Nature-based tourism as a form of predation risk affects body condition and health state of Podarcis muralis lizards

2006 ◽  
Vol 131 (3) ◽  
pp. 402-409 ◽  
Author(s):  
Luisa Amo ◽  
Pilar López ◽  
José Martı´n
Keyword(s):  
Predation Risk ◽  
Body Condition ◽  
Health State ◽  
Podarcis Muralis

Habitat deterioration affects antipredatory behavior, body condition, and parasite load of female Psammodromus algirus lizards

2007 ◽  
Vol 85 (6) ◽  
pp. 743-751 ◽  
Author(s):  
Luisa Amo ◽  
Pilar López ◽  
José Martín
Keyword(s):  
Predation Risk ◽  
Body Condition ◽  
Relative Abundance ◽  
Microhabitat Use ◽  
Health State ◽  
Habitat Deterioration ◽  
Antipredatory Behavior ◽  
Risk Of Predation ◽  
Psammodromus Algirus

Deforestation may increase predation risk for prey because it may make prey more conspicuous and limit the number of refuges suitable to avoid predators. Therefore, prey may need to increase the magnitude of escape responses. However, excessive antipredatory effort might lead to a loss of body mass and a decrease in defense against parasites, with important consequences for short- and long-term fitness. We analyzed whether Psammodromus algirus (L., 1758) lizards that inhabit patches with different levels of deterioration of the vegetation within the same oak forest differed in relative abundance numbers, microhabitat use, antipredatory strategies, and health state. Results showed lizards selected similar microhabitats regardless of the level of deterioration of the vegetation and relative abundance of lizards was similar in both areas. However, habitat deterioration seemed to increase predation risk, at least for females, because they were detected at longer distances in deteriorated areas. Females seemed to adjust their antipredatory behavior accordingly to high risk of predation by increasing approach distances allowed to predators. The costs associated with frequent antipredatory displays might explain why females in deteriorated habitats had lower body condition and greater blood parasite loads than females in natural areas. This loss of body condition and increased parasitemia might have deleterious consequences for female fitness and therefore affect the maintenance of lizard populations in the long-term.

scholarly journals Glucocorticoids, state-dependent reproductive investment and success in the face of danger in a long-lived bird

2020 ◽  
Author(s):  
Kristina Noreikienė ◽  
Kim Jaatinen ◽  
Benjamin B. Steele ◽  
Markus Öst
Keyword(s):  
Predation Risk ◽  
Telomere Length ◽  
Clutch Size ◽  
Body Condition ◽  
Nest Predation ◽  
Hatching Success ◽  
Reproductive Investment ◽  
Trade Off ◽  
Relative Telomere Length ◽  
Future Reproduction

AbstractGlucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.

Food supplementation and predation risk in harsh climate: interactive effects on abundance and body condition of tit species

Oikos ◽  
2016 ◽  
Vol 126 (6) ◽  
pp. 863-873 ◽  
Author(s):  
Chiara Morosinotto ◽  
Alexandre Villers ◽  
Rauno Varjonen ◽  
Erkki Korpimäki
Keyword(s):  
Predation Risk ◽  
Body Condition ◽  
Interactive Effects ◽  
Food Supplementation ◽  
Harsh Climate

An investigation of factors influencing erythrocyte morphology of red-backed salamanders (Plethodon cinereus)

2009 ◽  
Vol 59 (2) ◽  
pp. 201-209 ◽  
Author(s):  
John Maerz ◽  
Joseph Milanovich ◽  
Andrew Davis ◽  
Jayna DeVore
Keyword(s):  
Body Size ◽  
Body Condition ◽  
Oxygen Demand ◽  
Plethodon Cinereus ◽  
Future Research ◽  
Health State ◽  
Erythrocyte Morphology ◽  
Size And Shape ◽  
Plethodontid Salamanders ◽  
Body Sizes

AbstractAmphibians have long been known to display wide variation in erythrocyte morphology across species, but within species there has been little attention given to individual variation in red blood cell morphology. We captured 49 red-backed salamanders (Plethodon cinereus) from central Pennsylvania, USA and used image analysis procedures to measure erythrocyte morphology (size and shape) on blood smears made from all individuals. We then statistically examined whether variation in snout-vent-length, sex, tail loss, or capture location influenced these cell variables. Only snout-vent-length affected erythrocyte size and shape, with increasing body sizes associated with increasing cell areas and increasingly rounder cells. Further, erythrocyte shape was also associated with a measure of body condition that was corrected for body size, such that individuals with high body condition scores had rounder cells. Given the oxygen-carrying role of erythrocytes in all vertebrates, we suspect this discovery is related to size-related changes in oxygen demand, since total oxygen consumption increases with body size in an allometric manner. While our results warrant further investigation to understand the mechanism, the association we found between cell roundness and both body size and condition nevertheless indicates this parameter could be used to assess the health state of plethodontid salamanders in future research, provided non-destructive sampling is employed. Our results also underscore the value of hematological investigations in the study of animal biology.

