Behavioral Strategies of Silver Wood Pigeons in Utilizing Fragmented Coastal Habitats

 Background

The Silvery Pigeon (Columba argentina) is one of the rarest pigeon species in the world and is currently classified as Critically Endangered (CR) on the IUCN Red List (IUCN, 2019). This species has a highly restricted and fragmented distribution, occurring primarily in coastal areas and small islands across Southeast Asia, including Indonesia (Bruslund et al., 2022). Taxonomically, the species exhibits strong geographic variation, with populations separated by marine barriers and fragmented coastal habitats (Iqbal et al., 2022). This isolated distribution pattern results in each population depending on a limited extent of habitat, particularly coastal forests and natural coastal vegetation that are increasingly threatened by human activities (Manley, 2024). Such conditions render the Silvery Pigeon highly vulnerable to environmental change and highlight adaptive behaviour as a key factor in maintaining its persistence within fragmented coastal landscapes (BirdLife International, 2023).

Silvery Wood Pigeon stopped on a coconut tree

Within increasingly fragmented landscapes, behavioural strategies play a crucial role in enabling the Silvery Pigeon to survive (Cornelius, 2017). The ways in which this species selects sites, moves between habitat fragments, exploits coastal food resources, and avoids human disturbance represent behavioural adaptations to habitats that are no longer continuous (Wang, 2025). Therefore, understanding the behavioural strategies of the Silvery Pigeon in utilizing fragmented coastal habitats is essential for assessing the species’ resilience and for developing more effective conservation approaches grounded in behavioural ecology.

Silvery Wood Pigeon Habitat

The Silvery Pigeon is a pigeon species that is closely associated with coastal ecosystems, particularly coastal forests that retain their natural vegetation structure. This species is commonly found in lowland and hilly coastal forest vegetation on offshore islands (BirdLife International, 2023). In addition, the species also utilizes small islands dominated by coconut palms (Cocos nucifera). In such small-island landscapes, coconut trees function as key structural elements, providing perching sites, shelter, and movement pathways among limited vegetation fragments (Winarni et al., 2023).

Behavioral Strategies in Utilizing Fragmented Habitats

Within fragmented coastal landscapes, the Silvery Wood Pigeon (Columba argentina) exhibits behavioural strategies that reflect its capacity to adapt to limited and discontinuous habitats. One important pattern observed is the functional separation of habitats used for foraging and resting. Based on field observations by Tedi Wahyudi and Jonathan Slifkin in 2025 (unpublished), individual Silvery Wood Pigeons were recorded undertaking daily movements from small offshore islands to the main island (Simeulue Island) to forage, before returning to smaller islands (such as Tepi, Alahula, and Ina islands) in the late afternoon or towards evening to roost. This pattern indicates a structured use of space, in which the main island provides more diverse food resources, while the smaller islands function as relatively safe areas with lower levels of disturbance.

Birding in Tepi Islend 

The regular return to small islands for roosting highlights the importance of these locations as refuges. Small islands generally experience lower levels of human activity compared to main islands, thereby offering quieter and less disturbed conditions for this species (Cartwright, 2019). In the context of habitat fragmentation, this strategy allows the Silvery Wood Pigeon to exploit spatially dispersed resources without the need to remain permanently in areas subject to high anthropogenic pressure.

In addition, information from local communities further strengthens the understanding of the species’ behavioural strategies. According to local knowledge, the Silvery Wood Pigeon has been reported to nest on small islands, particularly in coconut palms (Cocos nucifera). The use of coconut trees as nesting sites suggests a degree of tolerance to structurally simple habitats, provided they offer sufficient height, open visibility, and low levels of disturbance. This observation indicates that small islands do not function solely as resting sites, but may also serve as potential breeding habitats.

Silvery Wood Pigeon in a cage

Overall, the behavioural strategies of the Silvery Wood Pigeon in utilizing fragmented coastal habitats are characterised by inter-island mobility, functional differentiation of habitat use, and the reliance on small islands as safe spaces for roosting and potentially for breeding. These patterns underscore the importance of coastal habitat fragments, including small islands dominated by coconut palms, as integral components of the ecological landscape supporting the survival of this critically endangered species.

Conservation Implications

Understanding the behavioural strategies of the Silvery Wood Pigeon has important conservation implications, particularly given that this species is classified as Critically Endangered. The species’ reliance on fragmented coastal habitats, including small islands that are often overlooked in conservation planning, demonstrates that even small areas can hold high ecological value. Therefore, conservation efforts should not focus solely on large, intact coastal habitats, but should also prioritise the protection of networks of small islands that function as resting sites and potentially as breeding areas.

Beyond habitat protection, conservation approaches must take into account the daily movement patterns of the Silvery Wood Pigeon between the main island and surrounding small islands. Disturbance to any component of this landscape can have direct consequences for the species’ survival. Given its IUCN status, every remaining habitat fragment used by the Silvery Wood Pigeon is highly valuable, and the integration of field-based behavioural data with local ecological knowledge from coastal communities is essential for developing effective and forward-looking conservation strategies.