Variable tropical moisture and food availability underlie mixed winter space-use strategies in a migratory songbird

Identifying environmental correlates driving space-use strategies can be critical for predicting population dynamics; however, such information can be difficult to attain for small mobile species such as migratory songbirds. We combined radio-telemetry and high-resolution GPS tracking to examine space-use strategies under different moisture gradients for wood thrush ( Hylocichla mustelina ). We explored the role moisture plays in driving food abundance and, in turn, space-use strategies at a wintering site in Belize across 3 years. Individuals occupying drier habitats experienced lower food abundance and poorer body condition. Using data from our radio-tracked study population and GPS tracking from across five breeding populations, we detected low rates of overwinter site persistence across the wood thrush wintering range. Contrary to expectations, individuals in wetter habitats were more likely to engage in permanent mid-winter relocations, up to 148 km. We suggest facultative movements are instead a condition-dependent strategy that enables wintering wood thrush to locate alternative habitat as food availability declines throughout the dry season. Increased aridity is predicted across the wintering range of wood thrush, and future research should delve deeper into understanding how moisture impacts within and between season space-use dynamics and its ultimate impact on the population dynamics of this declining species.

Aircraft events correspond with vocal behavior in a passerine

Airports can affect birds by hindering acoustic communication. Here, we investigated the impacts of aircraft events on vocal behavior in wood thrush (Hylocichla mustelina) breeding one mile from an airport in Ithaca, NY, USA. We identified the number of wood thrush songs between 0500 and 0800 h at various distances from the airport and on days with various morning flight schedules. We also analyzed the number of sites from which birds sang during the peak of aircraft events (proxy of number of wood thrush). We found that birds sang more from 0600 to 0640 h when there were aircraft events during this period. This increased vocal behavior is likely explained by increased song output per individual wood thrush, rather than more wood thrush vocalizing. Increased song rate may negatively affect wood thrush fitness through increased energetic demands and/or time tradeoffs with other important behaviors, such as foraging. Identifying the noise thresholds associated with fitness costs (if any) and how different behavioral strategies (i.e. changing the pattern of vocalizations) may allow individuals to evade these costs would be useful for establishing conservation policy in breeding habitats used by passerines, such as the wood thrush.

The changing trend in songbirds’ abundance, variety and physical condition in Connecticut’s forestry habitat

Songbirds are facing rapid population declines in Connecticut due to habitat loss. Man-made habitats such as powerline corridors are one of the few remaining ideal habitats for songbirds in the state. This study aims to determine if the abundance and variety of song-birds in four selected forests (i.e. Naugatuck State Forest, Sharon Audubon Society, Miles Wildlife Sanctuary, and Great Mountain Forest Species Variety) in Connecticut show patterns of decline from 2005 to 2014. This study also compares the physical condition of songbirds captured along a powerline corridor in the Naugatuck State Forest with those captured in the rest three non-fragmented forests in Northwestern Connecticut using Mann-Whitney U tests. Weight and wingspan are used as indicators of bird physical condition. The results demonstrate that the three non-fragmented forests experienced a steady decline in the variety of songbirds between 2005 and 2014. In addition, songbirds’ abundance decreased steadily during the same period, except that of the ovenbird (Seiurus aurocapilla) and wood thrush (Hylocichla mustelina) in Miles Wildlife Sanctuary. The results from the Mann-Whitney U test have shown that after sex- and age-controlled features, the physical conditions of the three selective songbirds – veery (Catharus fuscescens), ovenbird, and wood thrush – tend to be better in the Naugatuck State Forest than in the three non-fragmented forests – Sharon Audubon Society, Miles Wildlife Sanctuary, and Great Mountain Forest Species Variety. Given are recommendations on how to protect the shrubland habitat along powerline corridors and how to create the shrubland habitat in non-fragmented forests.

Song of the Wood Thrush

Chapter 1 begins with the song of the wood thrush and then focuses on divine animals in the Bible. It examines the Gospels’ “pigeon God” in which the Spirit-bird alights on Jesus at the time of his baptism, signaling the unity of all things: divine life and birdlife, divinity and animality, spirit and flesh. And it argues that the Bible’s seeming prohibitions against animal deities is vitiated by Moses’ and Jesus’ ophidian shamanism that privileges snake-totemism as a source of salvation in Numbers and John, respectively. It examines intimations of “Christian animism”—the belief that all things, including so-called inanimate objects, are alive with sacred presence—in George E. “Tink” Taylor, Lynn White Jr., and the Martyrdom of Polycarp, a second-century CE avian spirit possession narrative. It concludes that insofar as the Spirit is ornithomorphic, it behooves us to care for the natural world as the site of God’s daily presence.

When God Was a Bird

At one time, God was a bird. In ancient Egypt, Thoth was the Ibis-headed divinity of magic and wisdom. Winged divine beings—griffins and harpies—populated the pantheon of Greek antiquity, and Quetzalcoatl was the plumed serpent deity of the pre-Columbian Aztecs. It is said that in spite of—or better, to spite—this time-honored wealth of divine avifauna, Christianity divorced God from the avian world in order to defend a pure form of monotheism. This narrative, however, misses the startling scriptural portrayals of God as the beaked and feathered Holy Spirit, the third member of the Trinity who, alongside the Father and Son, is the “animal God” of historic Christian witness. Appearing as a winged creature at the time of Jesus’ baptism (Luke 3:21-22), the bird-God of the New Testament signals the deep grounding of archi-original biblical faith in the natural world. This book calls this new but ancient vision of the world “Christian animism” in order to signal the continuity of biblical religion with the beliefs of indigenous and non-Western communities that Spirit enfleshes itself within everything that grows, walks, flies, and swims in and over the Earth. To this end, it weaves together philosophy (Heidegger, Girard), theology (Augustine, Hildegard, Muir), and the author’s own birdwatching visitations (wood thrush, pileated woodpecker, great blue heron, American dipper, domestic pigeon) to argue that all things are alive with sacred personhood and worthy of human beings’ love and protection in a time of ecocidal, even deicidal, climate change.