scholarly journals Flight initiation distance of Urosaurus ornatus from the Sierra de Samalayuca, Mexico

2021 ◽  
Vol 16 (1) ◽  
pp. 53-57
Author(s):  
Julio A. Lemos-Espinal ◽  
Geoffrey R. Smith
Keyword(s):  
Substrate Temperature ◽  
Flight Initiation Distance ◽  
Extrinsic Factors ◽  
Urosaurus Ornatus ◽  
Tree Lizards ◽  
Study Population ◽  
Males And Females ◽  
Intrinsic And Extrinsic Factors ◽  
Flight Initiation ◽  
Prey Individual

In lizards, flight initiation distance (FID), the distance between a prey individual and a predator when escape begins, can be affected by numerous intrinsic and extrinsic factors, including sex, temperature, and level of conspicuousness. Here we report on a study of FID in a population of Ornate Tree Lizards, Urosaurus ornatus, from the Sierra de Samalyuca, Chihuahua, Mexico which are cryptic due to their dorsal coloration blending into their background. Urosaurus ornatus in our study population allowed close approaches (mean FID = 65 cm). Mean FID did not differ between males and females. We also found no effect of body, air, or substrate temperature on FID. The short FID we observed may be related to the cryptic nature of U. ornatus.

When and how do predator starting distances affect flight initiation distances?

2005 ◽  
Vol 83 (8) ◽  
pp. 1045-1050 ◽  
Author(s):  
W E Cooper, Jr.
Keyword(s):  
Bird Species ◽  
Ecological Factors ◽  
Flight Initiation Distance ◽  
Lizard Species ◽  
Urosaurus Ornatus ◽  
Approach Speed ◽  
Monitoring Costs ◽  
Sceloporus Virgatus ◽  
The Relationship ◽  
Flight Initiation

The distance separating predator and prey when the predator begins to approach, starting distance, was recently shown to affect flight initiation distance in many bird species, raising questions about the effect's generality, variation with ecological factors, and economic basis. I studied the effect in two lizard species that forage by ambush and escape into nearby refuges. Monitoring costs during approach are absent because ambushers remain immobile while scanning for prey and predators. Risks are minimized because of the proximity to refuge. Flight initiation distance increased weakly with starting distance in Sceloporus virgatus Smith, 1938 significantly only at rapid approach speed. It was not significant in Urosaurus ornatus (Baird and Girard, 1852) at slow approach speed. Flight initiation distance is predicted to increase with starting distance, owing to monitoring costs and assessment by prey of greater risk during prolonged approaches. The significant effect in S. virgatus, which lacks monitoring costs, is the first indication that risk affects the relationship between starting distance and flight initiation distance. Conditions in which starting distance is important and its possible effects in earlier studies are discussed, as well as standardizing approaches and possible artifactual effects of starting distance.

scholarly journals Island tameness and the repeatability of flight initiation distance in a large herbivore

2017 ◽  
Vol 95 (10) ◽  
pp. 771-778 ◽  
Author(s):  
Doreen Cabrera ◽  
Daniel Andres ◽  
Philip D. McLoughlin ◽  
Lucie Debeffe ◽  
Sarah A. Medill ◽  
...  
Keyword(s):  
Risk Aversion ◽  
Evolutionary Dynamics ◽  
Flight Initiation Distance ◽  
Time Intervals ◽  
Large Herbivore ◽  
Feral Horses ◽  
Sex Effects ◽  
Males And Females ◽  
Temporal And Spatial ◽  
Flight Initiation

Antipredator behaviours can be lost relatively quickly in populations that are relieved of predation, as is known for several species inhabiting islands. Flight initiation distance (FID) is often studied in the context of island tameness; however, little is known about the factors that influence and maintain FID variation in predation-free populations. Here, we studied FID in foals of an isolated predator-free population of feral horses (Equus caballus L., 1758) on Sable Island, Canada, to determine if FID could be used for research on consistent individual differences in risk aversion and island tameness. In addition to testing for temporal, spatial, and sex effects on FID, we compared repeatability estimates at two temporal scales (within and among days). Similar FID for measurements obtained on the same day and for males and females indicated an absence of short-term desensitization and sex effects. In contrast, FID decreased for measurements made on subsequent days and from east to west, which could reflect habituation to human presence and (or) other temporal and spatial processes. Repeatability was high (0.42 ± 0.06), but tended to decrease with increasing time intervals. This study highlights the potential of FID for individual-based research on the ecology and evolutionary dynamics of risk aversion in predation-free populations.

scholarly journals Modulation of the multistate folding of designed TPR proteins through intrinsic and extrinsic factors

2012 ◽  
Vol 21 (3) ◽  
pp. 327-338 ◽  
Author(s):  
J. J. Phillips ◽  
Y. Javadi ◽  
C. Millership ◽  
E. R. G. Main
Keyword(s):  
Extrinsic Factors ◽  
Intrinsic And Extrinsic Factors

