transmission is critical to linking individual responses to climate with population-level disease dynamics.

scholarly journals Diurnal variation in the production of vocal information about food supports a model of social adjustment in wild songbirds

2019 ◽  
Vol 286 (1897) ◽  
pp. 20182740 ◽  
Author(s):  
F. Hillemann ◽  
E. F. Cole ◽  
S. C. Keen ◽  
B. C. Sheldon ◽  
D. R. Farine
Keyword(s):  
Social Adjustment ◽  
Radio Frequency Identification ◽  
Time Of Day ◽  
Food Detection ◽  
Bird Feeders ◽  
Frequency Identification ◽  
Response Measures ◽  
Group Members ◽  
Vocal Activity ◽  
Set Up

Wintering songbirds have been widely shown to make economic foraging decisions to manage the changing balance of risks from predation and starvation over the course of the day. In this study, we ask whether the communication and use of information about food availability differ throughout the day. First, we assessed temporal variation in food-related vocal information produced in foraging flocks of tits ( Paridae ) using audio recordings at radio-frequency identification-equipped feeding stations. Vocal activity was highest in the morning and decreased into the afternoon. This pattern was not explained by there being fewer birds present, as we found that group sizes increased over the course of the day. Next, we experimentally tested the underlying causes for this diurnal calling pattern. We set up bird feeders with or without playback of calls from tits, either in the morning or in the afternoon, and compared latency to feeder discovery, accumulation of flock members, and total number of birds visiting the feeder. Irrespective of time of day, playbacks had a strong effect on all three response measures when compared to silent control trials, demonstrating that tits will readily use vocal information to improve food detection throughout the day. Thus, the diurnal pattern of foraging behaviour did not appear to affect use and production of food-related vocalizations. Instead, we suggest that, as the day progresses and foraging group sizes increase, the costs of producing calls at the food source (e.g. competition and attraction of predators) outweigh the benefits of recruiting group members (i.e. adding individuals to large groups only marginally increases safety in numbers), causing the observed decrease in vocal activity into the afternoon. Our findings imply that individuals make economic social adjustments based on conditions of their social environment when deciding to vocally recruit group members.

scholarly journals Feeder use predicts both acquisition and transmission of a contagious pathogen in a North American songbird

2015 ◽  
Vol 282 (1815) ◽  
pp. 20151429 ◽  
Author(s):  
James S. Adelman ◽  
Sahnzi C. Moyers ◽  
Damien R. Farine ◽  
Dana M. Hawley
Keyword(s):  
Social Network ◽  
Disease Management ◽  
Feeding Behaviour ◽  
Bacterial Pathogen ◽  
Study Finding ◽  
Mycoplasma Gallisepticum ◽  
Individual Heterogeneity ◽  
House Finches ◽  
Behavioural Characteristics ◽  
Bird Feeders

Individual heterogeneity can influence the dynamics of infectious diseases in wildlife and humans alike. Thus, recent work has sought to identify behavioural characteristics that contribute disproportionately to individual variation in pathogen acquisition (super-receiving) or transmission (super-spreading). However, it remains unknown whether the same behaviours enhance both acquisition and transmission, a scenario likely to result in explosive epidemics. Here, we examined this possibility in an ecologically relevant host–pathogen system: house finches and their bacterial pathogen, Mycoplasma gallisepticum , which causes severe conjunctivitis. We examined behaviours likely to influence disease acquisition (feeder use, aggression, social network affiliations) in an observational field study, finding that the time an individual spends on bird feeders best predicted the risk of conjunctivitis. To test whether this behaviour also influences the likelihood of transmitting M. gallisepticum , we experimentally inoculated individuals based on feeding behaviour and tracked epidemics within captive flocks. As predicted, transmission was fastest when birds that spent the most time on feeders initiated the epidemic. Our results suggest that the same behaviour underlies both pathogen acquisition and transmission in this system and potentially others. Identifying individuals that exhibit such behaviours is critical for disease management.

scholarly journals Quantity and Quality of Aquaculture Enrichments Influence Disease Epidemics and Provide Ecological Alternatives to Antibiotics

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 335
Author(s):  
Anssi Karvonen ◽  
Ville Räihä ◽  
Ines Klemme ◽  
Roghaieh Ashrafi ◽  
Pekka Hyvärinen ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Bacterial Infections ◽  
Environmental Heterogeneity ◽  
Pathogen Transmission ◽  
Central Component ◽  
Flavobacterium Columnare ◽  
Disease Epidemics ◽  
The Impact ◽  
Environmental Microbes

Environmental heterogeneity is a central component influencing the virulence and epidemiology of infectious diseases. The number and distribution of susceptible hosts determines disease transmission opportunities, shifting the epidemiological threshold between the spread and fadeout of a disease. Similarly, the presence and diversity of other hosts, pathogens and environmental microbes, may inhibit or accelerate an epidemic. This has important applied implications in farming environments, where high numbers of susceptible hosts are maintained in conditions of minimal environmental heterogeneity. We investigated how the quantity and quality of aquaculture enrichments (few vs. many stones; clean stones vs. stones conditioned in lake water) influenced the severity of infection of a pathogenic bacterium, Flavobacterium columnare, in salmonid fishes. We found that the conditioning of the stones significantly increased host survival in rearing tanks with few stones. A similar effect of increased host survival was also observed with a higher number of unconditioned stones. These results suggest that a simple increase in the heterogeneity of aquaculture environment can significantly reduce the impact of diseases, most likely operating through a reduction in pathogen transmission (stone quantity) and the formation of beneficial microbial communities (stone quality). This supports enriched rearing as an ecological and economic way to prevent bacterial infections with the minimal use of antimicrobials.

