Specialization on Guadua Bamboo Seeds by Three Bird Species in the Atlantic Forest of Argentina

Abstract

Most bamboos are semelparous. Their synchronous masting events occur on a cycle of 3–120 yr and represent an extremely pulsed resource for granivorous birds. Although many bird species feed occasionally on bamboo seeds, there are constraints to specializing on such a fluctuating resource and few bird species are known to specialize on bamboo seeds. Three of these bird species are endemic to the Atlantic forest of South America: the purple‐winged ground‐dove Claravis godefrida, buff‐fronted seedeater Sporophila frontalis, and Temminck's seedeater Sporophila falcirostris. All three species are irregularly recorded in the province of Misiones, Argentina. We compared the temporal and spatial patterns of records of these birds in Misiones to masting events of the five common bamboos: yatevóGuadua trinii, takuaruzúGuadua chacoensis, takuapíMerostachys claussenii, pitinga Chusquea tenella, and takuarembóChusquea ramosissima. All bird records coincided with times and places where Guadua bamboos (G. trinii and G. chacoensis) were known or estimated to have seeds. None of the bird species occurred during masting events of Merostachys or Chusquea, unless Guadua was also masting. We discuss relevant ecological and morphological features of the birds that might bear on their association with Guadua bamboos and that might be key to their conservation.

Predation of the Buffy-fronted Seedeater Sporophila frontalis (Aves: Emberizidae) on Merostachys neesii (Poaceae: Babusoideae) seeds during a masting event in the Atlantic forest

“…Granivorous birds specialized on bamboos depend on the ephemeral seed resource available at large intervals of time and they have to wander actively to fi nd these resources (Neudorf & Blanchfi eld 1994, Areta et al 2009). Apparently, this is the case of S. frontalis in Atlantic forest (Collar et al 1992, Sick 1997.…”

“…birds, rodents) (Olmos 1996, Sick 1997, Areta et al 2009). For instance, our results estimated the mean of 19 ± 8 seeds per hour in the 1.75 m 2 seed traps as a coarse example of large seed production.…”

“…Several bird species are already pointed as associated with bamboos in the Neotropical region (Stotz et al 1996). Additionally, the increments of bird populations during bamboo fruiting events are widely reported in the literature (Davis 1945, Collar et al 1992, Olmos 1996, Sick 1997, Vasconcelos et al 2005, Areta et al 2009). …”

“…In the Atlantic forest, some species of emberizids, e.g., Haplospiza unicolor Cabanis, 1851, Sporophila falcirostris (Temminck, 1820), S. frontalis (Verreaux, 1869), S. schistacea (Lawrence, 1862), and Tiaris fuliginosus (Wied, 1830) are the most observed birds during flowering and fruiting events of several bamboo species, including Chusquea spp., Guadua spp., Merostachys spp., and Parodiolyra spp. (Collar et al 1992, Olmos 1996, Vasconcelos 2002, Vasconcelos et al 2005, Sick 1997, Sigrist 2006, Areta & Bodrati 2008, Areta et al 2009). …”

“…Inter-masting events in Merostachys spp. is sparsely cited in the literature and it may vary from 3 to 34 years (Pereira 1941, Giovannoni et al 1946, Smith et al 1981, Sendulsky 1995, 2001, Sick 1997, Guilherme & Ressel 2001, Jaksic & Lima 2003, Areta et al 2009). Sendulsky (2001) …”