Slate-throated Redstart Myioborus miniatus

  • Order: Passeriformes
  • Family: Parulidae
  • Polytypic: 12 subspecies
  • Authors: William D. Harrod and Ronald L. Mumme

Demography and Populations

The most detailed data come from a five-year study in Monteverde, Costa Rica (Mumme 2015). Breeding males remained on the same territory throughout their life, but 26% of females engaged in between-year breeding dispersal in which they moved relatively short distances (90-240 m) to pair with a different male following the death of their original mate. Annual survival was estimated to be 0.56 for males and 0.43 for females, but these values may be unrepresentative and uncharacteristically low, possibly due to human disturbance at the study site; annual survival at YacambĂș National Park in Venezuela is considerably higher, 0.79 (Martin et al. 2015). Because of the lower rate of female survival observed in Monteverde, the population sex ratio was male-biased, with both unpaired territorial males and unpaired non-territorial male floaters present at least some years (Mumme 2015).

In Costa Rica, natal dispersal is female-biased; the distance between the natal nest and the site of first breeding averaged 935 m (range 340-1960 m, n = 5) for females and 485 m (range 260-1250 m, n = 13) for males. First-year survival was estimated to be 0.29, but this is almost certainly an underestimate because of undetected long-distance dispersal off of the study area, particularly by females. Both males and females can nest successfully as one-year-olds in their second calendar year (SY), but many SY males appear to be non-territorial floaters. Because of the relatively small clutch sizes, high nest predation, and low incidence of double brooding in Costa Rica, annual fecundity (1.8 fledglings per female) is considerably lower that of temperate zone Parulidae (Mumme 2015).

Recommended Citation

Harrod, W. D. and R. L. Mumme (2018). Slate-throated Redstart (Myioborus miniatus), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA.