Op Ed

Submitted by Lindsey Airth, Western University

Have you ever been in a situation where you felt like timing was everything? For many migrating birds and species, timing is everything. But recent increases in annual global temperatures over the past decades are now showing the effects of temperature change on animal migration patterns (1,6). Birds migrate because they must move from areas of lower, decreasing resources to areas of higher, increasing resources to increase their chances for survival and reproduction. Many bird species instinctually do this in response to the timing of cyclic changes in seasonal phenomena. Information and data related to seasonal events is important to understand, and he study of it is known as phenology (8). Bird migration is heavily influenced by environmental factors like temperature, hours of daylight, and wind speeds (2,6). Climate change affects wildlife in many ways, but changes in phenology and the negative impacts associated with it is one that is often overlooked by most people, including wildlife enthusiasts.  

Currently, the most harmful effect of phenology change is desynchronization between reproduction and food resources for migrating birds. Typically, migratory birds use hours of daylight, or photoperiods at their wintering site as their phenological cue to determine when to depart their wintering site. At the breeding site, temperature is used as the phenological cue for plant growth and subsequent insect food supply. The photoperiods of the wintering site should synchronize in a way that migrating birds arrive at their breeding site with enough time and resources to successfully breed and feed their young. In some species, the birds arrive and breed too late to keep up with the timing of the availability of their food supply (2,6). We now understand this desynchronization can be rooted to spring indices and first leaf presence of the year (4).

 Compared to the long-term average, 2022 reports of first leaf presence were reported anywhere from 7 days earlier to 9 days later in the southeastern US, and up to 22 days earlier in the western US (4). Arizona experienced ranges of up to 18 days outside of the long-term average leaf out period (4). Plants provide the food source for the insects that the birds eat, but how can birds know when the plants will grow to subsequently eat the food source, especially if these dates can range from days up to weeks? Making the wrong decision could mean life or death for these animals, and this is the problem migratory birds are trying to adapt to. Is there anything we as humans can do to help? Yes, absolutely! The best way to help resynchronize migratory animal phenology is by data collecting. A program through the United States Geological Survey (USGS) called ‘Nature’s Notebook’ is one way to collect data. ‘Nature’s Notebook’ a great way that people of the community can use phenology to observe and track seasonal changes in plants and animals. Anyone can become a Citizen scientist and utilize the features of the notebook. You are even able to choose specific locations and species you want to track! (3).

Changes in animal and plant phenology are among the most sensitive biological indictors of local, regional, and global health and change (4). The more data we can collect on local levels, the more information there will be to make the best decisions and conservation efforts to resynchronize the phenological events and patterns in migrating birds. Data collected through this network is used for many different purposes including invasive species removal projects, improved tree leaf-out models, and indicators for important species events (4). Join a featured campaign on ‘Nature’s Notebook’, or create your own local network today to contribute! 

Works Cited

 1. Climate Change Response: Bird Migrations | Climate and Global Change Center | University of Pittsburgh. Www.climatecenter.pitt.edu. Retrieved February 18, 2022, from https://www.climatecenter.pitt.edu/news/climate-change-response-bird-migrations

 2. Effects of Climate Change on Terrestrial Birds of North America | Climate Change Resource Center. Www.fs.usda.gov. https://www.fs.usda.gov/ccrc/topics/effects-climate-change-terrestrial-birds-north-america

3. Nature’s Notebook | USA National Phenology Network. (2019). Usanpn.org. https://www.usanpn.org/natures_notebook

4. Phenology Visualization Tool | USA National Phenology Network. (n.d.). Www.usanpn.org. https://www.usanpn.org/data/visualizations

5. Projects - Climate Adaptation Science Centers. Cascprojects.org. Retrieved February 20, 2022, from https://cascprojects.org/#/project/5050cb0ee4b0be20bb30eac0/4f833d39e4b0e84f608680cd

6. Rushing, C. S., Royle, J. A., Ziolkowski, D. J., & Pardieck, K. L. (2020). Migratory behavior and winter geography drive differential range shifts of eastern birds in response to recent climate change. Proceedings of the National Academy of Sciences, 117(23), 12897–12903. https://doi.org/10.1073/pnas.2000299117

7. When Timing is Everything: Migratory Bird Phenology in a Changing Climate | U.S. Geological Survey. Www.usgs.gov. Retrieved February 20, 2022, from https://www.usgs.gov/news/when-timing-everything-migratory-bird-phenology-changing-climate

8. Why Phenology? | USA National Phenology Network. Www.usanpn.org. https://www.usanpn.org/about/why-phenology

9. You, yes, you! Consider helping take the pulse of our planet | U.S. Geological Survey. Www.usgs.gov. https://www.usgs.gov/news/featured-story/you-yes-you-consider-helping-take-pulse-our-planet