Can the Plain Pigeon Withstand Another Hurricane?
The next decade will be critical for the once widespread, Puerto Rico Plain Pigeon, as conservationists call for urgent action to avert extinction.
After the storm - and still in decline
Once widespread, the Puerto Rico Plain Pigeon (Patagioenas inornata wetmorei) is again facing the brink. Following devastating blows from Hurricanes Irma and María in 2017, a new study has revealed that the population has yet to recover. The results paint a worrying picture: the subspecies remains well below historical population levels, and its future now hangs on the success of urgent conservation efforts.
The study, conducted by Rivera-Milán and colleagues and published in Bird Conservation International, used a combination of field surveys and statistical modelling to estimate current abundance, predict future trends, and assess extinction risk. Despite earlier resilience to past hurricanes, the aftermath of Irma and María has left the pigeon population in a prolonged bottleneck, with just over 1,000 individuals estimated in the wild between 2018 and 2024.
From forests to fragments - historical causes of decline
The subspecies was listed as endangered in 1970, following decades of population losses due to habitat destruction, hunting, and earlier storms. Although the pigeons once benefitted from regrowth in abandoned agricultural land, more recent pressures - including urban development, nest disturbance near human habitation, and introduced predators - have undercut potential gains. Nest predation by black rats and Pearly-eyed Thrashers remains a key issue, particularly in fragmented forest habitats.
A model of uncertainty - predictions for the next decade
To forecast the population's trajectory, the researchers applied a Bayesian state-space logistic model incorporating nearly four decades of survey data. The results were sobering. While the mean carrying capacity was estimated at around 41,580 individuals, predicted population size for 2025–2034 was a mere 7,173, with wide uncertainty. The probability of reaching a sustainable threshold of 5,000 individuals ranged between 32.6% and 63.1% - but the risk of total extinction during the same period ranged from 19.9% to 33.2%.
Perhaps most alarming, the chance of the population exceeding 30,000 individuals - the benchmark reached in the 1990s - was effectively negligible, falling between 0% and 18.1%. These figures underscore both the fragility of recovery and the limitations of current reproductive success.
Breeding bottlenecks and biological brakes
The Plain Pigeon faces an uphill battle even under favourable conditions. With a clutch size of just one egg - rare among columbids - and repeated breeding failures due to nest predation and habitat disturbance, its reproductive capacity is significantly constrained. In contrast to other doves and pigeons on the island, the species has not shown signs of active nesting or calling during surveys in recent years.
This poor reproductive output, combined with a relatively low intrinsic growth rate, results in a prolonged recovery time - estimated at six years on average, and up to ten in the worst case. These biological and ecological constraints mean that even small increases in anthropogenic or natural pressures could tip the species past a point of no return.
Urgent priorities for conservation action
The authors emphasise the importance of active management. Recommendations include targeted predator control at nesting sites, better enforcement against illegal hunting, and engagement with private landowners to protect nesting and foraging habitats. Public education campaigns are also highlighted as a means to reduce human disturbance near active nests.
Despite being a genetically and ecologically distinct subspecies, the Puerto Rico Plain Pigeon has been underrepresented in regional conservation agendas. Without dedicated action to bolster its numbers above 5,000 - the threshold for demographic sustainability - its future remains precarious. As climate change continues to drive more intense hurricanes, the urgency to act becomes ever more pressing.
June 2025
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