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Graduate School ETD Form 9 (Revised 12/07) PURDUE UNIVERSITY GRADUATE SCHOOL Thesis/Dissertation Acceptance This is to certify that the thesis/dissertation prepared By Juanita E. Losier Entitled THE EFFECTS OF MICROWAVE RADAR ON THE BEHAVIOR OF EUROPEAN STARLINGS (STURNUS VULGARIS) For the degree of Master of Science Is approved by the final examining committee: Esteban Fernandez-Juricic Chair Jeffrey Lucas Richard Howard To the best of my knowledge and as understood by the student in the Research Integrity and Copyright Disclaimer (Graduate School Form 20), this thesis/dissertation adheres to the provisions of Purdue University’s “Policy on Integrity in Research” and the use of copyrighted material. Esteban Fernandez-Juricic Approved by Major Professor(s): ____________________________________ ____________________________________ Approved by: Peter J. Hollenbech Head of the Graduate Program 12/05/2012 Date Graduate School Form 20 (Revised 9/10) PURDUE UNIVERSITY GRADUATE SCHOOL Research Integrity and Copyright Disclaimer Title of Thesis/Dissertation: THE EFFECTS OF MICROWAVE RADAR ON THE BEHAVIOR OF EUROPEAN STARLINGS (STURNUS VULGARIS) For the degree of Master Science Choose of your degree I certify that in the preparation of this thesis, I have observed the provisions of Purdue University Executive Memorandum No. C-22, September 6, 1991, Policy on Integrity in Research.* Further, I certify that this work is free of plagiarism and all materials appearing in this thesis/dissertation have been properly quoted and attributed. I certify that all copyrighted material incorporated into this thesis/dissertation is in compliance with the United States’ copyright law and that I have received written permission from the copyright owners for my use of their work, which is beyond the scope of the law. I agree to indemnify and save harmless Purdue University from any and all claims that may be asserted or that may arise from any copyright violation. Juanita E. Losier ______________________________________ Printed Name and Signature of Candidate 12/04/2012 ______________________________________ Date (month/day/year) *Located at http://www.purdue.edu/policies/pages/teach_res_outreach/c_22.html ! THE EFFECTS OF MICROWAVE RADAR ON THE BEHAVIOR OF EUROPEAN STARLINGS (STURNUS VULGARIS) A Thesis Submitted to the Faculty of Purdue University by Juanita E. Losier In Partial Fulfillment of the Requirements for the Degree of Master of Science December 2012 Purdue University West Lafayette, Indiana UMI Number: 1535056 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. UMI 1535056 Published by ProQuest LLC (2013). Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, MI 48106 - 1346 ii ! To PJ iii ! "#$%&'()*+),)%-.! ! ! ! /01223!+045367!.143!"4381607!(302!#5197!/32381!':2;<6=>0<?3<!124!/092!(024027! [email protected]!A3<3!93<3!;0<!B3!?93C3!51C?!?9<33!631<C!?91?!91D3!E023!180D3!124!836024= 5:C?32:[email protected]:2E!B3!A932!F!<12!1A167!124!G:HG:[email protected]?! ?93!400<!124!<3B:24:2E!B3!?91?!F!H12!1H9:3D3!?9:[email protected]!23D3<[email protected]<!;1:?9!:2!B3!20! B1??3<!90A!B126!?:[email protected]?34!B6C35;[email protected]!155!1<3!A91?!B1??3<!124!A:[email protected][email protected]!F! 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TABLE OF CONTENTS Page ABSTRACT.........................................................................................................................v CHAPTER 1: INTRODUCTION ........................................................................................1 CHAPTER 2: METHODS ...................................................................................................6 Bird Housing ............................................................................................................6 Experimental Setup ..................................................................................................6 Experiment ...............................................................................................................8 Behavioral Analysis .................................................................................................9 Surface Body Temperature Analysis .....................................................................10 Statistical Analysis .................................................................................................12 CHAPTER 3: RESULTS ...................................................................................................13 Reaction Time Results ...........................................................................................13 Behavioral Response Results .................................................................................13 Surface Body Temperature Results .......................................................................14 CHAPTER 4: DISSCUSSION ..........................................................................................15 LITERATURE CITED ......................................................................................................22 TABLES ............................................................................................................................28 FIGURES ...........................................................................................................................34 v ! ABSTRACT Losier, Juanita, E. M.S, Purdue University, December 2012. The Effects of Microwave Radar on the Behavior of European Starlings (Sturnus vulgaris). Major Professor: Esteban Fernandez-Juricic. Bird strikes account for an annual loss of $650,000,000 in the United States due to aircraft loss, damage, and delays; worldwide, there have been nearly 219 deaths since 1988. Investigations into novel methods of deterring birds from striking planes could ultimately lead to a decrease in loss of life and damage caused to aircraft. Previous observations suggest three things: 1) birds respond to aircraft as they would a predator, 2) birds can detect different levels of microwave frequencies and 3) birds might respond to microwaves produced by weather radar. The goal of this study was to determine whether birds react to microwaves produced by radar in the same way as they do to predators. I used wild caught European Starlings (Sturnus vulgaris), which were exposed to two treatments (radar or a stuffed ground predator) in an enclosure under semi-natural conditions. I found that the behavioral responses to the radar differed from those to the predator. When starlings were exposed to the predator, they moved and flew around the enclosure more frequently, moved their heads faster and hung from the walls of the enclosure longer, likely to track the predator visually. However, when starlings were exposed to the radar, they moved less and reduced their head movements. I did not find significant differences in the time to detect the radar compared to the predator. When starlings were exposed to the radar some body parts (back, cheek, chest, chest, and neck) had higher temperatures than when exposed to the predator; but I found the opposite temperature effect in their eyes and mouth. These results suggest that Starlings respond to radar by reducing their locomotive and visual exploration behaviors and increasing the temperature of some body parts, which may be associated with the hyperthermic effects that microwaves can cause in animals. Future work should focus on how these responses ! D:! may vary at different distances from the radar, which could have implications for the potential use of these devices to minimize bird strikes. 