Biology 342 Fall 2010
(scroll below titles to see the assignment details)
ET and Lindsey Dono --- abstract --- poster
Caw of Duty- Suburban Warfare
CROWS VENDING MACHINES OR MACHINES VENDING CROWS
Dec 10 - Abstracts
Dec 15th - Assessment ON OR BEFORE POSTER PRESENTATION
Dec 15th - Poster Evaluations
Quinn Amacher & Isabel Cylinder
It has been shown that visual exposure to a predator reverses female guppies’ usual preference for flashy males (1). In other studies regarding effects on female mate choice, an “upper-range” has been established for the flashiness of males, where a male that is bright enough will override any reversal imposed by an effect (2). Can an exceptionally flashy male override the predation effect? Female mate choice preference was measured before and after visual exposure to a predator by total time spent in the proximity of males housed in adjacent tanks. Results failed to demonstrate not only an override of a predation effect, but also any predation effect itself. Our ability to construct a varied spectrum of flashiness in males was limited by available resources. Our results have led us to reconsider our experimental design based on the potential for experimenter artifact.
Emily Crotteau & Michelle Ichikawa
In the wild, animals must often expose themselves to the risk of predation while foraging, so they must make trade-offs between food acquisition and potential harm. Studies have shown that crayfish vary their response to predation based on hunger and perceived value of the food. Because the common commercially available crayfish, Procambarus clarkii, has become an invasive species in the Pacific Northwest, this research sought to explore foraging behaviors and predation responses where interspecies variation could leave native crayfish at a disadvantage. The experiment consisted of testing unpaired fed and unfed crayfish with two types of predatory stimuli while in the presence of a food source. The two treatments were fast, aerial splashing and a slowly passing fish-shaped shadow, representative of wild crayfish predators. Response type and duration were recorded, in addition to the occurrence of feeding. The results indicate that response type is correlated to the type of stimulus, but hunger and feeding behaviors were not found to have significant influence. In conjunction with previous research, our results indicate that P. clarkii modify their response to predation, but it is unclear how the perceived value of food modulates their response. This adaptation may be related to the success of P. clarkii at invading new habitats, but further research must be done to see how this plays into interspecific competition for resources and predator avoidance.
Amelia Munson & Megana Sankaran
The lorikeets in Lorikeet Landing at the Oregon Zoo are living in a vastly different environment than they would be in the wild. The number one difference is increased rainfall and lower average temperatures. Although these birds are captive bred, many animals held in captivity exhibit stereotypic behavior as a result of stress. We looked at the amount of time the lorikeets spent inside as a function of the weather (sun or rain). We then looked at the number of birds grooming as is it a stereotypic behavior often seen in parrots in captivity. The birds are more likely to be inside when it is raining. We found that birds are more likely to spend time grooming when they are indoors than out. When they are in the outside portion of the enclosure there are more naturalistic features for them to interact with thus decreasing stress induced behaviors. Overall, this suggests that in climates with heavy rainfall zoos must pay special attention to enhance the indoor enclosures of lorikeets in order to decrease stereotypic behavior.
Caitlin Miller & Madeline Dansky
This study investigates the effect of increasing the number of males in the presence of a focal female on male sexual behaviors and courtship interactions in the guppy (Poecilia reticulata). If male guppies are able to perceive the relative ratios of males to females at a given time, males theoretically may be expected to adjust their sexual behaviors and aggression based on the competitive demands of a situation. Three components of guppy male sexual behavior were examined: display behavior, rapid 'swim spurts', and aggressive nipping at a focal female. Behavioral trials were performed on 8 male guppies that were subjected to a series of trials consisting of three different treatments in which 1 male, 2 males or 4 males were exposed to a single female. Both the males and females in the experiment had been isolated from the other sex for at least two weeks, and in each trial a novel female of approximately the same size was used. The behaviors of each male guppy were recorded continuously in 10-minutes trials that were performed over the course of a five-day period. During which, the trial order, treatments, and male assignments were all systematically randomized. Experimental analysis of this relationship in the guppy demonstrates that males showed a statistically significant increase in aggressive behaviors (nips at female). There was no statistical decrease in courtship (the number of displays) with an increase in the number of males present, but this trend was noted across trials. These results suggest that males recognize the competing presence of other males, spending less time performing courtship displays and undergoing aggressive sexual behavioral escalation
Nathaniel Raley and Rachel Baden
Scientists have long known that patterns in bird vocalizations can communicate information to both conspecifics and other species. This experiment was designed to investigate acoustic patterns in the intraspecific vocalizations of a wild population of American Crows (Corvus brachyrhynchos) on Reed College campus. We explored whether the environmental, social and behavioral contexts of the call had any effect on its acoustic properties. In the course of our fieldwork, we used a digital audio recorder and parabolic microphone to capture over 200 crow calls, which were analyzed using the free software Raven Lite. Six different acoustic properties were noted for each call, in addition to contextual variables. We found several characteristic call patterns, which differed significantly depending on the size of the group and the behavior accompanying the call. Preliminary analysis suggests that environmental factors such as location and time of day have no significant effect on call structure, and that variability is better explained by behavioral and social circumstances. Based on our findings, we conclude that the population of crows at Reed College uses different calls depending on context.
