ISSS608 2017-18 T3 Assign Akanksha Shrirang Yadav eda
VAST Mini Challenge 1: Are The Beloved Pipits Disappearing?
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To answer question 1 of the challenge, following visualizations were built.
A View of The Overall Trend Across Years
Number of Sound Recordings Plotted Against Years – Bird Species Wise
To begin with, the count of recordings (as per species) over the duration of data collection was plotted against the duration of collection to understand the trend through years. It could be noticed that for initial years there aren’t enough data points for almost all the species. Hence, for further analysis for plotting trends, data from year 2002 onwards was considered.
How the Birds are Dispersed Across the Preserve & the Location of the Alleged Dumping Site
Looking At the Distribution & Movement of All Birds Species Across the Preserve
Below figure shows the distribution of bird sound recordings across the preserve for each species:
As can be observed, few of the bird species have never been spotted or recorded near the alleged dumping location such as “Qax”, “Pinkfinch”, and “Bent-beak Riffraff”. Although, bulk of the “Rose-crested Blue Pipit” clusters have been spotted at the dumping location or in region nearby the dumping location, this does not give a conclusive indication about the situation of the Pipit. Since, from the overall time trend it can noticed that the species which have not been spotted near the dumping location show an overall decreasing trend since 2013.
Interestingly, bird species “Carries Champagne Pipit” & “Green tipped Scarlet Pipit” show an increasing trend since 2015 despite being spotted near the dumping location.
A Closer Look At Rose-crested Blue Pipit
Now, let’s take a closer look at the species that we are interested in – “Red-crested Blue Pipit”
Yearly Pattern
As stated earlier, we would be considering only 2002 & above data for analysis. The trend for number of recordings through these years and overall movement of the birds across the preserve is shown in graph below:
Overall time trend shows that the beloved pipit reached the peak of sightings during the year 2015, after which the call recordings dwindled sharply. From the distribution plot, they seem to have been recorded/observed at or near the dumping site from years 2007 to 2014, however the birds seem to be moving away from the dumping site gradually. Also noticeable is the moderate increase in bird calls rather than bird songs over the years. A call can be a sign of distress, a cry for help such as warning sound or sharp note to drive an enemy away or a begging plea. A bird song on the other hand might be an indication of a bird’s health & vibrancy.
Quarterly (Seasonal) & Monthly Patterns
From the Quarterly plot, more birds seem to be returning back during the second quarter over the years with the more numbers showing up in the months of March, April & May. However, most of the birds tend to flock away in quarter 3. Also notice, how the bulk of the bird sounds are songs during these months as apposed to quarter 4, in which case there are more bird calls than songs.