1 ! CHAPTER 1: INTRODUCTION A bird strike is the collision between a bird and an aircraft; and, currently, in 2012, there is no type of aircraft or airport that is immune to the hazardous threat of bird strikes. The Wright brothers recorded the first bird strike in 1905 when Orville Wright encountered a flock of birds in-flight (Cleary et al., 2005). Since this incident, bird strikes have been a problem. Overall strikes account for an annual loss of 650 million dollars in the United States alone (due to aircraft loss, damage, and delays; Dolbeer 2011; Dale 2009; Dolbeer 2009;); worldwide, there have been nearly 219 deaths since 1988 (Dolbeer 2011; FAA 2011). As human growth increases exponentially, the number of airports increases as well as the number of airplanes in the sky, both of which contribute to the threat of bird strikes. Various factors contribute to the possibility of bird strikes. Many airports are built with little regard to the bordering environment and organisms that inhabit them. For example, the natural habitat surrounding modern airports may provide shelter, food, and safety for a wide range of birdlife (Dolbeer 2011; Washburn et al. 2011; Blackwell et al., 2009a; Dolbeer 2009; Blackwell & Wright 2006; Dolbeer 2005). Airplanes are being built to produce less noise and fly faster, as jet travel replaces the piston-powered engine (FAA 2011; Dolbeer 2011). This has resulted in providing animals with less warning when planes are approaching, and less time to maneuver out of the way when alerted to the presence of an airplane (Dolbeer 2009; Beason 2004). The location of airports, the construction of airplanes as well as the abundance of birds in the area all have the potential to cause a disaster (DeVault et al., 2009). For example, while a larger bird can cause serious damage to a plane, so can flocks of smaller birds (DeVault et al., 2012; Dolbeer 2011; Bernhardt et al., 2010; Thorpe et al., 2010; Klope et al., 2009; Martin et al., 2011; Blackwell & Wright 2006; Bradwell et al., 2006). 2 ! Nowadays, there are multiple methods employed to lower the risk of bird strikes at airports. Most attempts have been concentrated in the vicinity of the airport, on the ground, such as trapping birds at airports, using trained falcons, loud noises (i.e. guns, recorded bangs), painted birds on runways to discourage live birds (ACRP 2011; Brenhardt et al., 2009; Barras et al., 2001), etc. However, there is no specific method that has been developed to minimize the chances of bird-strikes when aircraft are beyond the airport property (i.e., above 500 ft.). Some recent studies show that birds react to aircraft as they would an approaching predator. By looking at the remains of birds that have been struck by airplanes researchers can determine how birds react to approaching airplanes (Dove et al., 2009; Bernhardt et al., 2010). Bernhardt et al., (2010) preformed necropsies on birds that had been involved in bird strikes. Their observations indicated that birds that had been hit by airplanes had injuries indicating birds had been in the midst of an antipredator maneuver. There is anecdotal evidence suggesting that onboard weather radar could be used for deterring birds: some pilots have noticed the rapid dispersal of approaching flocks once they turn on their radar (T. DeVault, personal communication). However, there have been no empirical studies, under controlled conditions, assessing how birds respond to weather radar as a first step to determine its effectiveness as a potential bird deterrence technique outside of the airport property. Radars are used to detect information about distant objects (i.e. velocity of objects, types of approaching object, or changes in incoming weather patterns). To do this, radars transmit a signal, which bounce off an object and then travel to a receiver (similar to how sound echoes). The signals that radars transmit are either radio waves or microwaves (types of electromagnetic waves). Radio waves have wavelengths from 10cm or greater while microwaves range from 10 cm to 1/10 mm (Stimson et al., 1998). There are a wide range of radars, all of which are classified based on their application (tracking, navigation, use, range, etc.). MERLIN is a radar system used by the Air Force, and some airports, to detect incoming or departing flocks of birds in the vicinity of an airport. Information that is collected is then passed on to pilots who correct their path (ACRP 2011; Coates et al., 2011; Nohara & Beason 2011, Bruderer 1997). Alternatively, 3 ! there is airborne weather, which transmits microwave frequencies to acquire advanced warning of incoming weather conditions (Stimson 1998; Skolnik 1981). There are several different types of weather radars (i.e. S-band, C-band, X-band, Ka-band). X-band radar is used for the short distance detection of minute changes in the weather; it has a wavelength of 2.5-4cm and transmits frequencies that are between 7-11GHz (Skolnik 1981). X-band is often used in modern weather radars such as the more common low powered (100-watt) solid-state vacuum tube systems or high-powered (10-kilowatt) magnetron systems (Honeywell 2007; Skolnik 1981). Magnetron systems are being replaced by solid-state systems because they provide the same coverage and resolution with less energy. Solid state (non-magnetron) radars provide additional wind shear prediction systems, which is why they are built into the nose of the airplane (Honeywell 2007; Scholnik 1981). Microwaves, which are emitted by solid-state radar, are a form of non-ionizing radiation; the microwave phonons lack the energy required to ionize atoms or induce ion formation (Stimson 1998); which means that microwaves do not contain sufficient energy to chemically change substances through ionization. When living tissue is exposed to microwaves, molecules vibrate at a faster rate, which causes friction inducing a hyperthermic effect (Byman et al. 1986; Adair & Adams 1983; Schwab & Schafer 1972). Previous experiments suggest that birds and mammals can detect low levels of microwaves (Kumar et al., 2011; Bruderer et al., 1999, Byman et al., 1986). Aversion, panic, anxiety, disorientation as well as overheating and specific aversion behavior were demonstrated in mice (Kessari et al., 2011) and monkeys (Adair & Adams 1983); birds also showed behaviors indicating thermal overload (Ahlbom et al., 2004; Wasserman et al.1986; Chou & Guy1985; Byman et al., 1984; Wasserman et al., 1984a; Wasserman et al., 1984b; Adair & Adams 19831983; Schwab & Schafer 1972; Richards 1968). Wasserman (1984a) found that when birds were exposed to 2.45GHz, they responded as soon as 30 seconds after the onset of radar exposure with behaviors of gasping, panting, wing spreading, crouching and loss of muscular coordination. Birds that were trained to fly in wind tunnels, and then made to fly while exposed to microwaves (2.45GHz) would try repeatedly to land or expose their legs during flight to cool down, while control 4 ! groups (not exposed to microwaves) displayed no such behaviors (Byman et al., 1984). Chou & Guy (1985) conducted tests using parakeets, quail, pigeons, chickens, and turkeys and exposed them to three set frequencies (775, 915, and 2450 MHz) with varied intensities, and measured the onset of behavioral responses. Overall, there was a significant decreased in latency to aversion, overheating and stress responses as the intensity was increased. Despite the above studies it is not well understood how birds react to microwaves, as the evidence has produced conflicting results. Wasserman et al., (1984b) placed Blue Jays into an experimental enclosure with four compartments, two shielded from microwaves and two unshielded. He found that when in the unshielded compartments, birds performed non-random movements within the chamber that correlated with the availability of microwaves and the intensity. The fact that these birds also selected a shielded room over an unshielded one indicates that birds can detect microwaves and are inclined to move to avoid its effects. Conversely, Bruderer et al., (1999) monitored flocks of birds migrating at night and, from the ground, exposed them to a steady beam of light and compared their behavioral responses to those that were exposed to X-band radar. Overall, they found that birds reacted more intensely to the search light than to the Xband radar. Although in many cases there was flock disorientation immediately following radar exposure. From the perspective of using weather radars in the future to deter birds from aircraft, the first question that needs to be addressed is whether birds respond to radar in the same way as they do to predators (i.e., avoidance responses). The goal of this study was to assess how European Starlings (Sturnus vulgaris) responded behaviorally and thermally to a 9.33 GHz solid-state weather radar compared to predator exposure. European Starling are a good study species because they are highly abundant in North America (McGraw & Middleton 2009; Schwab & Marsh 1967), move in large flocks during the winter (Goodwin 2001), and are commonly involved in bird strikes. From 1990 to 2001 European Starlings were responsible for 852 of the strikes reported to the FAA and recorded on their National Wildlife Strike Database (Barras et al., 2001). 