Population dynamics under parasitic sex ratio distortion.
We analyse the population dynamic effects of sex ratio distortion by vertically transmitted, feminizing parasites. We show that, for diploid hosts, sex ratio distortion may lead to extinction as males become too rare to maintain the host population through reproduction. Feminizers can magnify Allee effects, broadening the range of conditions leading to extinction of small populations. Depending on male mating constraints and strength of density dependence, feminizers may either increase or decrease the equilibrium host density. Under conditions leading to deterministic host extinction, stochastic elimination of the parasite may allow the host population to recover. Hence, infection by parasitic sex ratio distorters may be transient in finite populations. We consider the implications of this process for parasite prevalence, host population regulation, and sex ratio evolution.
Hatcher
M J
MJ
School of Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom.
Taneyhill
D E
DE
Dunn
A M
AM
Tofts
C
C
D000818:Animals; D005075:Biological Evolution; D003445:Crustacea / Q000235:genetics / Q000469:parasitology / Q000502:physiology; D005111:Extrachromosomal Inheritance / Q000235:genetics*; D005260:Female; D005262:Feminization / Q000235:genetics; D005828:Genetics, Population; D006790:Host-Parasite Interactions / Q000235:genetics*; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D008957:Models, Genetic; D010273:Parasitic Diseases, Animal / Q000453:epidemiology / Q000235:genetics* / Q000635:transmission*; D011157:Population Dynamics; D011237:Predictive Value of Tests; D015995:Prevalence; D015203:Reproducibility of Results; D012098:Reproduction; D012744:Sex Ratio; D013269:Stochastic Processes