Tuesday 31 July 2018

[Maine-birds] commensal feeding observation

Greetings, birding/atlasing friends! Just wanted to quickly share a snippet of the joy and wonderment that I'm experiencing through participation in our Maine Bird Atlas.

Like many of us, I'm scrutinizing bird plumage and behavior at every opportunity (you don't want to be in a moving car with me right now :-) in an effort to confirm late-season breeding. Last night I happened to be reading about commensal feeding among birds and *blammo!* this morning I observed a very cool instance of it!

In commensal associations, one species (the "beater") helps another species (the "attendant") at no cost to itself. Cows and Cattle Egrets are an example.

In my "yard" (a regenerating clearcut), the Indigo Bunting is El Supremo when it comes to feeding on the seed heads of tall grasses. The male in particular is very adept at jumping up on a stem and bending it down until it hangs up on other stems, forming a sturdy "feeding tripod." The INBU's beak is great for managing tiny grass seeds, but quite a few rain down on the ground about 2 feet below. There wait a pair of Chipping Sparrows (one adult, one juvenile). These two suck at jumping on grass stems (they should just give it up) but love gleaning seeds from the ground. The adult gathers up a bunch and transfers them to the youngster, which can now forage for itself in the interim. When the INBU moves to a new seed head, the CHSPs move with it.

Super cool!

Go Maine breeding birds!

Peace and "Happy Atlasing!"

Scott Cronenweth
Industry, ME
scottcronenweth@icloud.com

--
Maine birds mailing list
maine-birds@googlegroups.com
http://groups.google.com/group/maine-birds
https://sites.google.com/site/birding207
---
You received this message because you are subscribed to the Google Groups "Maine birds" group.
To unsubscribe from this group and stop receiving emails from it, send an email to maine-birds+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

0 comments:

Post a Comment