5 ! I conducted a semi-natural experiment, where I exposed an individual starling to either solid-state weather radar, placed 5 meters away, or a predator model. I used two parameters to measure their behavioral responses to these stimuli: first, reaction time (time to respond to the predator or radar following onset of exposure) and second, several behavioral responses (proportion of time scanning head up and rate of hanging on enclosure walls, flying, scanning head up, crouching, walking around, and foraging). Many of the selected behaviors have been associated with predator detection and in radar response literature (Fernandez-Juricic & Rodriguez-Prieto 2010; Devereux et al., 2005; Tisdale & Fernandez-Juricic 2009; Chou & Guy 1985; Byman et al., 1984; Wasserman et al.1986; Wasserman et al., 1984a; Wasserman et al., 1984b). 6 ! CHAPTER 2: METHODS Bird Housing Between 2010 and 2011, European starlings were either caught from different areas in Tippecanoe County, Indiana using an Australian Trap (1.5mx1.5mx1.5m) and a Decoy Trap (1.2mx2.4x2.1m), and or (all juveniles used in experiment 2) obtained from a USDA facility in Ohio. Following capture they were transported to and held at Purdue University’s on-campus Small Animal Housing facility. There, the birds were kept in an indoor aviary (1.9mx1.5mx1.8m) under a 12hr light cycle and given food and water ad lib. Approximately 48 hours before being tested, birds were transported to the Purdue owned Ross Reserve. At the Ross Reserve, Starlings were kept in outside aviaries (3x2x2m), under natural light. On average, there were 25 birds per aviary; birds were given food (mixture of bird chow/wild bird chow and cat food) and water ad lib (Asher & Bateson 2007). All animal procedures were approved by the Purdue Animal Care and Use Committee (PACCU) Protocol # 10-120. Experimental setup A track (3m long x 0.32m wide) was stretched along the 3-meter front end of the experimental arena (refer to Figure 1). A stuffed cat on a skateboard was used as a predator during certain trials. A clear fishing line, attached to the skateboard, stretched across the track allowing the researcher to pull the cat across the track. The track was perpendicular to the bird’s enclosure and the cat faced outwards towards the bird (refer to Figure 2). The track was padded with soft rubber foam to reduce the amount of noise the predator produced during a trial. To ensure that the bird could not view the cat or skateboard, blinders (0.76mx0.3m) were attached to either end of the track. The 7 ! enclosure, where the bird remained during the course of a trial, had a cylindrical metal top (0.61m-diameter, 0.48m-high, 2.5cm openings) on a wooden base (0.65m-diameter). The enclosure sat opposite the track, one meter from the end of the arena. For each trial, the wooden base of the enclosure was lined with seven cups of Metro-Mix potting soil that had been mixed with 10 mealworms the night before. The experimental arena was enclosed using shepherd hooks and tarp. The shepherd hooks were arranged in a rectangle (6mx3m) and tarp was strung between the shepherd hooks using zip-ties. Tarps were weighed down with cement blocks to minimize any noise or movement during a trial. The tarp prevented the birds from viewing anything outside the experimental enclosure, including the radar. An individual bird was used for each trial; the behavior of that bird was recorded using three cameras observing from different angles, and a fourth, JVC Enverio, camera observed the actions of the stuffed cat (camera 4a; refer to Figure 1). Camera 4b, a FLIR EX320 Infrared thermography camera (hereafter referred to as an IRT camera), recorded the relative temperature of the bird during the course of a trial. The IRT used a 25° lens (dimensions 320 x 240 pixels) and had a set emissivity value of 0.95 (as recommended by Speakman & Ward 1998). Camera 4c, a JVC Enverio, was directed towards the bird and was used to determine the behavioral response of the birds to its assigned treatment. Camera 4d, a security camera, was attached to 2.5cm PVC pipes (painted black), directed downwards for an overhead view of the bird (0.5m high). All cameras were kept in a similar position throughout all the trials. Coaxial cables ran from all four cameras and connected to a quad splitter Ganz DVR recording unit, which allowed all four cameras to be recorded on a single screen simultaneously. The DVR was set outside on the porch of a cabin approximately five meters from the experimental arena. The radar used for this experiment was a Honeywell Solid State Weather Radar model number RDR-4000. The radar was pre-set to have a peak transmission power of 35-63W and a transmission frequency of 9336-9376MHz. The antenna had a diameter of 30” and had a gain of 35 decibels (dBi). RDR-4000 airborne radars has a beam that is three degrees wide that scans 180 degrees from 0-18,288 m to 320nm. For this experiment, the radar was screwed to a base that held it in a horizontal position four feet 8 ! off the ground. The radar was connected to an Agilent DC System Power Supply Model Number N5751A and used 180-200 VAC and 0.5 Amps. For each trial the power unit was set to provide the radar with 185.3 volts and 0.5 amps. For safety reasons, the observer wore a UniTech RF garment (jumpsuit, helmet, socks and gloves) during the course of a trial. The presence of the metal cylindrical top (which sat on the base of the experimental enclosure) did not affect the intensity of the radar microwaves. We measured microwave intensity with a field meter (Holaday Hi E100 ETS Lindgren), which was placed 5 m away from the radar under two conditions: with and without the metal enclosure. We obtained 52 measurements over a period of 4 minutes in each condition. We did not find significant differences in microwave intensity with and without the metal enclosure (F 1,102 = 0.472; P =0.494). Experiment From October to December 2011, I ran an average of 7 trials each morning, from 0730- 1200. All trials were conducted at the Purdue owned Ross Reserve. Following their initial capture, each bird was banded using a unique 1-3 color band combination on their left and or right leg. The 35 birds, 39 males and 12 females, were assigned a predator state (yes/no) and a radar state (yes/no), and the distance was set at 5 meters. Twelve to eighteen hours the night before their trial, birds were removed from the main aviary and placed in a “food deprivation cage” (0.61mx0.61mx0.76m) where their food was removed. The morning of a trial, the appropriate bird was removed from the food deprivation cage and transported in a cotton “bird bag” to a cabin, where its weight, sex, and band color were recorded. The experimenter used a Mastech light meter (LX1330B) to measure light intensity (lux) and a Kestral 3500 portable weather station to measure temperature (C°), humidity (%), and wind speed measurements (km/hr) of the experimental arena (Figure 1). Once the information was recorded each