Table A.1.

Total number of participants, observations submitted, and percentage of observations originating from urban areas contributed to eButterfly, iNaturalist, Nature's Notebook, and eBird in the U.S., March–June 2015–2020.

Program	Year	Participants	Observations	%Urban observations
eButterfly	2015	318	10,373	28%
	2016	299	8066	22%
	2017	281	10,391	23%
	2018	223	6361	20%
	2019	204	5722	23%
	2020	184	5547	19%
iNaturalist	2015	9963	185,519	36%
	2016	17,745	351,788	37%
	2017	21,242	589,864	38%
	2018	32,876	902,758	40%
	2019	75,578	1,441,358	41%
	2020	110,023	1,945,420	45%
Nature's Notebook	2015	1411	107,850	30%
	2016	1582	106,068	44%
	2017	1922	123,691	46%
	2018	2188	132,627	44%
	2019	1937	126,387	47%
	2020	1744	98,256	51%
eBird	2015	66,846	1265,152	38%
	2016	79,622	1,464,060	37%
	2017	91,016	1744,873	38%
	2018	107,925	2,144,422	39%
	2019	130,385	2,486,899	39%
	2020	128,225	2,948,944	46%