Songbird Survival

Bruant des prés • Ipswich Sparrow • Msikue’j • Passerculus sandwichensis princeps

by Liza Tsitrin AKA Blue Nautilus Art, who has always been inspired by the beauty, mystery and power of nature.

Seasonal migrations between breeding and wintering sites are a common life history trait among North American songbirds. Migrations expose birds to a range of ecological conditions which can affect behavioural decisions such as timing, pathway selection, and stopover duration. Ultimately, these behavioural decisions result in individual birds selecting or avoiding particular regions, and habitats within those regions. These decisions can have profound effects on survival and thus population size. Many migratory songbird populations are declining, with changing conditions and habitat loss in migratory areas likely contributing to these declines. There is a clear need to understand when and where birds migrate, what habitats they choose during migration, and the behaviours that underlie these habitat choices.

Complexities associated with tracking individual birds have long been a barrier to studying migration. The advent of tracking devices such as Very High Frequency (VHF) radio-tags have fundamentally advanced study of migratory ecology, and the miniaturization of such devices has recently expanded their use to songbirds. In radio-telemetry, an animal is affixed with a VHF radio-tag that emits a uniquely coded pulse, which is detected by receivers. Receivers identify the incoming pulse and record tag identity, time, and GPS location. An array of automated receivers, the Motus Wildlife Tracking System (www.motus.org), track migratory songbirds carrying radio-tags at hemispheric scales.

Ipswich Sparrow migratory pathways from wintering grounds on the Delmarva Peninsula, USA to breeding grounds on Sable Island, Canada in spring 2018. Pathways of individual birds are indicated by blue lines. Location of Motus receivers are indicated by red circles.

I study the spring migratory ecology of a songbird listed under the Species at Risk Act as Special Concern, the Ipswich Sparrow (Passerculus sandwichensis princeps). This bird breeds exclusively on Sable Island, Nova Scotia, an isolated sand spit 300 km east of the mainland, and winters in coastal dunes habitat along the eastern seaboard.

The goals of my project are to: 1) quantify the temporal and spatial attributes of spring migration in the Ipswich Sparrow by age and sex cohorts, and 2) identify key regions (and habitats within them) in Nova Scotia that support migrating sparrows. To do this, I am collecting two years of radio-telemetry data from sparrows as they migrate from wintering grounds on the Delmarva Peninsula, USA to Sable Island.

By Sydney Bliss from Sackville, New Brunswick, Masters student at Dalhousie University in K’jipuktuk (Halifax).