of the cameras was turned on and allowed to warm up for 1-2 minutes. The DVR was then turned on and a white board, listing the bird’s unique band color combination, treatment, and radar distance, was displayed to the camera along with a Fisher Scientific stopwatch. At this 9 ! point, the bird was released into the experimental enclosure, and the experimenter would leave the arena. A trial officially commenced once the bird took its first peck at the ground, therefore, in some cases, the experimenter was still within the experimental arena. At the conclusion of a trial the experimenter would re-enter the arena and recapture the bird and return it to the main aviary. I compared the behavior and surface temperature of an individual birds under two treatments: (1) radar on and no predator (hereafter, radar treatment) and (2) radar off and predator (hereafter, predator treatment). I used 51 individuals of mixed sex and age (5 adult females, 9 adult males, 2 juvenile females, and 19 juvenile males). The first treatment, predator treatment, placed birds individually into the experimental enclosure and allowed them to forage for three minutes. At this point the observer pulled the predator model across the track. After seven minutes the trial concluded. Nineteen birds were used in this treatment (3 adult females, 5 adult males, and 11 juvenile males). In the radar treatment, the focal individual was allowed to forage for two minutes. After that, the radar was turned on for eight minutes. After 8 minutes of exposure, the trial concluded and the radar was turned off. Under the radar treatment, the weather radar was always at the same distance (5 m) from the enclosure with the bird. Sixteen individuals were used in this treatment (2 adult females, 4 adult males, 2 juvenile females, and 8 juvenile males). The time from the first peck that the bird took and the time it took the bird to be exposed to the radar or predator was different (2 minutes and 3 minutes respectively). The difference in exposure time is a result of constraints placed on the experimental design by a previous experiment. Behavioral analysis Virtual dub (Version 1.10.2, free online software at http://www.virtualdub.org/) was used to determine the reaction times to either the radar or predator through frame-by-frame analysis of the videos obtained. Jwatcher (Blumstein & Daniel, 2007) was used to 10 ! quantify the different behaviors of the birds after the radar was turned on or the predator was exposed to the birds. To measure reaction times, I identified behaviors that could be associated with responses to predators and anti-predator behavior (Blackwell et al., 2009; Tisdale & Fernandez-Juricic 2009; Devereux et al., 2005; Table 1 lists and defines these behaviors). I then recorded the frame and behaviors that occurred immediately following the onset of a treatment to calculate reaction times from the treatment. In order to measure the different behavioral responses of the bird to the main treatment, I used Jwatcher, behavioral transcription software. Melissa Hoover coded the following behaviors: proportion of time scanning head up, rate of hanging on cage, rate of flying, rate of scanning head up, rate of crouching, rate of movement, rate of wing flip, and rate of pecking (Table 2 lists and defines all behaviors). I divided the radar treatment into two intervals: before and after radar exposure. Before the radar exposure, coding began one minute after the bird’s initial peck, and continued for 1 minute until the radar was turned on. After the radar exposure, coding was done over 8 minutes. The predator treatment was divided into two intervals: before and after the exposure to the predator. Before predator exposure, coding began one minute after the first peck, and continued for 2 minutes, until the predator was released. After the predator exposure, coding was conducted for 7 minutes. Surface Body Temperature Analysis I used an Infrared Thermography Camera (hereafter referred to as an IRT camera), FLIR EX320, with a 27 mm lens (1/250 spot ratio and dimensions 320 x 240 pixels), and an emissivity value of 0.95 (as recommended by Speakman & Ward 1998) to record the relative temperature of a starling when it was exposed to a predator or radar. All images were recorded in grey (white hot, black cold) color pallet. The IRT camera was connected to the DVR video equipment, which meant I could examine the variation in temperature of the bird over the course of the trial. 11 ! I took into account the fact that Steen & Steen (1965) proposed that the legs of birds provide the best location for heat dissipation, while non-vascularized areas, such as feathers, are used to primarily to keep heat in in cold environments and allow cool air in in hot environment, but due to a low sample size, I was unable to include the temperature of the leg in the analysis. Speakman et al. (1986) recorded the change in body temperatures of European Starlings in flight as they were exposed to a wide range of ambient temperatures. He found that as birds flew in environments with high ambient temperatures, they used their head, ventral brachial areas (the wings), and feet to dissipate heat. For this experiment I used an IRT camera to monitor how the surface body temperature of different areas of the starling may have changed in response to exposure to microwaves. I selected the spot meter setting, which would independently select the maximum temperature within view of the camera. Throughout an individual trial the spot meter would scan an object (in this case the Starling) and select the maximum temperature (between back, chest, cheek, eye, head, mouth, and neck). In the cases where the Starling was outside of the brackets the IRT camera could not track a change in temperature. To increase accuracy of the IRT camera’s thermal reading I developed a set of guidelines, following preliminary tests, which allowed me to acquire more accurate surface body temperatures during analysis. These guidelines accounted for the sporadic movements of the bird and any adjustments made by the IRT camera to ensure that the temperature measurements were accurate. Throughout analysis there were three cases where the bird was within brackets, outside brackets, or outside view of the camera. If the bird was within the brackets and moving (Figure 3a), the cursor had a 3-frame delay in tracking the movement of the bird and providing accurate temperatures. In these cases I would wait for the cursor to land on the immobile bird and count five additional frames before recording a temperature. If the bird was outside the brackets but still on screen (Figure 3b) the IRT camera detected the temperature of the bird but did not display it since it was outside the brackets. In these circumstances once the bird entered the brackets I waited an additional thirteen frames before recording the temperature. The last guideline was for circumstances where the bird was completely off screen (Figure 3c). I would wait until 12 ! the bird moved within the brackets and then count eighteen frames, which allowed the IRT camera time to adjust to the bird’s temperature and indicate it with the cursor. In order to determine whether exposure to the radar had an affect on the surface body temperature of the bird I divided each of my trials into intervals based on whether it was before or after its treatment. I divided each of those intervals into 20-second bouts. During these 20-second bouts I recorded three temperatures for each area of the body (back, cheek, chest, eyes, head, mouth, and neck) when they were indicated by the IRT camera’s cursor (Figure 4). For the birds involved in either treatment I calculated an average temperature for those seven areas of the body. Statistical Analysis I used a General Linear Mixed Models (GLM) in SAS 9-3 statistical software to determine changes in reaction times, behavioral responses, and surface body temperature between the radar and predator treatments. 