I had the content below at the top of the main "Birdwatching In IslandWalk" page. It was a distraction there, so I have given it its own page here.
Here's the link to the IslandWalk hotspot at eBird.org.
[Originally created 2023-08-29]
This is really not enough data yet to do much analysis on, but I figured I would start this table, which is the most aggregated form of the data. Even so, the Avg Birds # can be thrown off by a vulture or crow get-together, which can be 50-200 birds, but not too badly I think. Not sure what the increases mean, but I guess that's better than decreases.
OK, I've thought about it a bit, I think what's going on is that 2020 goes thru March, 2021 goes thru April, 2022 goes thru May. Mating season starts in late February, early March. All the passerines, in particular the mockingbirds & grackles, start singing 5-10x as much, so their numbers soar. I hate to cut the counts off in March tho. This year I am planning to be in IW October-April. I could use that as a consistent sample moving forward. This would all be so much easier if I were in IW year-round, but my wife wants no part of that :-(. If anyone else can step up and help, that would be great.
| Season | Counts | Avg Species | Avg Birds |
|---|---|---|---|
| Dec-2020 : Mar-2021 | 9 | 22.0 | 170.4 |
| Dec-2021 : Apr-2022 | 22 | 24.8 | 209.9 |
| Dec-2022 : May-2023 | 26 | 25.4 | 222.3 |
[Updated 2024-11-15]
Added 2023-2024 season row.
| Season | Counts | Avg Species | Avg Birds |
|---|---|---|---|
| Dec-2020 : Mar-2021 | 9 | 22.0 | 170.4 |
| Dec-2021 : Apr-2022 | 22 | 24.8 | 209.9 |
| Dec-2022 : May-2023 | 26 | 25.4 | 222.3 |
| Oct-2023 : Apr-2024 | 32 | 24.6 | 256.3 |
I think I will go to the 2022-2023 data and get rid of May.
Note, as I filter this data more, I am NOT going back and updating the annual IslandWalk Birds posts. Those are our raw data, I will leave them alone.
[Updated 2024-12-21]
Got rid of May-2023. Hmmm, average birds got closer to the prior season, but we lost 7 bird lists.
| Season | Counts | Avg Species | Avg Birds |
|---|---|---|---|
| Dec-2020 : Mar-2021 | 9 | 22.0 | 170.4 |
| Dec-2021 : Apr-2022 | 22 | 24.8 | 209.9 |
| Dec-2022 : Apr-2023 | 19 | 25.4 | 205.3 |
| Oct-2023 : Apr-2024 | 32 | 24.6 | 256.3 |
Next up, get rid of crows, vultures, & starlings. No, check that, let's get rid of Oct & Nov 2023 on the most recent season & see what that does.
[Updated 2024-12-22]
Got rid of Oct & Nov 2023 on the most recent season. Down from 89 bird lists to 74. Avg Birds is still ~51 over the average of the prior 2 years, up 24.5%.
| Season | Counts | Avg Species | Avg Birds |
|---|---|---|---|
| Dec-2020 : Mar-2021 | 9 | 22.0 | 170.4 |
| Dec-2021 : Apr-2022 | 22 | 24.8 | 209.9 |
| Dec-2022 : Apr-2023 | 19 | 25.4 | 205.3 |
| Dec-2023 : Apr-2024 | 24 | 24.9 | 258.4 |
I think I know the cause, but 1st, let's remove the crows, vultures, & starlings, which I'm pretty sure are just a source of noise in the data. Note, these species will be removed from the Avg Birds, but not the Avg Species.
Removed the crows, vultures, & starlings. I also noticed that the 2020-2021 data is all from December & January except for 1 list in early March that was only 5.0 miles because my arches went out at the 4.5 mile mark.
| Season | Counts | Avg Species | Avg Birds |
|---|---|---|---|
| Dec-2020 : Mar-2021 | 9 | 22.0 | 154.0 |
| Dec-2021 : Apr-2022 | 22 | 24.8 | 187.9 |
| Dec-2022 : Apr-2023 | 19 | 25.4 | 184.9 |
| Dec-2023 : Apr-2024 | 24 | 24.9 | 238.9 |
So the 1st season is down by 16 Avg Birds, the other 3 down by ~ 20. But, Avg Birds is still 53 over the average of the prior 2 years, up 28.1%. Removing the noise made the increase greater!
I looked at the 2023-2024 spreadsheet for the highest counts. Oh, I get it!
The gist of it is, the 3 migratory diving birds we get show up in widely ranging numbers, if they show up at all.
After 0 lesser scaup the prior season (4 sightings, average 13.0 before that), in 2023-2024 they appeared in 10 lists, average 54.7, max 94. We also had a lot more hooded mergansers: from 6/3.7 to 3/2.7 to 10/14.7. Ring-necked ducks were 0 to 1/4.0 to 2/7.0. This month, over 3 days ring-necked on Lake #3 went from 3 to 10 to 20. I checked today, still 20.
So that explains some of difference. We also have the increased numbers of gallinule & coots.
I conclude that looking at aggregate numbers has limited use. The consistency betweek 2021-2022 and 2022-2033 is encouraging, but, the encouragement ends there. Not a bad sanity check though.
I'm not sure looking at groups (swimmers, divers, etc.) will help that much. I looked at the line & bar graphs built into eBird, they all seem oriented to plotting within a year, rather than year to year. I did find it was easy to download all my data into a CSV, ready for import into a spreadsheet or database - it was ~6000 records. They do include the list metadata, so I can filter by X. and X2. in the description.
More to come, I guess ...
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