Author Contributions
K.N. designed the research; K.N. and A.P. crowd-sourced and analyzed photographs; K.N. and D.R. carried out fieldwork in the Yukon; G.N., K.N. and A.P. managed and monitored the CitSci project platform; K.N. managed the iNaturalist project page and sought permissions for use of photographs; N.Y. extracted elevation data; S.R. analyzed the data; J.B., J.B., A.J., K.N. and D.R. institutions provided funding, administrative support, and/or outreach assistance. All authors contributed to the writing of the manuscript and approved the final version.
Table 1: Descriptions and estimates of model parameters based on photographs taken between 1948 and 2018 as part of the community science project. Note: DOY= day of year, and CI = credible interval.σ -terms describe random variation between years.* indicates that the parameter is associated with thez -transformed predictor variable.