Birds change migration patterns

Birds are changing their migration patterns in response to climate change in a number of ways.

Some species are shifting their breeding and nesting locations to cooler areas in response to warmer temperatures.

Others are changing their migration timing to match changes in the timing of seasonal events, such as the emergence of insects or the flowering of plants. For example, some bird species are now arriving at their breeding grounds earlier than they did in the past, in response to warmer spring temperatures. This may result in birds arriving before their preferred food sources are available, or missing important breeding opportunities if their arrival is not timed correctly with peak food availability.

Other species are changing their migration routes, perhaps to take advantage of newly available food sources or to avoid areas with unfavorable weather conditions. For example, some species of waterfowl have been observed wintering farther north as milder winters have allowed for open water and food sources.

Recent research has also found that some birds are flying faster during their migration. Researchers studied 33 years of migration data for the American Redstart, a small songbird that migrates between Canada and the Caribbean. They used historical information along with automated radio tracking and light-level tags. These are tracking devices that use daylight to estimate location.

As climate change alters their habitats, it is taking the American Redstarts longer to get into shape for the huge journey. Jamaica for example has become increasingly dry as climate change lessens rainfall. There are fewer insects too, the mainstay of the birds’ diet.

The Redstarts are thus delaying their migration northward by around 10 days, the researchers found. However, the American Redstarts apparently compensate for their later departures by flying faster, and taking fewer and shorter stopovers to refuel on the way. All these changes can take a toll on the birds’ health.

“Increased migration speed led to a drop of more than 6 per cent in their overall survival rate”

Bryant Dossman, lead study author

Unfortunately, I think we will begin to see more negative effects of birds changing their migration patterns. However, evolution as it is, birds will also be adapting to overcome the challenges of climate change on their migrations. It’s a matter of watching and waiting.

American Redstart
American Redstart by Hans Toom from Pixabay

20 comments

  1. Interesting points and I guess what I was trying to underpin in my novel about the journey of key animals in flight from Navasola! I will try and link your post to the serialisation of Part 1 that is out next week. I am a bit underwhelmed as it has taken so long.

    Liked by 2 people

  2. Fascinating stuff. Sadly, swifts, which were abundant summer visitors when we first moved here are now increasingly rare. The local habitat still seems fairly swift-friendly, so it’s a sad loss. Not sure whether it’s down to declining numbers everywhere, or whether they don’t like this address.

    Like

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