(text by Peter Taylor; photos by Peter Taylor and Lynnea Parker)
Black-capped Chickadees (Poecile atricapillus; hereafter, chickadees) are primarily woodland birds, while cattails (Typha sp.) are wetland plants; so, you might not expect the two to have much to do with each other. However, cattails often grow at wet forest edges and clearings, especially in roadside ditches and along other rights-of-way as well as in boreal wetlands. And chickadees are opportunistic little birds, ever on the lookout for resources as they rove in and near their woodland homes.
On 8 February 2018, while birding along a forested trail off Maple Creek Road, Anita Drabyk and I were puzzled to see cattail fluff drifting across the trail. We soon traced the source to a chickadee, hard at work tearing cattail heads apart (Fig. 1).
Figure 1: Black-capped Chickadee on a cattail head near Maple Creek Road, Lac du Bonnet area.
A few weeks later, on 1 March 2018, John Markert and I were hiking along a new power-line right-of-way off Provincial Road 304 near Black River when we saw two chickadees similarly engaged in ripping cattail heads apart (Fig. 2).
Figure 2: Black-capped Chickadee on a cattail head near Black River.
By now paying closer attention to the cattails, I noticed many heads breaking apart in similar fashion (Fig. 3), with seeds parachuting away singly or in small clusters on the slightest breeze (Fig. 4). How much of this was due to chickadee action, and how much to other agents?
Figure 3: Cattail bed near Black River, showing seed heads with varying degrees of breakup.
Figure 4: Cattail head breaking up near Davidson Lake, MB, 23 February 2018: note airborne seeds drifting away to the right.
What were these chickadees up to? It was too early in the year for them to be collecting nest material, and there was no indication that they were picking up the fluff or feeding on the minute seeds. I concluded that they were most likely seeking insect life within the cattail heads. An online search turned up a few similar photographs and a few anecdotal remarks about chickadees frequenting cattail marshes, but the most informative item I found was a 5 May 2017 article by Bill Marchel at the Minnesota Star Tribune website.
Bill managed to photograph a chickadee extracting a small grub from a cattail head, which was identified by entomologist Robert Dana as almost certainly the larva of a Shy Cosmet moth (Limnaecia phragmitella), a tiny but widespread species whose larvae feed on cattail heads (. The action of these larvae is known to cause cattail heads to burst apart, which may well be a visual cue for foraging chickadees, as well as giving them a starting point for tearing up the heads. This moth is not the only insect to feed on cattail heads, so other species may also provide food for foraging chickadees.
While visiting the Nature Manitoba office later in 2018, I happened to mention these chickadee observations. Lynnea Parker, intern with Nature Manitoba's Chimney Swift Initiative and the Important Bird Areas program, said that she had photographed a chickadee on a cattail head at the FortWhyte Alive nature centre in Winnipeg. She kindly let me use her photograph, taken on 17 May 2017 (Fig. 5). In this case, the chickadee was clearly collecting the fluff from a largely intact seed-head, presumably for its insulating properties as a nest-lining material.
Figure 5: Black-capped Chickadee collecting cattail fluff at FortWhyte Alive, Winnipeg.
In conclusion, chickadees seem to benefit from cattails in at least two ways, and cattails in turn get a little help from the chickadees with seed dispersal. As for germination of those seeds, that is another, very long story for which the Internet provides a handy starting point.