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Blog post #8: Graphs and Tables

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My favourite part of the research project so far has been organizing and graphing my data. I liked being able to summarize the data in order to find the patterns.  I had no issues with organizing my data into an Excel spreadsheet, however I did have troubles choosing the best graph to represent the results.  I had counted the number of red hips and black hips present at various Nootka Rose bushes around Dallas Road and Beacon Hill Park in Victoria, along a gradient that varied in the distance to the ocean and transferred the raw data into the spreadsheet. From there, I calculated the ratio of red to black hips at each bush and took the average for each discrete zone along the gradient. I had predicted the ratio of red hips to black hips would increase linearly as the distance from the ocean increased. Although the plants growing on the cliff’s edge did have the lowest ratio (a higher number of black hips), the intermediate site actually had the highest ratio.

 

This prompted me to consider reasons why an intermediate distance may have the highest ratio of red hips to black hips. Because I am using this ratio as a proxy for survival, the rose bushes that have a higher ratio may live in a micro-environment that promotes better survival.  I thought the cliff plants would have the lowest red: black ratio because of the harsh conditions associated with living near a cliff.  However, I thought conditions would improve at greater distances because I thought the exposure to wind may also decrease and soil conditions may improve.  I will have to research reasons why the bushes on Beacon Hill would have a lower survival.

Blog 5: Design Reflections

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Initial date collected went over all as predicted. On average the partly sheltered trees had amount a 50 50 ratio of living and dead moss growing on the tree trunks. The 5 trees observed were selected by simple random technique and locations were easy to find. In total took about 30 minutes. Will continue to use the simple random technique when observing 10 trees each from the 3 categories (sheltered, partially sheltered, and exposed).

(Exposed trees are trees that have very littler branches covering the trunk of the tree to the weather at the park)

Red Squirrel Living in my woodpile

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Elliot, Post 1.

My observations are on a red squirrel (Tamiasciurus hudsonicus) that has taken up residence in my woodpile.  The squirrel arrived here 3 years ago and appears to be staying.  The squirrel was busy in the fall gathering walnuts, maple leaf seeds, green pine cones, fall sunflower seeds, and nuts to store in the woodpile next to my home.  He was also active in the  fall chewing on wood for its pulp and stripping cardboard boxes to insulate his home for the winter.  The squirrel is now very active and can be heard during the day and seen munching pine cone seeds.  He appears to like eating sitting on top of certain posts as is evidenced by the pine seed shells underneath these poles.  I have observed him travelling certain corridors that occur mainly on trees but also on roofs like my own home and garage.  I have heard him make different calls and am wondering if each call has a certain significance.

Questions

Why has the squirrel left the forest to come live in an urban community?

Why has the squirrel chosen this particular woodpile?

What else does this squirrel eat?

What are its predators?

Are squirrels becoming a pest in urban environments?

What is the squirrel’s territorial range?

Are these squirrels an abundant species or a threatened species?

Post 9: Field Research Reflections

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I had a limited amount of time to carry out my field research project as I travelled a long way to the beach for only a day. There were of course various other reasons, one of them being that I’m starting a full time job thus I would like to finish my studies as soon as possible with concentration before starting work and I’m recently married. Marriage comes with a lot of responsibilities. I had done my fair bit of research before I even went to the beach to do any measurements and I had been thinking about a research topic for a very long time. I recently went to Morocco for my honeymoon and collected some sea shells as a souvenir. I was looking at the various sea shell sizes at home and was questioning the reason behind the varying sizes, so I thought I’d do a sea shell size related topic. I then went online and did some research as to what is involved in measurements at the beach.

In my opinion the most challenging part of this research project was figuring out a topic to base my research on. Once I had a topic in mind the rest was straightforward. Although I found similar research studies to mine online, I have gained a lot of appreciation for how ecological theory is developed. It is only after completing my own research project that I understood the amount of effort that goes into developing the theory and experimental design. It is also very necessary to have the right equipment for the research project. Sometimes what seems like a very simple study comes with a lot of complications.

Post 8: Tables and Graphs

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I found it quite simple to organize and summarize my data as the results of my field data were not so complicated. I resorted to a table to display the length and aperture measurements on both Castle beach and Jetty beach. I also made a separate column for the length to aperture ratio for both beaches. Upon calculating all the ratios, I totalled the ratios for the exposed and sheltered shores and took a mean. One of my results at Castle beach was anomalous (n=8) since it had a large variance from the mean value of 1.58. Therefore, it does not fit the remaining values and I did not use it in my calculation. The lengths of the dog whelks are generally smaller and the aperture is larger at Castle beach, giving a smaller ratio. For instance, the highest value for the length to aperture ratio at Castle beach was 1.74 while the highest value at Jetty beach was 2.04. Similarly, the lowest value for the length to aperture ratio at Castle beach was 1.37, whereas the lowest value at Jetty beach was 1.42.

An interesting investigation involving dog whelks may be comparing the genetics of dog whelks on exposed and sheltered shores and trying to explain what differences in the genetic makeup cause the variation in shell size on the shores. This study can involve more shores and replicates. However, varying abiotic and biotic factors such as weather and predators may cause discrepancies in the results.

Post 7: Theoretical Perspectives

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The theoretical basis of my research project examines how rocky shore exposure to wave action at Jetty beach and Castle beach, Pembrokeshire, affects the length to aperture ratio of dog whelks at 4 metres above chart datum. The factors affecting the desiccation of dog whelks are temperature, relative humidity, wind speed and light intensity. These abiotic factors may cause the dog whelks to migrate up or down the shore depending on the varying conditions. Predation and feeding are definitely biotic factors affecting dog whelks. Crabs and birds are common predators and thicker and longer shells provide protection against crabs on sheltered shores. The reason dog whelks stay on the lower shore relative to the upper shore may be for protection against birds so they may not be seen.

