Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!deimos!unmvax!nmtsun!john
From: john@nmtsun.nmt.edu (John Shipman)
Newsgroups: rec.birds
Subject: Re: Hummers: What is it they are doing?!!!
Summary: It's a courtship display
Message-ID: <3859@nmtsun.nmt.edu>
Date: 28 Feb 90 21:00:57 GMT
References: <2562@ncr-sd.SanDiego.NCR.COM>
Reply-To: john@nmtsun.nmt.edu (John Shipman)
Distribution: na
Organization: Zoological Data Processing
Lines: 33

Donna Mitchell (donnam@palomar.SanDiego.NCR.COM) writes:
+--
| ...a question:  Over the years I have noticed this aerobatic
| trick that the [Allen's] hummers do:  They fly straight up in
| the air...very high.  Then, drop straight back to earth (wings
| tucked in), and at the last moment swoop back upwards and make
| a whistle-pop sound.  (It's like making a big "J")...Any ideas
| what they are doing?!!!
+--
From ``The Birder's Handbook'' by Ehrlich et al., p. 334:

  DISPLAYS: Male flies before female in J-shaped pattern, swooping
  down from a height of 75', making a prolonged metallic buzz at
  the bottom, then curving upward ca. 25' and hovering.  Often
  preceded and followed by pendulumlike rocking display covering
  ca. 25'.

So it's a mating display, and you did an excellent job of describing
it.  I recommend Ehrlich's book; it's like a one-volume condensation
of Bent's _Life Histories_.

+--
| It is enjoyable to watch, but I do get concerned about getting
| hit in the head.  They have come close a couple of times.
+--
I don't think you need to worry.  Hummers have outstanding reflexes,
and time passes much faster for them; your movements probably look
like those of a tree sloth to them, and if you were to get in
their way they would most likely be able to dodge.
-- 
John Shipman/Zoological Data Processing/Socorro, New Mexico
USENET: ucbvax!unmvax!nmtsun!john  CSNET: john@jupiter.nmt.edu
``Let's go outside and commiserate with nature.''  --Dave Farber