ABSTRACT
The endemic Little Vermilion Flycatcher (LVF), Pyrocephalus nanus, has suffered a drastic decline on Santa Cruz Island, where it was common 30 years ago. Currently, less than 40 individuals remain in the last remnants of natural humid forest in the Galapagos National Park on this island. This small population has low reproductive success, which is contributing to its decline in Santa Cruz. Previous studies have identified Avian Vampire Fly, Philornis downsi, parasitism, changes in food sources, and habitat alteration as threats to this species. In Santa Cruz, invasive plants may strongly affect the reproductive success of the LVF because they limit accessibility to prey near the ground, the preferred foraging niche of these birds. Since 2019, we restored the vegetation in seven plots of one hectare each by removing invasive blackberry plants and other introduced plant species. In all nests that reached late incubation, we also reduced the number of Avian Vampire Fly larvae. In this study, we compared foraging and perch height, pair formation, incubation time and reproductive success between managed and unmanaged areas. As predicted, we found significantly lower foraging height and perch height in 2021 in managed areas compared to unmanaged areas. In 2020, daily failure rate (DFR) of nests in the egg stage did not differ between management types; however, in 2021, DFR in the egg stage was significantly lower in managed areas than in unmanaged areas. The DFR during the nestling stage was similar between managed and unmanaged areas in 2020, but in 2021, only nests in managed areas reached the nestling stage. Females brooded significantly more during the incubation phase in managed areas. Additionally, we found significantly higher reproductive success in managed areas compared to unmanaged areas in 2021, but not in 2020. Habitat restoration is a long-term process and these findings suggest that habitat management positively affects this small population in the long term.
ABSTRACT
Avian haemosporidian parasites (Order: Haemosporida) are a diverse group of microorganisms that spend part of their life cycle in the erythrocytes of avian hosts. Parasite presence has been confirmed in all Ecuadorian regions, but some ecosystems, such as the deciduous dry forest of the Coastal region, have not been evaluated for parasite presence. Data on presence or absence, and prevalence, of haemosporidian blood parasites were obtained from avian blood samples collected in two different dry deciduous forests in Guayaquil, Ecuador: Bosque Protector Prosperina and Área Nacional de Recreación Parque Lago. Mist netting was performed between December 2018 and September 2019; blood smears were prepared from blood taken from 35 individuals of 20 bird species and all samples were analyzed by optical microscope observation. Most species showed no evidence of parasite infection, but haemosporidia were found on a blood smear obtained from a Black-capped Sparrow, Arremon abeillei (Passerelleidae), confirming this species as a newly discovered host of blood parasites.
