scholarly journals Cascading effects of predator activity on tick-borne disease risk

2017 ◽  
Vol 284 (1859) ◽  
pp. 20170453 ◽  
Author(s):  
Tim R. Hofmeester ◽  
Patrick A. Jansen ◽  
Hendrikus J. Wijnen ◽  
Elena C. Coipan ◽  
Manoj Fonville ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Disease Risk ◽  
Predator Species ◽  
Cascading Effects ◽  
Path Analyses ◽  
Mammalian Predators ◽  
Tick Borne Disease ◽  
Predator Abundance ◽  
Larval Burden ◽  
Tick Burden

Predators and competitors of vertebrates can in theory reduce the density of infected nymphs (DIN)—an often-used measure of tick-borne disease risk—by lowering the density of reservoir-competent hosts and/or the tick burden on reservoir-competent hosts. We investigated this possible indirect effect of predators by comparing data from 20 forest plots across the Netherlands that varied in predator abundance. In each plot, we measured the density of questing Ixodes ricinus nymphs (DON), DIN for three pathogens, rodent density, the tick burden on rodents and the activity of mammalian predators. We analysed whether rodent density and tick burden on rodents were correlated with predator activity, and how rodent density and tick burden predicted DON and DIN for the three pathogens. We found that larval burden on two rodent species decreased with activity of two predator species, while DON and DIN for all three pathogens increased with larval burden on rodents, as predicted. Path analyses supported an indirect negative correlation of activity of both predator species with DON and DIN. Our results suggest that predators can indeed lower the number of ticks feeding on reservoir-competent hosts, which implies that changes in predator abundance may have cascading effects on tick-borne disease risk.

Effects of habitat and introduced mammalian predators on the breeding success of Yellow-eyed Penguins Megadyptes antipodes, South Island, New Zealand

1999 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Hiltrun Ratz ◽  
Brian Murphy
Keyword(s):  
New Zealand ◽  
Breeding Success ◽  
East Coast ◽  
Marked Effect ◽  
Forest Edge ◽  
Introduced Predators ◽  
Mammalian Predators ◽  
Predator Abundance ◽  
Breeding Seasons ◽  
Predator Guild

The endemic Yellow-eyed Penguin Megadyptes antipodes is threatened by habitat loss and introduced predators on mainland New Zealand. Nine colonies in the Catlins (south-east coast of South Island) were studied to measure breeding success, penguin abundance, and predator abundance in three successive breeding seasons (1991/92 to 1993/94). Nest numbers increased in all nine colonies in the three years despite predation (probably by Stoats Mustefa erminea) being the most important cause of breeding failure. Larger colonies with higher breeding success were in small gullies with limited shrubs and bushes rather than in the most intact mature forest colonies hitherto assumed to be optimal habitat for the birds. Penguin nests were concentrated near the forest edge, but predators were not, so the predation risk was not elevated near the forest edge. Fragmentation of the original forest habitat had no observable adverse effect on breeding success. Stoats dominated the predator guild, while Ferrets M. furo and Feral Cats Felis catus were rare. Trapping to kill predators early in the season had no marked effect on subsequent predation losses, but trapping intervention when a predation outbreak occurred curtailed further chick deaths. A simple population model predicts that Yellow-eyed Penguins populations will grow provided the average total chicks loss is less than 43% per season, or at least 0.85 chick per nest fledges each year. This requires predation losses to be less than 34%.

Valuation when baselines are changing: Tick-borne disease risk and recreational choice

2019 ◽  
Vol 58 ◽  
pp. 101119
Author(s):  
Daniel Slunge ◽  
Thomas Sterner ◽  
Wiktor Adamowicz
Keyword(s):  
Disease Risk ◽  
Tick Borne Disease

scholarly journals Invasive honeysuckle eradication reduces tick-borne disease risk by altering host dynamics

2010 ◽  
Vol 107 (43) ◽  
pp. 18523-18527 ◽  
Author(s):  
B. F. Allan ◽  
H. P. Dutra ◽  
L. S. Goessling ◽  
K. Barnett ◽  
J. M. Chase ◽  
...  
Keyword(s):  
Disease Risk ◽  
Tick Borne Disease

scholarly journals Evaluating the utility of camera traps in field studies of predation

