ssh-copy-id doesn't copy the latest id file even though the documentation says it should

The man page says:

     The default_ID_file is the most recent file that matches: ~/.ssh/id*.pub,
     (excluding those that match ~/.ssh/*-cert.pub) so if you create a key
     that is not the one you want ssh-copy-id to use, just use touch(1) on
     your preferred key's .pub file to reinstate it as the most recent.

But when I run "ssh-copy-id USER@HOST" the script tries to copy my RSA key even though the documentation suggests that the newer id_ed25519.pub would be copied.

~$ ls -t1 .ssh/id*.pub
.ssh/id_ed25519.pub
.ssh/id_rsa.pub

~$ ssh-copy-id -n USER@HOST
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
=-=-=-=-=-=-=-=
Would have added the following key(s):

ssh-rsa REDACTED
=-=-=-=-=-=-=-=

Specifying the correct key works.

~$ ssh-copy-id -n -i .ssh/id_ed25519 USER@HOST
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
=-=-=-=-=-=-=-=
Would have added the following key(s):

ssh-ed25519 REDACTED
=-=-=-=-=-=-=-=

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: openssh-client 1:6.6p1-2ubuntu2
ProcVersionSignature: Ubuntu 3.13.0-45.74-generic 3.13.11-ckt13
Uname: Linux 3.13.0-45-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.14.1-0ubuntu3.6
Architecture: amd64
CurrentDesktop: Unity
Date: Tue Feb 10 22:13:41 2015
InstallationDate: Installed on 2014-05-16 (270 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
RelatedPackageVersions:
 ssh-askpass N/A
 libpam-ssh N/A
 keychain N/A
 ssh-askpass-gnome 1:6.6p1-2ubuntu2
SSHClientVersion: OpenSSH_6.6.1p1 Ubuntu-2ubuntu2, OpenSSL 1.0.1f 6 Jan 2014
SourcePackage: openssh
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.ssh.moduli: [modified]
modified.conffile..etc.ssh.ssh.config: [modified]
mtime.conffile..etc.ssh.moduli: 2015-01-07T03:30:12.433235
mtime.conffile..etc.ssh.ssh.config: 2015-01-12T19:17:20.650115