STATUS OF BARN SWALLOWS (Hirundo rustica erythrogaster) AND CLIFF SWALLOWS (Petrochelidon pyrrhonota) IN THE LITTLE CAMPBELL WATERSHED A ROCHA CANADA CONSERVATION SCIENCE SERIES August 2014 AUTHORS: Hannah F. R. Hereward, A Rocha Canada Christy Juteau, A Rocha Canada Andrew Baylis, A Rocha Canada CONTACT: [email protected] STATUS OF BARN SWALLOWS (Hirundo rustica erythrogaster) AND CLIFF SWALLOWS (Petrochelidon pyrrhonota) IN THE LITTLE CAMPBELL WATERSHED Aug 2014| i Executive Summary Swallows (Hirundinidae) are a group of migratory bird species found across the world. Barn Swallows (Hirundo rustica erythrogaster) and Cliff Swallows (Petrochelidon pyrrhonota) both migrate to North America annually for the breeding season. Populations of both species have declined over the last 40 years. The purpose of this study was to begin a local monitoring programme for Barn and Cliff Swallows within the Little Campbell River watershed (LCRW), British Columbia, Canada. Barn Swallow nests were monitored at nine sites throughout the LCRW. One Cliff Swallow colony was monitored at A Rocha’s Brooksdale Environmental Centre between April and August 2014. Cliff Swallow banding took place twice within the breeding season. We banded 30 Cliff Swallows (20 birds on June 29 and 10 on July 12, 2014). The arrival and departure dates of both species were documented at each site. We analyzed the effect of surrounding land cover within 400 m of each site on the number of Barn Swallow chicks fledged. Old Barn Swallow nests were present at all nine sites but only five sites contained active nests. In total, we monitored 25 active and 39 inactive Barn Swallow nests and 11 inactive and 47 active Cliff Swallow nests. Amount of pasture within 400 m of the nest site was positively associated with the number of Barn Swallow chicks fledged per site (rs = 0.718, p = 0.019). While our results suggest a dependence on pastures and open fields for Barn Swallow nesting success, further annual studies are needed to determine the status of Barn and Cliff Swallow populations within the Little Campbell River watershed. STATUS OF BARN SWALLOWS (Hirundo rustica erythrogaster) AND CLIFF SWALLOWS (Petrochelidon pyrrhonota) IN THE LITTLE CAMPBELL WATERSHED Aug 2014| ii Acknowledgements We would like to thank all the land-owners who allowed us to check nests on their properties weekly. Also we would like to thank Campbell Valley Park for allowing us to access the park and buildings throughout the season. Thank you to Andrew Baylis and Rebecca Hannigan for aiding in fieldwork. Recommended Citation: Hereward, H., F., R., Juteau, C., and Baylis, A. 2014. Status of Barn Swallows and Cliff Swallows in the Little Campbell River watershed. A Rocha Canada Conservation Science Series. A Rocha Canada, Surrey, B.C., Canada. Cover illustrations: From left to right: Barn Swallow (Hirundo rustica erythrogaster) building a nest, Little Campbell Hatchery and Semiahmoo Fish and Game Club, Cliff Swallow (Petrochelidon pyrrhonota) in the hand during banding, A Rocha Brooksdale. All rights reserved. Content (excluding the illustrations) may be used without permission, with appropriate credit to the source. STATUS OF BARN SWALLOWS (Hirundo rustica erythrogaster) AND CLIFF SWALLOWS (Petrochelidon pyrrhonota) IN THE LITTLE CAMPBELL WATERSHED Aug 2014| iii Table of Contents Executive Summary ............................................................................................................... ii Acknowledgements .............................................................................................................. iii Table of Contents ................................................................................................................. iv Introduction ............................................................................................................................ 5 Cliff Swallows ................................................................................................................................ 5 Barn Swallows ............................................................................................................................... 6 Methods ................................................................................................................................ 8 Barn Swallow Site Selection ........................................................................................................... 8 Cliff Swallow Site Selection ............................................................................................................ 8 Site Assessment........................................................................................................................... 