The black redstart is a small passerine bird known for its vividly colored tail, which is bright reddish-orange. The male has dark plumage, with a black or dark grey back and a distinctive white wing patch. Females and juveniles are generally more subdued, with greyish-brown plumage, but they too have the characteristic red tail. This bird is known for its lively behavior, constantly flitting between branches or rocks, while frequently flicking its tail. The black redstart’s song is melodic, often interspersed with harsh, metallic notes.

Scientific Classification:

• Kingdom: Animalia
• Phylum: Chordata
• Class: Aves
• Order: Passeriformes
• Family: Muscicapidae
• Genus: Phoenicurus
• Species: Phoenicurus ochruros

Dimensions and Weight: The black redstart measures between 13 and 15 cm in length, with a wingspan ranging from 23 to 26 cm. Adults weigh between 12 and 20 grams. Its small size and slender build make it a highly agile bird, particularly during flight.

Habitat: This bird is highly adaptable and found in a wide range of habitats. Traditionally associated with rocky, mountainous areas, it has also adapted to urban environments, nesting among buildings, walls, and old structures. It is common in gardens, parks, and rural areas. In Europe, including Italy, it can be found both in high-altitude mountain areas and lower elevations, while it migrates to milder areas in winter.

Behavior and Habits: The black redstart is known for its lively and territorial behavior. Males aggressively defend their territory, displaying complex and lively songs. During the breeding season, which lasts from April to July, the female builds a nest in cavities of trees, rocks, or buildings, where she lays 4 to 6 eggs. Both parents participate in raising the chicks, which leave the nest about two weeks after hatching. The black redstart is insectivorous, feeding primarily on insects and larvae, though it supplements its diet with fruits and berries in the autumn.

Dangers, Enemies, and Threats: The main predators of the black redstart include birds of prey, snakes, and small carnivorous mammals that may attack the nest. However, human activities, such as pesticide use, habitat loss, and the reduction of natural nesting sites, pose the most significant threats to the species. Climate change could also affect its distribution by altering food availability and migration conditions.

Protected or Endangered Species: The black redstart is not considered globally threatened, but it is monitored and protected in some European regions to preserve its natural habitats. Due to its ability to adapt to urban environments, the black redstart population is generally stable, though excessive urbanization and pesticide use could pose future risks.

References__________________________________________________________________________

Villavicencio CP, Windley H, D'Amelio PB, Gahr M, Goymann W, Quispe R. Neuroendocrine patterns underlying seasonal song and year-round territoriality in male black redstarts. Front Zool. 2021 Feb 24;18(1):8. doi: 10.1186/s12983-021-00389-x. 

Abstract. Background: The connection between testosterone and territoriality in free-living songbirds has been well studied in a reproductive context, but less so outside the breeding season. To assess the effects of seasonal androgenic action on territorial behavior, we analyzed vocal and non-vocal territorial behavior in response to simulated territorial intrusions (STIs) during three life-cycle stages in free-living male black redstarts: breeding, molt and nonbreeding. Concurrently, we measured changes in circulating testosterone levels, as well as the mRNA expression of androgen and estrogen receptors and aromatase in the preoptic, hypothalamic and song control brain areas that are associated with social and vocal behaviors. Results: Territorial behavior and estrogen receptor expression in hypothalamic areas did not differ between stages. But plasma testosterone was higher during breeding than during the other stages, similar to androgen receptor and aromatase expression in the preoptic area. The expression of androgen receptors in the song control nucleus HVC was lower during molt when birds do not sing or sing rarely, but similar between the breeding and the nonbreeding stage. Nevertheless, some song spectral features and the song repertoire differed between breeding and nonbreeding. Territorial behavior and song rate correlated with the expression of steroid receptors in hypothalamic areas, and in the song control nucleus lMAN. Conclusions: Our results demonstrate seasonal modulation of song, circulating testosterone levels, and brain sensitivity to androgens, but a year-round persistency of territorial behavior and estrogen receptor expression in all life-cycle stages. This suggests that seasonal variations in circulating testosterone concentrations and brain sensitivity to androgens is widely uncoupled from territorial behavior and song activity but might still affect song pattern. Our study contributes to the understanding of the complex comparative neuroendocrinology of song birds in the wild.

Apfelbeck B, Mortega KG, Kiefer S, Kipper S, Goymann W. Life-history and hormonal control of aggression in black redstarts: Blocking testosterone does not decrease territorial aggression, but changes the emphasis of vocal behaviours during simulated territorial intrusions. Front Zool. 2013 Feb 21;10(1):8. doi: 10.1186/1742-9994-10-8. 

Abstract. Introduction: Many studies in behavioural endocrinology attempt to link territorial aggression with testosterone, but the exact relationship between testosterone and territorial behaviour is still unclear and may depend on the ecology of a species. The degree to which testosterone facilitates territorial behaviour is particularly little understood in species that defend territories during breeding and outside the breeding season, when plasma levels of testosterone are low. Here we suggest that species that defend territories in contexts other than reproduction may have lost the direct regulation of territorial behaviour by androgens even during the breeding season. In such species, only those components of breeding territoriality that function simultaneously as sexually selected signals may be under control of sex steroids. Results: We investigated black redstarts (Phoenicurus ochruros), a species that shows periods of territoriality within and outside of the breeding season. We treated territorial males with an anti-androgen and an aromatase inhibitor during the breeding season to block both the direct and indirect effects of testosterone. Three and ten days after the treatment, implanted males were challenged with a simulated territorial intrusion. The treatment did not reduce the overall territorial response, but it changed the emphasis of territoriality: experimental males invested more in behaviours addressed directly towards the intruder, whereas placebo-treated males put most effort into their vocal response, a component of territoriality that may be primarily directed towards their mating partner rather than the male opponent. Conclusions: In combination with previous findings, these data suggest that overall territoriality may be decoupled from testosterone in male black redstarts. However, high levels of testosterone during breeding may facilitate-context dependent changes in song.