The Effect of Supplemental Food on Body Condition and the Timing of Reproduction in a Cooperative Breeder, the Florida Scrub-Jay

The Condor ◽  
1996 ◽  
Vol 98 (2) ◽  
pp. 234-244 ◽  
Author(s):  
Stephan J. Schoech
Keyword(s):  
Body Condition ◽  
Florida Scrub ◽  
Timing Of Reproduction ◽  
Supplemental Food

Are roads and traffic sources of physiological stress for the Florida scrub-jay?

2012 ◽  
Vol 39 (4) ◽  
pp. 301 ◽  
Author(s):  
Gina M. Morgan ◽  
Travis E. Wilcoxen ◽  
Michelle A. Rensel ◽  
Stephan J. Schoech
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Physiological Stress ◽  
Condition Index ◽  
Physiological Effects ◽  
Negative Effects ◽  
Florida Scrub ◽  
The Road ◽  
Threatened And Endangered Species ◽  
Chronic Stressor

Context Anthropogenic disturbances induce physiological and behavioural responses in numerous species. The negative effects of human disturbance are of special concern to threatened and endangered species. Aims The present study aims to compare physiological stress measures and reproductive success of Florida scrub-jays (Aphelocoma coerulescens) living near roads with jays that live away from roads. Specifically, it aims to test whether roads are stressful. Methods We assessed physiological measures that can serve as indicators of ‘stress’ to determine whether a highway that bisects our study site had physiological effects on adult male Florida scrub-jays. We captured male breeders from three territory types, including scrub habitat that (1) bordered a highway with a grassy shoulder that created an ‘edge’ habitat (roadside), (2) bordered human-maintained habitat (a plowed firebreak of sand with adjacent pasture) that served as a control for the edge-effect of the road (pasture) and (3) contained only natural scrub habitat (interior). We measured baseline concentrations of the stress hormone corticosterone (CORT), body mass, and a suite of longitudinal body measures to generate a body condition index in males from each territory type over three breeding seasons. Key results Roadside jays had greater body mass than did interior and pasture jays, although there were no differences in overall baseline CORT concentrations or body condition among territory classes. There was no difference in clutch initiation date or size and nestling and independent-young survival. Conclusions Our results suggest that the road through our study site has physiological effects on Florida scrub-jays; however, there is mixed evidence as to whether it acts as a chronic stressor. Implications Our findings provide evidence that roads and road-associated disturbance has neutral or potentially beneficial physiological effects of roads on Florida scrub-jays. Knowledge of these effects of roads and disturbance on jays will hopefully provide additional opportunities to improve conservation of this species.

Timing of reproduction in wild mink: the influence of spawning Pacific salmon

1997 ◽  
Vol 75 (3) ◽  
pp. 376-382 ◽  
Author(s):  
M. Ben-David
Keyword(s):  
Body Condition ◽  
Pacific Salmon ◽  
American Mink ◽  
Day Length ◽  
Timing Of Breeding ◽  
Southeast Alaska ◽  
Timing Of Reproduction ◽  
Seasonally Breeding ◽  
Free Ranging ◽  
Wild Mink

In many species of seasonally breeding mammals, reproduction occurs later at higher latitudes. Records of timing of reproduction in free-ranging American mink (Mustela vison) in North America and Europe suggest a similar trend. Observations on mink in southeast Alaska, however, revealed a deviation from this pattern, suggesting that factors other than latitude and associated day length may affect timing of breeding for this species in this area. I investigated timing of reproduction and body condition of wild, free-ranging mink on Chichagof Island, southeast Alaska, and hypothesized that seasonal food availability, especially abundant carcasses of spawning Pacific salmon (Onchorhynchus sp.), would determine timing of breeding in this population of mink. Blood progesterone levels, body condition, and testicle lengths were recorded for 24 adult mink, livetrapped from mid-March to late July in 1992 and 1993. Results suggest that these free-ranging mink mate during the later part of April to early May, and parturition occurs in late June to early July. Although male mink seemed to respond to photoperiodism in initiating reproduction, timing of reproduction in female mink was shifted so that lactation coincided with the availability of carcasses of Pacific salmon.

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.

Seasonality, body condition, and timing of reproduction inPropithecus verreauxi verreauxi in the Kirindy Forest

2005 ◽  
Vol 67 (3) ◽  
pp. 347-364 ◽  
Author(s):  
R.J. Lewis ◽  
P.M. Kappeler
Keyword(s):  
Body Condition ◽  
Timing Of Reproduction

scholarly journals Condition-dependent reproductive effort in frogs infected by a widespread pathogen

2015 ◽  
Vol 282 (1810) ◽  
pp. 20150694 ◽  
Author(s):  
Elizabeth A. Roznik ◽  
Sarah J. Sapsford ◽  
David A. Pike ◽  
Lin Schwarzkopf ◽  
Ross A. Alford
Keyword(s):  
Body Condition ◽  
Reproductive Effort ◽  
Disease Susceptibility ◽  
Batrachochytrium Dendrobatidis ◽  
Pathogenic Fungus ◽  
Good Condition ◽  
Life History Strategy ◽  
Negative Effects ◽  
Timing Of Reproduction ◽  
Factors Affecting

