Plotting Bird Observations on a Map with R

Made with: R

Video overview: (https://youtu.be/XwbC2oFqorQ)

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This is a program that makes use of the tidiverse, dplyr, ggplot2, maps and sf R packages to build a visualization tool that shows the observations of a particular bird species in a US map.

These are the functions that were created:

bd_dot_file

Name: bd_dot_file

Description: Prepares a file for input to the bd_dot_plot function

Usage: bd_dot_file(species, state)

Arguments:

species: a character vector of one or several bird species as denominated by their SPECIES_CODE, e.g. c(“norcar”, “rebwoo”)` for the northern cardinal and red belly woodpecker.

state: a string with the state code where we want to see bird observations

Output:

A tibble including the LATITUDE and LONGITUDE where the species passed as an argument have been located in the state passed as an argument.

Examples:

bd_dot_file(c("norcar", "rebwoo"), "FL") will return a tibble with the LATITUDE and LONGITUDE where northern cardinals and red belly woodpeckers have been spotted in Florida.

bd_dot_file(c("norcar", "rebwoo"), "XX") will return a warning message since “XX” is not a valid state.

bd_dot_file(c("norcar", "rebwoo")) will return a tibble with the LATITUDE and LONGITUDE where northern cardinals and red belly woodpeckers have been spotted in all contiguous US states, since no particular state is provided.

bd_dot_file(c("nonexistingspecies"), "FL") will return a warning message since the species argument provided doesn’t include any valid species

bd_dot_file("", "FL") will return a warning message since the species argument wasn’t provided and one is needed

bd_dot_plot

Name: bd_dot_plot

Description: Bird Observations Geographical Plot

Usage: bd_dot_plot(locs, title)

Arguments:

locs: a tibble displaying the LATITUDE and LONGITUDE of all observations for a selected group of bird species, previously provided to the bd_dot_file function.

title: a character string with the title we want to give to our chart.

Output:

A ggplot showing a the locations in the US map where the selected group of bird species has been spotted, in the state provided to the bd_dot_file function.

Examples:

bd_dot_plot(locs, "Northern Cardinal observations in FL") will return a geom_jitter ggplot over a US map showing spots where the northern cardinal has been spotted in FL (if the user selected FL as state argument in bd_dot_file).

bd_dot_plot("") will result in a warning explaining that the argument needs to be a data frame.

bd_dot_plot(locs) will return a geom_jitter ggplot over a US map showing spots where the Northern Cardinal has been spotted in the state provided by the user in bd_dot_file. If no state was provided it will show all observations in the continental US. Since no title is provided, the default title of “Scatterplot” will be used.

validate_species

Name: validate_species

Description: a helper function to determine if the value of a species entered by the user corresponds to a valid bird species.

Usage: validate_state(species)

Arguments:

species: a character vector, e.g. c("norcar", "baleag")

Output: If input contains an invalid species: a warning message will alert user and stop program. If input contains all valid species codes: return to the function that called it without returning a value, as through a pass.

Examples:

validate_species(c("norcar", "xxxxxx")) will warn the user that xxxxxx is not a valid species.

validate_state("norcar", "baleag") will pass and go back to the calling function, since values provided are valid bird species.

validate_state("") will warn the user that is not a valid species.

validate_state

Name: validate_state

Description: a helper function to determine if the value of a state entered by the user corresponds to a valid state in the continental US.

Usage: validate_state(state)

Arguments:

state: a character string of length 2, e.g. “FL” for Florida

Output:

If input is an invalid string: a warning message stopping the program.

If input is a valid string: returns to the function that called it without returning a value, as through a pass.

Examples:

validate_state("FL") will return to the function that called it without a warning message, since “FL” is a valid state.

validate_state("XX") will return a warning message and stop the program, since the state “XX” is invalid.

validate_state("") will return to the function that called it without a warning message, and the function that called it will consider data for all states, without filtering for any state in particular, since none was provided.

© 2025 Mario Sanchez Carrion