scholarly journals Selection on innate immunity and body condition in Florida scrub-jays throughout an epidemic

2010 ◽  
Vol 6 (4) ◽  
pp. 552-554 ◽  
Author(s):  
Travis E. Wilcoxen ◽  
Raoul K. Boughton ◽  
Stephan J. Schoech
Keyword(s):  
Body Condition ◽  
Winter Mortality ◽  
Health State ◽  
Physiological Measures ◽  
Florida Scrub ◽  
Bacterial Killing ◽  
Selection Gradient ◽  
Naturally Occurring ◽  
Living Species ◽  
Significant Positive Selection

Opportunities to investigate selection in free-living species during a naturally occurring epidemic are rare; however, we assessed innate immunocompetence in Florida scrub-jays before the population suffered the greatest over-winter mortality in 20 years of study. Propitiously, three months prior to the epidemic, we had sampled a number of male breeders to evaluate a suite of physiological measures that are commonly used to estimate the overall health-state of an individual. There was a significant, positive selection gradient for both Escherichia coli bacterial killing capability and body condition, suggesting that directional selection had occurred upon each of these traits during the disease epidemic.

Trade-offs in the choice of refuges by common wall lizards: do thermal costs affect preferences for predator-free refuges?

2004 ◽  
Vol 82 (6) ◽  
pp. 897-901 ◽  
Author(s):  
Luisa Amo ◽  
Pilar López ◽  
José Martín
Keyword(s):  
Avoidance Response ◽  
Predation Risk ◽  
Chemical Cues ◽  
Thermal Conditions ◽  
Movement Rate ◽  
Podarcis Muralis ◽  
Refuge Use ◽  
Trade Off ◽  
Trade Offs ◽  
Common Wall

Prey often respond to predator presence by increasing refuge use. However, some types of refuges may expose prey to other types of predators. In addition, in selecting refuges ectothermic animals may have a conflict between safety and thermal suitability. In this paper we examined in the laboratory whether common wall lizards, Podarcis muralis (Laurenti, 1768), (i) prefer to use warm refuges to cold ones, (ii) prefer safe refuges to those with chemical cues of a saurophagous snake, and (iii) whether lizards face a trade-off between using a warm but snake-scented refuge or a cold but odorless one. Results did not show differences in refuge use in relation to refuge temperature, because common wall lizards only entered to investigate it, but they were not forced to hide. So, common wall lizards did not have to be at suboptimal temperatures for longer times. Common wall lizards avoided the use of predator-scented refuges, regardless of thermal conditions, and they also increased their movement rate, trying to escape from the terrarium. Because snakes are inconspicuous inside refuges, an avoidance response to their chemicals may enhance the survival possibilities of common wall lizards. We conclude that in common wall lizards, predation-risk costs are more important than thermal costs in determining refuge use.

Does body condition affect fecundity in a cyclic population of snowshoe hares?

1999 ◽  
Vol 77 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Karen E Hodges ◽  
Carol I Stefan ◽  
Elizabeth A Gillis
Keyword(s):  
Predation Risk ◽  
Body Condition ◽  
Age Structure ◽  
Lepus Americanus ◽  
Decline Phase ◽  
Skeletal Size ◽  
Nutritional Deficit ◽  
Snowshoe Hares ◽  
Cyclic Changes ◽  
Cyclic Fluctuation

Snowshoe hares (Lepus americanus) undergo a 10-year cycle in abundance, with cyclic changes in reproduction occurring 3 years prior to numeric changes. Reproduction may be associated with body condition, which might change with nutrition or predation pressure. We describe hare body condition (as a mass - skeletal size relationship) through a cycle in the southern Yukon from 1989 to 1996, test the effects of food and predation risk on body condition, and examine whether changes in body condition are related to cyclic reproductive changes. Hare body condition was lowest during the decline phase but rapidly improved during the low phase. Although yearling hares were in poorer condition than adults, changes in age structure cannot explain the cyclic fluctuation in condition. Food addition and predator reduction both resulted in better body condition. Body condition did not affect reproduction. The highest natality occurred when hares were in intermediate condition, while the lowest natality occurred when hares were in the best condition. Although changes in food and predation risk affect hare body condition, we found no relationship between body condition and cyclic reproductive changes. Rather, during times of nutritional deficit, female hares may maintain mass during gestation and lactation, but at a proximate cost to their offspring. Thus, inferences based on indices of condition incorporating body mass may be misleading.

scholarly journals Body condition and pregnancy in northern Yellowstone elk: Evidence for predation risk effects?

2011 ◽  
Vol 21 (1) ◽  
pp. 3-8 ◽  
Author(s):  
P. J. White ◽  
Robert A. Garrott ◽  
Kenneth L. Hamlin ◽  
Rachel C. Cook ◽  
John G. Cook ◽  
...  
Keyword(s):  
Predation Risk ◽  
Body Condition ◽  
Risk Effects
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