The Lake Titicaca Grebe Rollandia microptera is a poorly studied endemic species found in the Lake Titicaca watershed of Peru and Bolivia. Multiple surveys from the early 2000s indicated that the species was suffering a rapid population decline with an unknown cause. At the same time as these surveys, reports emerged that there was an increase in burning of the totora wetlands which are thought to be the primary habitat for the Lake Titicaca Grebe. However, since 2003, no work has been published either on the current population of the Lake Titicaca Grebe, or the extent of the totora wetlands in the Lake Titicaca region. This paper used satellite data to monitor the change in extent of habitat potentially suitable for the Lake Titicaca Grebe to determine whether habitat loss is likely to be a major driver of population declines in this species. We found that the extent of potentially suitable wetland remained stable between 2001 and 2020, though there are more local regional trends of change in extent of totora. We also found that multiple areas exist that might support Lake Titicaca Grebe populations, but where ornithological knowledge is lacking. We suggest no change to the IUCN status of the Lake Titicaca Grebe, but recommend that further fieldwork is required to monitor the species’ current population, especially in previously unstudied but potentially habitable areas.

Human–wildlife conflict is often a driver of species declines, and understanding the material basis of this conflict is the first step in addressing it. The Titicaca Grebe Rollandia microptera is an endangered endemic species found solely in the Lake Titicaca watershed of Peru and Bolivia, and has experienced population declines due to fisheries bycatch. Human fishers often have negative opinions of the Titicaca Grebe, because they consider it as a competitor for declining fish stocks. We tested that assumption by an analysis of the bird’s diet and found that the Titicaca Grebe does not compete with fishers for more lucrative fish species such as trout Oncorhynchus sp. and Pejerrey Odontesthes bonariensis, but does compete for the less desirable (to human fishers) native Orestias sp.

Reverse mounting has been extensively documented across avian taxa but has not received significant attention from behavioural ecologists or evolutionary biologists. In this review, we focus on the little which is known about this widespread behaviour, focusing on the existing adaptive and non-adaptive hypotheses for its origin and maintenance. We found evidence of reverse mounting in 42 species, across 11 orders and 21 families. This is likely to be a significant undercount of the number of species which exhibit reverse mounting. We highlight significant gaps in our knowledge of reverse mounting, and how they can be addressed. These include a lack of experimental studies on reverse mounting, as well as a complete lack of any studies on the neurobiology or endocrinology of reverse mounting. We also speculate about the potential evolutionary consequences of reverse mounting, in the context of how other previously overlooked non-reproductive sexual behaviours have been found to have significant evolutionary consequences.