As tropical treelines are less studied than arctic, sub-arctic, and temperate elevational treelines, we hope this study illuminates the need for further attention to climate change mediated mountain ecosystem dynamics in the tropics.

We assessed the effect of spatial variables and distance to coast on treeline structure (change in treeline elevation) and function (change in treeline NDVI), revealing that treelines are moving up and becoming more dense, with the most rapid change in low latitudes.

We used remote sensing to assess patterns of treeline dynamics in 115 high mountain peaks across western North and Central America, from Costa Rica to Canada.

Overall, our findings suggest that nest orientation most likely controls the rate of change in the microclimate, rather than the microclimate itself. Most significantly, nest orientation affects the timing of morning warming in the hot summer breeding season. (5/5)

We faced previously collected pairs of Grasshopper Sparrow and Eastern Meadowlark nests in different directions during the summer of 2019. This allowed us to compare nest temperature, humidity, and wind speed within and among pairs. (4/5)

We noticed Grasshopper Sparrow and Eastern Meadowlark nest orientation differed between drought and non-drought years. These species build domed nests in the grass, so their entrances face a certain direction. (3/5)

Here is the paper for anyone interested: journal.afonet.org/vol95/iss1/a...