Estimating the global population size and highlighting conservation priority areas for the endangered Titicaca grebe

The Titicaca grebe (Rollandia microptera) is a poorly studied endangered
species, only found in the Lake Titicaca watershed of Peru and Bolivia.
Population surveys undertaken in the early twenty-first century suggested
that the species had declined in number by >70%. We conducted a
population survey of the grebe between March and August 2022 in Peru and
Bolivia, using both maximum entropy and Bayesian occupancy models to
estimate factors affecting habitat suitability for the grebe. We conducted
surveys between March and August 2022 in Peru and Bolivia. Contrary to the
International Union for Conservation of Nature (IUCN) population estimates
of <1,000 individuals, there are likely tens of thousands of
individual grebes. The population estimation was sensitive to the type of
model used. Distance from shore and fishing intensity were the most
significant factors influencing grebe populations. The Reserva Nacional
del Titicaca, the only protected area in the lake, covers some of the most
suitable Titicaca grebe habitat across its entire range.  The
population of the Titicaca grebe is significantly higher than previous
estimates, but we do not recommend a change to its conservation status
because of the lack of conservation efforts for this species, and the
long-term risks associated with global warming and fisheries bycatch.