Population Dynamics of Chewing Lice (Phthiraptera) Infesting Birds (Aves)

Abstract

In the past 25 years, studies on interactions between chewing lice and their bird hosts have increased notably. This body of work reveals that sampling of live avian hosts, collection of the lice, and the aggregated distributions of louse infestations pose challenges for assessing louse populations. The number of lice on a bird varies among host taxa, often with host size and social system. Host preening behavior limits louse abundance, depending on bill shape. The small communities of lice (typically one–four species) that live on individual birds show species-specific patterns of abundance, with consistently common and rare species, and lower year-to-year population variability than other groups of insects. Most species of lice appear to breed continuously on their hosts, with seasonal patterns of abundance sometimes related to host reproduction and molting. Competition may have led to spatial partitioning of the host by louse species, but seldom contributes to current patterns of abundance.

Infestation parameters for chewing lice (Phthiraptera: Amblycera, Ischnocera) parasitising true thrushes (Aves: Passeriformes: Turdidae) in Manitoba, Canada

“…In almost all cases, the sex ratio of male to female lice for Manitoba thrushes was less than 1.0, regardless of whether the lice were Amblycera or Ischnocera, as often observed for chewing lice on passeriform birds (Marshall 1981;Clayton et al 1992;Galloway and Lamb 2021). The sex ratio in R. elongatus was particularly low: out of 89 adult lice collected from 570 American robins, only eight were males.…”

“…Louse populations show seasonal patterns of abundance on some bird species (Galloway and Lamb 2021), with the pattern more evident for mean intensity than for prevalence (Galloway and Lamb 2015). For all three species of Manitoba thrushes, American robin, Swainson's thrush, and hermit thrush, where sample size was sufficiently large, migrating birds arriving in spring carried more lice than those migrating south in autumn.…”

Population Diversity of Chewing Lice (Phthiraptera) Infesting Ducks and Geese (Family Anatidae) in Southeast Parts of Pakistan

“…3.33±0.614 (Table 2; Figure 3). The gender-wise population was also checked to determine the reproductive capability of these lice species, as the female population is always observed higher than males and the nymphal population is higher than adults (Hamstra and Badyaev, 2009;Naz et al, 2010;Kumar et al, 2013;Ahmad et al, 2015;Begum et al, 2019;Siyal et al, 2019;Galloway and Lamb, 2021); in the present study, 137 males, 178 females and 90 nymphs were collected; the sex ratio showed the similar results, but age ratio showed the abundance of nymphs is lower than adults (Table 2). This factor may be affected by the weathering conditions, as the climate of Sindh province is normally getting more dry, warm and windy, especially near the water bodies.…”

“…The water in the lakes and rivers of Sindh become dry or has less water during most of the summer season spanning about 7 months of the year and the temperature reaches up to 45-50℃ (Khan and Gadiwala, 2013; Abbas et al, 2018;Umar et al, 2018). Hence, it is possible that due to the sandy airy parts near the rivers and lakes like River Indus, the fine particles of dust and sand can penetrate the feathers and help the birds to eliminate the lice, especially the young nymphs that have a weak grip on feathers of their hosts (Clayton et al, 2010;Grossi, 2013;Bush and Clayton, 2018;Galloway and Lamb, 2021). The effects of average humidity and temperature of the study sites were also observed (Table 3) that where the humidity was low with the rise of temperature, the abundance of the lice population was recorded relatively higher (Figures 3a and 3b).…”

“…There have been many studies conducted on the population distribution of the chewing lice on various birds of the order Anseriformes, conducted all over the world, focusing on the abundance, mean intensity of infestation and prevalence of lice in birds, however, the seasonal variations in the population of lice have also been studied on these birds (Buscher, 1965;Canaris et al, 1981;Thul, 1985;Hinojosa-Sáez et al, 2009;Naz et al, 2010;Grossi, 2013;Kumar et al, 2013;Ahmad et al, 2015;Bulgarella et al, 2018;Galloway and Lamb, 2021). The variation in the temperature and humidity corresponds to the change in the population of lice and increases the rate and intensity of the infestation of these important commodities.…”