Intrinsic and extrinsic factors that may influence DNA preservation in skeletal remains: A review

2021 ◽  
Vol 325 ◽  
pp. 110859
Author(s):  
Caterina Raffone ◽  
Miriam Baeta ◽  
Nicole Lambacher ◽  
Eva Granizo-Rodríguez ◽  
Francisco Etxeberria ◽  
...  
Keyword(s):  
Skeletal Remains ◽  
Extrinsic Factors ◽  
Dna Preservation ◽  
Intrinsic And Extrinsic Factors

scholarly journals Conceptualizing Mobility Inequality: Mobility and Accessibility for the Marginalized

2021 ◽  
pp. 088541222110128
Author(s):  
Isti Hidayati ◽  
Wendy Tan ◽  
Claudia Yamu
Keyword(s):  
Conceptual Understanding ◽  
Thought Experiments ◽  
Future Research ◽  
Planning Practice ◽  
Extrinsic Factors ◽  
Research Directions ◽  
Future Research Directions ◽  
Intrinsic And Extrinsic Factors

The burgeoning landscape of literature on mobility inequalities has led to discrepancies between a conceptual understanding of mobility inequalities and its implementation in planning practice. Reviewing 270 publications across five decades, this article identifies intrinsic and extrinsic factors and approaches for understanding and analyzing mobility inequality. Using two thought experiments to critically locate variations in factors and approaches, dilemmas and challenges in addressing mobility inequality for the marginalized are exposed. The article concludes with future research directions for investigating mobility inequality.

scholarly journals European birds adjust their flight initiation distance to road speed limits

2013 ◽  
Vol 9 (5) ◽  
pp. 20130417 ◽  
Author(s):  
Pierre Legagneux ◽  
Simon Ducatez
Keyword(s):  
Habitat Structure ◽  
Territory Size ◽  
Speed Limit ◽  
Vehicle Speed ◽  
Flight Initiation Distance ◽  
Speed Limits ◽  
Behavioural Responses ◽  
Road Speed ◽  
Flight Initiation ◽  
Local Speed

Behavioural responses can help species persist in habitats modified by humans. Roads and traffic greatly affect animals' mortality not only through habitat structure modifications but also through direct mortality owing to collisions. Although species are known to differ in their sensitivity to the risk of collision, whether individuals can change their behaviour in response to this is still unknown. Here, we tested whether common European birds changed their flight initiation distances (FIDs) in response to vehicles according to road speed limit (a known factor affecting killing rates on roads) and vehicle speed. We found that FID increased with speed limit, although vehicle speed had no effect. This suggests that birds adjust their flight distance to speed limit, which may reduce collision risks and decrease mortality maximizing the time allocated to foraging behaviours. Mobility and territory size are likely to affect an individuals' ability to respond adaptively to local speed limits.

scholarly journals Occlusal Characteristics and Spacing in Primary Dentition: A Gender Comparative Cross-Sectional Study

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Madhuri Vegesna ◽  
R. Chandrasekhar ◽  
Vinay Chandrappa
Keyword(s):  
Cross Sectional Study ◽  
Primary Dentition ◽  
Clinical Approach ◽  
Primary Molar ◽  
Cross Sectional ◽  
Normal Occlusion ◽  
Class 1 ◽  
Study Population ◽  
Different Populations ◽  
Males And Females

Context. Occlusion in primary teeth varies among children of different populations and races. Aim. To assess and compare the occlusal characteristics and spacing in primary dentition among 3–6-year-old Dravidian children. Materials and Methods. The study included 2281 school going children. The primary molar relation, canine relation, overjet, and overbite were assessed using Foster and Hamilton criteria. Spacing conditions were registered according to Kisling and Krebs criteria. Results. The flush terminal plane molar relation (80.3%) was the most common primary molar relation. The distal step molar relation was more frequently found in female children (12.8%) than in males (8.6%). Class 1 canine relation was the most prevalent canine relation (81.3%) among males and females. Ideal overjet (84.3%) and overbite (72.7%) were observed among the majority of the children. Spaced type of arches occurred more frequently than closed arches in this sample. The incidence of primate spaces was more in males than in females. Conclusion. The study population has fewer deviations from normal occlusion which indicates decreased tendency for malocclusion in permanent dentition. However, further longitudinal studies are necessary to identify the potential limitations of a clinical approach relying on early orthodontic diagnosis and intervention.

scholarly journals Effect of Intrinsic and Extrinsic Factors on Global and Regional Cortical Thickness

PLoS ONE ◽  
2014 ◽  
Vol 9 (5) ◽  
pp. e96429 ◽  
Author(s):  
Koushik A. Govindarajan ◽  
Leorah Freeman ◽  
Chunyan Cai ◽  
Mohammad H. Rahbar ◽  
Ponnada A. Narayana
Keyword(s):  
Cortical Thickness ◽  
Extrinsic Factors ◽  
Intrinsic And Extrinsic Factors
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