13 ! CHAPTER 3: RESULTS Reaction Time Results There were no significant differences between the time it took the European Starlings to detect the radar (2.09±0.29) as compared to the predator (1.98±0.25; F1, 31=0.07, P=0.794). Additionally, ambient temperature (F1, 31=0.04, P=0.832) and body mass (F1, 31 =1.13, P=0.328) did not have a significant effect on the reaction time of the starlings to the treatments (radar or predator). Behavioral Response Results The analysis indicated an effect of treatment (predator or radar) and before and after exposure (before or after treatment) on the behavioral responses (flying, hanging on cage, scanning head up, crouching, pecking, movement, and wing flipping) of starlings (refer to Table 3). Starlings that were exposed to the predator flew more after being exposed to the predator, as compared with birds that flew more before being exposed to the radar (Figure 5a). Starlings that were exposed to the predator hung on the cage more after being exposed to the predator, as compared with birds who hung more before being exposed to the radar (Figure 5b). Body mass had a positive effect on the hanging rate of the bird. Starlings spent a large proportion of time scanning with their head up after being exposed to the predator, as well as before they were exposed to the radar (Figure 5c). Starlings had a higher rate of scanning with their head up after they were exposed to the predator and before they were exposed to the radar, as compared to birds that were exposed to the radar (Figure 5d). Body mass had a positive effect on the head up rate of the bird. Starlings crouched more after being exposed to the predator, and before being exposed to the radar, as compared to birds that were exposed to the radar (Figure 5e). The pecking 14 ! rate of the starlings was not significantly influenced by exposure to the radar or predator (Figure 5f). The ambient temperature positively influenced the pecking rate of starlings. Starlings moved around their enclosure more after they were exposed to the predator as well as before they were exposed to the radar (Figure 5g). Starlings that were exposed to the radar rearranged their wings more after being exposed to the radar, but before being exposed to the radar they had low rates of wing reshuffle, as well as after being exposed to the predator (Figure 5h). Additionally, ambient temperature and body mass had a negative effect on the rate of wing flip. None of the other studied factors (sex, food deprivation time) significantly influenced the behavioral responses of the starlings. Surface Body Temperature Results Treatment (predator or radar) had a significant effect on the surface body temperatures (of the back, cheek, chest, eyes, head, mouth and neck) of starlings. After birds were exposed to the radar their back, cheek, chest, head and neck, had higher temperatures than birds that had been exposed to the predator. However, after starlings were exposed to the radar they had lower temperatures in their eyes and mouth, compared to birds that had been exposed to the predator (Figure 6 and Table 4). 15 ! CHAPTER 4: DISCUSSION Overall, I found that starlings did not respond to radar as they would a predator behaviorally as well as in terms of surface body temperature. I discuss these results in light of the literature. Birds have a multitude of behavioral responses that help them avoid heat stress; observed behaviors have been panting, wing spreading, sleeking plumage, altering of body orientation in relation to sun, seeking shade, covering feet with body, urohydrosis, bathing, rearranging feathers, reducing body movements, if bird is flying- increasing altitude, or exposing legs to airstream; (Ruben & Jones 2000; Bennett & Ruben 1999; Ward et al., 1999; Speakman 1998 Swaddle & Witter 1997; St-Laurent & Larochlle 1994, Wasserman et al., 1984a; Wasserman et al., 1984b; Bryant 1983, Steen & Steen 1965). According to previous studies, a bird’s response to increased ambient temperatures depends on the size, activity, and species of the bird (reviewed in Speakman 1998). Multiple experiments have examined the behavioral responses of birds exposed to an increase in temperature while participating in strenuous activity (i.e. flying). Bryant (1983) made field observations of the behavior of tropical birds at different times of the day. He noted a drastic decrease in active birds at midday once temperatures had peaked. Birds that continued being active at midday were observed panting, continually altering their body orientation in relation to sun, and flying with legs hanging. Some birds would continue activity in short bursts—seeking shade in between; while other birds would cease the majority of their activity when the sun was at its highest. Overall, Bryant (1983) found that birds in the field alter their activity when they have the greatest potential for over-heating. Torre-Bueno et al., (1976) trained wild-caught starlings to fly in a wind tunnel and then manipulated the ambient temperatures. In temperatures above 28°C, starlings were observed panting (open bill, that widened as temperature and flying 16! ! time increased), attempting to land repeatedly, and extending legs (to expose to cool airstream). The above studies indicate that birds will alter their activities when exposed to increased ambient temperatures. Moreover, other studies have shown that birds exposed to microwaves (2.45GHz or more) will behave as though they had been exposed to an increase in ambient temperature, with the same or increased thermoregulatory behaviors. Similar behaviors were seen in budgerigars (Byman et al., 1986) trained to fly in a wind tunnel and exposed to microwaves (2.45GHz). As the intensity of the microwaves and flying time increased, the birds attempted to land more often and would expose their legs to the airstream. In the above experiments, the birds partook in strenuous exercise in environments that had either steadily increasing ambient temperatures or caused an increase in surface body temperature. At moderate ambient temperatures, in the wild, birds rarely drag legs or pant during flight (Ward et al 1999). While flying is a very strenuous activity, and, depending on the length of time a bird flies or the time of day, can lead to hyperthermia (Byman et al., 1986; Bryant 1983; TorreBueno et al., 1976; Heinrich et al., 1971). Activities, such as flying, can cause a 10 to 23-fold increase in the normal basal metabolic rate of a bird (Mcfarland & Budgell 1970). In my experiment, starlings responded to an increase in temperature (exposure to microwaves) by reducing a majority of their behavioral responses: flying and moving around the cage less, moving their heads slower and hanging from the cage of the enclosure for shorter periods of time. Overall, starlings reduced their locomotive and visual explorative behaviors once they were exposed to the radar. Conversely, I found that once starlings were exposed to the radar they had an increase in their rate of wing flips, which was higher then those that had been exposed to the predator. Starlings that were exposed to the radar displayed a significant increase in wing rearrangement behavior (Figure 5g), in order to increase the circulation of air beneath their feathers. Birds can alter the position of their feathers (i.e. raise or flatten against their body), which modifies the insulation properties of their feathers, with this they can to insulate their body (when cold) or dissipate heat (when hot; McFarland & Budgell 1970). McFarland & Budgell (1970) investigated the position of body feathers in response to a step change in ambient temperature (20°C to 40°C within 30 sec and 17! ! maintained at 40°C for 10 min). They found that birds altered the physical property of their feathers (from normal to sleeked) as they increased the ambient temperature. Additional rearrangement of the feathers or feather maintenance circulates air along skin (reducing thermal