Jack Craig & Matt Yee
This experiment attempts to discover whether housing male guppies in the presence of their own sex, females, or alone, has an effect on their latency to display to a new female and the number of subsequent displays he offers. We housed 8 males (2 alone, 4 together, and 2 in separate tanks with 3 females each) for three weeks, then observed the interactions of each with a new female, recording latency and number of displays. We predicted that males housed alone or with other males would be faster and more frequent in their displays, the other treatment having been accustomed to the presence of females and therefore spared from whatever effects of deprivation may have. This would indicate that readiness to display is not strictly a genetically determined trait, but is instead malleable based on environmental factors. It seems logical that, in an environment with few females, the existing males should become more ready to spawn. Analyzing the data revealed results opposite of our hypothesis. A trend between displays in males housed alone and males housed with females was found along with a statistically significant difference in latency to display, both suggesting that males raised with females are more willing to mate when compared to males raised alone. Due to a wide variance in data from males housed with other males, we cannot make any conclusions about the willingness in males to mate in this environment. Future experiments should use a larger sample size to help yield clearer results.
Lucy Sudekum and Colin Townes-Anderson
Previous studies have shown that rate of learning, used as a scale of intelligence, in the common male guppies (Poecillia reticulata) increases their desirability in mate selection by female guppies over percent color saturation and body size. To show that male guppies have the ability to learn a maze while increasing their rate of completion was tested to affirm that guppies have the ability to learn and that their intelligence is quantifiable. To test this, we isolated male eight male guppies and introduced them to a maze with bloodworms at the end of the maze as a food incentive within ten minutes. The guppies were tested over a period of eight days and the rate at which they were able to finish the maze was recorded as a rate of learning. The results from this experiment show that there is no significant indicator of maze-learning ability in the guppies tested, due to the majority of the guppies not completing the maze within the allotted time period. However, we deem theses results inconclusive and call for further testing with a larger sample size, longer test period and flake fish food as the maze-completion incentive.
Chris Galvin, Katrina Gertz, Maria Zapetis
Weakly electric fish use electrolocation as a piltoing mechanism to navigate in the wild. Apteronotus albifrons were trained to seek a shelter in a maze consisting of an electric roadmap of alternating copper and PVC landmarks. They showed a correlation in total time taken to successfully navigate the maze over a period of 7 days, indicating path acquisition. With maze barriers removed and landmarks in place, the fish qualitatively exhibited the use of electrosense and landmark orientation in path recall.
Food choice in animals can be a crucial decision, determining not only the animal's nutrient intake, but also its social context. A recent study has found that, due to the makeup of their gut bacteria, Drosophila melanogaster raised on different types of food preferred mates that had been raised on the same foods as they had and that this mate choice preference was heritable (1). To examine whether food choice in Drosophila echoed the pattern observed in mate choice, wild-caught fruit flies were bred. Their offspring were separated by sex and given a choice in a Y-maze between two food sources: standard starch fly food mixed with molasses or applesauce. The flies were fed and mated on the food they had chosen; the offspring, upon emerging, were separated by sex and given the same type of choice. It was found that the progeny showed no preference for one food over the other regardless of what their parents had eaten. Though more data are needed for this conclusion to be drawn with any significance, it is possible to imagine many reasons outside of faulty experimental design for this lack of consistency in food preference by generation, such as the evolutionary benefit of opportunistic food choice.
