Herpes simplex virus 1 (HSV-1) is a neurotropic DNA virus that is responsible for several clinical manifestations in humans, including encephalitis. HSV-1 triggers toll-like receptors (TLRs), which elicit cytokine production. Viral multiplication and cytokine expression in C57BL/6 wild-type (WT) mice infected with HSV-1 were evaluated. Virus was found in the trigeminal ganglia (TG), but not in the brains of animals without signs of encephalitis, between 2 and 6 days postinfection (d.p.i.). Cytokine expression in the TG peaked at 5 d.p.i. TLR9-/- and TLR2/9-/- mice were more susceptible to the virus, with 60% and 100% mortality, respectively, as opposed to 10% in the WT and TLR2-/- mice. Increased levels of both CXCL10/IP-10 and CCL2/MCP-1, as well as reduced levels of interferon-γ and interleukin 1-β transcripts, measured in both the TG and brains at 5 d.p.i., and the presence of virus in the brain were correlated with total mortality in TLR2/9-/- mice. Cytokine alterations in TLR2/9-/- mice coincided with histopathological changes in their brains, which did not occur in WT and TLR2-/- mice and occurred only slightly in TLR9-/- mouse brain. Increased cellularity, macrophages, CD8 T cells producing interferon-γ, and expression levels of TLR2 and TLR9 were detected in the TG of WT-infected mice. We hypothesize that HSV-1 infection is controlled by TLR-dependent immune responses in the TG, which prevent HSV-1 encephalitis.
Scientists have long been trying to understand why the Neotropical region holds the highest diversity of birds on Earth. Recently, there has been increased interest in morphological variation between and within species, and in how climate, topography, and anthropogenic pressures may explain and affect phenotypic variation. Because morphological data are not always available for many species at the local or regional scale, we are limited in our understanding of intra‐ and interspecies spatial morphological variation. Here, we present the ATLANTIC BIRD TRAITS, a data set that includes measurements of up to 44 morphological traits in 67,197 bird records from 2,790 populations distributed throughout the Atlantic forests of South America. This data set comprises information, compiled over two centuries (1820–2018), for 711 bird species, which represent 80% of all known bird diversity in the Atlantic Forest. Among the most commonly reported traits are sex (n = 65,717), age (n = 63,852), body mass (n = 58,768), flight molt presence (n = 44,941), molt presence (n = 44,847), body molt presence (n = 44,606), tail length (n = 43,005), reproductive stage (n = 42,588), bill length (n = 37,409), body length (n = 28,394), right wing length (n = 21,950), tarsus length (n = 20,342), and wing length (n = 18,071). The most frequently recorded species are Chiroxiphia caudata (n = 1,837), Turdus albicollis (n = 1,658), Trichothraupis melanops (n = 1,468), Turdus leucomelas (n = 1,436), and Basileuterus culicivorus (n = 1,384). The species recorded in the greatest number of sampling localities are Basileuterus culicivorus (n = 243), Trichothraupis melanops (n = 242), Chiroxiphia caudata (n = 210), Platyrinchus mystaceus (n = 208), and Turdus rufiventris (n = 191). ATLANTIC BIRD TRAITS (ABT) is the most comprehensive data set on measurements of bird morphological traits found in a biodiversity hotspot; it provides data for basic and applied research at multiple scales, from individual to community, and from the local to the macroecological perspectives. No copyright or proprietary restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications or teaching and educational activities.
Studies about personalities in wild animals usually focus on five categories of behavioral traits that do not easily accommodate all aspects of parental care, a class of behaviors with direct consequence to reproductive success. Parental care can vary consistently between individuals and constitute parenting styles. Here we investigate the consistency of four behaviors of parental care across two breeding seasons of white‐rumped swallows Tachycineta leucorrhoa in southern Brazil. These behaviors are a prospection of potential nest‐sites, nest defense against predators or conspecifics, and chick feeding. If these first three behaviors are consistent, they can be classified according to the standard categories of personality as exploration, boldness, and aggressiveness, respectively. We find that all behaviors, except exploration, are consistent between individuals in the long term. We also show that, besides individual identity, couple identity is an important component explaining variation in behavior. This pattern can arise if behavior influences pair formation or if behavior is a consequence of a common environment affecting the couple. We show that, depending on the parental task, males or females are more consistent, suggesting that sexes are adopting different strategies of parental care allocation. We then investigate if there is a trade‐off between nest defense and chick feeding. We find that birds that defend more also feed the brood less often and suggest that testosterone might be the mechanism modulating this trade‐off. Lastly, we discuss the implications of our results to mate choice and highlight the need for studies linking parenting styles to fitness in swallow species.
Nest prospecting, that is, visiting potential future nest sites, may be a widespread bird behavior. Here we describe apparent prospecting while nesting by whiterumped swallows (Hirundinidae, Aves). In southern Brazil, birds tagged with passive-integrated transponders (PITtags) and breeding in nest boxes with PIT-tag readers: (1) often visited nest boxes that were in use by apparently unrelated birds (54 % of nests were visited at least once), (2) visited other boxes while caring for their own nestlings, (3) tended to have smaller broods than birds that were not recorded visiting, and (4) did not have a preference for any particular box. These patterns do not indicate any clear explanation for nest visiting, but they do show that prospecting is done by floaters (non-breeders) as well as actively breeding individuals. We suggest that these visits occur when time is available and that visitors may be assessing the availability of future nest sites.
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