Category: Post 5: Design Reflections

Methods:

3 transects (plots) on each study site were established at a length of 9.5m starting from the city sidewalk and running toward the house. Each transect has a 0.5m spacing on either side of the centre. The first transect centre is placed 0.5m from the edge (driveway) of the area being studied. The following transects are placed 1m away from the initial centreline of the previous transect to prevent overlap.

The total area sampled in each plot is 28.5m. Transects are labelled from A to F.

A, B, and C are located in the diverse site. D, E, and F are located on the grass lawn. They are labelled in order from South to North, with transect A at the most Southerly position.

Species recordings are plotted at the measured distance from the sidewalk along with a measured distance away from the transect line to provide an x,y coordinate of where the species was located and in what conditions.
A positive y location indicates a position South of the line and a negative y location indicates a position North of the line.
A further recording of whether or not the species was located in an area with vegetation or ground cover is made with a Y/N indication and a sub-indicator code for logs, rocks, and others. A recording without a sub indicator means that it was found on vegetation.

 

 

Results:

Number of species located in diverse area (Transects A,B,C):

Transect A: 11

Transect B: 2

Transect C: 1

Composition:

Spiders: 4

Beetles: 3

Caterpillars: 7

Location type (Transects A,B,C):

Total species in/on vegetation/cover: 10

Total species in non-vegetated/cover location: 4

Total: 14

 

Number of species located in grass area (Transects D,E,F):

Transect D: 0

Transect E: 0

Transect F: 5

Composition:

Ants: 5

Location type (Transects D,E,F):

Total species in/on vegetation/cover: 0

Total species in non-vegetated/cover location: 5

Total: 5

 

Changes in methodology:

The method I used to collect the data has so far been effective. Being able to sample the entire site has the advantage of eliminating many assumptions that would be necessary if I were performing randomized or representative samples of just a portion of the site.

This sampling strategy only works well because the site size is relatively small and it is possible to sample the entire area in a reasonable amount of time.

The challenge is to ensure that the transect line is placed in an exact location each time. For this, I used a tape measure and a length of string attached to a railroad spike. When the spike is placed in the ground, it is possible to accurately measure locations for the centreline of the transect without movement.

I will continue to sample this site in this manner so that my data remains consistent.

There were no major difficulties in implementing my sampling strategy in the field. Using the quadrat method, I subjectively chose 5 different locations, 2 grazing and 3 non-grazing, in order to observe the damaged caused to Ryegrass by geese feeding habits. I laid out a 100cm x 100cm grid and estimated the amount of damaged area by measuring it and estimating area. The only difficulty experienced was that getting an exact measurement of the damaged area is tough as it is not always in a square shape. However, I do not expect this to be a major detriment to the effectiveness of the experiment as the estimates will be fairly accurate and it appears that the data still shows accurate trends. The data trends were close to expected, but the total area of damaged grass was slightly higher than I originally expected. I plan on continuing to collect data using this technique as it is effective as well as time efficient. Overall, I think the sampling strategy was highly effective.

 

In my study, I will be sampling three different sites on Thompson Rivers University (TRU) to determine bird species abundance at each site. Point counts were made for seven bird species at the three sites. In other words, I monitored the presence or absence of seven bird species at three different sites on the TRU campus. In this case the predictor variable was the site of study and the response variable was the species abundance at each site. I found it challenging to narrow my focus area to just three distinct sites. When implementing my sample strategy I had to consciously make strict restrictions as to what was considered part of each of the three sampling sites. I plan to continue using the same technique, of recording which of the seven bird species are present at each site using the point count method. After sampling the site for the first time on March 21ist, I ensured that I continued to sample the three sites at the same time of day (10:30am) to remain consistent temporal boundaries.

My initial survey of a red squirrel’s area involved using rectangular quadrants that matched the property lines.  I have since changed to using a circular survey of 25 metres distance each and using 5 quadrants.  I have chosen this design to add  more ‘natural’ boundaries to my survey since a red squirrel’s territory is oval in shape.  I will be measuring the resources available in each quadrant from food availability, amount, cache areas, trees for both aerial walkways and protection from sky and ground predators.  I see using a circular design with the small distances  more informative as it also allows for a more detailed count of the resources in each area plus gives the distance of the food stuffs from the squirrel’s central ‘midden’.

The total area of 5 ha is slightly larger than a forest squirrel’s territory in a time of low food, but I believe the variety of food stuffs in an urban environment are far more than in the wild.

I am wondering why the red squirrel chose my woodpile as the central ‘midden’ or home cache considering there are a total of 5 wood piles in this area.  I believe it might have to do with the fact that my wood pile is very close to my home while the others aren’t.  This appears to be offering the squirrel more protection.

My predictor variable is the 1 red squirrel in this 5 ha territory. My response variable is the resources available to the squirrel.  My hypothesis is that my wood pile is the best because it offers a central location to radial access to all the variety of food resources within the 5 ha.  And I think a surprise will be that the human activity around my wood pile offers the squirrel more protection against predators.

Today is March 26, 2018, cool with a light snowfall.  This morning I noticed a smaller squirrel head poking out of the wood pile while the larger squirrel sat above on top of a post.  I believe the smaller squirrel is a female.

 

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)

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.