Learning where winds are coming from can help predict when birds will migrate.
By John Pogacnik, Biologist
We are in a bit of a holding pattern here for the next few days with winter returning in big way. Winter weather usually means north winds and north winds mean little or no spring migration. Wind direction is extremely important for migrating birds. If birds are heading north, they like to have the wind behind them, rather than having to struggle to fly into the wind wasting precious energy. In the spring, the ideal wind for migration is out of the southwest.
If we watch the daily weather forecasts we see that they include a prediction for wind speed and direction. This has always been a good place to check to see what the winds will be. However there are many times that we get a southwest wind, but the migration is slow. Why is that? In the past, we could pick up a newspaper and see the position of the high and low pressure weather systems. A high is like a mountain of air that flows clockwise around the high. Low pressure systems are troughs and the wind flows counterclockwise. Winds flow away from a high and they flow toward a low. By looking at how the systems interacted with one another, we were able to guess what would be coming. The southwest winds might be just occurring over a short distance or they could be reacting with another pressure system to bring southwest winds originating from Texas or the Gulf Coast states. Sound confusing? The good news is that advancements in technology have made it easier for us to predict the winds.
An application that makes things very easy to understand is https://www.windytv.com (it is also available as an app for Android and iPhone). It gives you a map with animated wind direction lines that are color coded to strength of the wind. You are able to see the winds flowing clockwise away from the highs and counterclockwise toward the lows. With this app, you can see where the winds are coming from and you are able to get a better idea how migration will be affected.
Winds are predicted to be out of the northeast and northwest for much of this week. Right now, southwest winds are predicted for Friday and then they appear to be headed back north. Earlier this season, we saw a lot of south winds with birds arriving earlier than normal. Now we have seen north winds that have slowed down migration. Birds like to migrate with the wind, but the main thing driving them to migrate is what is known as photoperiod. Photoperiod is the amount of light that occurs during the day. Right now in Northeast Ohio, sunrise is 7:38 AM and sunset is 7:28 PM for a total of 11 hours and 50 minutes of daylight. This amount of daylight triggers some birds to migrate. They might get pushed back by strong north winds, but when the south winds finally occur, they try to make up for it. During extended periods of north winds, photoperiod eventually takes over and birds will migrate, but you won’t see big migration days. Photoperiod is not something you need to pay attention to for watching migration, it’s just good to understand why its important to migrating birds.
As the week progresses, watch the winds and wind direction. Like any weather forecast, things can change at any time. But by watching what’s going on with the winds, you can understand what’s going on with migrating birds. See if Friday is indeed a day for a good migration. Once you better understand how the wind affects migration, you will be better able to predict it.
The north winds over the next several days will slow down migration considerably. The winds will be fairly strong so waterfowl, gulls and grebes will look for areas with protection. Also, the cold temperatures may freeze up smaller bodies of water, which means that birds will concentrate in areas of open protected water. Fairport Harbor and the other lakefront harbors are a good place to check for birds, as well as larger inland lakes.
Songbirds such as robins and blackbirds that have migrated to the area recently will have a hard time finding food if we get the amounts of snow that are predicted. Blackbirds and other species such as fox sparrows, song sparrows and juncos may head to birdfeeders. Trees that still have fruit on them like sumac will attract robins and bluebirds.
If we get southwest winds later this week, we could see a lot of new migrants.
Gulls seem to be in the news lately. Michigan’s second ivory gull has been seen the last few days in Flint. The ivory gull is a bird of the far north that rarely gets down this far. Ohio had its second sighting ever earlier this winter with a brief appearance of one near Columbus. An early laughing gull has been present in Lorain for more than a week and has been courting a ring-billed gull. Laughing gulls are typically seen along the East and Gulf Coast and are uncommon inland. Closer to home, a Glaucous gull and a Thayer’s gull have been seen along the lake at Fairport Harbor. Both are also birds of the far north, but are occasionally seen in Ohio in the winter.
There are a lot of robins and blackbirds back. A few fox sparrows have been seen.
Glaucous Gull
Birding at Lake Metroparks
Photos by John Pogacnik, Lake Metroparks Biologist
How do we know when different species of birds will migrate?
A great hawk migration needs two things: south winds and sunshine.
The recent warm periods have brought up birds a little earlier than normal.