How to read the animal migration map

Researchers fit small tags to a bird's back or a whale's body. A tag either reads its own position from GPS satellites, or sends a signal that Argos satellites use to work out where it is. After a study ends, the records are often published in open repositories.

This map only uses packages on the Movebank Data Repository released under CC0 or CC BY 4.0. Each species page names who tagged the animals, when and where, in a source box quoted as given.

The dots on the front page show where each animal was on today's month and day. When the date changes, the dots change too.

• The bold line is the animal you picked. Faint lines are other animals of the same species.
• The round dot is where it was on that day. Move the date slider and the dot follows.
• Long straight lines are days with no record. The animal did not necessarily travel along them.
• The map is a flat grid of longitude and latitude. Near the poles it stretches sideways, so each species page squeezes the width to fit its middle latitude.

A single animal can have tens of thousands of rows, too many to draw on a phone. So we reduce them in this order.

• Rows the researchers marked as outliers are dropped. We follow the dataset's visible and outlier columns.
• Argos positions are kept only in classes 3, 2 and 1. Classes 0, A and B carry large errors and are dropped.
• One point per day. It is the median latitude and median longitude of that day's fixes (UTC date).
• Points that jump away from the days around them are dropped. Each animal has a daily limit: 800 to 1,200 km for birds, 250 km for whales, 150 km for turtles.
• Up to 12 animals per species, longest records first. Each page also states how many animals are in the full dataset.

Distances add straight lines between daily points, so they are shorter than the real path. Countries are counted only where a daily point falls inside a border.

• Pick an animal. The id is the tag id the researchers used. We do not make up names.
• Press play to draw the route from the first day. Press pause to stop on a date.
• Drag the date slider to jump to any day. You see the distance so far and the country it was in.

The distance table for this week lists how far each animal moved in the seven days up to today's date. Open it every week and watch the numbers change with the seasons.

Each species page can be printed on one A4 page with the map and the records table. Ads and links do not print.

Some animals have no dot today. That species has no record on today's month and day. We do not fill the gap with made-up points.

Where is this animal right now? This map only covers past records. Live tracking data needs permission from each research team, so it is not here.

Are there cranes that visit Korea? The white-naped crane and demoiselle crane pages are birds tagged in Transbaikalia, Russia. The Countries column shows where they went.

What do you keep about me? Which animal you look at is never sent to the server. See the privacy page for details.