load), which is a thermoregulatory behavior in response to increased temperature (Ruben & Jones 2000; Swaddle & Waddle 1997; St-Laurent & Larochlle 1994). I propose that the drastic reduction in pecking, movement, flying, scanning, crouching and an increase in wing rearrangement following exposure to the radar, is the result of the birds seeking to avoid thermal overload in their back, cheek, chest, neck and head, areas of their body that had a higher temperature. Microwaves cause molecules to vibrate at a faster rate, causing friction and an increase in heat in living tissue (Stimson 1998; Scholnik, et al., 1962). In my analysis I compared the surface body temperature of birds that had been exposed to the radar to the surface body temperatures of birds that were exposed to the predator. My results indicate that birds that were exposed to the radar had higher temperatures on their back, cheek, chest, head, and neck, while birds that had been exposed to the predator had higher temperatures in their eyes and mouths. In this experiment, it is unclear whether the mouth and eyes increased in temperature as a direct result of the starlings being exposed to the predator; or whether the birds experienced an increase in temperature in their back, chest cheek, head, and neck as a direct result of being exposed to the radar, I will discuss this in light of the literature. In suddenly stressful situations (such as the appearance of a predator) organisms immediately react with a “fight or flight” response, a series of physiological reactions in response to acute stress (McEwen 2005). During this period the body will direct blood to areas that can aid in either escape, such as limbs (to escape) or lungs (to increase respiratory rate) etc. Birds that are exposed to a predator should direct blood flow to certain areas that would aid in their “flight” (i.e. legs, wings, brain, eyes, lungs, etc.; Siegel 1980). To explain the higher temperatures of the eye and mouth, we consider that birds exposed to the predator, experienced an acute stress response; therefore there were lower temperatures in areas where blood was diverted away (body core, in this case, the back, cheek, chest, head, and neck), to extremities that would aid in escape in the flight 18! ! response, and, higher temperatures in areas that would need increased blood flow (McEwen 2005; Siegel 1980): the eyes, for sharper vision-to detect potential predators and an escape route, and the mouth as respiration increases. Comparably, the starlings that had been exposed to the radar had higher temperatures in their back, cheek, chest, head, and neck, and, lower temperatures in their eyes and mouth, but, only when contrasted with the temperatures of birds that had been exposed to the predator. While it is possible that the higher temperature of the eyes and mouth and the lower temperature of the back, cheek, chest, head and neck were a direct response to being exposed to the predator, if we take into consideration both the behavioral and physiological response of the starling to the radar and compare it to the responses to the predator, an acute stress response seems less likely. Alternatively, I postulate that the insulation properties of feathers, may have affected the physiological and behavioral responses of starlings exposed to the radar. Feathers provide a layer of protection that allows birds to contain metabolically produced heat in cold environments and reduce heat absorption in hot environments (Ruben & Jones 2000; Wolf & Walsberg 2000; Swaddle 1997). To explain the high temperatures of the back, cheek, chest, head and neck of the birds exposed to the radar, I consider the responses of the chickens involved in an experiment conducted by Horowitz et al (1978). In this experiment they trained two groups of chickens to perform an instrumental task in response to a decrease in ambient temperature so that when the temperature was lowered birds learned to peck at areas of their enclosure to increase ambient temperatures. One set of chickens was featherless (plucked) and the other had their feathers (normal); both groups of chickens were subjected to a steady decrease in ambient temperatures. At ambient temperatures of 5°C and 0°C, plucked chickens were unable to reduce their heat loss and responded with their learned instrumental task. Plucked chickens kept pecking until the ambient temperature was high enough that they were able to maintain a body temperature not significantly different from the body temperatures of normally feathered chickens, without the aid of feathers. Normally feathered chickens, in reduced temperatures never preformed the trained instrumental task; instead they fluffed feathers or squatted to enclose unfeathered areas (feet and legs) in the feathers. This study 19! ! demonstrates the important role that feathers play in a birds thermoregulation: without feathers the plucked chickens had a reduced ability to naturally regulate their internal body temperature, and an increased motivation to increase the ambient temperature; feathered chickens self-maintained their internal body temperature and performed species-specific behaviors to keep extremities warm, in response to reduced temperatures. In my experiment, the IRT camera detected higher surface temperatures in birds exposed to the radar in areas that were covered by feathers (back, cheek, chest, head and neck) and a decrease in surface temperature around areas that were uncovered. I propose that areas covered by feathers (back, cheek, chest, head, and neck) reduced the starling’s ability to regulate temperatures in that area, while areas uncovered by feathers (eyes and mouth) were unencumbered by an insulating layer. Future experiments would help us determine whether the temperature increase (of the chest, cheek, chest and neck) or temperature decrease (of eyes and mouth) was a result of the fight or flight response or feather insulation. Taking into account the properties of feathers and my results it is clear that the areas that were exposed to the air (eye and mouth) could readily dissipate heat. While areas that were concealed by feathers: back, cheek, chest, neck, and head had a lower temperature than exposed areas: eyes and mouth. Microwave radiation has a penetrating depth of 10mm and has been shown to have biological effects on living tissue (heating surface, causing changes in nerve and muscle response, etc.). The resulting effects of exposure depend on the characteristic of the source, target, distance between source and target, and environmental conditions (Honeywell 2007; Stimson 1998; Wasserman et al. 1984, Scholnik, et al., 1962). In this case, the results indicate that the microwaves may have had a thermal effect on the feathered areas of the birds exposed to the radar. I postulate that microwaves had a thermal effect on the bird’s skin; which means that areas that were not covered by feathers (eyes and mouth) were able to dissipate heat normally, but areas insulated by feathers (back, cheek, chest, head and neck) trapped the heat between the feathers and the skin. 20! ! Whatever the reason for the thermal disparity between the various parts of the body, the results do indicate that being exposed to the microwaves has a cost. The starlings exposed to the microwaves drastically reduced their activities; I propose that this occurred in order to decrease the physiological strain of reducing elevated body temperatures. Other organisms may rely on their hearing or sense of smell to detect predators while birds will rely heavily on their visual systems (Blackwell et al 2009; Tisdale & Fernandez-Juricic 2009; Lima & Bednekoff 1998). With this in mind, once starlings were exposed to the radar they reduced the proportion of time being vigilant and rate of scanning. Conversely, if we take into account Lima & Bednekoff (1999), the birds may still be able to detect an approaching predator, so the reduction in vigilance behavior may not have as