In this paper we review the existing methods of quantifying avian wingtip shape, and compare their efficiency at detecting morphological adaptations to migration. We use multivariate derive two novel measures pointedness C2 convexity C3, based on measurements primary feather lengths. Size-constrained components analysis, a modified form principal is used ensure that are independent isometric size, have consistent interpretation in terms geometric shape wingtip. Our can be calculated easily...

Recent infectious disease models illustrate a suite of mechanisms that can result in lower incidence areas higher host diversity--the 'dilution effect'. These are particularly applicable to human zoonoses, which diseases wildlife spill over into populations. As many recent emerging the underlie effect' potentially widely and could contribute greatly our understanding diseases. The dilution effect has largely been observed context Lyme predictions underlying have rarely examined for other on...

Recent evidence suggests that certain features on the human face indicate hormonal levels during growth, and women judge attractiveness of potential partners based appearance these features. One entrenched notion is male facial are affected by testosterone used as direct cues in mate preference. Testosterone may be particularly revealing it purported to an honest indicator fitness. Increased impose immunocompetence handicap bearer only best males can carry this handicap. To date, tests...

The physiological and energy costs of avian molt are well documented, but indirect consequences such as changes in flight performance have received less attention. Here, we report two experiments that investigated performance, body mass regulation, behavior captive starlings (Sturnus vulgaris). In the first experiment, found a U-shaped change take-off escape during natural molt: birds ascended at shallowest trajectories midmolt. Birds' was also reduced molt. second manipulated plumage to...

It has been postulated that levels of fluctuating asymmetry in human faces may be negatively related to components fitness such as parasite-resistance; hence potential mates with low appear more attractive. However, previous investigations the relationship between and facial attractiveness have confounded manipulations 'averageness' mean trait size. In this experiment we performed a manipulation altered within face without altering size features. These were then rated on attractiveness....

The fields of behavioral ecology, conservation science, and environmental toxicology individually aim to protect manage the wildlife in response anthropogenic stressors, including widespread pollution. Although great emphasis field has been placed on understanding how single pollutants affect survival, a comprehensive, interdisciplinary approach that includes ecology is essential address compounds are risk for survival species populations an increasingly polluted world. We provide...

Variation in length and asymmetry of wing primary feathers can arise from a breakdown developmental homeostasis, feather abrasion incomplete growth during moult. Indirect predictions have been made concerning the impact on flight ability birds, but they not explicitly tested. Here we provide evidence both natural variation condition experimental manipulations to indicate that these factors influence aspects performance Common Starling Sturnus vulgaris. Damaged incompletely grown reduce...

Melanins are common feather pigments that contribute to signaling and crypsis. may also help feathers resist feather‐degrading bacteria (FDB). Two recent studies (Goldstein et al. 2004, Grande 2004) tested the resistance of melanized versus unmelanized FDB using in vitro experiments, but draw opposite conclusions. Goldstein (2004) concluded more than feathers, while feathers. To resolve this conflict literature, we replicated previous included additional tests not previously used. We...

Although previous studies have related variations in environmental noise levels with alterations communication behaviors of birds, little work has investigated the potential long-term implications living or breeding noisy habitats. However, to reduce fitness, both directly (because it is a physiological stressor) and indirectly (by masking important vocalizations and/or leading behavioral changes). Here, we quantified acoustic conditions active territories male Eastern Bluebirds (Sialia...

Mercury is a global pollutant that biomagnifies in food webs, placing wildlife at risk of reduced reproductive fitness and survival. Songbirds are the most diverse branch avian evolutionary tree; many suffering persistent serious population declines we know songbirds frequently exposed to mercury pollution. Our objective was determine effects environmentally relevant doses on success throughout their lives or only as adults. The two modes exposure simulated philopatric species versus...

There is increasing evidence that animals can acquire mate preferences through the use of public information, notably by observing (and copying) others in population. If females social mechanisms, sexual selection could act very rapidly to spread preference and drive elaboration preferred trait(s). Although there are reports ‘mate-choice copying’ polygynous species, no clear for this process monogamous species. Here, we investigated whether adult female zebra finches Taeniopygia guttata...

Parasites influence the expression of secondary sexual traits and health infected individuals. We set out to test reputed exogenous parasites, plumage bacteria, including feather‐degrading bacteria (FDB), on characteristics body condition wild adult eastern bluebirds Sialia sialis . Previous work has shown that FDB alter coloration structurally‐colored bluebird feathers in vitro ( Shawkey et al. 2007 ). In a correlational study how affect birds wild, we found female got duller with...

Vocal responses to anthropogenic noise have been documented in several species of songbird. However, only a few studies investigated whether these adjustments are made "real time" or longer-term particular soundscapes. Furthermore, increased ambient often is accompanied by structural changes the habitat, including introduction noisy roadways and removal native vegetation. To date, no simultaneously impact both acoustic disturbance on same species. The relevance each variables must be...