The Eurasian tree sparrow (Passer montanus) is a small passerine bird that is found across Europe, Asia and parts of Africa. Its natural range extends from the British Isles across Europe and Asia to Japan and Indonesia. However, it has also been introduced to many other parts of the world, including parts of Australia, New Zealand, North America and also the Philippines.
Quick Answer
The Eurasian tree sparrow is not native to the Philippines. It was introduced to the country in the early 20th century and is now found across many of the major islands. The native range of this species is Europe and Asia.
Native Range of Eurasian Tree Sparrow
The Eurasian tree sparrow naturally occurs across most of Europe and temperate Asia. Its breeding range extends from the British Isles eastwards across Europe to central Russia and Siberia. To the south, it breeds in Turkey, the Middle East, Central Asia and the Himalayas. The southern boundary of its breeding range is formed by the Mediterranean Sea, the Black Sea, the Caspian Sea, Iran, Afghanistan and the Himalayas.
In winter, Eurasian tree sparrows withdraw from the most northerly parts of their breeding range, but are otherwise resident across most of temperate Eurasia. Their natural winter range encompasses almost all of Europe, Turkey, the Middle East, Central Asia, most of China and southern Siberia.
The Eurasian tree sparrow is also found in the extreme northeast of Africa in Egypt’s Nile Delta and along parts of the Levant coast. However it is not native to any other part of Africa.
In summary, this species naturally occurs across all of Europe (except for some northwestern and northern areas), Turkey, the Middle East, Central Asia and most of temperate Asia as far as eastern Siberia, northern China, Japan and Southeast Asia. The Philippines lies well outside its native range.
Introduction to the Philippines
The Philippines is an archipelagic country located in Southeast Asia, consisting of over 7,600 islands. It lies between the Philippine Sea to the east, the South China Sea to the west and north, the Celebes Sea to the south and the Sulu Sea to the southwest.
The islands of the Philippines have a diverse range of natural habitats, including rainforests, mangroves, deciduous forests, grasslands and coral reefs. Many islands are of volcanic origin. The Philippines has a tropical monsoon climate with high year-round temperatures and distinct wet and dry seasons.
The Philippines has high levels of biodiversity and many endemic plant and animal species. Around 52% of its breeding birds and 39% of mammal species are endemic to the country or to wider Philippines-Wallacea area.
Introduction of Eurasian Tree Sparrow to the Philippines
The Eurasian tree sparrow is not part of the Philippines’ native avifauna. Historical records show that tree sparrows were intentionally introduced to the Philippines in the early 20th century.
One of the earliest records of Eurasian tree sparrows in the Philippines comes from Dean C. Worcester, an American zoologist who was appointed a member of the Philippine Commission in 1899. In his 1914 book A Hand-list of the Birds of the Philippine Islands, Worcester noted that the Eurasian tree sparrow was “purposely introduced and liberated near Manila, where it is increasing rapidly.”
According to the book Birds of the Philippines (Gonzales and Rees 1988), the tree sparrow was initially introduced from China to Manila in 1920. The species adapted readily to the city’s open habitats and grain stores and the population expanded rapidly. This book states that tree sparrows spread north and south of Manila in the late 1920s and 1930s, colonizing central Luzon and the Bicol Peninsula. Further deliberate introductions took place in Cebu City and Daraga in the late 1930s.
By around 1940, the Eurasian tree sparrow could be found on the islands of Luzon, Cebu, Leyte and Mindanao and has since further expanded its range across the archipelago.
Range expansion across the Philippines
Since its initial introductions to Manila and other Philippine cities in the 1920s to 1930s, the Eurasian tree sparrow has greatly expanded its range across the archipelago. It can now be found on many of the major and smaller islands, though remains absent from more remote islands.
According to the Handbook of Birds of the World Alive, the current resident range of the Eurasian tree sparrow in the Philippines includes:
- Luzon
- Catanduanes
- Marinduque
- Masbate
- Polillo
- Samar
- Biliran
- Bohol
- Cebu
- Guimaras
- Leyte
- Negros
- Panay
- Mindanao
- Basilan
- Dinagat
- Siargao
It occurs primarily in agricultural areas, plantations, rural gardens, urban areas and human habitation across these islands from sea level up to at least 1,500 m elevation.
