In size-structured groups, conflict over rank, resources or access to breeding opportunities is expected to be greatest among individuals that are similar in size. We tested this general prediction using the cooperatively breeding African cichlid, Neolamprologus pulcher. We predicted that, when size differences between group members were small, we would observe some or all of: increased aggress...

The ‘pay-to-stay hypothesis’ proposes that subordinate group members help dominants in order to be tolerated in the territory. Accordingly, helpers should be punished if they are not helping sufficiently and should increase helping behaviour thereafter. We tested whether helping and social behaviours of group members of the cooperatively breeding cichlid Neolamprologus pulcher change according ...

Introduction The horse industry in Great Britain contributes to 0.5 % of total consumer spending and is estimated to generate £3.4 billion expenditure each year. In 1997, British Thoroughbred bloodstock exports were estimated to be worth £160 million (DEFRA 2004) and undoubtedly horse breeding is integral to the industry. The value of Sport Horse breeding further adds to these data. However, ma...

self-assessment helps learners to acquire self-confidence and gives them insightfulfeedbacks. there is no valid self-assessment inventory for learners of english foracademic purposes (eap). this study aimed at developing an academicallyappropriate instrument to measure tertiary students’ english in academic situations.the study used both qualitative and quantitative methods in developing the se...

The red-cockaded woodpecker (Picoides borealis) is a federally endangered species. As such, populations need to be increased in order to achieve recovery goals outlined by the U.S. Fish and Wildlife Service. My thesis is composed of two chapters that represent opposite sides of this issue. The first chapter investigates whether military training activity negatively affects red-cockaded woodpeck...

It is generally assumed that there is sexual conflict over the mating system. In this view, polygyny benefits males at a cost to females, and it is hence unclear why females accept polygynous mating. However, in the facultatively polygynous fish, Neolamprologus pulcher, no costs of polygyny to females have thus far been detected. We hypothesized that the costs of polygyny remained undetected be...

The present study was designed to evaluate the effect of Ovsynch protocol in repeat breeding crossbred Jersey cows. A total of thirty four repeat breeding cross bred Jersey cows were subjected to Ovsynch protocol with timed artificial insemination. The pregnancy rate in Ovsynch protocol was 58.82 per cent where as it was 29.41 per cent in control group. Thus, the Ovsynch protocol can be effecti...

In many cooperatively breeding species, group members form a dominance hierarchy or queue to inherit the position of breeder. Models aimed at understanding individual variation in helping behavior, however, rarely take into account the effect of dominance rank on expected future reproductive success and thus the potential direct fitness costs of helping. Here we develop a kin-selection model of...

We analyzed reproductive investment in parental care (brooding and the provisioning of nestlings) in the acorn woodpecker (Melanerpes formicivorus), a cooperatively breeding species in which both polygynandry and helping-at-the-nest are common. As predicted based on the strategies pursued by birds of different sex and status, breeders generally invested more in parental care than helpers, and b...

In plant and animal breeding studies a distinction is made between the genetic value (additive plus epistatic genetic effects) and the breeding value (additive genetic effects) of an individual since it is expected that some of the epistatic genetic effects will be lost due to recombination. In this article, we argue that the breeder can take advantage of the epistatic marker effects in regions...