An Estimate of Avian Mortality at Communication Towers in the United States and Canada

Avian mortality at communication towers in the continental United States and Canada is an issue of pressing conservation concern. Previous estimates of this mortality have been based on limited data and have not included Canada. We compiled a database of communication towers in the continental United States and Canada and estimated avian mortality by tower with a regression relating avian mortality to tower height. This equation was derived from 38 tower studies for which mortality data were available and corrected for sampling effort, search efficiency, and scavenging where appropriate. Although most studies document mortality at guyed towers with steady-burning lights, we accounted for lower mortality at towers without guy wires or steady-burning lights by adjusting estimates based on published studies. The resulting estimate of mortality at towers is 6.8 million birds per year in the United States and Canada. Bootstrapped subsampling indicated that the regression was robust to the choice of studies included and a comparison of multiple regression models showed that incorporating sampling, scavenging, and search efficiency adjustments improved model fit. Estimating total avian mortality is only a first step in developing an assessment of the biological significance of mortality at communication towers for individual species or groups of species. Nevertheless, our estimate can be used to evaluate this source of mortality, develop subsequent per-species mortality estimates, and motivate policy action

Innovation Ambidexterity, Resource Configuration and Firm Growth: Is Smallness a Liability or an Asset?

This study examines when small- and medium-sized enterprises (SMEs) benefit from innovation ambidexterity for their growth. We argue that innovation ambidexterity in SMEs is sensitive to resource configuration, necessitating a careful fit assessment among firms??? internal resources (firm size), external resources (customer concentration) and the forms of innovation ambidexterity. Patent and utility model data from 912 firm-years for the 2000???2017 period in the Korean electronic parts industry were analysed using a feasible generalised least squares (FGLS) model. Consistent with our prediction, we establish that firm size is negatively related to the growth effect of balanced innovation ambidexterity (BIA), but positively to that of combined innovation ambidexterity (CIA), and that customer concentration is positively related to the growth effect of CIA. The three-way interaction patterns further demonstrate that smaller firms with high customer concentration achieve the best growth when pursuing BIA, whereas the same configuration can lead to the worst growth if they adopt CIA

Is market learning the missing link between family involvement – firm performance relationship? A resource-based perspective

Drawing on previous literature on proposing that there exists a positive relationship between family involvement and firm performance, this study refines the explanatory role of market learning in explaining the relationship between family involvement and firm performance to be conditional to firm age and environmental turbulence. The data from 344 small-medium enterprises show that family involvement is positively related to market exploitation while family involvement is negatively related to market exploration as family firms age. Also, we provide empirical evidence that family involvement is positively related to firm performance in turbulent environments through market exploration irrespective of the firm's age. Conversely, family involvement is positively related to firm performance through market exploitation in less turbulent environments irrespective of firm age. This study provides empirical evidence of the market exploration and exploitation capabilities may be the capabilities that glue family involvement to firm performance