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6487 ◽  
Author(s):  
Christopher K. Akcali ◽  
Hibraim Adán Pérez-Mendoza ◽  
David Salazar-Valenzuela ◽  
David W. Kikuchi ◽  
Juan M. Guayasamin ◽  
...  
Keyword(s):  
Observational Data ◽  
Video Recording ◽  
Field Studies ◽  
Camera Traps ◽  
Relative Fitness ◽  
Natural Habitats ◽  
Predator Species ◽  
Additional Information ◽  
Relative Contribution ◽  
Mammalian Predators

Artificial prey techniques—wherein synthetic replicas of real organisms are placed in natural habitats—are widely used to study predation in the field. We investigated the extent to which videography could provide additional information to such studies. As a part of studies on aposematism and mimicry of coral snakes (Micrurus) and their mimics, observational data from 109 artificial snake prey were collected from video-recording camera traps in three locations in the Americas (terra firme forest, Tiputini Biodiversity Station, Ecuador; premontane wet forest, Nahá Reserve, Mexico; longleaf pine forest, Southeastern Coastal Plain, North Carolina, USA). During 1,536 camera days, a total of 268 observations of 20 putative snake predator species were recorded in the vicinity of artificial prey. Predators were observed to detect artificial prey 52 times, but only 21 attacks were recorded. Mammals were the most commonly recorded group of predators near replicas (243) and were responsible for most detections (48) and attacks (20). There was no difference between avian or mammalian predators in their probability of detecting replicas nor in their probability of attacking replicas after detecting them. Bite and beak marks left on clay replicas registered a higher ratio of avian:mammalian attacks than videos registered. Approximately 61.5% of artificial prey monitored with cameras remained undetected by predators throughout the duration of the experiments. Observational data collected from videos could provide more robust inferences on the relative fitness of different prey phenotypes, predator behavior, and the relative contribution of different predator species to selection on prey. However, we estimate that the level of predator activity necessary for the benefit of additional information that videos provide to be worth their financial costs is achieved in fewer than 20% of published artificial prey studies. Although we suggest future predation studies employing artificial prey to consider using videography as a tool to inspire new, more focused inquiry, the investment in camera traps is unlikely to be worth the expense for most artificial prey studies until the cost:benefit ratio decreases.

scholarly journals Extinctions and threats to avifaunas on oceanic islands: Tests of influences of human populations and the filter effect

2015 ◽  
Author(s):  
Heather Zimbler-DeLorenzo ◽  
Bertram Zinner ◽  
Ronald J Scheibel ◽  
F. Stephen Dobson
Keyword(s):  
Population Size ◽  
Threatened Species ◽  
Human Population ◽  
Bird Species ◽  
Oceanic Islands ◽  
Human Populations ◽  
Partial Regression Coefficient ◽  
Predator Species ◽  
Filter Effect ◽  
Mammalian Predators

Extinctions and threats of extinctions in avifaunas on oceanic islands appear to be influenced by several island characteristics and introduced mammalian predators. These predators may have caused a “filter effect”; low numbers of threatened avian species on some islands might be due to high rates of past extinctions. Using path analysis, we examined these factors and the influence of human population size (as an indicator of human activity) on the number of species extinctions and threatened bird species on islands. Human population size had substantial influences on the number of extinctions (standardized partial regression coefficient ρ = 0.315, N = 172, P = 0.0005) but not on the number of threatened species on oceanic islands (ρ = -0.061, P = 0.43), independent of the number of introductions of predator species. The number of extinctions on islands produced a significant filter effect (viz., had a negative impact; ρ = -0.186, P = 0.003) on the number of currently threatened species. The activities of human populations, including mammalian predators they introduced, have likely resulted in a greater number of bird extinctions on these islands, and producing a significant filter effect, wherein islands with larger human populations now have fewer threatened species.

