scholarly journals Long-term trends in helminth infections of wood mice (Apodemus sylvaticus) from the vicinity of Malham Tarn in North Yorkshire, England

Parasitology ◽  
2020 ◽  
pp. 1-13
Author(s):  
Jerzy M. Behnke ◽  
Michael T. Rogan ◽  
Philip S. Craig ◽  
Joseph A. Jackson ◽  
Geoff Hide

Abstract Helminth infections in wood mice (n = 483), trapped over a period of 26 years in the woods surrounding Malham Tarn in North Yorkshire, were analysed. Although 10 species of helminths were identified, the overall mean species richness was 1.01 species/mouse indicating that the helminth community was relatively depauperate in this wood mouse population. The dominant species was Heligmosomoides polygyrus, the prevalence (64.6%) and abundance (10.4 worms/mouse) of which declined significantly over the study period. Because of the dominance of this species, analyses of higher taxa (combined helminths and combined nematodes) also revealed significantly declining values for prevalence, although not abundance. Helminth species richness (HSR) and Brillouin's index of diversity (BID) did not show covariance with year, neither did those remaining species whose overall prevalence exceeded 5% (Syphacia stroma, Aonchotheca murissylvatici and Plagiorchis muris). Significant age effects were detected for the prevalence and abundance of all higher taxa, H. polygyrus and P. muris, and for HSR and BID, reflecting the accumulation of helminths with increasing host age. Only two cases of sex bias were found; male bias in abundance of P. muris and combined Digenea. We discuss the significance of these results and hypothesize about the underlying causes.

Parasitology ◽  
2008 ◽  
Vol 135 (7) ◽  
pp. 751-766 ◽  
Author(s):  
J. M. BEHNKE

SUMMARYExperimental data establish that interactions exist between species of intestinal helminths during concurrent infections in rodents, the strongest effects being mediated through the host's immune responses. Detecting immune-mediated relationships in wild rodent populations has been fraught with problems and published data do not support a major role for interactions in structuring helminth communities. Helminths in wild rodents show predictable patterns of seasonal, host age-dependent and spatial variation in species richness and in abundance of core species. When these are controlled for, patterns of co-infection compatible with synergistic interactions can be demonstrated. At least one of these, the positive relationship betweenHeligmosomoides polygyrusand species richness of other helminths has been demonstrated in three totally independent data-sets. Collectively, they explain only a small percentage of the variance/deviance in abundance data and at this level are unlikely to play a major role in structuring helminth communities, although they may be important in the more heavily infected wood mice. Current worm burdens underestimate the possibility that earlier interactions through the immune system have taken place, and therefore interactions may have a greater role to play than is immediately evident from current worm burdens. Longitudinal studies are proposed to resolve this issue.


2006 ◽  
Vol 51 (4) ◽  
Author(s):  
Catarina Eira ◽  
Jordi Torres ◽  
José Vingada ◽  
Jordi Miquel

AbstractThis paper presents the first extensive data on the helminth community of the wood mouse Apodemus sylvaticus in a coastal sand dune area in Portugal. The 557 hosts analysed in this study were trapped seasonally between autumn 2002 and summer 2005 across 6 habitat types. Twelve helminth species were detected among which, Taenia parva larvae, Angiostrongylus dujardini, Heligmosomoides polygyrus, Syphacia stroma and S. frederici constitute the component species, accounting for 98.7% of all worms. H. polygyrus was the most prevalent helminth parasite. Species richness varied according to habitat and season. The highest species richness was found in sand dunes during winter whereas the lowest was detected along lake margins also during the winter. Some differences in prevalence and mean intensity values were found in relation to year (T. parva larvae and H. polygyrus), habitat (A. dujardini), season (T. parva larvae, H. polygyrus, A. dujardini and S. stroma) and host sex (T. parva larvae and S. stroma). These differences are discussed both in view of the host’s biology and habitat characteristics.


