Human activities can alter selective environments in ways that can reduce the usefulness of certain ornamental traits as honest signals of individual quality and, in some cases, may create evolutionary traps, where rapid changes in selective environments result in maladaptive behavioral decisions. Using the sexually dichromatic, socially monogamous Northern Cardinal (Cardinalis cardinalis) as a...

A central tenet of life-history theory is that investment in reproduction compromises survival. We tested for costs of reproduction in wild brown anoles (Anolis sagrei) by eliminating reproductive investment via surgical ovariectomy and/or removal of oviductal eggs. Anoles are unusual among lizards in that females lay single-egg clutches at frequent intervals throughout a lengthy reproductive s...

In conditions characterized by energetic constraints, such as in periods of low food availability, some trade-offs between reproduction and self-maintenance may be necessary; even year-round breeders may then be forced to exhibit some reproductive seasonality. Prior research has largely focused on female reproduction and physiology, and few studies have evaluated the impact of environmental fac...

ABSTRACT: The domestic canary (Serinus canaria) has been bred for hundreds of years to improve the quality its plumage and song. Reproduction in this species occurs seasonally, stimulated by a gradual increase day length. Although, occurrence seasonal breeding canaries is well known, whether reproduction can be manipulated remains unknown. Our objective was determine conditions captivity (photo...

In a seasonal environment, the suitable time window for females to reproduce is restricted by both environmental conditions and the availability of males. In simultaneous hermaphrodites, which are female and male at the same time, selection on a trait that is solely beneficial for one sexual function cannot occur independently. Therefore, it is assumed that the optimal time window for reproduct...

Ghezel sheep is one of the main breeds in the north-west of Iran which is reared for meat, milk and wool production. Improving reproduction of this breed will have a significant impact on the economic development of local farmers. Therefore, in the present study the effect of simultaneous use of estrus synchronization(controlled internal drug releasing (CIDR) and equine chorionic gonadotropin (...

Syferkuil Dam is situated 8 km NW of the University of the North and comprises a series of eight interconnected rectangular dams, having cement sides and mud bottoms. Throughout the experimental period, male and female adult specimens of the mouthbrooding tilapia, Oreochromis mossambicus were collected for further analysis. Aspects of the reproductive physiology of O. mossambicus that were inve...

The interplay between individual adaptive life histories and populations dynamics is an important issue in ecology. In this context, we considered a seasonal consumer-resource model with nonoverlapping generations. We focused on the consumers decision-making process through which they maximize their reproductive output via a differential investment into foraging for resources or reproducing. Ou...

Annual species may increase reproduction by increasing adult body size through extended development, but risk being unable to complete development in seasonally limited environments. Synthetic reviews indicate that most, but not all, species have responded to recent climate warming by advancing the seasonal timing of adult emergence or reproduction. Here, we show that 50 years of climate change...

AIM The present investigation was undertaken to study the reproduction performance and effect of non-genetic factors on reproduction performance of Jersey crossbred cows. MATERIALS AND METHODS Data on 355 Jersey crossbred cattle maintained at the Post-graduate Research Institute in Animal Sciences, Kattupakkam, Tamil Nadu, distributed over 30 years (1985 to 2014). The effect of various non-ge...