Foraging : an Ecology Model of Consumer Behaviour?
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Foraging Modes of Carnivorous Plants Aaron M
Israel Journal of Ecology & Evolution, 2020 http://dx.doi.org/10.1163/22244662-20191066 Foraging modes of carnivorous plants Aaron M. Ellison* Harvard Forest, Harvard University, 324 North Main Street, Petersham, Massachusetts, 01366, USA Abstract Carnivorous plants are pure sit-and-wait predators: they remain rooted to a single location and depend on the abundance and movement of their prey to obtain nutrients required for growth and reproduction. Yet carnivorous plants exhibit phenotypically plastic responses to prey availability that parallel those of non-carnivorous plants to changes in light levels or soil-nutrient concentrations. The latter have been considered to be foraging behaviors, but the former have not. Here, I review aspects of foraging theory that can be profitably applied to carnivorous plants considered as sit-and-wait predators. A discussion of different strategies by which carnivorous plants attract, capture, kill, and digest prey, and subsequently acquire nutrients from them suggests that optimal foraging theory can be applied to carnivorous plants as easily as it has been applied to animals. Carnivorous plants can vary their production, placement, and types of traps; switch between capturing nutrients from leaf-derived traps and roots; temporarily activate traps in response to external cues; or cease trap production altogether. Future research on foraging strategies by carnivorous plants will yield new insights into the physiology and ecology of what Darwin called “the most wonderful plants in the world”. At the same time, inclusion of carnivorous plants into models of animal foraging behavior could lead to the development of a more general and taxonomically inclusive foraging theory. -
EXTRA-PAIR MATING and EFFECTIVE POPULATION SIZE in the SONG SPARROW (Melospiza Melodia)
EXTRA-PAIR MATING AND EFFECTIVE POPULATION SIZE IN THE SONG SPARROW (Melospiza melodia) By Kathleen D. O'Connor B.A., Skidmore College, 2000 A THESIS SUBMITTED IN PARTIAL FUFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES THE FACULTY OF FORESTRY Department of Forest Sciences Centre for Applied Conservation Research We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA April 2003 © Kathleen D. O'Connor, 2003 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of Fpce_t Sciences The University of British Columbia Vancouver, Canada Date 2HApc. 20O5 DE-6 (2/88) Abstract Effective population size is used widely in conservation research and management as an indicator of the genetic state of populations. However, estimates of effective population size for socially monogamous species can vary with the frequency of matings outside of the social pair. I investigated the effect of cryptic extra-pair fertilization on effective population size estimates using four years of demographic and genetic data from a resident population of song sparrows (Melospiza melodia Oberholser 1899) on Mandarte Island, British Columbia, Canada. -
Water Stress Inhibits Plant Photosynthesis by Decreasing
letters to nature data on a variety of animals. The original foraging data on bees Acknowledgements (Fig. 3a) were collected by recording the landing sites of individual We thank V. Afanasyev, N. Dokholyan, I. P. Fittipaldi, P.Ch. Ivanov, U. Laino, L. S. Lucena, bees15. We find that, when the nectar concentration is low, the flight- E. G. Murphy, P. A. Prince, M. F. Shlesinger, B. D. Stosic and P.Trunfio for discussions, and length distribution decays as in equation (1), with m < 2 (Fig. 3b). CNPq, NSF and NIH for financial support. (The exponent m is not affected by short flights.) We also find the Correspondence should be addressed to G.M.V. (e-mail: gandhi@fis.ufal.br). value m < 2 for the foraging-time distribution of the wandering albatross6 (Fig. 3b, inset) and deer (Fig. 3c, d) in both wild and fenced areas16 (foraging times and lengths are assumed to be ................................................................. proportional). The value 2 # m # 2:5 found for amoebas4 is also consistent with the predicted Le´vy-flight motion. Water stress inhibits plant The above theoretical arguments and numerical simulations suggest that m < 2 is the optimal value for a search in any dimen- photosynthesis by decreasing sion. This is analogous to the behaviour of random walks whose mean-square displacement is proportional to the number of steps in coupling factor and ATP any dimension17. Furthermore, equations (4) and (5) describe the W. Tezara*, V. J. Mitchell†, S. D. Driscoll† & D. W. Lawlor† correct scaling properties even in the presence of short-range correlations in the directions and lengths of the flights. -