2013 ◽  
Vol 50 (1) ◽  
pp. 27-38 ◽  
Author(s):  
I. Torre ◽  
A. Arrizabalaga ◽  
C. Feliu ◽  
A. Ribas

AbstractParasites have been recognized as indicators for natural or man-induced environmental stress and perturbation. In this article, we investigated the role of two non-exclusive hypotheses on the response of helminths of wood mice to fire perturbation: 1) a reduction of the helminth infracommunity (species richness) in post-fire areas due to the temporal lack of worms with indirect (complex) life cycles linked to intermediate hosts that are more specialized than the final host, and 2) an increase of the abundance of helminths with direct (simple) life cycles as a response of increasing abundances of the final host, may be in stressful conditions linked to the post-fire recolonization process.We studied the helminth infracommunities of 97 wood mice in two recently burned plots (two years after the fire) and two control plots in Mediterranean forests of NE Spain. Species richness of helminths found in control plots (n = 14) was twice large than in burned ones (n = 7). Six helminth species were negatively affected by fire perturbation and were mainly or only found in unburned plots. Fire increased the homogeneity of helminth infracommunities, and burned plots were characterised by higher dominance, and higher parasitation intensity. We found a gradient of frequency of occurrence of helminth species according to life cycle complexity in burned areas, being more frequent monoxenous (66.6 %), than diheteroxenous (33.3 %) and triheteroxenous (0 %), confirming the utility of helminths as bioindicators for ecosystem perturbations. Despite the short period studied, our results pointed out an increase in the abundance and prevalence of some direct life cycle helminths in early postfire stages, whereas indirect life cycle helminths were almost absent. A mismatch between the final host (that showed a fast recovery shortly after the fire), and the intermediate hosts (that showed slow recoveries shortly after the fire), was responsible for the loss of half of the helminth species.


2013 ◽  
Vol 88 (3) ◽  
pp. 310-320 ◽  
Author(s):  
K. Boyce ◽  
G. Hide ◽  
P.S. Craig ◽  
C. Reynolds ◽  
M. Hussain ◽  
...  

AbstractThe prevalence of the digeneanPlagiorchissp. was investigated in a natural wood mouse population (Apodemus sylvaticus) in a periaquatic environment. Classical identification was complemented with the use of molecular differentiation to determine prevalence and verify species identity. Use of the complete ITS1-5.8S rDNA-ITS2 and partial 28S rDNA gene sequences have confirmed that the species reported at this location wasPlagiorchis elegansand notPlagiorchis murisas reported previously. This underlines the difficulties in identification of these morphologically similar parasites.Plagiorchis elegansis typically a gastrointestinal parasite of avian species but has also been reported from small mammal populations. Although the occurrence of this digenean inA. sylvaticusin the UK is rare, in the area immediately surrounding Malham Tarn, Yorkshire, it had a high prevalence (23%) and a mean worm burden of 26.6 ± 61.5. The distribution ofP. elegansfollowed a typically overdispersed pattern and both mouse age-group and sex were determined to be two main factors associated with prevalence. Male mice harboured the majority of worms, carrying 688 of 717 recovered during the study, and had a higher prevalence of 32.4% in comparison to only 8.7% in the small intestine of female mice. A higher prevalence of 43% was also observed in adult mice compared to 14% for young adults. No infection was observed in juvenile mice. These significant differences are likely to be due to differences in the foraging behaviour between the sexes and age cohorts of wood mice.


2015 ◽  
Vol 21 (7) ◽  
pp. 792-802 ◽  
Author(s):  
Anne Eskildsen ◽  
Luísa G. Carvalheiro ◽  
W. Daniel Kissling ◽  
Jacobus C. Biesmeijer ◽  
Oliver Schweiger ◽  
...  