To minimize the negative effects of an infection on fitness, hosts can respond adaptively by altering their reproductive effort or by adjusting their timing of reproduction. We studied effects of the pathogenic fungus Batrachochytrium dendrobatidis on the probability of calling in a stream-breeding rainforest frog ( Litoria rheocola ). In uninfected frogs, calling probability was relatively constant across seasons and body conditions, but in infected frogs, calling probability differed among seasons (lowest in winter, highest in summer) and was strongly and positively related to body condition. Infected frogs in poor condition were up to 40% less likely to call than uninfected frogs, whereas infected frogs in good condition were up to 30% more likely to call than uninfected frogs. Our results suggest that frogs employed a pre-existing, plastic, life-history strategy in response to infection, which may have complex evolutionary implications. If infected males in good condition reproduce at rates equal to or greater than those of uninfected males, selection on factors affecting disease susceptibility may be minimal. However, because reproductive effort in infected males is positively related to body condition, there may be selection on mechanisms that limit the negative effects of infections on hosts.

Body Condition, Migration, and Timing of Reproduction in Snow Geese: A Test of the Condition‐Dependent Model of Optimal Clutch Size

2003 ◽  
Vol 162 (1) ◽  
pp. 110-121 ◽  
Author(s):  
Joël Bêty ◽  
Gilles Gauthier ◽  
Jean‐François Giroux
Keyword(s):  
Clutch Size ◽  
Body Condition ◽  
Timing Of Reproduction ◽  
Snow Geese ◽  
Optimal Clutch Size ◽  
Dependent Model

scholarly journals Anthropogenic food provisioning and immune phenotype: Association among supplemental food, body condition, and immunological parameters in urban environments

2018 ◽  
Vol 8 (5) ◽  
pp. 3037-3046 ◽  
Author(s):  
Jusun Hwang ◽  
Yongbaek Kim ◽  
Sang-Won Lee ◽  
Na-Yon Kim ◽  
Myung-Sun Chun ◽  
...  
Keyword(s):  
Body Condition ◽  
Urban Environments ◽  
Food Provisioning ◽  
Immunological Parameters ◽  
Immune Phenotype ◽  
Supplemental Food ◽  
Food Body ◽  
Anthropogenic Food

scholarly journals Does Differential Access to Protein Influence Differences in Timing of Breeding of Florida Scrub-Jays (Aphelocoma Coerulescens) in Suburban and Wildland Habitats?

The Auk ◽  
2003 ◽  
Vol 120 (4) ◽  
pp. 1114-1127 ◽  
Author(s):  
Stephan J. Schoech ◽  
Reed Bowman
Keyword(s):  
Luteinizing Hormone ◽  
Body Condition ◽  
Condition Index ◽  
Egg Laying ◽  
Timing Of Breeding ◽  
Florida Scrub ◽  
Calendar Date ◽  
Aphelocoma Coerulescens ◽  
Endogenous Protein ◽  
Total Body

Abstract Timing of breeding in Florida Scrub-Jays (Aphelocoma coerulescens) varies both within and between years. Social status and breeding experience may explain much of the within-year variation, but the availability of certain foods may partially explain between-year patterns. Scrub-jays in suburban habitats with access to unlimited human-provided foods breed earlier and with less between-year variation in timing of breeding than jays in wildland habitats. We hypothesized that those differences in timing of breeding result from access to human-provided foods in the suburban site. Human-provided food may influence timing of breeding by improving the overall body condition of females, or it may influence breeding by providing nutrients essential for breeding. If condition mediated, breeding females in the two habitats should differ in certain physiological parameters relative to time before egg laying and calendar date. If the effect is not related to body condition, we expect differences in prebreeding females relative to calendar date, but not in relation to time before egg laying. To test those predictions, we measured plasma levels of total protein, calcium, luteinizing hormone, and estradiol. We also measured variables associated with body condition—body mass, a size-corrected condition index, and total body lipids. Most variables tended to increase with both days before laying and calendar date, except total body lipids, which decreased. Suburban females had higher levels of plasma protein relative to both days before egg laying and calendar date than female breeders in the wildland habitat. Luteinizing hormone differed between sites relative to calendar date but not days before laying. Our data suggest that suburban scrub-jays with access to predictable sources of high-quality human-provided foods accumulate endogenous protein that can be used to breed earlier.

scholarly journals Variation in Foraging Behavior, Diet, and Time of Breeding of Florida Scrub-Jays in Suburban and Wildland Habitats

The Condor ◽  
2003 ◽  
Vol 105 (3) ◽  
pp. 515-527 ◽  
Author(s):  
Arthur L. Fleischer ◽  
Reed Bowman ◽  
Glen E. Woolfenden
Keyword(s):  
Food Consumption ◽  
Foraging Efficiency ◽  
Timing Of Breeding ◽  
Food Handling ◽  
Florida Scrub ◽  
Supplemental Food ◽  
Aphelocoma Coerulescens ◽  
Consumption Rates ◽  
Time Of Breeding ◽  
Ad Libitum