Predation Risk and Feeding Site Preferences in Winter Foraging Birds
Eastern Illinois University The Keep Masters Theses Student Theses & Publications 1992 Predation Risk and Feeding Site Preferences in Winter Foraging Birds Yen-min Kuo This research is a product of the graduate program in Zoology at Eastern Illinois University. Find out more about the program. Recommended Citation Kuo, Yen-min, "Predation Risk and Feeding Site Preferences in Winter Foraging Birds" (1992). Masters Theses. 2199. https://thekeep.eiu.edu/theses/2199 This is brought to you for free and open access by the Student Theses & Publications at The Keep. It has been accepted for inclusion in Masters Theses by an authorized administrator of The Keep. For more information, please contact [email protected]. THESIS REPRODUCTION CERTIFICATE TO: Graduate Degree Car1dichi.tes who have written formal theses. SUBJECT: Permission to reproduce theses. The University Library is receiving a number of requests from other institutions asking permission to reproduce dissertations for inclusion in their library holdings. Although no copyright laws are involved~ we feel that professional courtesy demands that permission be obtained from the author before we ~llow theses to be copied. Please sign one of the following statements: Booth Library o! Eastern Illinois University has my permission to lend my thesis tq a reputable college or university for the purpose of copying it for inclul!lion in that institution's library or research holdings. Date I respectfully request Booth Library of Eastern Illinois University not allow my thesis be reproduced because ~~~~~~-~~~~~~~ Date Author m Predaton risk and feeding site preferences in winter foraging oirds (Tllll) BY Yen-min Kuo THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Master of Science in Zoology IN TH£ GRADUATE SCHOOL, EASTERN ILLINOIS UNIVfRSITY CHARLESTON, ILLINOIS 1992 YEAR I HEREBY R£COMMEND THIS THESIS BE ACCEPTED AS FULFILLING THIS PART or THE GRADUATE DEGREE CITED ABOVE 2f vov. -
Mimicry - Ecology - Oxford Bibliographies 12/13/12 7:29 PM
Mimicry - Ecology - Oxford Bibliographies 12/13/12 7:29 PM Mimicry David W. Kikuchi, David W. Pfennig Introduction Among nature’s most exquisite adaptations are examples in which natural selection has favored a species (the mimic) to resemble a second, often unrelated species (the model) because it confuses a third species (the receiver). For example, the individual members of a nontoxic species that happen to resemble a toxic species may dupe any predators by behaving as if they are also dangerous and should therefore be avoided. In this way, adaptive resemblances can evolve via natural selection. When this phenomenon—dubbed “mimicry”—was first outlined by Henry Walter Bates in the middle of the 19th century, its intuitive appeal was so great that Charles Darwin immediately seized upon it as one of the finest examples of evolution by means of natural selection. Even today, mimicry is often used as a prime example in textbooks and in the popular press as a superlative example of natural selection’s efficacy. Moreover, mimicry remains an active area of research, and studies of mimicry have helped illuminate such diverse topics as how novel, complex traits arise; how new species form; and how animals make complex decisions. General Overviews Since Henry Walter Bates first published his theories of mimicry in 1862 (see Bates 1862, cited under Historical Background), there have been periodic reviews of our knowledge in the subject area. Cott 1940 was mainly concerned with animal coloration. Subsequent reviews, such as Edmunds 1974 and Ruxton, et al. 2004, have focused on types of mimicry associated with defense from predators. -
Photosynthetic Pigments Estimate Diet Quality in Forage and Feces of Elk (Cervus Elaphus) D
