COURTSHIP OF THE GREAT CRESTED GREBE. 541 
he was going to shake with her. However, he then saw another 
odd bird (¢ sex) not far off, and, his pecker presumably being up, 
went off and drove it away too. After this he came back, and 
a short but vigorous bout of shaking ensued. I do not suppose 
he would have driven the second bird off if he had not been roused 
by the first. 
2. Then a second:—An odd cock was seen ‘in a very threat- 
ening attitude,” some twenty yards away from a pair. They got 
close together, the cock going into a fairly good threatening 
attitude: they then swam, the cock leading, towards the intruder, 
but suddenly turned tail; however, they soon faced round again, 
and waited a bit. ‘ Y” was now only about ten yards off. ‘Then 
the pair swam a little away (this is very odd) and then all three 
dived ; asa result, ““Y” was driven a short distance away, and 
the pair made as if to shake, but did not. “ Y” approached 
again, and the same scene was re-enacted almost identically (most 
ludicrous to watch, it was !); finally came several long dives on 
the part of all three birds, and “ Y” was driven right off. Strange 
to say, no shaking followed. 
Here, in face of an obviously hostile third bird, the pair 
united at once in common action (cf. Selous, in the case of Ring- 
Dotterel). 
3. Once I saw the odd bird approach “like a dolphin ”—pro- 
gressing for the most part subaqueously, but now and then lifting 
first head and then back out of the water, only to disappear 
again. What this may mean I do not know. 
4, In one case where there had been a flirtatious shake (‘ Y ” 
= 2), the rightful hen came up, and instead of at once driving 
“Y” away, started shaking, so that for a short time there was a 
parti a trois. She then drove “ Y” off, and then returned and 
had a long shake with X. This I have only seen once. 
5. Once where “ Y” (a hen) had called, X swam almost up to 
her, but at the last moment was seized with a ‘fit of repentance,” 
returned to his mate, and shook with her. Perhaps it was not 
repentance at all; perhaps on seeing her mate go off towards 
“Y,”’ the hen gave some sign that she was ready to shake, or 
rather that she was roused enough to shake. This would be all 
the cock wanted, and, seeing this, he came back. This is only a 
possible explanation, but it at least has its parallels in our own 
affairs. 
6. A variation on the above was given by the same cock a little 
earlier; this time he had actually shaken a bit with ““ Y”, but on 
seeing his mate approaching, he suddenly turned on “Y” and 
drove her off. The rightful hen did not trouble herself further ; 
but there was, curiously enough, no shaking on the part of the 
pair. 
7. An odd bird approached; Y (? sex) swam towards it. Both 
went into the threatening attitude and remained perfectly 
motionless, looking very fierce at each other at a distance of only 
38* 
