Birds using ferns as nesting sites

posted in: Nesting, Plants | 6

Most of us are familiar with birds building their nests in trees, shrubs, among grasses and sedges, and even on the ground. But how about ferns as nesting sites?

The Peaceful Doves (Geopelia striata) has been shown to build its nest in a pot of Bird’s nest fern (Asplenium nidus) LINK. Here, the pair constructed a simple platform of twigs as their nest, placed in the centre of the bird’s nest fern. However, it is the behaviour of the Indian Peafowl (Pavo cristatus) that shows that the fern has been given the correct common name when the bird laid her eggs in the fern’s rosette of fronds LINK without adding any nesting material.

Wells (1999, 2007) has documented a number of birds that nest in ferns, either directly on it as above, or constructing the nests between the fronds or frond bases:

Bird’s nest fern (Asplenium nidus) is commonly seen growing on the branches of old trees in the lowland. The simple but large fronds arise from a common central growing point to form a nest-like basket, thus the name. This basket collects falling leave from surrounding trees. As these leaves rot, they form a spongy mass of decaying organic matter that soaks up rainwater for the fern’s subsequent use. And as the decaying leaves rot, they release nutrients for the fern’s use. The fern is thus self sufficient in terms of water and nutrients, depending on the host’s branch only for support. A pair of Little Pied Flycatchers (Ficedula westermanni) was found making a nest between the lower frond bases. Also, a Verditer Flycatcher’s (Eumyias thalassinus) nest was located in this fern. Another bird found using the fern as a nest was the Barred Eagle Owl (Bubo sumatranus), simply using it as a nest without adding any material.

The epiphytic mountain fern, Aglaomorpha heraclea, is a litter-collecting fern of the highland (below left). A Malayan Whistling Thrush (Myophonus robinsoni) was once found nesting among the fronds of the fern that grew on a sapling.

Swamp fern (Acrostichum aureum) is usually found in degraded mangroves by the coast (above centre). The erect plant has pinkish young fronds. The upper frond lobes bear the spore sacs, appearing dark brown. Nest of the Copper-throated Sunbird (Leptocoma calcostetha) and the Olive-backed Sunbird (Cinnyris jugularis) were once found attached to the frond tip, On the other hand the Ashy Tailorbird (Orthotomus ruficeps) built their nests “into a one- to three-leaf sling stitched mainly from the inside with silk in regular tailorbird fashion, often with extra, anchoring stitches run out through the leaf from the nest wall.”

Oak-leaf fern (Drynaria quercifolia) is a lowland epiphyte (above right). It bears two types of fronds. The nest frond grown close to the branch and traps litter. Arising from within each nest frond is a normal frond that is lobed. The fern creeps along the host’s stem and branches by way of a fleshy rhizome that is hidden by the series of nest fronds. A pair of Yellow-breasted Flowerpeckers (Prionochilus maculates) was found building their nest out of the rhizome, probably this species of Drynaria.

The epiphytic ant fern (Lecanopteris carunosa) is usually encountered in mountain forests (above left). You will know that it is around when you see blackish, thorny structures along the forest path, looking like discarded durian shells. Look up to locate the fern on some branches above. The young fleshy rhizome is green and forms a thick crust around the branch of a tall tree. These rhizomes are hollow and harbour ants. They turn black with age, to litter the ground below. A pair of Little Pied Flycatchers was once found making their nest in the hollow of a dead rhizome suspended by a creeper.

The dragon’s scale fern (Pyrrosia piloselloides), is an epiphytic creeper with small, sterile oval fronds (above right). Fertile fronds are narrow and long, with prominent dark spore cases along the margin. This fern grows on tree trunk and branches of old trees, forming a tangle that attracts it own community of fauna. The thin, wiry stem is a favourite nesting material with many species of birds LINK.

YC Wee
Singapore
November 2011

References:
1.
Wee, Y. C. (2005). Ferns of the tropics. Times Editions-Marshall Cavendish, Singapore. 2nd ed. 190 pp.
2. Wells, D.R., 1999. The birds of the Thai-Malay Peninsular. Vol. I, Non-passerines. Academic Press, London. 648 pp.
3. Wells, D.R., 2007. The birds of the Thai-Malay Peninsular. Vol. II, Passerines. Christopher Helm, London. 800 pp.

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6 Responses

  1. I once found some round white balls about the size of mothballs in a staghorn fern which I had recently bought from a nursery. Thinking they were some sort of fertiilizer or pesticide pellet, I tried to remove them, only to discover they were actually eggs ! Sad to say, I never observed a similar nesting again despite having many ferns in my garden.

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  2. Tou Jing Yi

    The Buffy Fish Owl is known to use the Bird-nest Fern for nesting before.

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  3. Looking for studies on fern dependency on insects, especially giant moths. Had observation on changes to bird nest fern growth related to presence of visitation by giant moth.

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  4. Sorry, I have no information on this.

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