10 Nest Monitoring .......................................................................................................................... 10 Analysis ....................................................................................................................................... 10 Results ................................................................................................................................ 11 Cliff Swallow Nesting Activity and Banding .................................................................................. 11 Barn Swallow Nesting Activity ..................................................................................................... 11 Land Cover .................................................................................................................................. 12 Discussion ........................................................................................................................... 27 Breeding Phenology .................................................................................................................... 27 Nest Success ................................................................................................................................ 28 Land Cover .................................................................................................................................. 29 Further Study .............................................................................................................................. 29 References .......................................................................................................................... 29 STATUS OF BARN SWALLOWS (Hirundo rustica erythrogaster) AND CLIFF SWALLOWS (Petrochelidon pyrrhonota) IN THE LITTLE CAMPBELL WATERSHED Aug 2014| iv Introduction Swallows (Hirundinidae) are a group of migratory bird species found across the world (Turner, 2006). Six out of 18 swallow genera are found in western North America: Tachycineta, Stelgidopteryx, Riparia, Hirundo, Petrochelidon and Progne (Sibley, 2003; Sheldon et al., 2005; Dor et al., 2010). Cliff Swallows The Petrochelidon genus is split into 9 species (Sheldon et al., 2005). The Cliff Swallow (Petrochelidon pyrrhonota, previously Hirundo pyrrhonota) (Fig. 1) migrates between South America and North America, breeding in North America between May and July (Grant and Quay, 1977). Since 2000, Bunnell (unpublished data, 2014) has observed Cliff Swallow clutches in British Columbia as early as April 28, with 54% of first clutches occurring in June. Both parents assist in the nest building, incubating and rearing of 1 to 2 broods of chicks per year (Smith et al., 2005). Figure 1. Cliff Swallow (Petrochelidon pyrrhonota) and nests. Source: H Hereward, 2014. Cliff Swallows typically nest under large bridges and on buildings in close association with human habitation, but prior to extensive human habitation they nested on cliff and rock edges (Gorenzel and Salmon, 1982). Cliff Swallows nest in colonies containing 2 to over 3,700 nests (Brown, Brown and Danchin, 2000). Their nests are created from mud globules joined together to form an upside-down dome with an entrance tunnel (Samuel, 1971). The IUCN (International Union for the Conservation of Nature) categorises Cliff Swallows as ‘least concern’ and states that their populations are increasing (BirdLife International, 2012). Furthermore, the 2010 Wild Species report stated that Cliff Swallow populations are ‘secure’, meaning they remain widespread or abundant (Canadian Endangered Species Conservation Council, 2011). The 2011 Breeding Bird Atlas Survey in Canada demonstrates that although Cliff Swallows are widespread, they have declined within Canada by 50% over the last 40 years (Environment Canada, 2014). The reasons for this decline are currently unknown, but may be due to a decrease in insect abundance (their primary food source) and an increase in House Sparrows (Passer domesticus), which are known to take over Cliff Swallow nests (Leasure, Kannan and James, 2010; Nebel et al., 2010). STATUS OF BARN (Hirundo rustica erythrogaster) AND CLIFF SWALLOWS (Petrochelidon pyrrhonota) IN THE LITTLE CAMPBELL WATERSHED Aug 2014| 5 Barn Swallows Barn Swallows (Hirundo rustica) are comprised of 6 subspecies (Dor et al., 2010). The H. r. rustica subspecies ranges between Europe and North Africa. Two subspecies are distributed within Africa and the Middle East (savignii and transitiva). There are two Asian subspecies (tytleri and gutturalis) and one subspecies that breeds in North America (erythrogaster) (Fig. 2). Figure 2. Barn Swallow (Hirundo rustica erythrogaster) and nest. Source: H Hereward, 2014. Hirundo rustica erythrogaster breeds as far north as southern Alaska and as far south as Mexico. They annually