Effect of Urbanization on Presence, Abundance, and Coinfection of Bacteria and Protozoa in Ticks in the US Great Plains

2022 ◽  
Author(s):  
Bruce H Noden ◽  
Megan A Roselli ◽  
Scott R Loss
Keyword(s):  
Great Plains ◽  
Urban Areas ◽  
Disease Risk ◽  
Natural Ecosystems ◽  
Public Health Importance ◽  
Rickettsia Parkeri ◽  
Tick Abundance ◽  
Tick Infection ◽  
Tick Borne Disease ◽  
Microbe Diversity

Abstract Urbanization alters components of natural ecosystems which can affect tick abundance and tick-borne disease prevalence. Likely due to these changes, tick-borne pathogen prevalence has increased in many U.S. urban areas. Despite the growing public health importance of tick-borne diseases, little is known about how they are influenced by urbanization in North America, especially in the central U.S. where several pathogens occur at or near their highest levels of incidence nationally. To determine whether urban development influences tick infection with bacteria and protozoa, we collected ticks at 16 parks across a gradient of urbanization intensity in Oklahoma City, Oklahoma, USA and tested them using a variety of PCR assays. Adult ticks tested positive for Rickettsia parkeri, R. amblyommatis, R. rhiphicephali, ‘Candidatus R. andeanae’, Ehrlichia chaffeensis, E. ewingii, Panola Mountain Ehrlichia, ‘Borrelia lonestari’, Theileria cervi, Babesia spp. Coco, and Cytauxzoon felis. These results indicate the presence of a high diversity of tick-borne bacteria and protozoa across an expanding urban area in the U.S. Great Plains. Although there appeared to be some risk of encountering tick-borne microorganisms across the entire urbanization gradient, E. chaffeensis, E. ewingii, and T. cervi-infected ticks and microbe diversity decreased with increasing urbanization intensity. We identified a low rate of coinfection between different microorganisms, with coinfected ticks mainly collected from sites in the least-urbanized areas. This study suggests the need for awareness of tick-borne disease risk throughout urban areas in the central U.S., and highlights a need for studies of tick host habitat use and movement in cities.

GIS tools for tick and tick-borne disease occurrence

Parasitology ◽  
2004 ◽  
Vol 129 (S1) ◽  
pp. S329-S352 ◽  
Author(s):  
M. DANIEL ◽  
J. KOLÁŘ ◽  
P. ZEMAN
Keyword(s):  
Disease Surveillance ◽  
Disease Risk ◽  
Disease Outbreaks ◽  
Landscape Characterization ◽  
Gis Tools ◽  
Disease Occurrence ◽  
Tick Ecology ◽  
Computer Based ◽  
Tick Borne Disease ◽  
Data Location

Geographic information systems (GIS), their fundamental components and technologies are described. GIS is a computer-based system enabling the storage, integration, query, display and analysis of data using information on data location. Further, remote sensing (RS) methods and their application in landscape characterization are described. Landscape pattern analysis, combined with statistical analysis, allows the determination of landscape predictors of disease risk. This makes RS/GIS a powerful set of tools for disease surveillance, enabling the prediction of potential disease outbreaks and targeting intervention programs. The ‘pre-GIS era’ is briefly described including the early mapping of tick distribution, analyses and the display of biogeographical and medical data. The theory of natural focality of diseases (NFD) is explained and its significance in tick-borne diseases (TBD) research is discussed. Many problems of tick ecology and TBD epidemiology and epizootology have been addressed by means of GIS and examples of these studies are presented and discussed.

Predation on simulated duck nests in relation to nest density and landscape structure

2010 ◽  
Vol 37 (7) ◽  
pp. 597 ◽  
Author(s):  
Eliška Padyšáková ◽  
Martin Šálek ◽  
Lukáš Poledník ◽  
František Sedláček ◽  
Tomáš Albrecht
Keyword(s):  
Survival Rates ◽  
Predation Rate ◽  
High Density ◽  
Nest Density ◽  
Predator Species ◽  
Density Dependent ◽  
Landscape Type ◽  
Mammalian Predators ◽  
Littoral Vegetation ◽  
Nest Predator

Context Density-dependent predation has been recently discussed as a contributing cause of duck nest failure. Aims We tested whether nest density increases the nest predation rate (density-dependent predation) in patches of littoral vegetation surrounding fishponds in two contrasting landscape types, the first dominated by forest and the other dominated by agricultural fields. Methods In total, 576 simulated ground nests were deployed in 48 littoral patches in South Bohemia, Czech Republic, in two replicates (June and July), for two consecutive years (2005 and 2006). Nests were deployed either solitarily (low-density plots) or in groups of five nests (high-density plots). Key results Despite differences in local predator communities, we found no evidence of different survival rates of solitary nests and nests placed in high-density patches in either habitat. Mammalian predators were the most common nest predators, followed by birds. The composition of nest predator community depended on landscape type, with mammals predominating in forest landscape and birds in agricultural areas. Our data thus do not support the theory of density-dependent predation of duck nests in littoral patches, regardless of predominant nest predator type. Conclusions Based on our results, we conclude that nest predator responses to different habitats are complex, taxon specific, and context dependent. Implications Conservation efforts for waterfowl may need to be customised according to the nest-predator species primarily responsible for local nest mortality and the nature of the landscape mosaic.

