End of the School Year Sanity! Activities & Resources for Teachers
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Transcript of Grebes2
The Grebes of Lake Hodges
● Two Species: Western & Clark's ● Cross-breeding
● Mating rituals ● Fighting
● Nesting ● Second Brood
● Ferrying and feeding young
Presentation and Photography by Robert Harrington
A word about the photography
All photos taken with a Nikon D300 digital SLR
Lens: 200-400mm AF-S Nikkor f/4 IF-ED VR with 1.4x teleconverter*
All photos were taken handheld with aid of Bushhawk shoulder mount*
Many photos taken from the footbridge
Others taken from Bernardo Bay and Piedras Pintadas Trails
*Scenery photo taken with Nikkor 18-70mm f/3.5-4.5 AF-S Lens at 18mm
Clark's Grebe – Note white envelops eye
Male and female look alike (but they can tell)
Western Grebe – Note black around eye
Western (l) and Clark's (r) Grebes
Mating Rituals
Clark's Grebes (and Western, I assume) mate for life
They renew their bonds by food exchange and
two types of rituals:
The Rushing Ceremony, and
The Weed Ceremony
Food exchange
The Rushing Ceremony
Rushing Ceremony - finish
Rushing Ceremony – miscue
In flight - almost
The Weed Ceremony where they pick up and hold weeds (Clark's) – Jan 12, 2010
The Weed Ceremony – Western GrebesMarch 2, 2011
Nesting – Nests are built on small islands
Ferrying and Feeding Young
Young ride on the backs of both parents
As many as four at a time
Parents catch fish to feed young
Sometimes fish are too large for young to swallow
Young grow to full size in a few weeks
They continue to beg even when full grown
Ferrying young
Ferrying young
Getting dumped
Both parents ferry young
Babies on back
Feeding
Feeding
Feeding young
Feeding young – hm, too big?
Feeding young – Clark's
Feeding young – even almost full grown
Feeding young and not-so-young
Cross breeding, Clark's and Western Grebes
Cross breeding, Clark's and Western Grebes
Clark's vs. Western Grebe Fight
7 slides
Grebe Fight – Clark's chasing
Grebe Fight - Face-off
Grebe Fight – Clark's lunges...
Grebe Fight – and misses
Grebe Fight – Chase resumes
Grebe Fight – Western turns
Grebe Fight – table turned
Second brood of 2011 – May 14, 2011
The End