Abstract Supplemental food enables some birds to lay eggs earlier, perhaps by allowing birds to increase their energy intake or allocate energy from other activities to reproduction. We examined the relationships between prelaying behavior, food handling and consumption rates, and the timing of breeding of female Florida Scrub-Jays (Aphelocoma coerulescens) in suburban and wildland habitats. Scrub-jays in suburban habitats had access to ad libitum human-provided foods; wildland jays did not. During both years of this study, suburban scrub-jays bred earlier than their wildland counterparts. Wildland scrub-jays bred earlier in 1997 than in 1996, but the timing of breeding by suburban scrub-jays did not vary between years. Suburban scrub-jays spent less time foraging and more time perching than wildland jays. They handled more food per hour and per foraging hour, suggesting their foraging was more efficient. Despite this, food consumption rates did not differ between the two habitats. Neither time spent foraging or perching nor food consumption rates significantly influenced variation in time of breeding among individuals. Time of breeding was significantly influenced by site, year, and rate of food handling. Individuals that handled more food items per foraging hour, that is, those individuals that were most efficient, were the earliest breeders in both habitats. These results suggest that foraging efficiency increases with access to human-provided food and that resource predictability may be a perceptual cue for the appropriate timing of breeding. Variación en el Comportamiento de Forrajeo, la Dieta y la Época de Reproducción de Aphelocoma coerulescens en Ambientes Suburbanos y Silvestres Resumen. El alimento suplementario le permite a algunas aves poner huevos más temprano, quizás aumentando su ingestión de energía o permitiendo cambiar la asignación de energía de otras actividades a la reproducción. En este estudio examinamos las relaciones entre el comportamiento pre-postura, la manipulación de alimento y la tasa de consumo con la época de reproducción de hembras de la especie Aphelocoma coerulescens en ambientes suburbanos y silvestres. Las aves en ambientes suburbanos tenían acceso a alimento provisto ad libitum por humanos, mientras que las aves de las áreas silvestres no. Durante los dos años de estudio, las aves suburbanas se reprodujeron más temprano que las de las áreas silvestres. Las aves de áreas silvestres se reprodujeron más temprano en 1997 que en 1996, pero la época reproductiva de las aves de áreas suburbanas no varió entre años. Las aves suburbanas pasaron menos tiempo forrajeando y más tiempo perchadas que las de áreas silvestres, y además manipularon más alimento por hora y por hora de forrajeo, lo que sugiere que forrajearon más eficientemente. Sin embargo, las tasas de consumo de alimento no difirieron entre los dos ambientes. La variación entre individuos en el momento de la reproducción no fue influenciada significativamente por el tiempo invertido en forrajeo o descanso ni por la tasa de consumo de alimento, pero sí por el sitio, el año y la tasa de manipulación de alimento. Los individuos que manipularon más ítems alimenticios por sesión de forrajeo (los más eficientes), fueron los que se reprodujeron más temprano en ambos ambientes. Estos resultados sugieren que la eficiencia de forrajeo aumenta con el acceso a alimentos provistos por humanos y que la predecibilidad de los recursos podría ser percibida como una señal indicadora del momento de reproducción adecuado.

Reproductive ecology of wild tammar wallabies in natural and developed habitats on Garden Island, Western Australia

2012 ◽  
Vol 60 (2) ◽  
pp. 111 ◽  
Author(s):  
Lisa E. Schwanz ◽  
Kylie A. Robert
Keyword(s):  
Body Condition ◽  
Western Australia ◽  
Annual Variation ◽  
Environmental Changes ◽  
Reproductive Traits ◽  
Tammar Wallaby ◽  
Supplemental Food ◽  
Macropus Eugenii ◽  
Seasonally Breeding ◽  
Naval Base

Reproduction may be influenced by major environmental changes experienced by an entire population as well as variation within a population in maternal resource availability or quality. We examined relationships between body condition and reproductive traits in two wild populations of the seasonally breeding tammar wallaby (Macropus eugenii) on Garden Island, Western Australia, that differed in access to supplemental food resources. Body condition changed predictably over the year, with females losing condition over the dry summer and gaining condition over the winters, when lactation occurs and most annual precipitation falls. Body condition influenced reproduction, with females of greater body condition more likely to have a pouch young, and to have a larger pouch young, early in the reproductive season. This intrapopulation pattern was opposite to that seen across populations – females in a native bushland were in poorer condition yet were more likely to have pouch young, and had larger pouch young, in March than did females living in a water-supplemented habitat on a naval base. Body condition did not influence the probability of weaning a pouch young in a year, nor did reproductive success influence changes in body condition across seasons. Instead, annual variation in precipitation had a dramatic effect on population weaning success in the native bushland, but not on the naval base. In summary, individual variation in body condition as well as large climatic variation influenced the reproduction of tammar wallabies on Garden Island, but the nature of the effect depended on the different habitats experienced by the two study populations.

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