51 ARTICLE Photosynthetic pigments estimate diet quality in forage and feces of elk (Cervus elaphus) D. Christianson and S. Creel Abstract: Understanding the nutritional dynamics of herbivores living in highly seasonal landscapes remains a central chal- lenge in foraging ecology with few tools available for describing variation in selection for dormant versus growing vegetation. Here, we tested whether the concentrations of photosynthetic pigments (chlorophylls and carotenoids) in forage and feces of elk (Cervus elaphus L., 1785) were correlated with other commonly used indices of forage quality (digestibility, energy content, neutral detergent fiber (NDF), and nitrogen content) and diet quality (fecal nitrogen, fecal NDF, and botanical composition of the diet). Photosynthetic pigment concentrations were strongly correlated with nitrogen content, gross energy, digestibility, and NDF of elk forages, particularly in spring. Winter and spring variation in fecal pigments and fecal nitrogen was explained with nearly identical linear models estimating the effects of season, sex, and day-of-spring, although models of fecal pigments were 2 consistently a better fit (r adjusted = 0.379–0.904) and estimated effect sizes more precisely than models of fecal nitrogen 2 (r adjusted = 0.247–0.773). A positive correlation with forage digestibility, nutrient concentration, and (or) botanical composition of the diet implies fecal photosynthetic pigments may be a sensitive and informative descriptor of diet selection in free-ranging herbivores. Key words: carotenoid, chlorophyll, diet selection, digestibility, energy, foraging behavior, nitrogen, phenology, photosynthesis, primary productivity. Résumé : La compréhension de la dynamique nutritive des herbivores vivant dans des paysages très saisonniers demeure un des défis centraux de l’écologie de l’alimentation, peu d’outils étant disponibles pour décrire les variations du choix de plantes dormantes ou en croissances. -
Interpreting Temporal Variation in Omnivore Foraging Ecology Via
Functional Ecology 2009 doi: 10.1111/j.1365-2435.2009.01553.x InterpretingBlackwell Publishing Ltd temporal variation in omnivore foraging ecology via stable isotope modelling Carolyn M. Kurle*† Ecology and Evolutionary Biology Department, University of California, 100 Shaffer Road, Santa Cruz, CA 95060, USA Summary 1. The use of stable carbon (C) and nitrogen (N) isotopes (δ15N and δ13C, respectively) to delineate trophic patterns in wild animals is common in ecology. Their utility as a tool for interpreting temporal change in diet due to seasonality, migration, climate change or species invasion depends upon an understanding of the rates at which stable isotopes incorporate from diet into animal tissues. To best determine the foraging habits of invasive rats on island ecosystems and to illuminate the interpretation of wild omnivore diets in general, I investigated isotope incorporation rates of C and N in fur, liver, kidney, muscle, serum and red blood cells (RBC) from captive rats raised on a diet with low δ15N and δ13C values and switched to a diet with higher δ15N and δ13C values. 2. I used the reaction progress variable method (RPVM), a linear fitting procedure, to estimate whether a single or multiple compartment model best described isotope turnover in each tissue. Small sample Akaike Information criterion (AICc) model comparison analysis indicated that 1 compartment nonlinear models best described isotope incorporation rates for liver, RBC, muscle, and fur, whereas 2 compartment nonlinear models were best for serum and kidney. 3. I compared isotope incorporation rates using the RPVM versus nonlinear models. There were no differences in estimated isotope retention times between the model types for serum and kidney (except for N turnover in kidney from females). -
Foraging Ecology of a Winter Bird Community in Southeastern Georgia
