My particular research this summer is going to complement Florence\u2019s master\u2019s thesis work by asking new questions regarding the foraging data. While her project focuses on the behavioral states of foraging whales, I will be looking at the whale tracks to see if there are patterns in their foraging behavior found at the individual level. Traditionally, ecological studies have accepted classical niche theory, treating all individuals within a population as ecological equivalents with the same niche width. Any variances present among individuals are often disregarded as having an insignificant consequence on the population dynamics as a whole, but this simplification can overlook the true complexity of that population\u00a0. The presence of niche variation among conspecifics is known to occur in at least 93 species across a diverse array of taxa, so the concept of individual specialization, and how it can affect ecological processes is gaining recognition progressively in the field (Bolnick et al., 2003). My goal is to determine whether or not the gray whales in this study, and presumably others in the Pacific Coast Feeding Group (PCFG), exhibit individual specialization in their foraging strategies\u00a0. There are many ways in which individuals can specialize in foraging, but I will be specifically determining if fine scale spatial patterns in the location of foraging bouts exists, regardless of time.<\/p>\n
To address my question, I am using the whale tracking data from both 2015 and 2016, and learning to use some very important software in the spatial ecology world along the way through a method that Dr. Torres introduced to me. Starting in ArcGIS, I generate a kernel density layer of a raw track (Fig. 1\u00a0), which describes the relative distribution of where the tracked whale spent time (Fig. 2\u00a0). Next, using the isopleth function in the software Geospatial Modelling Environment, I generate a 50% density contour line that distinguishes where the whale spent at least 50% of its time during the track (Fig. 3\u00a0). Under the assumption that foraging took place in these high density areas, we use these 50% contour lines to describe foraging bout locations. I now go back to ArcGIS to make centroids within each 50% line, which mark the exact foraging bout locations (Fig. 4\u00a0).<\/p>\n These centroids will be determined for every track by an individual whale, and then compared relative to foraging locations of all tracked whales to determine if the individual is foraging in different locations than the\u00a0population. Then, the tracks of individuals who repeatedly visit the site at least three times will be compared with one another to determine if the repeat whales show spatial and\/or temporal patterns in their foraging bout locations, and if specialization at a fine scale is occurring in this population. If you did not quite follow all those methods, no worries, it was a lot for me to take in at first too. I\u2019ve finally gotten the hang of it though, and am grateful to now have these skills going into grad school.<\/p>\n Because I am interested in behavioral ecology and the concept of individuality in animal populations, I am extremely excited to see how this research plays out. Results could be very eye-opening into the fine scale foraging specialization of the PCFG sub-population because they already demonstrate diet specialization on mysid (as opposed to their counterparts in the Bering Sea who feed on benthic organisms) and large scale individual residency patterns along the Pacific Northwest (Newell, 2009; Calambokidis et al., 2012). Most significantly, understanding how individuals vary in their feeding strategies could have very important implications for future conservation measures for the whales, especially during this crucial foraging season where they replenish their energy reserves.\u00a0 Management efforts geared for an \u201caverage population\u201d of gray whales could ultimately be ineffective if in fact individuals vary from one another in their foraging strategies. Taking into account the ways in which variation occurs amongst individuals is therefore crucial knowledge for successful conservation approaches.<\/p>\n My project is unique from those of the other REUs because I am simultaneously in the midst of assisting in field season number two of Florence\u2019s project. While most of the other interns are back at Hatfield spending their days in the lab and doing data analyses like a 9-5 job, I am with the team down in Port Orford for field season. This means we\u2019re out doing research every dawn as weather allows. Though I may never have an early bird bone in my body, the sleepy mornings are totally worth it because ecology field work is my favorite part of research. To read more about our methods in the field, check out Florence\u2019s post<\/a>.