Evolution of body size is likely to involve trade-offs between body size, growth rate and longevity. Within species, larger body size is associated with faster growth and ageing, and reduced longevity, but the cellular processes driving these relationships are poorly understood. One mechanism that might play a key role in determining optimal body size is the relationship between body size and t...

We evaluated the possible use of a sexually dimorphic plumage trait as a status signal in interand intrasexual social interactions in free-living house sparrows, Passer domesticus. Males with larger black throat patches (bibs) tended to be dominant regardless of the opponent’s sex. This relationship was maintained after controlling for body size and age in multivariate analyses. However, the na...

Serial samples from the same individuals may be required for certain virological studies, however, some small animals cannot easily be blood-sampled. Therefore, we evaluated the use of Culex quinquefasciatus Say and Aedes albopictus Skuse mosquitoes as "biological syringes" to draw blood for virus titer determinations in small vertebrates. Groups of chicks (Gallus gallus), hamsters (Mesocricetu...

Waterfowl and shorebirds are well-recognized natural reservoirs of low-pathogenicity avian influenza viruses (LPAIV); however, little is known about the role of passerines in avian influenza virus ecology. Passerines are abundant, widespread, and commonly come into contact with free-ranging birds as well as captive game birds and poultry. We inoculated and subsequently challenged house sparrows...

Gonadotropin inhibitory hormone (GnIH) inhibits gonadotropin release in vitro in a dose-dependent manner (Tsutsui et al., 2000). In the present study, we investigated the relative neural distributions of GnRH and GnIH, and in vivo activity of exogenous GnIH in song sparrows (Melospiza melodia) and house sparrows (Passer domesticus). Using immunocytochemistry (ICC), GnIH-containing neurons were ...