Georgia Southern University Digital Commons@Georgia Southern Electronic Theses and Dissertations Graduate Studies, Jack N. Averitt College of Fall 2018 Foraging Ecology of a Winter Bird Community in Southeastern Georgia Rachel E. Mowbray Follow this and additional works at: https://digitalcommons.georgiasouthern.edu/etd Part of the Behavior and Ethology Commons, and the Population Biology Commons Recommended Citation Mowbray, Rachel E., "Foraging Ecology of a Winter Bird Community in Southeastern Georgia" (2018). Electronic Theses and Dissertations. 1861. https://digitalcommons.georgiasouthern.edu/etd/1861 This thesis (open access) is brought to you for free and open access by the Graduate Studies, Jack N. Averitt College of at Digital Commons@Georgia Southern. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of Digital Commons@Georgia Southern. For more information, please contact [email protected]. FORAGING ECOLOGY OF A WINTER BIRD COMMUNITY IN SOUTHEASTERN GEORGIA by RACHEL MOWBRAY (Under the Direction of C. Ray Chandler) ABSTRACT Classical views on community structure emphasized deterministic processes and the importance of competition in shaping communities. However, the processes responsible for shaping avian communities remain controversial. Attempts to understand distributions and abundances of species are complicated by the fact that birds are highly mobile. Many species migrate biannually between summer breeding grounds and wintering grounds. The goal of this study was to test four hypotheses that attempt to explain how migratory species integrate into resident assemblages of birds (Empty-Niche Hypothesis, Competitive-Exclusion Hypothesis, Niche-Partitioning Hypothesis, and Generalist-Migrant Hypothesis). I collected data on birds foraging during the winter of 2017-2018 in Magnolia Springs State Park, Jenkins County, Georgia, U.S.A. -
Nocturnal and Diurnal Foraging Behaviour of Brown Bears (Ursus Arctos) on a Salmon Stream in Coastal British Columbia
Color profile: Disabled Composite Default screen 1317 Nocturnal and diurnal foraging behaviour of brown bears (Ursus arctos) on a salmon stream in coastal British Columbia D.R. Klinka and T.E. Reimchen Abstract: Brown bears (Ursus arctos) have been reported to be primarily diurnal throughout their range in North America. Recent studies of black bears during salmon migration indicate high levels of nocturnal foraging with high capture efficiencies during darkness. We investigated the extent of nocturnal foraging by brown bears during a salmon spawning migration at Knight Inlet in coastal British Columbia, using night-vision goggles. Adult brown bears were observed foraging equally during daylight and darkness, while adult females with cubs, as well as subadults, were most prevalent during daylight and twilight but uncommon during darkness. We observed a marginal trend of increased cap- ture efficiency with reduced light levels (day, 20%; night, 36%) that was probably due to the reduced evasive behaviour of the salmon. Capture rates averaged 3.9 fish/h and differed among photic regimes (daylight, 2.1 fish/h; twilight, 4.3 fish/h; darkness, 8.3 fish/h). These results indicate that brown bears are highly successful during nocturnal foraging and exploit this period during spawning migration to maximize their consumption rates of an ephemeral resource. Résumé : Les ours bruns (Ursus arctos) sont généralement reconnus comme des animaux à alimentation surtout diurne dans toute leur aire de répartition. Les résultats d’études récentes sur les ours noirs durant la migration des saumons indiquent qu’ils font une quête de nourriture intense pendant la nuit et que l’efficacité de leurs captures est élevée à l’obscurité. -
Shell Resource Partitioning As a Mechanism of Coexistence in Two Co‑Occurring Terrestrial Hermit Crab Species Sebastian Steibl and Christian Laforsch*
Steibl and Laforsch BMC Ecol (2020) 20:1 https://doi.org/10.1186/s12898-019-0268-2 BMC Ecology RESEARCH ARTICLE Open Access Shell resource partitioning as a mechanism of coexistence in two co-occurring terrestrial hermit crab species Sebastian Steibl and Christian Laforsch* Abstract Background: Coexistence is enabled by ecological diferentiation of the co-occurring species. One possible mecha- nism thereby is resource partitioning, where each species utilizes a distinct subset of the most limited resource. This resource partitioning is difcult to investigate using empirical research in nature, as only few species are primarily limited by solely one resource, rather than a combination of multiple factors. One exception are the shell-dwelling hermit crabs, which are known to be limited under natural conditions and in suitable habitats primarily by the avail- ability of gastropod shells. In the present study, we used two co-occurring terrestrial hermit crab species, Coenobita rugosus and