Research on Signal Timing Method of Intersection Based on RFID

2011 ◽  
Vol 84-85 ◽  
pp. 410-414
Author(s):  
Wei He ◽  
Jie Xiong
Keyword(s):  
Comparative Analysis ◽  
Radio Frequency Identification ◽  
Main Parameter ◽  
Control Method ◽  
Research Work ◽  
Signal Timing ◽  
Key Points ◽  
Frequency Identification ◽  
New Research ◽  
Radio Frequency Identification Devices

Based on the RFID (Radio Frequency Identification Devices), this paper presents new research work of signal timing intersection in the aspects of the key points of design, the main parameter and timing methods. Finally, the intersection of signal timing of fuzzy control method based on RFID is proposed through comparative analysis of the intersection of several traditional signal timing methods.

An electrohydrodynamic (EHD) printing method with nanosilver ink for flexible electronics

2020 ◽  
Vol 34 (17) ◽  
pp. 2050154
Author(s):  
Xinyu Zhang ◽  
Xiang Chi ◽  
Zongan Li ◽  
Zhe Yuan ◽  
Jiquan Yang ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Radio Frequency Identification ◽  
Dc Voltage ◽  
Air Supply ◽  
Frequency Identification ◽  
Printing System ◽  
High Flexibility ◽  
Radio Frequency Identification Devices ◽  
Printing Method ◽  
Text Condition

In this paper, the electrohydrodynamic (EHD) printing method for the flexible electronics with nanosilver ink was studied. The effect of DC voltage and air pressure on the printed nanosilver line was experimentally researched on the printing system. The necessary working voltage was above 600 V DC voltage, and when the voltage reached 1100 V, the line width increased from [Formula: see text] to [Formula: see text]. The air supply of [Formula: see text] resulted an obviously larger width than that of [Formula: see text], but the printing process was unstable on the [Formula: see text] condition. The EHD printing was applied to realize nanosilver ink line ranged from [Formula: see text] to [Formula: see text] and a kind of antenna pattern for radio frequency identification devices (RFID) was fabricated. This kind of EHD printing method has the advantages of high flexibility and printing resolution and shows potential prospects in the field of flexible electronics.

scholarly journals Dynamics of Conjunctivitis and Mycoplasma Gallisepticum Infections in House Finches

The Auk ◽  
2001 ◽  
Vol 118 (2) ◽  
pp. 327-333 ◽  
Author(s):  
Barry K. Hartup ◽  
Jean M. Bickal ◽  
Andre A. Dhondt ◽  
David H. Ley ◽  
George V. Kollias
Keyword(s):  
Breeding Season ◽  
Annual Variation ◽  
Seasonal Fluctuation ◽  
Host Density ◽  
Mycoplasma Gallisepticum ◽  
Disease Prevalence ◽  
Significant Decline ◽  
Carpodacus Mexicanus ◽  
House Finch ◽  
House Finches

Abstract Conjunctivitis, an infectious disease caused by Mycoplasma gallisepticum (MG), has produced a significant decline in eastern House Finches (Carpodacus mexicanus) of North America. In this paper, we present findings from two complementary studies designed to clarify annual and seasonal trends of MG infections in House Finches from the northeastern United States. The first was a field study of House Finches common to urban and residential habitat from Mercer County, New Jersey. We documented conjunctivitis in 11% (188/1,651) of the birds examined. Conjunctivitis prevalence in House Finches ranged from 0 to 43% per month, and exhibited marked seasonal fluctuation (elevations during fall and winter months and lower disease prevalence during the breeding season). There was excellent intermethod agreement on disease prevalence when measured by either presence of physical signs (conjunctivitis) or MG infection (kappa = 0.75). During the peak of the breeding season (April through June), conjunctivitis was present in a greater proportion of males lacking a cloacal protuberance than males with a cloacal protuberance (P < 0.01), but was similar between breeding and nonbreeding females. The second study, a volunteer survey, revealed the proportion of northeastern U.S. monitoring sites with at least one diseased House Finch each month ranged from a peak of 59% (August 1995) to a minimum of 12% (July 1999). Subsequent to the epidemic peak of disease in 1995, a series of recurring cycles occurred, with elevations in those proportions noted in late fall and winter and minima during the breeding season. Mycoplasmal conjunctivitis now appears endemic among House Finches of that region and demonstrates dynamics consistent with annual variation in host density.

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