<\/p>\n Since Catherine\u2019s last update<\/a>, we\u2019ve had an eventful week. To our dismay, Downrigger Debacle 2.0 occurred. (To read about the first one, see Kelli\u2019s post<\/a>). This time it was not the line \u2013 our new line has been great. It was a little wire that connected the downrigger line to the pipe that the GoPro and TDR are connected to. It somehow snapped due to what I presume was stress from the currents. \u00a0\u00a0Again, it was Catherine and I in the kayak, with a very successful morning on the water coming to a close when it happened. Again, I was in the bow, and she was in the stern deploying the equipment \u2013 very d\u00e9j\u00e0 vu. When she reeled in an equipment-less line, we at first didn\u2019t know how to break it to Florence and Kelli who were up on the cliff that day. Eventually, Catherine radioed \u201cBrace yourselves\u2026\u201d and we told them the bad news. Once again, they both were very level-headed, methodical, and un-blaming in the moments to follow. We put together the same rescue dive team as last time, and less than a week later, they set off on the mission using the GPS coordinates I had marked while in the kayak. Apparently, between the dredging taking place in the harbor and the phytoplankton bloom, visibility was only about 2 feet during the dive, but they still recovered the equipment, with nothing but baked goods and profuse thanks as payment. We are very grateful for another successful recovery, and are confident that our new attachment mechanism for the downrigger will not require a third rescue mission (Fig. 6-8). Losing the equipment twice now has taught us some very important things about field work. For one, no matter how sound you assume your equipment to be, it is necessary to inspect it for weak points frequently \u2013 especially when salt water and currents are in the picture. Perhaps even more importantly, we\u2019ve gotten to practice our problem solving skills and see firsthand how necessary it is to act efficiently and calmly when something goes wrong. In ecological field research you have to be prepared for \u00a0anything.<\/p>\n In other news, unlike our slow-whale days during the first two weeks of the project, we have recently had whales to track nearly every day from\u00a0the cliff! In fact, the same, small, most likely juvenile, whale pictured in Catherine\u2019s last post has returned several times, and we\u2019ve nicknamed her \u201cButtons\u201d due to two distinguishing white spots on her tail peduncle near the fluke. Though we tend to refer to Buttons as \u201cher\u201d, we cannot actually tell what the sex is definitively\u2026until now. Remember in Catherine\u2019s post when she described how Buttons defecated a lot, and how our team if, given the opportunity, is supposed to collect the feces when we\u2019re out in the kayak for Leila\u2019s project<\/a>?\u00a0 Everything from hormone levels to reproductive status to, yes, sex, is held in that poop! Well, Miss (or Mr.) Buttons was in Tichenor Cove today, and to our delight, she performed well in the defecation department once again. Florence and I were on cliff duty tracking her and Kelli and Catherine were in Tichenor on the kayak when we\u00a0first noticed the defecation. \u00a0I then radioed down to the kayak team to stop what they were doing and paddle quickly to go collect it before it sank (Fig. 9). \u00a0Even in these situations, it is important to stay beyond 100 yards of the animal, as required by the MMPA. Florence and I cheered them on and our ladies did indeed get the poop sample, without disturbing the whale (Fig. 10). It was a sight to behold.<\/p>\n We were able to track Buttons for the remainder of our time on the cliff, and were extremely content with the day\u2019s work as we packed all the gear up later in the afternoon. Right before we were about to leave, however, Buttons had one more big treat for us. As we looked to the harbor before starting the trek back to the truck, we paused briefly after noticing a large, white splash in the middle of the harbor, not far from the dock. We paused for a second and thought \u201cNo, it can\u2019t be, was that —?\u201d and then we see it again and unanimously yelled \u201cBREACH!\u201d Buttons breached about five times on her way back to Tichenor Cove from where she had been foraging in Mill Rocks. It is rare to see a gray whale breach, so this was really special. Florence managed to capture one of the breaches on video:<\/p>\n![\"Fig.1](\"http:\/\/blogs.oregonstate.edu\/gemmlab\/files\/2016\/07\/img1.png\")
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