GPS Tracking of Eagle Data in Iowa

How do Eagles in Iowa Traverse?

We wanted to see how Eagles moved around in the “Hawkeye” state!

Background

  • Biologging is the use of attached sensors that go on animals to monitor their movement, heart rate & other behaviors

  • In this large scale observational study over 2 million data points were collected from 57 eagles over a 4 year period

Our variables

  • Overall, 9 numerical variables were drawn from this survey to chart out GPS points

  • We are only working with six variables in our data to analyze and determine what our tracking points say relating to 2 research questions:

  1. Can we use the movement variables KPH, Sn, AGL, |Angle|, Vertical rate, and |VR|, to differentiate between in-flight from perching points?
  2. What are some big takeaways from analysis and visualization of the in-flight points that we can determine?

Data

This is a massive set of data we’re gifted (2 million rows) we might have to use data scaling skills to make it smaller

# A tibble: 6 × 15
  Animal_ID TimeDiff segment_id segment_length LocalTime           Latitude Longitude       X        Y   KPH    Sn   AGL VerticalRate abs_angle absVR
      <int>    <int>      <dbl>          <int> <dttm>                 <dbl>     <dbl>   <dbl>    <dbl> <dbl> <dbl> <dbl>        <dbl>     <dbl> <dbl>
1       105        5          1             10 2019-06-25 16:44:10     41.6     -92.9 509745. 4609596.  0.07  0.52  9.55        -0.99      0.45  0.99
2       105        6          1             10 2019-06-25 16:44:16     41.6     -92.9 509746. 4609597.  0.07  0.17  9.55         0         0.21  0   
3       105        5          1             10 2019-06-25 16:44:21     41.6     -92.9 509747. 4609597.  0.2   0.14  9.55         0         0.91  0   
4       105        6          1             10 2019-06-25 16:44:27     41.6     -92.9 509747. 4609599.  0.16  0.22  9.55         0         3.14  0   
5       105        5          1             10 2019-06-25 16:44:32     41.6     -92.9 509747. 4609598.  0.11  0.08 11.6          0.39      2.69  0.39
6       105        6          1             10 2019-06-25 16:44:38     41.6     -92.9 509746. 4609599.  0.07  0.22 11.6          0         0.53  0

Methods

  • We want to minimize the dataset since 2 million is a lot of rows. Personally I grouped by Animal ID for random points which then created 997 rows of observations.
  • We then took PC loadings of the 6 variables, which we could then use to make PCA biplot of the random sample data.

But there is an issue, we need clustering to distinguish different movement patterns of the birds

Clustering the dataset

According to literature K-means was a very effective way of trying to cluster large datasets related to movement analysis

1st.) Silhouette

2.) WSS

Clustered PCA biplot and takeways