Emily Fong and Emily Zhang
Allelic variation on the foraging gene in Drosophila melanogaster results in two different strains, rover and sitter, that demonstrate significantly different food searching strategies as larvae. Those with the rover allele move more than those with the sitter allele during feeding. In adulthood, Pereira and Sokolowski reported that rover males copulate faster and for longer periods of time than sitter males (1991). Additionally, rover males exhibited more instances of courtship behavior such as wing vibrations and licking, which most likely contributed to their mating success. Based on this information, we decided to examine whether or not the strain of the partner has an effect on mating behavior. For instance, are rover males more likely to mate faster with rover or sitter females? Prior to behavioral observations, a total of 120 virgin Drosophila of both strains were separated by gender and placed in individual eppendorf tube. The flies were then sorted into pairs of rover-rover, sitter-sitter, rover male-sitter female, and sitter male-rover female. Three pairs from each group were observed per one-hour trial during which the flies' courtship latency, mating latency, copulation latency, copulation duration, and number of mating attempts made (after initial mating attempt) were recorded. A total of 5 trials were conducted. Results did not reproduce Pereira and Sokolowski's data, and no significant effect was found across strains and conditions, although a slight correlation between 1st courtship and 1st mating attempt latencies was observed. Only one pair of flies successfully mated, so that measure could not be analyzed. In light of these results, continuations using larger sample sizes and more trials are suggested, as is ascertaining ideal mating times (in order to ensure mating success).
Jason Leonard Neil Evans and Meg Moeller
Previous studies have found that fiddler crabs in the wild exhibit the "dear enemy" phenomenon, meaning they tend to fight more aggressively with outsider crabs than with neighbors. It is not known whether this is because they recognize their neighbor or because they have less to lose. We studied the fiddler crab (Uca pugilator) in a laboratory setting to discover whether they would recognize their neighbor in a neutral area. Aggressive behavior was recorded via behavioral sampling and was used to measure recognition. We did not find any significant difference in aggression levels between neighbor interactions and outsider interactions. Even though no significant results were found, if we had included non-aggressive contact behavior in our ethogram and had more crabs we might have seen a significant difference.
Graham Myers and Esther Ladizinsky
Mechanisms behind mate choice have been brought under scrutiny in nearly all fields of animal behavior study. Guppies provide a good model for exploring this aspect of biology due to their easily measurable displays during courtship. In our research, we sought to determine the extent to which these displays ensure success in mating. This was accomplished by pitting the courtship displays of two males from different breeds (fancy and standard) against each other in a mate choice paradigm. Both fancy and standard females were used to determine the attractiveness of males from both breeds. However, our research produced no significant results. Based on an ANOVA, neither average time spent viewing a male (p=0.2792 for fancy females and p=0.8322 for std. females), nor the number of interactions with a male (p=0.1294 for fancy females and p=1.0000 for std. females) were conclusive in determining a preference. Our results were not entirely dismissible though, as the fact that females did not prefer one breed or the other is unexpected and informative; one would suppose that they would prefer their own breed.
Zina Jenny and Terra
Male guppies will preferentially display their more orange side to females during courtship (Gross M. R. 2007). This experiment aimed to determine whether or not the guppies learned which of their sides was more orange based on cues from a female that they courted. This was tested by injecting orange elastomer into the less favored side of male guppies and observing whether or not their side preference changed accordingly. Each male was placed with a female, chosen randomly, for an observed trial prior to injection. They were then allowed an unobserved trial (learning trial) with another random female about a week after injection. The final observational trial was done within two days of the learning trial. Each trial started with the male and female separated in the tank by an opaque barrier. They were allowed to adjust for 10 minutes. The barrier was removed and data gathering began at the first interaction between the male and female. Data collection using the program JWatcher ran for thirty minutes and then the trial ended. Due to abysmally small sample size, a chi square analysis did not provide statistically significant results. However, several of the individual fish did exhibit a change in side display preference, which was the predicted behavior. We began the experiment with a sample size of n = 20. Over the course of experimentation, 12 of the males died before all three trials were completed, thus they were not able to provide data for analysis.
Briana Patton, Lisa Schomaker, Ella Gray
Female guppies (Poecilia reticulata) make their mate choice based on the male's body coloring, preferring more brightly colored 'flashier' males. The female's ability to distinguish between genuinely and artificially colored males was tested by comparing female interest in males of varying degrees of orange coloration under different lighting conditions. Each male was displayed to eighteen different females under orange light, blue light, and natural light. Orange lighting was intended to enhance the male's orange coloration, the blue light to diminish it. If the female were able to identify natural orange coloration under artificial lighting, it would be expected that the naturally more orange male would be preferred in all lighting conditions. However, this would indicate that a factor highly correlated with color rather than color itself was influencing mate choice. Analysis of data collected from the eighteen trials found that females significantly preferred the less orange male under orange lighting conditions, but was equally interested in both males under all other lighting conditions.
