Foraging ecology and occurrence of 7 sympatric babbler species (Timaliidae) in the lowland rainforest of Borneo and peninsular Malaysia

Abstract

Understanding foraging strategies of birds is essential to understanding mechanisms of their community assembly. To provide such information on a key Southeast Asian rainforest family, the babblers (Timaliidae), we evaluated foraging behavior and abundance in 7 morphologically and behaviorally similar sympatric species (Cyanoderma erythropterum, C. rufifrons, Stachyris maculata, S. nigricollis, S. poliocephala, Macronus ptilosus, and Mixornis gularis) in 5 habitats defined by structural complexity: (1) continuous native rainforest, (2) logged native rainforest fragments, (3) mature industrial tree plantation, (4) young industrial plantation, and (5) oil palm plantation. Enough data were obtained to compare abundance in all 7 species and foraging behavior in 5. All species were common in forest fragments and mature industrial tree plantations and less so in continuous rainforest and young industrial plantations; only M. gularis occurred in oil palm. In terms of foraging, M. gularis was the greatest generalist; C. rufifrons foraged mainly on live leaves in the forest midstory; and S. maculata, C. erythropterum, and M. ptilosus foraged mainly on dead leaves suspended in understory vegetation at significantly different heights. The dead-leaf substrate depends on a rich supply of falling leaves and extensive understory structure, conditions most common in native forest and old industrial plantations, and less so in mature forest, young plantations, and oil palm. Because of the importance of foraging data to understanding and managing biodiversity, we encourage the development of foraging fields in eBird (ebird.org), so that birdwatchers may help collect these relatively rare data.

Foraging niche segregation in Malaysian babblers (Family: Timaliidae)

“…Morphology of understorey plants plays an important role in capturing the falling dead leaves. The understorey shrubs, woody vines [ 62 ], ferns, small palms [ 63 ], and rattans [ 64 ], which were abundant in the study area are very useful in intercepting the forest canopy litterfall.…”

“…A recent study by [ 64 ] showed that C . erythropterum exhibited somewhat similar foraging strategies (e.g.…”

Occupancy patterns and upper range limits of lowland Bornean birds along an elevational gradient

“…Our lack of detailed ecological knowledge of most species makes even hypothesizing likely networks of competitors difficult (Jankowski et al, 2012), beyond the relatively coarse metric of foraging guild or at the limited scale of genus. Diffuse competition may often result in niche differentiation based on foraging manoeuvres and strata rather than area occupancy, even among morphologically similar species with similar diets, as has been found for babblers (Timaliidae) in Malaysia (Mansor & Ramli, 2017;Styring, Ragai, Zakaria, & Sheldon, 2016). Competition may also be difficult to detect because elevational range overlap of strongly competing species may be effectively eliminated.…”

Evidence for facilitation among avian army‐ant attendants: specialization and species associations across elevations

“…, Styring et al . ). In the Neotropics and Afro‐tropics, mixed‐species flocks of birds often forage at army‐ant swarm raids (Willis & Oniki , Peters et al .…”

“…Multi-species foraging flocks are characteristic of tropical forest avian communities; these flocks are important subjects for analyzing the ecology of mixed-species assemblages (Powell 1979, Peron & Crochet 2009, Cordeiro et al 2015, Goodale et al 2015, Styring et al 2016). In the Neotropics and Afro-tropics, mixedspecies flocks of birds often forage at army-ant swarm raids (Willis & Oniki 1978, Peters et al 2008.…”