A deeper dive into our CNC Hartford/New Haven data!

Congratulations to everyone who participated in central Connecticut’s first City Nature Challenge! We are so excited about the level of participation and quality of observations in Hartford and New Haven Counties' inaugural showing, and want to share some interesting insights from the data we all collected.

The stats tab of our project provides a great summary and overview of what was found. Additionally, iNaturalist allows users to export observation data, which gives us the opportunity for a deeper look at our project. Data was exported on Monday, May 6, and may change slightly should more observations from the April 26-29 period be uploaded.

Impact of the CNC on iNaturalist participation: 2024 vs. previous years

Across our two counties, there was a big increase in iNaturalist observations made during this year’s four-day CNC vs. the comparable four-day period in each of the past two years. In fact, there were 5.8 times more observations in our counties in 2024 vs. the CNC time period in 2023. You can see a breakdown of daily observations below:

Checking out this graph, it looks like Sundays are big days for observations, CNC or not!

It’s great to see that the diversity of these 2024 observations was also high - there were about 3.1 times more unique “species” values during the CNC this year than in the same time period in 2023, and 2.6x more than 2022. See the breakdown by day:

*Values may slightly differ vs. what is shared by iNaturalist stats. This analysis included all unique scientific names, even if not specified to the species level.

This year’s CNC period also saw a larger number of unique observers submitting observations each day compared to previous years. Some of this increase can likely be attributed to extra observation activity from existing users - that said, a number of people who followed our project page were brand new to the app, which means that our project succeeded in attracting some new iNaturalist users!

The data analyst in me must make the disclaimer that this is observational, rather than experimental data. We can't make confident claims about whether the CNC actually caused this increase in participation - but it’s more than plausible that our new project inspired a lot of additional participation this year. One hint is that, while participation also increased this year in some counties without a City Nature Challenge project, the increase was much smaller than what was observed in Hartford and New Haven Counties. In Litchfield county, for example, there were 500 observations made this year between April 26-29, vs. 421 in 2023, an increase of 18%. In contrast, across Hartford and New Haven Counties, we saw a whopping 478% increase.

It's also apparent from iNaturalist maps of the relevant weekends that Hartford and New Haven showed up in a bigger way this year:

Note that Fairfield County was the only Connecticut county with an established City Nature Challenge in 2023, and appears to have a higher concentration of 2023 observations with respect to the rest of the state - more evidence that the CNC is driving an increase in iNaturalist participation.


Observation hot spots

Within our counties, where were most observations taken? In many, but not all, cases, iNaturalist observation data gives us a clear indication of which town the observation was taken in. That data is mapped to Connecticut towns here:

Ignoring the 11% or so of observations for which a specific town couldn’t be determined (“NA” in this table), the top 5 sites of observation were Hamden, Madison, Guilford, Meriden, and New Haven – all towns in New Haven County. Interestingly, Hartford County towns took the next top 5 spots.

Types of observation by county

iNaturalist groups user observations into some main “iconic taxa”: birds, mammals, plants, etc. This gives us the opportunity to see what forms of life were most observed in each county during the CNC. There are so many reasons why a particular organism would draw someone’s attention, that we can’t really draw conclusions about the populations of particular taxa in one county compared to another. However it is interesting to see this breakdown showing somewhat different rates of taxa observations in the different counties:

Plants were clearly the predominant type of observation in both counties. Hartford County had a higher proportion of insects and fungi, while New Haven County showed its shoreline side with more birds (Aves) and molluscs. It was interesting to see that the majority of mammals observed were in New Haven, too.

Conclusion
We think that the most well-supported takeaway is that the City Nature Challenge really does encourage more of us to tune into the nature around us, spend some time outside, and get a little more familiar with our non-human neighbors. Especially with the added knowledge that iNaturalist as a whole achieved record participation in April.

Considering that the only form of publicity we had for this event was emailing different nature groups, posting on iNaturalist, sharing info with Connecticut-based Facebook groups, and leaving fliers where we could, we are really happy with the amount of participation in this first year.

Collectively, we 260+ participants did an excellent job building up the record of Connecticut biodiversity this year. Let's plan to beat these newly-established records in '25! Anyone interested in helping to organize, please be in touch.

• Chase (@hexagonaria) and Sarah (@chiforager)

PS: This post is already quite long enough, but I (@hexagonaria) am happy to talk about methods or other potential analyses if anyone's interested!

Posted on May 9, 2024 10:13 PM by hexagonaria