---
title: "What the sources say about the Common Blackbird | AnimalTracks.wiki"
description: "40 claims from the Common Blackbird profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/common-blackbird-1.webp"
canonical: "https://animaltracks.wiki/animals/common-blackbird/sources/"
---

# What the sources say about the Common Blackbird (*Turdus merula*)

> 40 claims from the Common Blackbird profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Common Blackbird](https://animaltracks.wiki/animals/common-blackbird/)

## Turdus merula. The IUCN Red List of Threatened Species 2024: e.T103888106A264548442.

https://doi.org/10.2305/iucn.uk.2024-2.rlts.t103888106a264548442.en

| The page says | The source says |
| :--- | :--- |
| Least Concern | Least Concern (note: GBIF copy of the Red List, taxon id checked against the DOI) |

## Dominoni et al. (2013). Urban-like night illumination reduces melatonin release in European blackbirds (Turdus merula): implications of city life for biological time-keeping of songbirds. Frontiers in Zoology.

https://doi.org/10.1186/1742-9994-10-60

| The page says | The source says |
| :--- | :--- |
| whose night-time hormones shift under city light | Daily patterns of melatonin concentrations were clearly affected by light-at-night in both seasons. |
| Blackbirds are widespread in Europe and breed successfully in cities. | Blackbirds are widespread in Europe and breed successfully in cities |
| Researchers caught adult males in Munich and in a forest 40 km away, moved them indoors | we caught adult male European blackbirds (urban = 20, rural = 20) with mist-nets set up at dawn in the city of Munich ... in a rural forest near the village of Raisting ... 40 km southwest of Munich ... birds were moved indoors into individual cages |
| kept one group under a dim 0.3 lux glow at night, the level recorded on free-living city blackbirds, and the other in near darkness (0.0001 lux) | The control group was exposed to 0.0001 lux (almost darkness), while the experimental group was exposed to 0.3 lux at night, simulating conditions recorded previously on free-living urban blackbirds. |
| The glowing group released less melatonin | Daily patterns of melatonin concentrations were clearly affected by light-at-night in both seasons. In winter, melatonin concentrations of light-at-night birds were lower in the early and late night than in those of birds kept in darkness. In summer, melatonin concentrations of the light-at-night birds were lower through all night |
| a hormone that is normally released at night | it is released at night and suppressed by daylight |
| They were also more active, with activity rising sharply before dawn. | Locomotor activity in light-at-night birds was overall higher than in control individuals, both during the day and at night, and it increased sharply before dawn. |
| In a captive study, yes. Blackbirds lit at 0.3 lux overnight had lower melatonin than birds in near darkness, and were more active, with a sharp rise before dawn. The authors suggest the birds responded as if the day were longer. | experimental group was exposed to 0.3 lux at night ... In summer, melatonin concentrations of the light-at-night birds were lower through all night compared to birds kept in darkness. Locomotor activity in light-at-night birds was overall higher ... and it increased sharply before dawn ... we suggest that birds responded to light-at-night as if they were exposed to a longer day than birds kept under dark nights |

## Dominoni, Quetting & Partecke (2013). Artificial light at night advances avian reproductive physiology. Proceedings of the Royal Society B: Biological Sciences.

https://doi.org/10.1098/rspb.2012.3017

| The page says | The source says |
| :--- | :--- |
| Under the same faint night light, captive blackbirds had their reproductive system developed up to a month ahead of birds given dark nights, and their moult came earlier too. | Captive city and forest blackbirds were exposed to either dark nights or very low light intensities at night (0.3 lux). Birds exposed to light at night developed their reproductive system up to one month earlier, and also moulted earlier, than birds kept under dark nights. |
| A second study tested the calendar. | Then we used these measurements to test for the effect of light at night on timing of reproductive physiology. |

## Nemeth & Brumm (2010). Birds and Anthropogenic Noise: Are Urban Songs Adaptive? The American Naturalist.

https://doi.org/10.1086/656275

| The page says | The source says |
| :--- | :--- |
| Where traffic fills a city with low rumble, birds have been seen singing both louder and higher. | In cities with intense low-frequency traffic noise, birds have been observed to sing louder and at a higher pitch. |
| Researchers picked blackbirds and great tits, two species that sing higher in urban areas, and modelled how far each species' song carries in city noise and in forest. | Here we present models of signal transmission ... two bird species that sing with higher pitch in urban areas, the great tit (Parus major) and the blackbird (Turdus merula). For both species, we calculated communication distances in response to different levels of urban noise and in their natural forest habitats. |
| In the models, a higher pitch only marginally increased how far a song carried, while singing louder had a strong and significantly larger effect. | Here we present models of signal transmission ... an increase in vocal pitch increased communication distance only marginally. In contrast, vocal amplitude adjustments had a strong and significantly larger effect. |
| The authors say their results indicate that raising the pitch is not very effective at beating traffic masking. | Our results indicate that frequency changes of urban songs are not very effective in mitigating masking from traffic noise |
| Modelled against city traffic, a blackbird's song carried much further when sung louder than when pitched higher. | Here we present models of signal transmission ... an increase in vocal pitch increased communication distance only marginally. In contrast, vocal amplitude adjustments had a strong and significantly larger effect. (note: vibe.reason) |

