Changes in land use in Sierra de Juárez, Oaxaca, Mexico
Often climate change isn't the only thing impacting a pollinator population at any given time.
Take for example the large Neotropical butterfly community that lives in the mountains of Sierra de Juárez, Oaxaca, Mexico. A USGS study used butterfly census data collected over 22 years to study changes to butterfly populations—like how many of each species and which species were found in specific areas—and determine the likely causes for those changes.
The study showed that climate change was the main influence on changes to butterfly populations at high elevations, finding that a majority of species were shifting their ranges uphill.
But the study found that at lower elevations, it was more likely land use change leading to changes in butterfly populations. Over the study period, at lower elevations there was a drastic increase in cropland, shown in purples and reds in the Landsat images, which did not occur at the higher elevation sites. The types of butterflies now found in the lower elevations has changed to species that can survive in many habitat types, known as generalists.
Read the study here: https://onlinelibrary.wiley.com/doi/10.1111/ddi.12473