DISTRIBUTION OF THE TUMBES TYRANT (TUMBEZIA SALVINI) WITH COMMENTS ON MARGINAL RECORDS

Abstract

· We present an updated potential distribution of the Tumbes Tyrant (Tumbezia salvini), a near-threatened species endemic of the Tumbesian region in Peru and Ecuador, and report odd records in its southernmost range. By collecting occurrence records for the species and climatic information across its range, we: 1) modelled the geographic distribution of the species and analysed its climatic niche using multivariate analysis; 2) assessed the position of the odd records across its geographical distribution and climatic niche; 3) assessed the temporal trends of the species occurrence records; and 4) analysed some elements about its conservation status. Our results show that the distribution is highly associated to the dry forest located in the lowlands and the western Andean foothills on the study region. In recent years, the species has been reported at higher elevations, such as our odd records, which may suggest a relatively recent range expansion due to increasing temperatures. However, we did not find a clear increasing temperature trend over the last 40 years in the region. Nevertheless, sampling frequency of occurrence records also increased over time after the year 2000, which may be due to a better recent detection of the species at both its geographical and environmental distribution margins. As the frequency of observed records at high elevations is low, we suggest that our observations are most likely marginal records inside the proposed distributional area for this species. We found that protected areas cover just 5% of the estimated range of the Tumbes Tyrant, despite the fact that the dry forest in the Tumbesian region is under serious threat by anthropic disturbance. Further appropriate monitoring of this species across its range and ecological niche through time will help evaluate its threat and subsequent conservation status.