Species names in all available languages
|English (United States)||Slate-throated Redstart|
|Serbian||Američka crvenrepka sa crvenim temenom|
|Spanish (Argentina)||Arañero Garganta Negra|
|Spanish (Costa Rica)||Candelita Pechinegra|
|Spanish (Ecuador)||Candelita Goliplomiza|
|Spanish (Honduras)||Chipe Pavito Garganta Ceniza|
|Spanish (Mexico)||Pavito Alas Negras|
|Spanish (Panama)||Candelita Gargantiplomiza|
|Spanish (Peru)||Candelita de Garganta Plomiza|
|Spanish (Spain)||Candelita plomiza|
|Spanish (Venezuela)||Candelita Gargantipizarra|
|Turkish||Kül Rengi Ötleğen|
William D. Harrod and Ronald L. Mumme revised this account. Arnau Bonan Barfull curated the media.
Myioborus miniatus (Swainson, 1827)
- miniata / miniatus
The Key to Scientific Names
Slate-throated Redstart Myioborus miniatus Scientific name definitions
Version: 2.0 — Published July 29, 2022
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At 10º N latitude in both Costa Rica (subspecies comptus) and Venezuela (subspecies ballux), Slate-throated Redstart is a strongly seasonal breeder that initiates nests from late March through late June, with the peak of nesting occurring in late April and early May (8, 47). Limited data from northeastern Mexico and the rare instances of nesting in the southwestern United States suggest that breeding occurs primarily in May and June at the northern limits of the range (29, 30, 26, 33).
Limited data from equatorial regions suggest that breeding seasons are more extended. For example, nesting occurs from late December through July near Cali, Colombia (3.5º N; 48, 44, 45). In eastern Ecuador (1º S), the congeneric Spectacled Redstart (Myioborus melanocephalus) nests from May–December (49), suggesting that Ecuadorian populations of Slate-throated Redstart may also have a similarly extended nesting season. In a high latitude Bolivian population at 18º S, nest building has been observed in mid-October, and two nests with nestlings were found in early-November and mid-December (S. K. Herzog, unpublished data).
Nests are placed on the ground on steep slopes in undisturbed forests or in banks along roads and trails in areas of human activity; occasional nests are built among epiphytes on a fallen log or in the root mass of an overturned tree (50, 4, 51, 8, 47).
Females are usually solely responsible for nest construction. Skutch (50) reported one nest in Costa Rica at which both members of the pair appeared to participate in nest construction, but this observation is likely erroneous or exceptional; in more extensive studies in both Costa Rica (8) and Venezuela (47), only females engaged in nest building.
Structure and Composition
In Venezuela, nest exteriors averaged 64.8 ± 25.0 mm high and 103.9 ± 21.2 mm wide. Internal cup dimensions averaged 49.1 ± 4.7 mm across with a depth of 31.4 ± 9.5 mm (47).
Egg size in Costa Rica averages 16.7 x 13.4 mm, and neither length nor width is significantly related to laying order (8).
In Venezuela, mean egg mass is 1.6 g (range 1.2–1.9 g; 47).
Color and Surface Texture
Eggs are dull white with dark red or brown spots (47).
Clutch size varies geographically. It averages 2.9 (range 1–4) in Costa Rica (8), but is substantially smaller in Venezuela, averaging 2.1 in Yacambú National Park (47) and 2.4 in Henri Pittier National Park (51). No information is available on clutch size from populations at either the northern (Mexico) or southern (Bolivia) limits of the breeding range.
Eggs are laid early in the morning, usually within the first few hours after dawn. Eggs typically are laid on consecutive days (8).
Onset of Broodiness and Incubation in Relation to Laying
Incubation does not begin until clutch completion (8).
Only females develop a brood patch.
The incubation period in Costa Rica is 14–15 d (mean 14.2 d), but is somewhat longer and more variable in Venezuela (14–18 d, mean 15.3 d; 8, 47). No information is available on incubation period from populations at either the northern (Mexico) or southern (Bolivia) limits of the breeding range.
Incubation is performed only by females. However, some males occasionally feed females on the nest; at 52 nests observed 6–8 h during incubation in Venezuela, 21 males (40%) fed their mates, averaging 0.1 feeding trips/h. Daily nest attendance by incubating females averaged 59% in Venezuela (47).
Growth and Development
The nestling period is typically 11–12 d in both Costa Rica and Venezuela (8, 47). Nestling growth curves in Costa Rica and Venezuela appear to be very similar (51, 8, 47). Body mass averaged 10.8 g for Venezuela nestlings immediately prior to fledging (age 10 and 11 d), and nestlings reached mean adult body mass (9.5 g) 7–8 d after hatching at both locations (8, 47).
Only females brood young (8, 47). In Venezuela, brooding attentiveness averaged 63% during the first three days after hatching but dropped to 11% after feather emergence. In Costa Rica, females ceased brooding 5–6 d after hatching.
Both females and males provision nestlings and fledglings (8, 47; see Young Birds). In Venezuela, the average rate of provisioning was 3.8 feeding visits/h during the first three days after hatching, but the rate increased to 9.4 feeding visits/h after feather emergence (47). In Costa Rica, provisioning rates appear to be considerably higher, averaging 20.3 feeding visits/h when nestlings were 5–9 d old (8).
Brood Parasitism by Other Species
Association with Parents or Other Young
Both parents continue to feed the young after fledging, and may do so at least until the young are 40 d old (28–29 d after fledging) (8).
Ability to get Around, Feed, and Care for Self
Juveniles begin to forage on their own when 30 d old (8).
More information needed on immature birds after reaching independence.