The Eurasian tree sparrow was initially introduced to major cities including Manila, Cebu City and Daraga. From these origins, it expanded its range into agricultural and rural areas across Luzon then spread southwards to the other Philippine islands.
Introduction to further islands – both accidental and intentional – has aided its spread. Shipping and cargo transports between the major islands allowed birds to colonize additional islands. It has also benefited from deforestation and development of agricultural land across the archipelago.
Today, the Eurasian tree sparrow has a predominantly lowland distribution in agricultural and urban areas across much of the Philippines, absent only from more remote and less populated islands. It can be described as a human commensal species within its non-native Philippine range.
Habitat and Ecology in the Philippines
The Eurasian tree sparrow occupies a broad range of disturbed and open lowland habitats in the Philippines. It has a close association with human settlements, particularly agricultural areas and urban environments. Typical habitat types include:
- Urban areas – parks, gardens, street trees, buildings
- Rural areas – agricultural land, plantations, orchards, farmland
- Open woodland habitats
- Coastal habitats including mangroves
In urban areas, the Eurasian tree sparrow is most abundant in city centres with trees and shrubs, gardens and street trees. It is likely able to exploit ample food sources provided by litter, food stall crumbs and spilt pet food. Nesting opportunities are provided by trees, vines on buildings, holes in walls, and other cavities.
In rural areas, it inhabits cultivated land, orchards, open areas with scattered trees, and buildings or villages. It often nests in tree holes, especially coconut palms. The conversion of forest to agricultural use across the Philippines has created favourable habitat for this species.
Unlike in its native range, the Eurasian tree sparrow in the Philippines is able to use a broader range of nesting habitats. As well as tree holes, it will nest in the roof spaces of buildings, holes in walls, and other cavities. The use of artificial sites has likely aided its colonisation of urban areas.
Eurasian tree sparrows feed predominantly on grains and seeds. Their diet in Philippine agricultural areas consists of cultivated rice, corn, sorghum as well as various weed seeds. They also consume some insects, especially during the breeding season to feed young. In urban areas, artificial food sources are likely important.
They are social birds, forming loose flocks when feeding and roosting. Flocks are usually small, up to 20 birds, in the non-breeding season. They are active during the day and return to communal roosts at night.
The breeding season of Eurasian tree sparrows in the Philippines is associated with the wet season, extending approximately from May to October. They can raise multiple broods during a single breeding season. Clutch size is typically 3-5 eggs.
Interactions with Native Species
The introduction of the Eurasian tree sparrow to the Philippines does not appear to have had major detrimental impacts on native biodiversity. However, there is evidence of local competitive effects and displacement of some native birds, especially other sparrow species.
Several factors may limit the ecological impacts of the Eurasian tree sparrow in the Philippines:
- Its habitat use is mostly restricted to open, disturbed areas rather than natural forest habitats.
- It occupies a somewhat different niche to native species, utilizing more artificial habitats.
- Native species have had time to adjust since its introduction nearly a century ago.
The strongest competitive effect is likely on the two native Philippine sparrow species: the similarly sized and ecologically similar Eurasian tree sparrow; and the larger chestnut munia. The Eurasian tree sparrow may compete with the native sparrows for food, nesting sites and other resources in agricultural areas, plantations, mangroves and urban habitats.
There is some evidence that the chestnut munia has declined in abundance in urban areas, where the introduced sparrow dominates. The Eurasian tree sparrow may be competitively dominant over the smaller native Philippine tree sparrow in disturbed lowland habitats.
Further research is needed to better understand the ecological relationships between the introduced Eurasian tree sparrow and native bird species sharing similar niches in the Philippines.
Conclusion
In summary, the Eurasian tree sparrow is an introduced, non-native species in the Philippines. It was deliberately introduced in the 1920s and has since expanded its range across many of the major Philippine islands in mostly agricultural and urban areas.
The Eurasian tree sparrow occupies an ecological niche as a human commensal species in urban and rural habitation. While introduced populations may compete with some native birds, overall impacts on Philippine ecosystems have not been severe.
The Eurasian tree sparrow should be distinguished from the native yet taxonomically similar Philippine tree sparrow. Both species are now commonly encountered across disturbed lowland areas of the Philippines in overlap with human settlement.