Kirtland’s Warbler Consuming Ants at Point Pelee (2018 Note)

RIP Michigan Birds & Natural History News...  I wrote this short note for the journal, that was published in 2018: 

Holden, B.R. 2018. Kirtland’s warbler consuming ants during migration in Ontario. Michigan Birds and Natural History. 25(3): 172–174

--- 

Figure 1. Female Kirtland's Warbler actively foraging on ants

At 0900 on 18 May 2013 my Father and I were birding along the west beach footpath of Point Pelee National Park (Ontario, Canada) when an alternate (Humphrey and Parkes 1959) female Kirtland’s Warbler (Setophaga kirtlandii) caught our eyes. We secured record photographs and subsequently reported the sighting to the Ontbirds listserv, which allowed many other observers to enjoy the sighting. The habitat was that of a westerly facing beach dune community, notable with scattered Juniperus species. The bird was present in the same general area for the remainder of the day allowing us to return in the evening to obtain additional photographs. Known for their accommodating nature (Bocetti et al.), I was able to obtain a number of detailed images with a Canon 1DM4 DSLR and 600mm lens. Review of these images, both in the field and afterwards, showed that the bird was catching and consuming ants (Order: Hymenpotera) (Figures 1,2).

While the order is known to account for a sizeable portion of the species diet on the breeding grounds (Deloria-Scheffield et al. 2001) seemingly little has been published on migrant individuals at stopover locations; presumably due to the general scarcity of observations and subsequent inability to complete any detailed study.

The Kirtland’s Warbler is a rare but regular migrant in Ontario with 75 records accepted by the Ontario Bird Records Committee through 2016 (Burrell et al. 2016), with this individual representing the 58th (Holden 2014). The majority of observations have occurred in the extreme south-west portion of the province during spring migration, presumably on route to the species stronghold in the lower peninsula of Michigan (Probst 1991). Recent records well east in Ontario may be attributed to isolated breeding populations in Ontario, such as Renfrew County first discovered in 2006 (Richard 2008); which has been active every year thereafter (Richard 2013), as well as other unpublished occurrences. It is hoped that this note and associated images will shed a small amount of light on the species diet during at a stopover site during migration, a poorly known period of its life cycle.

Figure 2. Kirtland's Warbler eyeing up ants on a small trunk

Literature Cited

Bocetti, C.I., Donner D.M. and H.F. Mayfield. Kirtland’s Warbler (Setophaga kirtlandii), The Birds of North America Online (A. Poole, ED.). Ithaca: Cornell Lab of Ornithology; Retrieved from the birds of North America Online: http://bna.birds.cornell.edu/bna/species/019doi:10.2173/bna.19

Burrell M.V.A., Charlton B.N. and K.G.D. Burrell. 2017. Ontario Bird Records Committee Report for 2016. Ontario Birds 34(2):58-85.

Deloria-Sheffield C.M., Millenbah, K.F., Bocetti, C.I., Sykes Jr., P.W. and C.B. Kepler. 2001. Kirtland’s Warbler Diet as Determined Through Fecal Analysis. Wilson Bulletin

Holden, B.R. 2014. Ontario Bird Records Committee Report for 2014. Ontario Birds 32(2):54-81.

Humphrey, P.S. and K.C. Parkes. 1959. An approach to the study of moots and plumages. Auk 76:1-31.

Probstm J.R. 1991. Kirtland’s Warbler. In: The Atlas of Breeding Birds of Michigan (R. Brewer, G. McPeek, and R. Adams Jr., Eds.), Michigan State University Press, East Lansing, Michigan, USA. pp. 414-417.

Richard, T. 2013. Seven Years Later: Kirtland’s Warbler at Garrison Petawawa, 2006-2013. Ontario Birds 31(3):148-159.

Richard, T. 2008. Confirmed Occurrence and Nesting of the Kirtland’s Warbler at CFP Petawawa, Ontario: A First for Canada. Ontario Birds 26(1)2-15.