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Individual Highlight

Have bird distributions shifted along an elevation gradient with climate change over a 17-year period in El Yunque National Forest?

Photo of Map of Luquillo Mountains, including El Yunque National Forest/Luquillo Experimental Forest and its locations in NE Puerto Rico where bird population monitoring occurred. The black circles represent sites sampled in 2015 with automated acoustic recorders and yellow circles sites with historical point count data. Different colors represent differences in elevation (m a.s.l.).  Map of Luquillo Mountains, including El Yunque National Forest/Luquillo Experimental Forest and its locations in NE Puerto Rico where bird population monitoring occurred. The black circles represent sites sampled in 2015 with automated acoustic recorders and yellow circles sites with historical point count data. Different colors represent differences in elevation (m a.s.l.). Snapshot : Expected elevational shifts in bird distributions with global warming may be species-specific and, hence not readily predictable for many bird species.

Principal Investigators(s) :
Arendt, PhD, Wayne J.Wunderle, Joseph M., Jr.
Research Location : El Yunque National Forest/Luquillo Experimental Forest, Puerto Rico.
Research Station : International Institute of Tropical Forestry (IITF)
Year : 2018
Highlight ID : 1452

Summary

As climate warms most species are expected to escape the heat by shifting their distributions upwards in elevations. However,given the growing evidence of multiple responses of species distributions due to climate change and the lack of studies in the tropics, we evaluated the responses of a montane bird community to climate change in El Yunque National Forest/Luquillo Experimental Forest. To test for elevational shifts, we compared the distribution of 21 species in 1998 and 2015 using occupancy models. The historical data set was based on point counts, while the current data set was based on acoustic monitoring. We detected a similar number of species in historical (35) and current data set (33). We show an overall pattern of no significant change in range limits for the majority of species, although there was a significant shift in the range limit of eight species (38%). Elevation limits shifted mostly upward, and this pattern was more common for upper than lower limits. Our results demonstrate the variability of species responses to climate change and emphasize the importance of long-term population monitoring, especially the value of acoustic monitoring for cost-effective monitoring of animal abundance and distributions. The results from acoustic monitoring also provide invaluable baseline data for future studies of extreme weather events (e.g., hurricanes and droughts), which managers can use to assess responses of vulnerable or sensitive wildlife species.

Forest Service Partners

External Partners

 
  • Marconi Campos-Cerqueira and T. Mitch Aide, University of Puerto Rico, Rio Piedras, PR.