The urban parks of Barcelona, Spain, are home to a thriving colony of tropical monk parakeets. These vibrant green birds, native to South America, have adapted well to their new European environment. As they live in large groups, they communicate with each other using an array of distinct sounds – offering scientists a unique window into understanding the intricate relationships between individual social connections and vocal variety.

For animals that live in complex societies, communication is the key that unlocks the benefits of group living. From dolphins’ clicks and whistles to primates’ calls, it’s well-known that species with more intricate social lives tend to have more diverse ways of communicating. However, a recent study on wild parrots has drilled deeper into the social and vocal lives of individual birds.

Researchers at the Max Planck Institute of Animal Behavior spent two years closely observing 337 monk parakeets in Spain, documenting their social lives and recording over 5,599 vocalizations – an astonishing number that provides a wealth of data for analysis. By examining these calls in terms of repertoire diversity (the variety of sounds a bird can make) and contact-call diversity (how unique this specific type of call is), the team was able to uncover some fascinating insights.

The study revealed that individual parakeets living in larger groups did indeed produce more variable repertoires of sounds. Interestingly, female parakeets had a more diverse repertoire than males – an unusual finding for birds. This suggests that females may be the more social sex, and their vocalizations reflect this.

Social network analysis showed that parakeets with more central positions in the social structure – those that were potentially more influential in the group – tended to have more diverse vocal repertoires. In other words, the most social individuals seemed to have a better vocabulary than less social individuals.

The researchers also found that close friends who allowed each other to approach within pecking distance sounded less like each other, as if they were trying to sound unique in their little gang. These findings offer clues about the evolution of complex communication, including human language.

As Simeon Smeele, the first author of the study, notes, “The next big step is to better understand what each of the sounds mean – a real mammoth task, since most of the social squawking happens in large groups with many individuals talking at the same time!” The study provides a crucial foundation for further research into the intricate relationships between communication and group living in animals.

The Lesser Goldfinches, a small songbird traditionally found in the Southwest, are expanding their range northward through the Pacific Northwest at an unprecedented rate. This remarkable shift provides insights into how species adapt to environmental change.

Researchers from Washington State University and the Cornell Lab of Ornithology analyzed data from birdwatchers participating in two initiatives from the Cornell Lab — Project FeederWatch and eBird — to track the species’ movement. The study found that Lesser Goldfinch populations increased dramatically in Washington (110.5%), Idaho (66.3%), and Oregon (16.9%) between 2012 and 2022.

“When I first arrived in eastern Washington, I was pretty new to birding and Lesser Goldfinches were new to me,” said Mason Maron, lead author and graduate of Washington State University. “I was seeing groups of 30 or 40 at a time, and I sort of assumed that was normal until I started meeting local birders who said, ’10 years ago we never had Lesser Goldfinches.'”

What’s fascinating is how these birds are adapting to human-modified landscapes. They’re not just moving north randomly; they’re following specific corridors, particularly along rivers and through urban areas where temperatures are warmer and where both native and non-native plants provide food.

The research identified maximum annual temperature, annual rainfall, urban development, and proximity to major rivers as key factors associated with the northward expansion. Although the authors noted Lesser Goldfinches appear at backyard bird feeders often, when they looked at how bird feeders might affect establishment, surprisingly, bird feeders played a minimal role in establishing new populations.

“There wasn’t really a significant association with bird feeders,” Maron said. The first individuals to arrive in a new area might go to feeders because they provide easy-to-access food, but Maron explained, “it’s not going to be enough to sustain a whole population.”

Rivers emerged as crucial corridors for expansion. “These rivers carry weedy plants and seeds really well,” said Maron. “We, as people, like to live along the river, so we disturb the soil and that really creates this sort of chain of the perfect conditions for them.”

Once established in new areas, the goldfinch populations remain stable. “Our results are suggestive of this species being able to pretty rapidly colonize new environments,” said Jordan Boersma, co-author and research associate at the Cornell Lab of Ornithology.

The Lesser Goldfinches might be shifting north in response to climate and habitat changes reported by this study, and indeed, the Cornell Lab of Ornithology’s eBird Status and Trends project indicates that Lesser Goldfinches are declining in the southern parts of their range.

Citizen science projects have been gaining popularity worldwide, allowing individuals to contribute to scientific research while promoting public awareness and engagement. Two such platforms, iNaturalist and eBird, encourage people to observe and document nature, but how accurate is the ecological data that they collect? A recent study published in Citizen Science: Theory and Practice offers a compelling answer.

Researchers from the University of California, Davis, conducted an analysis of data collected by participants on both platforms. They found that citizen science data from iNaturalist and eBird can reliably capture known seasonal patterns of bird migration in Northern California and Nevada. This demonstrates that even though the two platforms differ substantially in their data collection methods and user demographics, they can be combined to produce robust datasets.

The study began as a student capstone project in Laci Gerhart’s Wild Davis field course, which teaches students about urban ecology and California ecosystems. Cody Carroll, now an assistant professor at the University of San Francisco, took the course in 2020 while completing his doctorate in statistics at UC Davis. After Carroll graduated, the team regrouped and took the project a step further by combining the iNaturalist data with data from eBird.

The researchers compared data for 254 different bird species observed in Northern California and Nevada in 2019 and 2022. They found that the two platforms showed similar seasonal patterns for over 97% of bird species. To “ground truth” their findings, Gerhart and Carroll teamed up with Rob Furrow, an assistant professor of teaching in the Department of Wildlife, Fish and Conservation Biology.

The combined iNaturalist and eBird data recapitulated a variety of known bird seasonality patterns within the region. For example, California Scrub-Jays are present year-round, whereas Bufflehead ducks arrive in mid-fall and depart in early spring. Western Tanagers pass through in late spring when they journey south for winter, and again in late summer as they fly back northwards to breed.

This study shows that citizen science data can be trusted, despite differences between platforms and user demographics. The findings have significant implications for scientific research and conservation efforts. As Gerhart notes, “Contributors to multiple, smaller projects can help make real discoveries about bigger issues.”

The researchers made a point to publish their results in an open-access journal and created a dashboard that allows people to explore and visualize the seasonality patterns for all 254 bird species. This demonstrates a commitment to transparency and public engagement, essential principles of citizen science.

In conclusion, this study demonstrates the power of publicly generated data and the importance of combining multiple datasets to address broader scientific questions. It also highlights the potential of citizen science platforms like iNaturalist and eBird to inspire people to connect with nature while contributing to important biological research.