Spring migration is one of the best times of year to go birding, but when exactly is it? Understanding how to track spring migration can help you take advantage of the best seasonal birding in your area.

When Is Spring?

The spring season varies depending on where you live and how local geography impacts seasonal weather patterns. Areas of low elevation closer to the Equator, for example, experience spring much earlier than areas of high elevation further from the Equator – spring occurs much sooner in Florida than in Alaska.

In the Northern Hemisphere, spring lasts from early March through late May, and in the Southern Hemisphere, spring lasts from mid-September through early November.

Factors That Affect Spring Migration

Birds do not have calendars to let them know when it is time to migrate, and they rely on other factors to provide clues that it is the right time to head toward their breeding grounds. In addition to geography, factors that influence the exact timing of spring migration include:

• Light: Seasonal light levels change as the Earth revolves around the sun, and birds are attuned to when longer days are sufficient to indicate spring.
  
  
• Weather: Local weather patterns can impact spring migration. A harsh, long winter can intrude into spring and delay birds' migration, while a mild winter can encourage birds to migrate sooner.
  
  
• Food: The availability of reliable food sources is an important factor in the exact timing and route of birds' spring migration. As insects, tree buds and nectar-producing flowers become available in the spring, birds will begin to migrate.
  
  

• Species: Different bird species begin their spring migration at different times depending on how far they need to travel. Shorebirds that nest in Arctic regions are some of the earliest migrants because they have the furthest to go, while many warblers and hummingbirds migrate much later in the season.

Tracking Your Local Spring Migration

While understanding the factors that affect spring migration can help you plan your seasonal birding to take advantage of when birds begin to appear, the longer you watch birds the more you can track the exact migration dates of your favorite birds.

• Check the dates of local or regional birding festivals. These events are planned to make the most of the peak migration season and can give you a clue about the dates of the most productive migration in your area.
  
  
• Watch your backyard birds year after year, tracking returning migrants' arrivals at your feeders and bird houses by marking dates on a calendar or in a birding journal. Over time, you will discover that many species of birds arrive during the same week each year.
  
  
• Be aware of new growth and budding on your local trees and in your flowerbeds. As more spring flowers bloom and more trees blossom, you will know it is time for spring migration to begin.
  
  
• Learn which birds are the earliest migrants in your area. Shorebirds and ducks are some of the earliest migrating birds, depending on regional habitats, and yellow-rumped warblers are one of the earliest migrating warbler species. When you begin to see these birds appear, you will know more spring migrants won't be far behind.
  
  
• Watch for nesting behavior from your year-round resident birds. As they begin their courtship behavior and constructing nests, migrating birds will also begin to arrive to make preparations of their own.

The more you become aware of the timing of spring migration, the more you will learn birds' behavior patterns from season to season, and the better prepared you will be to take advantage of this peak birding season.

Make the Most of Migrating Spring Birds

When you realize that spring is here and migration is beginning, how can you take advantage of the season to make the most of every bit of spring birding?

• Choose early-blooming trees, shrubs and flowers with colors that attract birds for your bird-friendly landscaping. This will make your yard a haven for early-migrating birds, attracting them right to your bird houses, feeders and bird baths.
  
  
• Keep your bird feeders filled with a variety of different foods for birds, including seed, nuts, suet and nectar, to meet birds' different food preferences. This will provide a nutritious banquet for your visiting birds, both resident species and spring migrants.
  
  
• Visit different habitats frequently during spring to see which new species have arrived. Some spring migrants may only stay in the area for a few days, so the more frequently you go birding, the more likely you are to see a wider range of migrating species.

Spring is a fantastic season for birding, and once you know when spring migration is, you can take advantage of the season to see a wider variety of birds as they arrive back at their nesting grounds or pass through your area on their way to the best places to raise their young.

Photo – Japanese White-Eye © Kuribo