Polly Want A City? Population Boom Sparks Call For Cull Of London’s Invasive Parakeets

Image Credit: Chinmaysk, CC BY-SA 3.0, Image Cropped
Species data for understanding biodiversity dynamics: The what, where and when of species occurrence data collection (2021) Petersen et al., Ecological Solutions and Evidence, https://doi.org/10.1002/2688-8319.12048
With the rise of the internet, GPS’ and smartphones, the amount of openly available species occurrence data has reached previously unfathomable numbers. This increase is mostly due to the engagement of the citizen scientist – regular people getting out there in nature and taking part in data collection and research. From people taking photos of flowers in their backyard to organised salamander spotting safaris, citizen scientists have opened up data that previously would have cost massive amounts to produce.
The Global Biodiversity Information Facility (GBIF) is the largest hub of such data, collating data ranging from amateur observation to museum specimens to professional surveys. It is well-known, however, that this kind of openly available data comes with a myriad of caveats: some species groups are reported much more than others (I am looking at you, bird-watchers), and “roadside bias” (see Did You Know?) haunts the records. But how are the records distributed among different land-cover types on a country-scale, does it differ between groups of conservation concern, and does it depend on who the reporters are?
Read moreFor bird scientists, there are pros and cons to the public’s love affairs with birds. The bird community is a huge source of information and a great place to raise awareness of conservation issue. Yet at the same time, our idealisation of birds has led to a lot of misconceptions, both about their population health and their private lives.
Professor Dan Baldassare came into bird ecology through a fascination with animal behaviour. The author of the fantastic paper “The Deal With Birds” (which we’ll get into in a subsequent article, Dan has spent his academic career studying the lives of a range of birds, from the striking Northern Cardinal to the incredible vampire ground finch.
I spoke to Dan recently about our relationships with birds, some of the positives that have come from it, and how our perception of them may have blinded us to some of the realities of their lives.
Birds like this American tree sparrow are declining rapidly, shows a study which looks at huge declines in North American bird populations (Image Credit: Ryan Hodnett, CC BY-SA 4.0, Image Cropped)
Decline of the North American avifauna (2019) Rosenberg et al., Science, DOI: 10.1126/science.aaw1313
When we talk about species loss, we generally focus on extinctions. Too often, when we start to rally around a species, it’s because there are a particularly low number of that species left. In many cases, they’ve often crossed a threshold, from which it’s impossible to pull them back from the brink of extinction.
Often this draws attention away from non-threatened species. Often that’s fine – they’re non-threatened right? But downward population trajectories in these species can still damage ecosystems by lessening the impact of their ecological function, lead to local (if not total) extinctions, and of course, leading them to eventually be threatened.
This week’s authors wanted to look at bird population declines in America, but from the perspective of total abundance, as opposed to a more species-specific view.