scholarly journals A 117 year retrospective analysis of Pennsylvania tick community dynamics

2018 ◽  
Author(s):  
Damie Pak ◽  
Steven B. Jacobs ◽  
Joyce M. Sakamoto
Keyword(s):  
Retrospective Analysis ◽  
Community Composition ◽  
Tick Species ◽  
Temporal Dynamics ◽  
Disease Risk ◽  
Dermacentor Variabilis ◽  
Disease Spread ◽  
Disease Case ◽  
Tick Borne Disease

AbstractBackgroundTick-borne diseases have been increasing at the local, national, and global levels. Researchers studying ticks and tick-borne disease need a thorough knowledge of the pathogens, vectors, and epidemiology of disease spread. Three surveillance approaches are commonly used to provide insight into tick-borne disease risk: human disease case surveillance, active tick surveillance, and passive tick surveillance. Long-term passive surveillance can provide up-to-date data on the spatial variability and temporal dynamics of ectoparasite communities and shed light into the ecology of rarer tick species. We present a retrospective analysis on compiled data of ticks from Pennsylvania over the last 117 years.MethodsWe compiled data from ticks collected during tick surveillance research, and from citizen-based submissions to the Penn State University Department of Entomology (PSUEnt). Specimens were deposited at the PSUEnt arthropod collections that eventually became The Frost Entomological Museum. While most of the specimens were submitted by the public, a subset of the data were collected through active methods (flagging or dragging, or removal of ticks from wildlife). We analyzed all data from 1900-2017 for tick community composition, host associations, and spatio-temporal dynamics.ResultsIn total there were 4,491 submission lots consisting of 7,132 tick specimens. Twenty-four different species were identified, with the large proportion of submissions represented by five tick species. We observed a shift in tick community composition in which the dominant species of tick (Ixodes cookei) was overtaken in abundance byDermacentor variabilisin the early 1990s, and then replaced in abundance byI. scapularis. We analyzed host data and identified overlaps in host range amongst tick species, suggesting potential hubs of pathogen transfer between different tick vectors and their reservoir hosts.ConclusionsWe highlight the importance of long-term passive tick surveillance in investigating the ecology of both common and rare tick species. Information on the geographic distribution, host-association, and seasonality of the tick community can help researchers and health-officials to identify high-risk areas.

Long-Term Study of Borrelia and Babesia Species Distribution in Ixodes Ricinus and Dermacentor Recticulatus Ticks Removed From Humans in Poland, 2016-2019

2021 ◽  
Author(s):  
Renata Welc-Falęciak ◽  
Małgorzata Bednarska ◽  
Adrianna Hamera ◽  
Emilia Religa ◽  
Milena Poryszewka ◽  
...  
Keyword(s):  
Disease Risk ◽  
Babesia Species ◽  
Term Study ◽  
Important Indicator ◽  
Long Term Study ◽  
Questing Ticks ◽  
Tick Borne Disease ◽  
Larger Sample ◽  
Better Than

Abstract Monitoring changes in the prevalence of different Borrelia genospecies/ species in ticks might be an important indicator of risk assessment and of differences in pathogenicity in humans. Furthermore, the evaluation of pathogens in feeding ticks represents the risk of human exposure better than studies on questing ticks. The objective of our study was to assess the prevalence and distribution of Borrelia and Babesia species in ticks removed from humans, in a larger sample collected for several months during four years of studies. We confirmed high Borrelia prevalence, including B. miyamotoi, in ticks removed from humans as well as the shift in Borrelia genospecies/ species frequency of occurrence during the four-year study. Despite the fact that Babesia prevalence was relatively low, the majority of tested isolates are considered to be pathogenic for humans. The results of our study have also shown that Borrelia and Babesia coinfections in ticks are more common in Borrelia-infected ticks. Even if the overall risk of developing Lyme borreliosis after a tick bite in Europe is rather low, the knowledge of prevalence and distribution of Borrelia and Babesia species in ticks might be an important indicator of both tick-borne disease risk and pathogenicity assessment.

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