Puerto Rico plain pigeon, scaly-naped pigeon and red-tailed hawk: population dynamics and association patterns before and after hurricanes

Abstract

Since the 1980s, 3 major hurricanes have made landfall on Puerto Rico: Hugo in September 1989 (Saffir-Simpson scale, category 4), Georges in September 1998 (category 3) and María in September 2017 (category 4). María was the most devastating hurricane since the 3 major hurricanes that occurred in 1899-�1932. Major hurricanes can cause severe abundance declines and population bottlenecks by decreasing survival and reproductive rates and increasing predation and competition for limited resources. In April to June 1986-2021, we used distance sampling to estimate abundance and monitor the population dynamics of the endangered Puerto Rico plain pigeon Patagioenas inornata wetmorei and the abundant scaly-naped pigeon P. squamosa and red-tailed hawk Buteo jamaicensis. Here, we fit a Bayesian state-space logistic model with distance sampling abundance estimates to generate posterior estimates of maximum population growth rate and population carrying capacity, and predict abundance in April to June 2020-2030. In addition, we used N-mixture and 2-species models to assess association patterns in April to June 2015-2019. The scaly-naped pigeon and red-tailed hawk populations did not decline, or recovered faster from their declines than the plain pigeon population after the hurricanes. The association patterns between species were positive but variable for the 2 pigeon species and negative but variable for the plain pigeon and red-tailed hawk. At lowered abundance (i.e. mean ± SE estimates N̂ = 1043 ± 476 island-wide and N̂ = 522 ± 157 at the centre of abundance in the east-central region in April to June 2018-2021), the plain pigeon may become extinct if another hurricane with the path and intensity of María makes landfall on the island during the current decade.

Spatial Occupancy, Local Abundance and Activity Rhythm of Three Ground Dwelling Columbid Species in the Forests of Guadeloupe in Relation to Environmental Factors

“…Such conditions actually limit the performance of alternative methods such as point-count sampling, distance sampling, or capture-mark-recapture (CMR) [26,50,53,94,95]. In particular, auditory point count method and auditory distance-sampling have maximal efficiency only when conducted during the peak of calling activity [96,97] and/or when broadcasting the call of the target species [47]. The CMR method allows a reliable estimation of demographic parameters of terrestrial columbid species [26,98], but requires a considerable logistical effort [41].…”

Factors affecting spatial occupancy and local abundance of the Forest Thrush, Turdus lherminieri, in Guadeloupe forests

“…However, the performance of methods relying on visual and auditory cues to survey tropical forest birds may vary according to habitat type, in direct relation to habitat characteristics and sound attenuation (Waide and Narins 1988;Anderson et al 2015), possibly affecting conclusions about habitat selection. In addition, auditory point count method has maximal efficiency only when conducted during the peak of calling activity (Levesque and Lartiges 2000;Rivera-Milán et al 2022) and/or when broadcasting the call of the target species (Cambrone et al 2021). A potential alternative survey method consists in relying on camera traps.…”