Torrey Pines Bird Survey

Torrey Pines

Torrey Pines State Natural Reserve is a nature reserve located in San Diego, California. It is home to the rarest species of pine tree in North America as well as to many bird species. The reserve's impressive biodiversity includes many different species of birds that make this conservation area their home or that may use it as their stopover point along their seasonal migration routes. The Torrey Pines Docent Society conducts bird surveys every month. While this data is specifically visualized for the Docents at Torrey Pines, anyone can enjoy and learn from this data.

The Data

The Torrey Pines Bird Survey data follows 174 species of birds over a fifteen-year period, from 2006 through 2020. Regular fluctuations in the data make clear the recurring seasonal presence of migratory bird species. You can use the graph below to display the bird count data of a single species or to display the data of as many as five different species for comparison Explore, have fun and see if you learn anything!

Note: While the data here contains 174 different species of birds, this does not reflect the true amount of unique species that have been seen at Torrey Pines. The data has been simplified to only include bird species that have been seen on more than 5 occassions over the past 15 years.

Data Collection Methodolgy

A party of Docents from Torrey Pines spread out at the reserve once a month to survey different species of birds. They tally the birds they see and/or hear. Over the course of the years, the number of Docents conducting the survey has increased and could also be one of the reasons why some birds may be trending upwards.

Bird Trends

The three-month moving average graph below helps users to discern trends in the bird count data. One sees that the California Quail population trends downwards over the years, for example, whereas the California Thrasher trends upwards. Note that trends in the Torrey Pines Bird Survey may be a strictly local phenomenon. The California Thrasher’s upward trend at Torrey Pines is contradicted by the population’s general decline in California during this same period. The graph of another species, the Royal Tern, presents an inverted bell curve, which suggests that the population of this species is bouncing back after a previous decline. In order to increase the visibility of the trends, the data displayed below is a moving average of the data displayed above. The moving average is over the course of 15 months to depict as smooth a line as possible.

Note About Name Changes

In the period covered by the Torrey Pines Bird Survey the common names of several North American bird species changed. Consequently, data for those species may reside under more than one name. For example, the Western Scrub Jay is now commonly known as the California Scrub Jay.


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