Avian Response to Hurricane Maria in Coffee Plantations

Insights on impacts and resiliency of avian species with respect to
hurricanes in the Caribbean have largely focused on responses measured in
protected habitats.  We assessed avian responses in non-protected
habitat, specifically shade-restored coffee plantations, because their
structural complexity retains many attributes of secondary forests, and
may contribute to landscape scale species resiliency.  We tallied
species richness and estimated occupancy probability of 12 resident avian
species, after adjusting for imperfect detection, to assess the impact of
hurricane Maria (20 September 2017) in shade-restored coffee
plantations.  For five of those species, we also estimated local
colonization and extinction probabilities to assess their prospect of
rebounding (resiliency) in the context of two stages of shade
restoration.  We used survey data collected March-June 2015-2017
(pre-hurricane) and 2018 (post-hurricane) in 58 coffee farms and satellite
imagery to assess vegetation structure.  Restored farms were
grouped into two categories based on time-since-restoration:
newly-restored and fully-restored. We predicted that mean percent forest
cover in fully-restored farms (~30-40%) would revert to levels in
newly-restored farms (<15%), with concomitant changes in occupancy
by avian species.  As predicted, mean percent forest cover (16.17
± 4.27%) in fully-restored farms post-hurricane reverted to pre-hurricane
levels in newly-restored farms (15.00 ± 5.61%).  The loss
represented 30-38% relative to the pre-hurricane cover levels. 
Detections of focal species dropped an average of 41% post-hurricane, with
associated reductions in occupancy for 9/11 species.  Occupancy
of the Puerto Rican Bullfinch and Puerto Rican Spindalis reverted to
levels detected in newly-restored plantations prior to the hurricane as
predicted.  Prospects of rebounding were more likely for species
with invariant or increases in colonization probability (e.g.,
Yellow-faced Grassquit, Northern Mockingbird, Puerto Rican
Spindalis).  Rebounding for frugivores like the Puerto Rican
Bullfinch would be protracted given that colonization rates dropped from
0.56 ± 0.12 (pre-hurricane) to 0.04 ± 0.2 (post-hurricane), regardless of
restoration stage.  Our work showed that the avian community
associated with restored coffee farms exhibited a high degree of
ecological resistance as the similarity in species composition before and
after the hurricane was 81%, and all 12 focal species continued to occupy
farms under both restoration stages.  The prospect of the focal
species to rebound (resiliency) was species-specific, and in some cases,
mediated by their affinity to a particular farm restoration
stage.  The strength of hurricanes is projected to intensify with
global warming.  Pockets of undamaged or partially damaged
shade-grown or fully-restored coffee plantations may contribute to species
resiliency by increasing landscape level habitat redundancy, and
facilitate habitat shifts to secure food resources or harbor source
populations to colonize recovering, hurricane-damaged habitat tracts.