large a cost as I am proposing. My results indicate that weather radars do have an effect on the behavioral and thermal responses of starlings. Starlings that were exposed to the radar appeared to reduce their activity in order to avoid radar-induced heat-stress. At this point, there is little generalization I can make based on my results as the experiment was conducted under some restricted conditions: animals were at a fixed distance from the radar (5 meters). However, I can speculate about some potential bird-aircraft encounter scenarios assuming that the effects I found hold at farther distances. First, under a bird-aircraft encounter with the radar activated, I hypothesize that birds would reduce their behavioral responses due to thermal stress, lose altitude, and thus reduce the chances of a bird strike. Second, a bird-aircraft encounter with the radar activated, I hypothesize that birds would reduce their attention towards the aircraft given the distracting effects of the radar, and actually increase the chances of a bird strike by failing to avoid the aircraft on time. These scenarios are speculative and should be subject to empirical testing in the future. Future experiments in a more natural setting should investigate whether weather radar reduces bird activity (as found in this study) or birds do try to leave and avoid the heating effects. Additional experiments should determine the maximum distance at which the bird is behaviorally influenced by the radar. Realistically, in order for the weather radars to be used as a bird strike deterrent several things must be taken into account, including: the speed of the aircraft and the speed of the bird, the distance between the ! 21! bird and a plane, the avoidance behaviors of birds etc. Future experiments should explore these different factors. LITERATURE CITED 22! ! LITERATURE CITED Adair, E.R. & Adams, B.W. (1983) Behavioral thermoregulation in the squirrel monkey: adaptation processes during prolonged microwave exposure. Behavioral Neuroscience. 97 (1): 49-61 Ahlbom, A., Green, A., Kheifets, L., Savitz, D. & Swerdlow, A. (2004) Epidemiology of Heath Effects of Radiofrequency Exposure. Environmental Health Perspectives. 112(17):1741-1754. Asher, L. & Bateson, M. 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(1986) Thermal modeling of small birds exposed to microwave radiation (2.45 GHz CW) Journal of Applied Ecology. 23, 449-459 Byman, D., Wasserman, F.E., Schlinger, B.A., Battista, S.A. & Kunz, T.H. (1984) Thermoregulation of budgerigars exposed to microwaves (2.45 GHz, CW) during flight. Physiological Zoology. 58(1):91-104 Bryant, D.M. (1983) Heat stress in tropical birds: behavior thermoregulation during flight. IBIS. 125:313-323 Chou, C. & Guy, A. W. (1985) Absorption of Microwave Energy by Muscle Models and by Birds Differing Mass and Geometry. Journal of Microwave Power. Coates, P.S., Casaza, M.L., Halstead, B.J., Fleskes, J.P. & Laughlin, J.A. (2011) Avian radar to examine relationships among avian activity, bird strikes, and meterological factors. Human-wildlife interactions. 5(2):249-268 Dale, L.A. (2009) Personal and corporate liability in the aftermath of bird strikes: a costly consideration. Human-Wildlife Conflicts. 3(2):216-225 24! ! Dolbeer, R.A. (2011); Increasing trend of damaging bird strikes with aircraft outside the airport boundary implications for mitigation measures. Human-Wildlife Conflicts. 5(2): 235-248 Dolbeer, R.A. (2009) Birds and aircraft-fighting for airspace in even more crowded skies. Human-Wildlife Conflicts. 3(2):165-166 Dolbeer, R.A. (2005) Increasing trend of damaging bird strikes with aircraft outside the airport boundary: implications for mitigation measures. Human Wildlife Interactions. 5(2):235-248 Personal communications with Travis DeVault, of APHIS, July 2010 DeVault, T.L., Belant, J.L., Blackwell, B.F. & Seamans, T.W. (2012) Interspecific variation in wildlife hazards to aircraft: implications for airport wildlife management. Wildlife Society Bulletin. 35(4):394-402 DeVault, T.L., Kubel, J.E., Rhodes, O.E, & Dolbeer, R.A. (2009) Habitat and bird communities at small airports across the Midwestern USA. Prevention and Control of Avian Damage. Proceedings of the 13th WDM Conference. Dove, C.J., Dahilan, N.F, Heacker, M. (2009) Forensic bird-strike identification techniques used in an accident investigation at wiley post airport, Oklahoma, 2008. Human-Wildlife Conflicts. 3(2):179-185 Federal Aviation Administration (FAA). (2011) Bird harassment, repellent and Deterrent Techniques for use on and near Airports: A synthesis of airport practice. Airport Fernandez-Juricic, E. & Rodriguez-Prieto, I. (2010) Risk allocation in Anti-Predator Behavior. Encyclopedia of Animal Behavior. 3:75-78 ThermaCAM EX320 User’s Manual. (2006) FLIR Systems 2006. Publ. No. 1558146 Rev.a156 Goodwin, D. (2001) The starling, Sturnus vulgaris. Laboratory birds: refinements in husbandry and procedures. Laboratory Animals 35, S1:121 Honeywell International Inc. (2007) Installation Design Guide and Line Maintenance Manual: RDR-4000 Weather Radar System. 34-41-67. 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Animal Behaviour. 58(3): 537-543 Martin, A.J., Belant, J.L., DeVault, T.L., Blackwell, B.F., Burger Jr., L.W., Riffell, S.K. & Wang, G. (2011) Wildlife risk to aviation: a multi-scale issue requires a multiscale solution Human-Wildlife Interactions. 5(2):198-203 McGraw, K.J., & Middleton, A.L. (2009). European starling (Sturnus vulgaris), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/048/articles/introduction McEwen, B.S. (2005) Stressed or stressed out: What is the difference? Journal of Psychiatry Neuroscience. 30(5):315-318 McFarland, D & Budgell, P. (1970) The thermoregulatory role of feather movements in the Barbary dove (Streptopelia risoria). Physiology and Behavior. 5:763-771 Nohara, T.J., Beason, R.C. &Weber, P. (2011). Using radar cross-section to enhance situational awareness tools for airport avian radars. Human-Wildlife Interactions. 5(2):210-217 Richards, S.A. (1968) Vagal control of thermal panting in mammals and birds. Journal of Physiology. 199:89-101 Ruben, J.A & Jones, T.D. (2000) Selective facts associated with the origin of fur and feathers. American Zoology. 40:585-596 26! ! Schwab, R.G. & Schafer, V.F. (1972) Avian thermoregulation and its significance in starling control. Vertebrate Pest Conference Proceedings collection: Proceedings of the 5th Vertebrate Pest Conference. Schwab, R.G. & Marsh, R.E. (1967) Reliability of external sex characteristics of the starlings in California. Association of Field Ornithologists. 38(2):143-147 Siegel, H.S (1980) Physiological stress in birds. Bioscience. 30(8):529-534 Skolnik, M.I. Introduction to Radar Systems: Chapter 1, McGraw-Hill, 1981 (second edition) Speakman, J.R. & Ward, S. (1998) Infrared thermography: principles and applications. Zoology 101. 3: 224-232 Steen, I & Steen, J.B. 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Available from: http://www.virtualdub.org/ Ward, S., Rayners, J., Moller, U., Jackson, D.M., Nachtigall, W. & Speakman, J.R. (1999) Heat transfer from starlings Sturnus vulgaris during flight. The Journal of Experimental Biology. 202:1589-1602 27! ! Washburn, B.E., Bernhardt, G.E. & Kutschbach-Brohl, L.A. (2011). Using dietary analysis to reduce the risk of wildlife-aircraft collisions. Human-Wildlife Conflicts. 5(2):204-209 Wasserman, F.E., Patterson, D.A., Kunz, T.H., Battista, S.P., Byman, D. (1986) Effect of chronic continuous wave microwaves radiation (2.45 GHz) on the foraging behavior of white-throated sparrow. Space Power. 6:99-105 Wasserman, F.E., Dowd, C., Schlinger, B.A., Byman, D., Battista, S.P. & Kunz, T.H. (1984b) Thermoregulatory behavior of birds in response to continuous wave 2.45GHz microwave radiation. Physiological of Zoology. 50:80-90 Wasserman, F.E., Dowd, C., Byman, D., Schlinger, B.A., Battista, S.P., & Kunz, T.H. (1984c) Aversion/attraction of Blue Jays to microwave irradiation. Physiology & Behavior. 