{"id":89549,"date":"2020-09-17T06:20:31","date_gmt":"2020-09-17T12:20:31","guid":{"rendered":"https:\/\/www.featheredphotography.com\/blog\/?p=89549"},"modified":"2020-09-17T07:02:28","modified_gmt":"2020-09-17T13:02:28","slug":"wilsons-warblers-wood-warblers-and-rictal-bristles","status":"publish","type":"post","link":"https:\/\/featheredphotography.com\/blog\/2020\/09\/17\/wilsons-warblers-wood-warblers-and-rictal-bristles\/","title":{"rendered":"Wilson’s Warblers, Wood Warblers And Rictal Bristles"},"content":{"rendered":"

Here’s a little warbler detail I’ll bet many birders miss. Until recently I’d certainly missed it.<\/p>\n

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1\/2500, f\/5.6, ISO 1000, Canon 7D Mark II, Canon EF 500mm f\/4L IS II USM + EF 1.4 III Extender, not baited, set up or called in<\/em><\/p>\n

I photographed this male Wilson’s Warbler four days ago near a seep in a remote area of Box Elder County. When I first saw this photo I wondered what those black spikey things were that poked forward at the top of his bill.<\/p>\n

They seemed to be centered on the midline directly above his bill and I couldn’t see any of them to either side of his bill so at first I ruled out the possibility that they were rictal bristles. Besides, in my ignorance I’d never before noticed rictal bristles on any warbler I’d photographed.<\/p>\n

But I wanted a better look at them, whatever they were.<\/p>\n

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A huge crop of the same photo revealed that they actually are rictal bristles and they aren’t on the midline. Most of them that I’d been seeing in the first version of the photo originated on the left side of his bill. I’d just been deceived by the darker top of his bill into thinking it was part of the mass of bristles (or whatever they were).<\/p>\n

And now I could see bristles on the right side of his bill too.<\/p>\n

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I was surprised. Though I’d never thought about it much I was unaware that any warbler species had conspicuous rictal bristles. Yellow Warblers like this bird are the most common warbler I see and photograph and they certainly don’t appear to have bristles. So I did a little research.<\/p>\n

Family Parulidae is composed of several New World genera of wood warblers. One of them is genus Wilsonia, a small genus that includes Hooded Warblers, Canada Warblers and Wilson’s Warblers and it turns out that all three species have conspicuous rictal bristles around the bill. At this point at least it’s my presumption that other genera and other species of warblers do not have rictal bristles, maybe yes and maybe no..<\/p>\n

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As we’ve discussed in previous posts the actual function of rictal bristles is poorly understood. It has long been speculated that rictal bristles are either sensory (to help them sense or capture prey) or that they might aid in preventing captured insects from scratching the bird\u2019s eyes while they\u2019re being held in the bill.\u00a0But\u00a0those potential functions are only educated guesses and there\u2019s apparently no specific evidence to support either one.<\/p>\n

Bird authority Dan Gleason included the following about the function of rictal bristles in a comment on an earlier blog post:<\/p>\n