Mischka Moechtar & Amber Bang
Serotonin, or 5-HT, is known to enhance agonistic behavior in crayfish, which can influence aggressive encounters aimed at attaining dominance. We applied this to study the effect of two competing factors that influence dominance: the addition of serotonin, and resident-intruder status dynamics. Crayfish are freshwater crustaceans known to exhibit aggressive behavior towards others for control of resources. As the resource is space in this experiment, resident crayfish, having already established dominance over territory, are more likely to win aggressive encounters against intruding crayfish in establishing dominance (Peeke et al.1995, Ranta Linstrom 1992). We hypothesized that crayfish with added serotonin would exhibit more aggressive behavior in comparison to the control crayfish, and that this would be evident through which crayfish demonstrated more dominance in each encounter. We used 12 pairs of crayfish comprised of one resident and one intruder in each pair, matched evenly by size determined by a principal component analysis. Serotonin creatinine sulfate complex was injected into intruders designated to the experimental group, and they were placed in resident territory for 15 minutes to observe interactions. Control group intruders were injected with a saline solution. The occurrence of attack, approach, retreat and escape behaviors was recorded, and assigned dominance/winning points. Using a chi-square analysis, we found that though there was a slight correlation between aggression levels and the addition of serotonin, this did not significantly enhance aggression in the experimental intruders.
Mikey Badr & Will Gester
The Siamese Fighting Fish (Betta Splendens) is characterized by aggressive tendencies in the males. In addition to providing a fitness advantage in wild, aggressive behavior has been selected for in captive populations. Previous experiments have successfully conditioned similarly aggressive fish to attenuate aggression in anticipation of a mating opportunity. Male Bettas (n=8) were measured and distributed into conditioned (experimental) and unconditioned (control) group, accounting for size. We attempted to use classical conditioning techniques to teach male Bettas to anticipate the presence of another male by associating exposure to a mirror (which previous experiments have shown to elicit a equivalent reaction to another male) with a red light. After a number of conditioning sessions, the males who had been trained to associate the light with an upcoming conflict were placed in an arena separated from a control male by an opaque divider. After presentation of the light, the divider was lifted and aggressive behavior was scored over ten minutes for both fish using an ethogram. Statistical analysis revealed no significant association between aggressive behavior and conditioning treatment or body size.
Geoff Derven, Wren Kominos-Marvell, Frank Sosa
Black Ghost Knifefish emit low voltage signals with an electric organ through a process known as Electric Organ Discharge (EOD). As their vision is poor, this EOD allows them to distinguish between minute changes in their environment, thereby providing Knifefish with a means for electrolocation. For our experiment, three Knifefish were placed in separate tanks, each faced with an identical pathway of plastic and metal cubes. The cubes were ordered so that there was an increase in metal at the end of the tank, where a food sample was also placed. The Knifefish were then repeatedly timed for locating the food. Once the food-path was learned, the cubes were reversed, altering the electrical field of their environment. Although there was clear evidence of path learning, this means that no significant difference was found from switching the cubes. As the Knifefish were observed with continuous behavioral sampling, one Knifefish was noted to be much faster at finding the food after the cube shift, while another Knifefish took much longer. These results point to the possibility of other sensory means as factor in Knifefish navigation.
Rebecca Shafer & Genevra Kuziel
Corvus brachyrhynchos, the common American crow, is a small, resourceful, and cautious bird. These crows cohabitate the Reed campus area with larger, bolder birds: several species of seagulls. In the winter, the crows congregate in large numbers at a communal roost (location unknown) at night and during the day travel in fixed smaller groups to regular feeding places called Diurnal Activity Centers. In our experiment we drove to different DACs in southeast Portland that ranged from 1-20 birds (averaging appr. 5 birds) and poured 2 cups of croutons ~30 feet from our car. We then watched and scored behaviors as the initial group of birds ate, hoarded, and hid the food before or after calling other crows to the area with the distinctive caw caw caw call. In about half of our trials seagulls entered the food site and would always consume the remaining food in a matter of seconds. We examined the data with regard to marginal value theorem and game theory. Because the circumstances of each trial were so different (number of crows, number of seagulls, locations of other crows and seagulls, random inexplicable behaviors of the birds) our data returned somewhat inconclusive results.