2006 ◽  
Vol 17 (3) ◽  
pp. 316-334 ◽  
Author(s):  
David W. Steadman ◽  
Sharyn Jones

AbstractWe compare the bone assemblages of Milford 1 (TOB-3) and Golden Grove (TOB-13) in Tobago, West Indies. Milford 1 is a small preceramic occupation (ca. 3000-2800 cal B.P.), whereas Golden Grove is a large ceramic-period village (ca. 1700-900 cal B.P.). Species richness at TOB-13 is greater than at TOB-3, both in marine (67 vs. 39 fishes) and terrestrial (32 vs. 9) taxa. Major shifts in marine exploitation from the preceramic to ceramic periods can be seen in relative abundance of tuna, toadfishes, and in fishes inhabiting mangrove and brackish water environments, and decreases in relative abundance of parrotfish, carnivorous reef fishes, and sea turtles. The abundance of tuna bones at TOB-13 is uniquely high among West Indian archaeological sites. For terrestrial taxa, the difference in species richness exceeds the expected, including decreased specialization on big game (peccaries) at TOB-13, with a greater tendency to hunt reptiles, birds, and mammals of all sizes at TOB-3. Factors underlying the shifts in fishing and hunting may include different collection methods and food preferences of non-Arawakan (preceramic) vs. Arawakan (ceramic) peoples, as well as human-induced declines in populations of peccaries, sea turtles, and selected fish species. Another possible factor is site setting, with the inhabitants of TOB-13 having enhanced access to mangrove habitats.


Author(s):  
N. V. Kiseleva

In the birch-pine forests of the Ilmeny Reserve the bank vole is predominated by numbers, the pygmy wood mice being in the second place. The results of our monitoring of the numbers of these rodents for 27 years (1991–2018) are presented. 1,610 rodents were caught,of which the bank vole accounted for 52.6%, the pygmy wood mouse for 32%, and other species for 15.4%. The autumn abundance of the bank vole was 4.6±1.8 and 18.9±2.6 ind./100 trap-days for 1991–1999 and 2000 – 2018, respectively; that of the pygmy wood mouse was 2.1±1.9 and 18.9±2.6 ind./100 trap-days, respectively. Since 2000, the peak amplitude of the bank vole number has increased by 1.1– 2.5 times, that of the pygmy wood mouse has increased by 2.5–4.2 times. Since 2006, the number peaks of these rodents began to repeat after 2–3 years. Over eighteen years (2000–2018), the autumn abundance of the bank vole twice (2008 and 2017) reached its peak values, at which the reproduction of voles ceased in July or early August. The correlation coefficient of the autumn abundance of the bank vole and pygmy wood mouse for 1996–2018 was 0.64±0.1. The spring abundance of the pygmy wood mouse has begun to more often exceed the spring abundance of the bank vole. Changes in the population cycles of the bank vole and pygmy wood mouse were obviously associated with some climatic features of the recent decades.


Parasitology ◽  
2009 ◽  
Vol 136 (7) ◽  
pp. 793-804 ◽  
Author(s):  
J. M. BEHNKE ◽  
C. EIRA ◽  
M. ROGAN ◽  
F. S. GILBERT ◽  
J. TORRES ◽  
...  

SUMMARYWe analysed 3 independently collected datasets of fully censused helminth burdens in wood mice,Apodemus sylvaticus, testing thea priorihypothesis of Behnkeet al.(2005) that the presence of the intestinal nematodeHeligmosomoides polygyruspredisposes wood mice to carrying other species of helminths. In Portugal, mice carryingH. polygyrusshowed a higher prevalence of other helminths but the magnitude of the effect was seasonal. In Egham, mice withH. polygyrusshowed a higher prevalence of other helminth species, not confounded by other factors. In Malham Tarn, mice carryingH. polygyruswere more likely to be infected with other species, but only among older mice. Allowing for other factors, heavy residualH. polygyrusinfections carried more species of other helminths in both the Portugal and Egham data; species richness in Malham was too low to conduct a similar analysis, but asH. polygyrusworm burdens increased, so the prevalence of other helminths also increased. Our results support those of Behnkeet al.(2005), providing firm evidence that at the level of species richness a highly predictable element of co-infections in wood mice has now been defined: infection withH. polygyrushas detectable consequences for the susceptibility of wood mice to other intestinal helminth species.


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