C. perlatus, to investigate how resource partitioning is realized in nature and whether it could be a driver of coexistence. Results: Field sampling of eleven separated hermit crab populations showed that the two co-occurring hermit crab species inhabit the same beach habitat but utilize a distinct subset of the shell resource. Preference experiments and principal component analysis of the shell morphometric data thereby revealed that the observed utilization patterns arise out of diferent intrinsic preferences towards two distinct shell shapes. While C. rugosus displayed a preference towards a short and globose shell morphology, C. perlatus showed preferences towards an elongated shell morphol- ogy with narrow aperture. Conclusion: The two terrestrial hermit crab species occur in the same habitat but have evolved diferent preferences towards distinct subsets of the limiting shell resource. -
Social Relations Chapter 8 Behavioral Ecology
Social Relations Chapter 8 Behavioral Ecology: Study of social relations. Studies interactions between organisms and the environment mediated by behavior 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Some differences between males and females…besides the obvious!!! • Females produce larger, more energetically costly gametes. • Males produce smaller, less energetically costly gametes. Female reproduction thought to be limited by resource access. Male reproduction limited by mate access. http://www.youtube.com/watch?v =NjnFBGW3Fmg&feature=related2 Hermaphrodites • Hermaphrodites Exhibit both male and female function. Most familiar example is plants. So, how do organisms choose their mate??? 3 Mate Choice • Sexual Selection Differences in reproductive rates among individuals as a result of differences in mating success. Intrasexual Selection: Individuals of one sex compete among themselves for mates. Intersexual Selection: Individuals of one sex consistently choose mates among members of opposite sex based on a particular trait. http://www.youtube.co m/watch? v=eYU4v_ZTRII 4 How much is too much??? • Darwin proposed that sexual selection would continue until balanced by other sources of natural selection • Given a choice, female guppies will mate with brightly colored males. However, brightly colored males attract predators. It’s a trade-off! 5 Class Activity!!! • In groups, using guys in a bar looking for dates example, come up with a scenario of sexual selection either going too far or succeeding!!! Be creative!!! 6 Sexual Selection in Plants??? Nonrandom Mating Found Among Wild Radish • Wild radish flowers have both male (stamens) and female (pistils) parts, but cannot self-pollinate. • Marshall found non-random mating in wild radish populations. -
Seabird Foraging Ecology
2636 SEABIRD FORAGING ECOLOGY Ballance L.T., D.G. Ainley, and G.L. Hunt, Jr. 2001. Seabird Foraging Ecology. Pages 2636-2644 in: J.H. Steele, S.A. Thorpe and K.K. Turekian (eds.) Encyclopedia of Ocean Sciences, vol. 5. Academic Press, London. SEABIRD FORAGING ECOLOGY L. T. Balance, NOAA-NMFS, La Jolla, CA, USA Introduction D. G. Ainley, H.T. Harvey & Associates, San Jose, CA, USA Though bound to the land for reproduction, most G. L. Hunt, Jr., University of California, Irvine, seabirds spend 90% of their life at sea where they CA, USA forage over hundreds to thousands of kilometers in a matter of days, or dive to depths from the surface ^ Copyright 2001 Academic Press to several hundred meters. Although many details of doi:10.1006/rwos.2001.0233 seabird reproductive biology have been successfully SEABIRD FORAGING ECOLOGY 2637 elucidated, much of their life at sea remains a mesoscales (100}1000km, e.g. associations with mystery owing to logistical constraints placed on warm- or cold-core rings within current systems). research at sea. Even so, we now know a consider- The question of why species associate with different able amount about seabird foraging ecology in water types has not been adequately resolved. At terms of foraging habitat, behavior, and strategy, as issue are questions of whether a seabird responds well as the ways in which seabirds associate with or directly to habitat features that differ with water partition prey resources. mass (and may affect, for instance, thermoregula- tion), or directly to prey, assumed to change with Foraging Habitat water mass or current system.