Erratum: The Evolution of Helping. I. An Ecological Constraints Model

1983 ◽  
Vol 121 (5) ◽  
pp. 755-755
Author(s):  
Stephen T. Emlen
Keyword(s):  
Ecological Constraints ◽  
Constraints Model

scholarly journals Local predation pressure predicts the strength of mobbing responses in tropical birds

2012 ◽  
Vol 58 (5) ◽  
pp. 781-790 ◽  
Author(s):  
Luis Sandoval ◽  
David R. Wilson
Keyword(s):  
Predation Pressure ◽  
Ecological Constraints ◽  
Tropical Birds ◽  
Factors Affecting ◽  
Seeking Safety ◽  
Risk Of Predation ◽  
Increased Risk ◽  
Adverse Environmental Conditions ◽  
Constraints Model ◽  
Glaucidium Brasilianum

Abstract Many birds join cooperative mobbing aggregations and collectively harass predators. Individuals participating in these ephemeral associations benefit by deterring the predator, but also incur energetic costs and increased risk of predation. Explaining the evolution of mobbing is challenging because individuals could prevail by selfishly seeking safety while allowing others to mob. An important step in understanding the evolution of mobbing is to identify factors affecting its expression. The ecological constraints model suggests that animals are more likely to cooperate under adverse environmental conditions, such as when local predation pressure is high. We tested this prediction by comparing the mobbing responses of several species of birds to the local abundance of their primary predator, the ferruginous pygmy-owl Glaucidium brasilianum. We used acoustic playback to elicit mobbing responses in environments where owls were common, uncommon, or rare. Stimuli were either the song of a ferruginous pygmy-owl or the mobbing calls of three of the owl’s common prey species. During each playback, we characterized mobbing responses by noting the number of species and individuals that approached the loudspeaker, as well as the closest approach by any bird. Mobbing responses to both stimuli were strong in locations where Ferruginous Pygmy-owls were common, intermediate where owls were uncommon, and weak where they were rare. This pattern persisted even after controlling for differences in species richness and composition among the three environments. Results support the ecological constraints model and provide strong evidence that intense predation pressure increases the expression of cooperative mobbing in tropical birds.

Middle School Physical Education Teachers’ Perspectives on Overweight Students

2016 ◽  
Vol 35 (2) ◽  
pp. 127-137 ◽  
Author(s):  
Sarah A. Doolittle ◽  
Paul B. Rukavina ◽  
Weidong Li ◽  
Mara Manson ◽  
Angela Beale
Keyword(s):  
Middle School ◽  
Physical Education ◽  
Physical Education Teachers ◽  
Ecological Constraints ◽  
The Social ◽  
Multiple Case ◽  
Treat All ◽  
Teachers Perspectives ◽  
Constraints Model

Using the Social Ecological Constraints model, a qualitative multiple case study design was used to explore experienced and committed middle school physical education teachers’ perspectives on overweight and obese students (OWS), and how and why they acted to include OWS in physical education and physical activity opportunities in their school environments. Three themes emerged. 1) OWS are “the same, but different.” Teachers attempted to treat all students the same, but perceived variations among OWS’ participation in PE and related individual constraints. 2) Teachers’ concerns lead to individual goals and specific actions. Teachers identified specific goals and approaches to help individual OWS who needed extra attention. 3) OWS are a responsibility and challenge. Many of these teachers felt a responsibility to devote extra time and effort to help struggling OWS to succeed. These teachers avoided obesity bias, and exhibited beliefs and actions similar to a caring perspective.

Sign in / Sign up

Export Citation Format

Share Document