By Kali Reichert
Geographic Range
The nightingale wren has a very limited range. It is found from far southeast Mexico through to Costa Rica (the northern portion of Central America). It has been seen by a few observant researchers, birdwatchers, and tourists in this area.
(Stiles & Skutch 1989)
Biogeographic Regions:
neotropical
(native
).
Habitat
Microcerculus philomela lives in thick evergreen forests, which are also usually very moist, and have a large amount of cover on the forest floor. Most of the time M. philomela can be found on the forest floor, or perched on low branches and plants, and are very difficult to spot unless they are singing. Ravines and foothills in these forests are favorite environments of these birds. (Stiles & Skutch 1989)
Terrestrial Biomes:
rainforest
.
Physical Description
(0.63 oz)
Adults are usually 10-11 cm in length and weigh 18 g.
Both male and female adults have dark black markings, usually scaling on their breast and throat which have a greyish base color, but can appear almost completely black. Their dorsal side is dark brown, with black scalloping around the edges, as well as on the wings. There are a lighter spots on the wing coverts. They have a black bill and black legs.
Immature wrens have markings similar to adults, but are over-all paler in color, creating more contrast between light and dark markings.
Young wrens are even paler than immature wrens, though still similar, also with a marked contrast in color. Their scaling is mostly grey, instead of black, and their base color is more of a light cream or buff shade.
(Stiles & Skutch 1989; Howell & Webb 1995)
Some key physical features:
endothermic
; bilateral symmetry
.
Reproduction
Very little is known about the nesting habits of Microcerculus philomela due to their secretive nature. Their mating season runs from May or June until September. They have been observed using previously existing nests on the floor of forests in the dirt to lay eggs and raise their young. Some biparental care has also been observed. The average clutch size is about 2-3 eggs. The incubation period usually lasts for 19-20 days during which the parents are directly involved with caring for the eggs. Once hatched, the observed time to fledging is about 16-17 days. No observations have been made of the time it takes young to reach sexual maturity. Most wrens are polygamous, so it can be hypothesized that nightingale wrens are as well, but no research supports the idea at this time.
(Stiles & Skutch 1989; Christian & Roberts 2000)
Key reproductive features:
iteroparous
; gonochoric/gonochoristic/dioecious (sexes separate); sexual
; oviparous
.
Behavior
Nightingale wrens are very elusive, which makes them difficult to study, as well as to observe and enjoy in the wild. Their markings and habit of hiding on the forest floor or in low vegetation help them to be safe, and also avoid intervention from humans. The song of these birds is largely what helps people locate them in the forest and distinguish them from other birds. Microcerculus philomela males learn only one song during their lifetime, but this song can be altered to fit different uses, such as mating and marking territory.
(Howell & Webb 1995)
Key behaviors:
flies; motile
.
Food Habits
Nightingale wrens are mostly insectivores that forage in the debris of the forest floor for insects, arachnids, and other small forest invertabrates. A peculiar behavior when searching for food is the constant motion of the tail beating on the ground as they walk. This could be used as a method of drawing food out into the open to be eaten.
(Stiles & Skutch 1989)
Economic Importance for Humans: Positive
Nightingale wrens are popular on birding resorts in Central America. Along with the many other diverse species of birds found in this region, they create an attraction for tourists and an industry for this kind of resort.
Conservation Status
IUCN Red List: [link]:
Least Concern.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
We have no text on this topic for this species. Look to the sidebar on the right for some limited information.
Other Comments
Until recently, Microcerculus philomela was considered a subspecies of Microcerculus marginatus, which is located immediately south of the range of M. philomela. They were all lumped, along with Microcerculus luscina, under the name nightingale wren. Their geographic differences, along with distinct differences in song and physical traits have separated the groups. They are sometimes referred to as Northern and Southern nightingale wrens, respectively. This division is likely the beginning of speciation in this group of very closely related birds.
(Stiles & Skutch 1989)
Contributors
Kali Reichert (author), University of Michigan.
Phil Myers (editor), Museum of Zoology, University of Michigan.

