Simple Summary
Deforestation can negatively affect birds, but its causal effects are not well understood. In this study, we analyzed how bird populations are affected by high levels of deforestation in Mexico. We used public bird observation records across the country to focus on ten bird species. We compared areas with high deforestation to areas with low or no deforestation over the past years. Our results show that five of the ten bird species studied tend to become less common in places where deforestation is more intense, although one species exhibited an increase in abundance. This research helps us better understand how deforestation influences bird numbers, which can be useful for developing conservation actions that are based on solid scientific evidence.
Abstract
In this study, we used a causal analysis approach to assess the impact of deforestation on bird abundance in Mexico. Based on records in the eBird and GBIF databases, ten species were selected in 807 grids on the mainland. Relative abundances by species were estimated using a fixed-effects panel data regression for the period 2016–2018. Deforestation was used as a quasi-natural experiment, classifying treatment and control groups according to the distribution of relative abundances by quintiles of gross deforestation rates during the period 2001–2018. The treatment group was defined as relative abundances of birds present in grids in the last deforestation quintile (≥4% to 12%); the control group included relative abundances of birds present in grids of the first four quintiles (<4%). Extended regression models were used to estimate the impacts of high deforestation rates on the relative abundance of birds, finding mixed causal effects: five showed statistically significant declines in abundance (Ruddy Ground Dove (Columbina talpacoti), Black Vulture (Coragyps atratus), Melodious Blackbird (Dives dives), Bewick’s Wren (Thryomanes bewickii), and Rufous-backed Thrush (Turdus rufopalliatus)), while one specie Yellow-winged Cacique (Cassiculus melanicterus) exhibited significant increases. These findings highlight the importance of causal effect studies in contributing to empirical evidence-based conservation decision-making.