## BirdFacts: Blackbird. British Trust for Ornithology.

https://www.bto.org/understanding-birds/birdfacts/blackbird

| The page says | The source says |
| :--- | :--- |
| Gardens, parks, hedgerows, woodland and farmland across Britain and Ireland, almost everywhere except the highest ground | can be found almost everywhere in Britain & Ireland, apart from the highest ground |
| BTO measurements of live birds put the adult average at 101.8 g, and 90 percent of adults weigh between 87 and 122 g | Wing length and body weights are from live birds ... 5th and 95th percentiles and sample size in brackets ... All adults 101.8±12.1 g (87-122 g, N=65475) (note: BTO gives 5th and 95th percentiles in brackets, so 90 percent of adults lie between them) |
| A bird that survives to breeding age typically lives about 3 years. | Typical life expectancy of bird reaching breeding age 3 years with breeding typically at 1 year |
| The oldest ringed blackbird in Britain was 15 years, 2 months and 5 days old, a record set in 2000. | Maximum age from a ringed bird 15 years, 2 months, 5 days (set in 2000) |
| In Britain and Ireland blackbirds turn up almost everywhere except the highest ground | can be found almost everywhere in Britain & Ireland, apart from the highest ground |
| The UK held 5.1 million breeding pairs in 2016 | UK (breeding) 5.1 million pairs (2016) |
| its breeding population was 21 percent lower in 2024 than in 1967 | UK breeding population -21% (1967 to 2024) |
| British ringing data put the typical life expectancy of a bird that reaches breeding age, usually at 1 year old, at about 3 years. The oldest ringed bird in Britain, a record set in 2000, was 15 years, 2 months and 5 days old. | based on BTO ringing and nest recording data ... Typical life expectancy of bird reaching breeding age 3 years with breeding typically at 1 year ... Maximum age from a ringed bird 15 years, 2 months, 5 days (set in 2000) |
| About 100 g. BTO weighings of live adults average 101.8 g, and nine in ten adults fall between 87 and 122 g. | Wing length and body weights are from live birds ... 5th and 95th percentiles and sample size in brackets ... All adults 101.8±12.1 g (87-122 g, N=65475) (note: BTO gives 5th and 95th percentiles in brackets, so nine in ten adults lie between them; about 100 g rounds 101.8 g) |
| Almost everywhere in Britain | can be found almost everywhere in Britain & Ireland, apart from the highest ground |

## Blackbird. Welsh Wildlife Trusts.

https://www.welshwildlife.org/wildlife-explorer/birds/thrushes-chats-flycatchers-starling-dipper-and-wren/blackbird

| The page says | The source says |
| :--- | :--- |
| A blackbird is about 24 cm long with a 36 cm wingspan. | Length: 24cm Wingspan: 36cm |
| Males are entirely black, set off by a yellow bill and a yellow eye-ring. | Male blackbirds are unmistakable - they are entirely black, with a yellow bill and yellow ring around the eye. |
| Females are dark brown with streaking on the chest and throat. | Females are dark brown, with streaking on the chest and throat. |
| heads cocked to one side, listening for earthworms | can be seen with their heads cocked to one side, listening for earthworms |
| They also eat insects, berries and fruit. | They also feed on insects and berries |
| Listening for worms on the lawn | listening for earthworms |

## Blackbird. RSPB.

https://www.rspb.org.uk/birds-and-wildlife/blackbird

| The page says | The source says |
| :--- | :--- |
| A lawn-hopping songster whose night-time hormones shift under city light. | Often seen hopping on the ground or turning over leaves. |
| Gardens, parks, hedgerows, woodland and farmland | common garden visitor, denizen of the local park, bird of hedgerow and woodland, coastal scrub and farmland |
| Worms, insects, berries and fruit | eating worms, insects, berries and fruit |
| A leading voice in the UK's dawn chorus | They’re a leading voice in the UK’s dawn chorus |
| They also eat insects, berries and fruit. | eating worms, insects, berries and fruit |
| Most UK blackbirds stay all year, though some northern birds migrate south for winter, and large numbers from northern Europe join the residents each autumn. | Most UK Blackbirds stay all year, although some northern birds migrate south in winter. ... in autumn, we are joined by large numbers from northern Europe |
| The song runs year-round, but peaks between March and June | The song can be heard all year round, but most regularly during the breeding season between March and June. |
| blackbirds are a leading voice in the UK's dawn chorus | They’re a leading voice in the UK’s dawn chorus |