Apart from the environmental factors affecting the dog whelks’ shells, genetic factors may also affect the shape of their shells. Human activity may also disrupt the species habitat. Crothers explains that dog whelks spend hours on top of their feed in order to digest it, therefore I returned them to their original spot to minimize disruption to their feeding cycle when I was measuring their shells.

Keywords: Dog-whelks, shell size, exposure

Post 6: Data Collection

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I have recorded 30 replicates on each beach for a total of 60 replicates. I measured the length and aperture of the dog whelks and calculated a ratio to help me compare the results for both beaches. I took each measurement with a Vernier caliper and measured the height of the shore above chart datum using a clinometer and a meter ruler. I took each measurement at random along a 20 m transect and recorded the results.

I had to finish taking my measurements before the tide rose up too high. I didn’t have a hard time implementing the sample design. Plus I gave myself plenty of time to record my results from Jetty beach to Castle beach.

I noticed an ancillary pattern that the length to aperture ratio of the dog whelks at Castle beach is generally smaller compared to Jetty beach. The pattern supports my hypothesis and prediction which stated that the exposure to wave action influences the length to aperture ratio of dog whelks thus the length to aperture ratio will be smaller in the exposed beach.

 

Post 5: Design Reflections

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For my preliminary investigations I surveyed both Castle beach and Jetty beach to see at which height dog whelks were most abundant. At Jetty beach I noticed that the dog whelks were mainly present on the middle shore. From my research I knew that the tide at 11:30 AM was 2.07 m above chart datum. Therefore, I measured the height to the middle shore at 4 m above chart datum by using a clinometer and a meter ruler. I stood at 2.07 m above chart datum and held the clinometer perpendicular to the meter ruler and measured 1 m above chart datum. With the help of my husband I marked the point at 3.07 m above chart datum and then I measured 0.93 m the same way as mentioned up to the area where there was an abundance of dog whelks. I initially planned to lay out a 15 m transect line, however I changed this to 20 m instead so the results are more representative of the shore. At 4 m above chart datum I laid out a 20 m transect line and took my measurements. I repeated the process at Castle beach. In order to measure the length and aperture of the dog whelks I did try to use a 30 cm ruler at first but I found that the Vernier caliper provided more precision and accuracy.

The data that I collected suggests that the length to aperture ratio of the dog whelks at Castle beach is generally smaller compared to Jetty beach. This so far supports my hypothesis. I plan to continue collecting data using the same technique and I will definitely use a Vernier caliper instead of a 30 cm ruler for more precision and accuracy of the measurements.

Post 4: Sampling Strategies

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In the virtual forest tutorial I used the area based sampling method for all three sampling strategies. The technique from the fastest estimated sampling time to the slowest estimated sampling time was systematic sampling technique at 12 hours and 7 minutes, haphazard at 12 hours and 27 minutes and random sampling at 12 hours and 47 minutes. The 2 most common species in the Snyder-Middleswarth Natural Area were Eastern Hemlock and Red Maple. The 2 rarest species were Striped Maple and White Pine. The percentage error for Eastern Hemlock for systematic, random and haphazard sampling were respectively: 3.34%, 4.23%, and 8.17%. The percentage error for Red Maple for systematic, random and haphazard sampling were respectively: 5.38%, 40.45%, and 19.42%. The percentage error for Striped Maple for systematic, random and haphazard sampling were respectively: 90.29%, 18.86%, and 28.57%. The percentage error for White Pine for systematic, random and haphazard sampling were respectively: 100%, 50% and 296.42%. The accuracy changed with species abundance. For the two most common species the sampling strategy that was more accurate was systematic. For the two rarest species the sampling strategy that was more accurate was random sampling. The accuracy declined for rare species. The large percentage error may be because 24 was not a sufficient number of sample points to capture the number of species in this community or to accurately estimate the abundance of these species.

Post 3: Ongoing Field Observations

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The organism that I plan to study for this research project is Nucella lapillus or commonly known as dog whelk. As per observation dog whelks are small and their shell colour is creamy brown. Upon walking around the beaches, I observed that the dog whelk shells are less pointy at Castle beach compared to Jetty beach and the shell size is also smaller at Castle beach than Jetty beach; the aperture of the shell is broader at Castle beach than Jetty beach.

The three locations that I selected are the upper shore, the middle shore, and the splash zone at both shores. I noticed that the dog whelks on the upper shore of both beaches were fairly distributed and not very abundant compared to the middle shore of both beaches. The middle shore had a high distribution and abundance of dog whelks at both Castle beach and Jetty beach. The splash zone had the lowest distribution and abundance of dog whelks at both beaches. The reason dog whelks are mainly found in the middle shore may be due to the balance in emersion and immersion and the decrease in harshness of the environment. The upper shore and splash zone may have harsher environments, so the dog whelks may move to the part of the shore that is the middle ground for survival. I hypothesize that the exposure to wave action influences the length to aperture ratio of dog whelks. Thus I predict that the length to aperture ratio will be smaller in the exposed beach. Based on my hypothesis and prediction a potential response variable is the length to aperture ratio of the dog whelks. A potential explanatory variable is the exposure to wave action on the shores of Castle beach (exposed) and Jetty beach (sheltered). The response variable is continuous and the predictor variable is categorical.