33: 805-807 Wolf, B.O & Walsberg, G.E. (2000) The role of the plumage in heat transfer processes of birds. American Zoology. 40:575-584 TABLES 28! ! TABLES Table 1. Descriptions of behaviors used to assess reaction times to radar and predator model. Behavior Step forwards Step back Foot Lift Side Step Turn Description Bird takes 1-3 steps forwards and then stops Bird puts one leg back and moves backwards motion Bird lifts foot then places in same place Bird steps to side Pivot, bird lifts one leg and places it at an angle of about 90° to the first foot and brings body and leg Peck Bird uses beak to probe at ground Regurgitation Bird purges food Fly Bird extends wings and flaps them to leave ground Hop/Jump Bird pushes off with feet from ground, and returns Hanging on enclosure Bird one or both feet and hangs on side of enclosure Backwards flip Bird flips backwards Land Bird settles on the ground Lift head while head up Bird lifts head while in head up position. Lower head while head up Bird lowers head while in head up position Horizontal movement of Bird shifts head in a horizontal movement while in a head while head up head up position Lift head while head down Bird lowers head while head in head down position Lower head while head down Bird lowers head while the head in head down position Horizontal movement of Bird shifts head in a horizontal movement while in a head while head down head down position Decrease in head movement Frame where the head movement rate decreases rate Crouch Bird bends legs, body get closer to the ground Neck Extension Bird extends neck Body Upright Bird changes from a crouched to an upright position Grooming Bird runs beak through feathers or feet Feather Rustle Full body shake where bird sways Puff Bird extends feathers out so it appears enlarged Wing Flip Bird rearranges its wings Freeze Bird ceases movement for 3 or more frames 29! ! Table 2: Descriptions of behaviors used to quantify the behavioral responses to radar. Behavior Description Movement Bird uses hind feet to propel itself into motion (forwards or backwards, at a walk, hop or run) Bird flaps wings and leaves the ground or side of enclosure Bird bends legs and lowers chest to the ground. Bird is touching the side or top of enclosure Locomotion Fly Crouch Hang on Enclosure Vigilance Scan Head up Movement of the head above the plane of the body Peck Bird examines the ground with its beak; Wing Flip Bird rearranges wings along back Foraging Maintenance 30! ! Table 3. Effect of treatment, before and after exposure (to radar or predator), treatment x before and after exposure, controlling for ambient temperature and body mass, on the reaction time of European starlings under two experimental treatments: With Predator and With Radar. Results from generalized linear model. An asterix indicates behavioral responses that were log transformed. Significant values are in bold face. F df P 0.78 1.75 4.96 1, 31 1, 31 1, 31 0.383 0.196 0.033 0.16 3.85 1, 31 1, 31 0.692 0.059 0.26 1.42 4.82 1, 31 1, 31 1, 31 0.613 0.243 0.037 0.44 5.61 1, 31 1, 31 0.51 0.024 0.49 0.76 4.72 1, 31 1, 31 1, 31 0.491 0.391 0.038 0.38 3.38 1, 31 1, 31 0.53 0.076 2.61 2.33 4.8 1, 31 1, 31 1, 31 0.116 0.137 0.036 0.09 5.39 1, 31 1, 31 0.764 0.027 4.93 5.81 1, 31 1, 31 0.034 0.022 6.76 1, 31 0.014 0.54 3.03 1, 31 1, 31 0.468 0.092 0.38 1, 31 0.543 Fly rate Treatment Before and after exposure Treatment x before and after exposure Ambient temperature Body mass Hang on Enclosure Rate Treatment Before and after exposure Treatment x before and after exposure Ambient temperature Body mass Proportion of time head up Treatment Before and after exposure Treatment x before and after exposure Ambient temperature Body mass Head up rate Treatment Before and after exposure Treatment x before and after exposure Ambient temperature Body mass Crouching rate** Treatment Before and after exposure Treatment x before and after exposure Ambient temperature Body mass Pecking rate** Treatment 31! ! Before and after exposure Treatment x before and after exposure Ambient temperature Body mass 0.97 0.47 1, 31 1, 31 0.331 0.497 8.85 0.95 1, 31 1, 31 0.006 0.336 Treatment Before and after exposure Treatment x before and after exposure Ambient temperature Body mass 0.94 0.03 4.09 1, 31 1, 31 1, 31 0.339 0.874 0.052 2.79 0.16 1, 31 1, 31 0.105 0.696 Treatment Before and after exposure Treatment x before and after exposure Ambient temperature Body mass 0.55 4.19 1, 31 1, 31 0.463 0.049 0.73 1, 31 0.399 4.18 5.21 1, 31 1, 31 0.049 0.029 Movement rate Wing Flip rate** 32! ! Table 4. Effect of treatment, body part, treatment x body part, ambient temperature and body mass, on the temperature of a bird’s body part under two experimental treatments: With Predator and With Radar. Results form generalized linear mixed model. Significant values are bolded. Treatment Body Part Treatment x Body Part Temperature Body Mass F 2.38 2549.42 226.91 4.97 0.78 df 1,28 6,162 6,162 1,28 1,28 P 0.134 <.0001 <.0001 0.034 0.385 FIGURES 33! ! FIGURES Fig. 1. (1) Tarp surrounded the entire arena (6m x3m) and was strung up on (2) shepherd hooks with zip ties. (3) The experimental enclosure was 1 m from the back of the arena. (4) Four cameras recorded the behavioral responses of the bird, temperature changes of the bird, and the movement of the predator model. (4a) Predator Camera-observed the position and movement of the predator model in all trials. (4b) Bird Camera-recorded the movements and behaviors of the bird in all trials. (4c) IRT Thermal camera (EX320)supplied surface thermography information of the bird for each trial. (4d) Overhead Camera- provided top view of the bird’s movements and behaviors. (5) The track was 5m away, at the front of the enclosure. ! Fig. 2. (A) Predator model and the enclosure. (B) Close up of predator model, note the blinders on either side of the track. 34! ! 35! Fig. 3. I used three guidelines in order to ensure that the temperature measurements were accurate: (A) within brackets and moving, (B) outside brackets, (C) outside the view of the IRT camera, ! 36! Fig. 4. (A) Original Photo taken with Flir EX320 Infrared Camera (B) Figure depicts the parts of the body that were selected to draw temperatures from for the thermal analysis. The cursor would detect the hottest area of the body and settle; once it settled (according to detailed thermal guidelines) I recorded the temperature. The areas of the body measured for the detailed thermal analysis are indicated within the figure: back, neck, head, eye, mouth cheek, and chest (shown: Experiment #2/Radar Treatment; Trial # 86 at distance 5; III). Upper left hand corner are the readings from the body positions on the bird. The scale on the right hand side indicates the temperature scale for both photos. ! 37! Fig. 5. Fixed effects of behavioral responses and interaction between treatment and before and after exposure (to radar or predator). a) Rate at which the bird flew before and after being exposed to the radar or predator. b) Rate at which bird hung on enclosure before and after being exposed to the radar or predator. c) Relative Proportion of time the bird spent in a head up position before and after being exposed to the radar. d) Rate at which bird was in a head up position while being exposed to the radar and predator. e) Log of the crouch rate of the bird before and after being exposed to the radar or predator. f) Log of the peck rate of the bird before and after being exposed to the radar or predator. g) Log of the wing flip rate before and after being exposed to the predator. h) Rate of movement of bird before and after being exposed to the predator and radar. ! 38! Fig.6. Figure displays the statistical results from the detailed thermal analysis: the fixed effect of treatment (Radar treatment or Predator treatment) on the temperature of the various body parts of the bird (head, chest, cheek, neck, back, mouth and eye).