MoMovius feat Swesley on da beats
Orange coloration in guppies has been positively correlated with female mate choice. This is accepted to be an honest indicator because elevated systemic carotenoid levels are positively correlated with strength of immune response, as well as with sperm motility. However, the relationship between skin pigmentation and carotenoid levels in the major organs has never been tested. This study attempts to elucidate the relationship between carotenoid area in skin and liver carotenoid absorbance, as well as the effect of this relationship on dichotomous mate choice. Twenty male guppies were randomly separated into carotenoid high and carotenoid low diet treatment groups, and were maintained on this diet for ten days. The carotenoid high group received fancy guppy food (Abs@420 = 0.632), while the low carotenoid group was fed yolk food (Abs@420 = 0.280). While this diet did slightly elevate liver carotenoids in the high carotenoid treatment, no significant difference was observed for skin or liver carotenoid levels between the two experimental treatments. Female mate choice did not reflect a preference for either of the treatment groups. This may be due to the lack of a significant difference between the carotenoid levels of the two groups. This experiment should be carried out over a longer period of time in order to garner definitive results in the future.
This was an experiment to see if wild American crows can be taught to recognize an object and associate it with an action to gain a food reward. I made and set up a vending machine which, whenever a quarter slid down a ramp, dispensed an amount of food (dogfood proved to be the most successful) onto a main feeding tray. It was hoped that the crows would learn to associate the quarter sliding down the ramp with the dispensing of dogfood. Unfortunately, no crow was ever observed making this connection, despite the fact that quarters were accidentally knocked down the ramp by just the shaking of the machine by crows were landing on it. Difficulties also arose in getting crows to engage the machine at all- a series of baits were attempted and discarded before settling on dog food, a small amount of food had to be placed on the feeding tray initially to get them to investigate, and data about the likely locations of crows on the campus of Reed college had to be collected in order to place and set up the machine. Luckily, where murders of crows congregated to forage was fairly consistent in both the where and when. Data was collected by both ad libitum and video recordings of crows approaching and feeding from the initial baiting of the machine. Either a large murder would flock around it (the ones on the ground not actively feeding would just stare up and watch) or a small group of 3-4 would occasionally interact with it.
Quinn Langdon and Katherine Thomas
The Drosophila melanogaster gene eagle (eg), is part of the nuclear hormone receptor superfamily, a known transcription factor, and acts as a zinc finger protein. Furthermore, eg is known to be involved in serotonin neuroblast fate determination. In recent years, QTL analyses have identified eg, among other genes, as being involved in the determination of fly mating speed. However, the precise role that eg plays in effecting mating has not yet been elucidated. To further identify this role, three-day-old adult male flies were assayed for their mating behaviors with equally aged virgin females. The male flies were then categorized into one of three groups: mated flies, who copulated with the female, unmated flies, who actively courted but did not copulate with a female, and virgin males, who were kept isolated from females. Q-PCR was then utilized to quantify eg expression of the flies to determine if there were expression differences between mated, unmated, and virgin males. Q-PCR results indicated that eg expression was not significantly different in unmated versus mated flies. However, the data did show that eg was expressed at significantly higher levels in male flies exposed to females as compared to virgin males.
Lauren Carley, Michael Turvey & Jessie Ellington
Previous research has shown that schooling behavior in fish functions to protect groups from predators, provide hydrodynamic benefits and enhance foraging. (1) The prevalence of schooling in many fish species and its various functions in fish populations led us to question whether threespine stickleback (Gasterosteus aculeatus) in environments near Reed College exhibit schooling behavior. Furthermore, studies have shown population-based differences in schooling behavior within species. (2, 3) To examine these differences, we observed schooling behavior in threespine stickleback caught from two different, isolated ecosystems: Reed Lake and Ritmanis Pond. We also investigated the effects of hunger stress on schooling behavior by starving the fish for at least two days prior to testing using two different experimental paradigms. The results of a netting assay showed that stickleback from Ritmanis Pond are caught in significantly larger groups than those from Reed Lake, suggesting that they are more likely to school (p= 0.02); however, feeding condition didn't have an effect on schooling behavior. In a second experiment, fish from Reed Lake were more likely to follow a motorized decoy fish than fish from Ritmanis Pond (p= 0.0031), although tendency to follow the decoy was low in both populations (range from 0-6.8% when observed with scan sampling at 30-second intervals). Interestingly, the results of the decoy test also suggest a gene-by-environment interaction on schooling behavior, although it is not statistically significant (p=0.12).
1. Landa, J (1998). Environmental Biology of Fishes 58(4):353-364.