![]() Recently, however, the largest meta-analysis to date revealed that badge size is at best an unreliable signal of dominance status ( Sánchez-Tójar et al., 2018). Large badge size has been thought to convey an individual’s propensity to win in male-male competitive interactions the logic was that possessing information a priori about a competitor could save both the badge-holder and his opponents from wasted energy and risk of injury ( Rohwer, 1975). Arguably, this badge is one of the factors that made this species a model in behavioral ecology ( Sánchez-Tójar et al., 2018). The most conspicuous morphological difference between male and female sparrows is the large black throat badge of males. Image Credits: All images taken by Janneke Case in Tampa, Florida, United States, in 2019. ( D) Male house sparrow provisioning nestlings. This topic remains contentious ( Box 1), but these declines have been attributed to a multitude of factors, including infectious disease, pollution, pesticide use, predator dynamics, new building methodologies and more efficient grain harvesting and storage ( Shaw et al., 2008 Summers-Smith, 2003 Singh et al., 2013 Bell et al., 2010 Dadam et al., 2019). Though still widespread, significant declines have been reported in the native range of the species since the 1970s. A reliance on humans is evident from their colonization of Northern Europe, Eastern Europe and Central Asia in the early 1800s, as agriculture spread and urbanization increased ( Summers-Smith, 1963). However, they also continue to increase their geographic range by exploiting ongoing and accelerating anthropogenic change ( Ravinet et al., 2018 Saetre et al., 2012). ![]() Becoming commensal some 10,000 years ago, house sparrows are now strongly associated with habitats that have been modified by humans. House sparrows are native to parts of Asia, North Africa and most of Europe, (with the exception of Italy which is occupied by the Italian sparrow P. Native distribution and natural range expansions Here, we explore the natural history of house sparrows and the contributions that these birds have made to basic biology and beyond. ![]() Their ubiquity and close association with humans have undoubtedly led to their detailed study across biological and even sociological disciplines. It is for this relationship with people that they received their species identifier domesticus, which derives from the Latin domus or 'house', from Carl Linnaeus in 1758 ( Jobling, 2009 Anderson, 2006). Considered anthrodependent, some populations have gone extinct locally without human presence ( Ravinet et al., 2018 Summers-Smith, 1988). House sparrows can be found living and breeding in climactically extreme environments from deserts in southern California to cities above the Arctic circle, where they are found almost exclusively in close proximity to human habitation ( Hanson et al., 2020b). The species is one of the most widely distributed and common birds in the world, represented by 12 different subspecies ( Summers-Smith, 2009). Flocks tend to break up through the autumn and birds return to their nesting colony sites.House sparrows are small, sexually dimorphic birds in the family Passeridae. Later, rural flocks may move on to grainfields to feed on the ripening grain, often joined by adult birds, once they have finished nesting. These may be areas of wasteland or around garden feeding sites. Newly independent young often gather in large flocks, anywhere there is an abundance of seed, invertebrates and other suitable foods. She can begin laying her next clutch of eggs within days of the previous brood leaving the nest. Post-fledging care is frequently left to the male as the hen prepares for the next brood. ![]() They are unable to feed themselves for about a week after leaving the nest and are cared for by their parents for around a fortnight. The young fledge 14-16 days after hatching. cold weather) and become more important after the chicks leave the nest. Seeds and vegetable matter are also given, particularly during periods when invertebrates are scarce (e.g. The youngsters are fed on a variety of invertebrates, including aphids, caterpillars, beetles and grasshoppers. Chicks are brooded for 6-8 days, but can control their own body temperature only when 10 or 11 days old. The parents share nesting duties equally. Both sexes incubate, and the chicks hatch after 11-14 days. The female lays two to five eggs at daily intervals and often starts to incubate part way through egg-laying.
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