Roosting behaviour of a migratory songbird on Jamaican coffee farms: landscape composition may affect delivery of an ecosystem service

Abstract

SummaryRecent evidence indicates that insectivorous birds in shade coffee farms provide economically significant ecosystem services by reducing insect pests, which should encourage cultivation practices favouring birds and other wildlife. However, the provisioning of this service may be dependent on landscape composition and movement patterns of these mobile consumers. Very little information is currently available on bird movements in coffee-dominated landscapes. We examined roosting behaviour in Black-throated Blue Warblers Dendroica caerulescens on two Jamaican coffee farms using radio telemetry in order to determine whether birds commute between nocturnal roosts and diurnal foraging ranges in coffee habitat. Nocturnal tracking revealed most birds moved outside diurnal foraging ranges on the farms to roost in forested habitat patches, sometimes up to 1 km away. Of 42 roost locations, only eight roosts were within the coffee farm perimeter: one individual in a coffee bush, and seven others in shade trees or vegetated riparian strips. Logistic regression confirmed that birds strongly selected continuous forest and individual trees over coffee for roosting. These findings reflect the ecological connectivity between coffee habitats and the adjacent landscape and raise the possibility that the provisioning of pest reduction services could be at least partly dependent on a farm's proximity to forest patches.

Mismatch between diurnal home ranges and roosting areas in the Wood Thrush (Hylocichla mustelina): Possible role of habitat and breeding stage

“…Nocturnal tracking began at least 1 hr after sunset and continued until no later than 1 hr before sunrise (Jirinec et al 2011). We ensured that birds were settled in for the night by confirming signal immobility prior to recording roost locations.…”

“…Because we recorded roost positions to 10 m GPS accuracy, 20 m constitutes twice the maximum position error. Accordingly, we designated individual roosts as sampling units, rather than individual birds (Jirinec et al 2011).…”

“…For birds, the preference for roosting in areas with high vegetation cover has been suggested as an antipredation strategy for the Capercaillie (Tetrao urogallus; Finne et al 2000) and the Sichuan Partridge (Arborophila rufipectus; Liao et al 2008). For some species, such as the Black-throated Blue Warbler, long commutes to roosts are necessitated by diurnal use of agricultural habitat likely lacking suitable roost sites (Jirinec et al 2011). Wood Thrushes, in contrast, appeared to occupy DHRs in continuous forested areas that did not differ dramatically from roosting habitat, yet they often made commutes nonetheless.…”

“…However, mounting evidence indicates that many forest migrants roost away from their daytime activity ranges. To our knowledge, this phenomenon has been specifically documented on the wintering grounds for the Prothonotary Warbler (Protonotaria citrea; Warkentin and Morton 1995), Northern Waterthrush (Parkesia noveboracensis; Smith et al 2008), Black-throated Blue Warbler (Jirinec et al 2011), and Bicknell's Thrush (Catharus bicknelli; Townsend et al 2009). Additionally, a recent report provides some evidence for disjunct roosting areas in the Yellow-rumped Warbler (Setophaga coronata) during the migratory stopover period (Slager and Rodewald 2015).…”

“…For example, zoonotic disease transmission potential has been linked to roost characteristics of American Robins (Turdus migratorius), where West Nile virus vectors preferentially feed on individuals higher in the forest canopy, but the risk of infection decreases for birds roosting in groups (Janousek et al 2014). In Jamaican coffee farms, nearby forest appears to provision the delivery of an economically substantial ecosystem service by Black-throated Blue Warblers (Setophaga caerulescens), as birds forage on coffee pests during the day (Kellermann et al 2008) after commuting from nocturnal roosts in the woods and large shade trees (Jirinec et al 2011). A roost, defined in this paper as the nocturnal location of a bird-often a solitary one-has an important function in avian ecology.…”