Ruby-throated Hummingbird (Archilochus colubris) Allen T. Chartier Washtenaw Co., MI 7/5/2006 © Allen Chartier This species sponsored in memory of Ginny Merlotti. (Click to view a comparison of Atlas I to II) Buzzing wings, strident sputtering calls, and a Ontario, it is common throughout the southern portions of the province north to the north shore flash of green and red; virtually anyone can of Lake Superior, having expanded northward recognize our smallest bird, the Ruby-throated somewhat between their two atlas periods Hummingbird. Its combative demeanor and (Cadman et al. 1987, Cadman et al. 2007). aerobatic flight has endeared it to thousands of homeowners who have placed feeders out for In Michigan, Ruby-throated Hummingbirds them in ever increasing numbers. This is the were considered a common breeding species in only breeding hummingbird species throughout the LP but relatively rare in the UP by Wood eastern North America, ranging from the (1951) and Zimmerman and Van Tyne (1957), Canadian Maritimes south to central Florida and whereas Payne (1983) considered it an west to around the 100th meridian from east uncommon transient and summer resident. Texas to eastern North Dakota, and extending Ruby-throated Hummingbirds have been westward across southern Manitoba, recorded arriving as early as the first week in Saskatchewan, and Alberta. They winter from April (Reinoehl 2003), though males generally southern Mexico through Central America to arrive in the first few days of May, followed by extreme northern Panama with many females a few days later. In the UP, spring undertaking nonstop migratory flights across the migration can extend into early June (Binford Gulf of Mexico (Robinson et al. 1996). 2006). Fall departure is generally before the first frost, typically in late September or early Distribution October, with adult males beginning migration In the Great Lakes region, the Ruby-throated in August and rarely lingering past Labor Day. Hummingbird is widely distributed in all states. Increasingly, Ruby-throated Hummingbirds It is described as a common breeder in have been recorded lingering into mid and late Wisconsin (Cutright et al. 2006), common in October (Wuepper 2006, Dombroski 2007, Illinois with more detections in the southern half Byrne 2008) including as far north as Houghton of the state (Kleen et al. 2004), more common in County (Binford 2006). The latest records have the southern third of Indiana (Castrale et al. included 26 November 2007 at Marquette 1998), and most prevalent in southern and (Dombroski 2008), 26 November 2009 in eastern Ohio (Peterjohn and Rice 1991). In © 2011 Kalamazoo Nature Center Ruby-throated Hummingbird (Archilochus colubris) Allen T. Chartier Allegan County (Chartier and Wuepper 2010.) species, although the presence of males and and 1 December 2010 in Wayne County (pers. females during the breeding season likely does obs.). indicate breeding. Of the 422 reports of Probable breeding, 49% were based on the The distribution of breeding Ruby-throated presence of a pair, which, if based on Hummingbirds is essentially unchanged with a observations of a single male, could statewide increase from nearly 28% of all underestimate the number of breeding females blocks in MBBA I to nearly 32% in MBBA II. present. They were detected in nearly 24% of all UP blocks during MBBA II, compared with slightly Courtship displays of the males are spectacular more than 17% in MBBA I, which may reflect a and easily observed; most often the U-shaped true increase, or increased effort in the UP flight, and 25% of Probable breeding reports during MBBA II. Likewise, there was an were based on courtship being observed. increase in the southern LP from nearly 38% of However, this aggressive U-shaped display is blocks in MBBA I to more than 44% in MBBA only the initial phase of courtship, and has been II. The number of homeowners putting out observed being performed to other males, other hummingbird feeders has almost certainly species, and even inanimate objects (Robinson increased significantly since MBBA I, which et al. 1996, Sargent 1999, pers. obs.). Receptive may account for this increase. The northern LP females will respond to the “U” display by showed a slight decrease in blocks reporting the moving to a dense tree or shrub, where the male species from MBBA I to MBBA II. follows and initiates a “shuttle” display, flying rapidly left-to-right about a foot or so with Concentrations of breeding confirmations in loudly whirring wings and rapid chipping notes, Kalamazoo County are likely due to intensive followed by copulation. The two then separate, field work there during the MBBA II period, with the male quickly seeking other females to and concentrations in Oakland, Washtenaw, and court (Robinson et al. 1996, Sargent 1999). Jackson Counties are probably due to newly initiated banding studies there (Chartier unpubl. Hummingbird nests are difficult to find, and data). only 79 blocks reported nests (43% of all Confirmed reports) during the MBBA II period. Breeding Biology Although the Ruby-throated Hummingbird has Ruby-throated Hummingbirds breed in a variety not yet been proven to regularly raise a second of forested and semi-open habitats including brood in Michigan, there is some evidence that deciduous, mixed, and coniferous woodland, this at least occasionally may occur (Schipper preferring edges and openings to forest interior, 2005). Dates of females carrying eggs, based on as well as rural, urban and residential areas, but in-hand observations, may provide some not in prairies, fields or shrublands (Robinson et evidence that double broods could be fairly al. 1996, Sargent 1999). Their mating system is frequent (A. Chartier unpubl. data). Harriman polygynous, with males mating with multiple (2006) stated that observations of fledged young females and forming no pair bond. Polyandry, between 10 June and 15 September suggested with both males and females having multiple that the species is double-brooded in Wisconsin. mates, may also be possible though this has not In Michigan, fledging has not been confirmed in been studied (Robinson et al. 1996). So the atlas recent years before mid-July and juveniles, definition that an observed “pair” indicates especially males, are known to linger into Probable breeding (Kalamazoo Nature Center October (Chartier unpubl. data), thus more 2004) does fit well with the biology of this © 2011 Kalamazoo Nature Center Ruby-throated Hummingbird (Archilochus colubris) Allen T. Chartier concrete evidence should be provided to Hummingbird is able to co-exist with humans in confirm two broods at our latitudes. urban, suburban, and rural areas, nesting in low densities in these habitats (pers. obs.). They are Abundance and Population Trends most numerous in and near woodlands with The estimated number of Ruby-throated edges and openings, and so could potentially be Hummingbirds detected in MBBA II was a impacted by large-scale deforestation. Pesticide between 4,252 and 10,492 “pairs” statewide, use in gardens planted to attract hummingbirds based on one pair found in 1,452 blocks, two to would likely have a negative impact on local ten pairs in 804 blocks, and 10-50 pairs in 20 populations. blocks. This is likely a significant underestimate for the state. As with breeding confirmations, Literature Cited the highest number of individuals was concentrated in the southwestern LP and Binford, L.C. 2006. Birds of the Keweenaw portions of the southeastern LP, in addition to Peninsula, Michigan. Miscellaneous several isolated locales throughout the NLP and Publications. Museum of Zoology, UP. Large numbers of Ruby-throated University of Michigan, No. 195. Ann Hummingbirds can be found at many more UP Arbor, MI. sites than are suggested by MBBA II data (pers. Byrne, A.M. 2008. Michigan Bird Survey: obs.). The PIF estimate of the North American Autumn 2008 (August-November). population of Ruby-throated Hummingbird is Michigan Birds and Natural History 16(2): 7,000,000, and the estimate for Michigan is 73-110. 200,000 (PIF 2007). The BBS trend data from Cadman, M.D., P.F.J. Eagles, and F.M. 1966-2008 (Sauer et al. 2008) shows a Helleiner. 1987. Atlas of the Breeding statistically significant increase in Ruby- Birds of Ontario. University of Waterloo throated Hummingbirds of 4.98% for Michigan Press. Waterloo, Ontario. and 5.00% for USFWS Conservation Region 3. Cadman, M.D., D.A. Sutherland, G.G. Beck, D. Ruby-throated Hummingbirds are not easily Lepage, and A.R. Couturier (eds.). 2007. detected on BBS routes, with a mean of 0.38 Atlas of the Breeding Birds of Ontario, individuals detected on 53 Michigan routes and 2001-2005. Bird Studies Canada, a mean of 0.58 individuals detected on 372 Environment Canada, Ontario Field routes in Conservation Region 3. Ornithologists, Ontario Ministry of Natural Resources, and Ontario Nature. Toronto, Conservation Needs Ontario. The Ruby-throated Hummingbird is not Castrale, J.S., E.M. Hopkins, and C.E. Keller. considered threatened in any part of its range, 1998. Atlas of Breeding Birds of Indiana. and populations in Michigan currently appear Indiana Department of Natural Resources, stable, although more study is needed. Little is Division of Fish and Wildlife, Nongame and known about breeding density, number of Endangered Wildlife Program. Indianapolis, broods, and annual productivity of Ruby- IN. throated Hummingbirds in Michigan. Welter Chartier, A.T. 2008. Nesting Proximity of (1935) described two simultaneously occupied Ruby-throated Hummingbirds in Michigan. nests in Rowan County, Kentucky, that were Michigan Birds and Natural History 15(3): less than 69 meters apart, and two 93-96. simultaneously occupied nests only 50 meters Chartier, A.T. and J.T. Wuepper. 2010. apart were found in Monroe County, Michigan Michigan Bird Survey: Autumn 2009 (Chartier 2008). The Ruby-throated © 2011 Kalamazoo Nature Center Ruby-throated Hummingbird (Archilochus colubris) Allen T.