  Using $e^+e^-$ annihilation data taken at the CESR collider with the CLEO-c
detector, measurements of hyperon pair production cross sections and elastic
and transition electromagnetic form factors have been made at the charmonium
resonances: $\psi(2S)$, $\sqrt{s}=3.69$ GeV, $|Q^2|=13.6$ GeV$^2$,
$\mathcal{L}=48$~pb$^{-1}$; $\psi(3770)$, $\sqrt{s}=3.77$ GeV, $|Q^2|=14.2$
GeV$^2$, $\mathcal{L}=805$~pb$^{-1}$; and $\psi(4170)$, $\sqrt{s}=4.17$ GeV,
$|Q^2|=17.4$ GeV$^2$, $\mathcal{L}=586$~pb$^{-1}$. %High efficiency particle
identification has resulted in good statistical precision in the results.
Results with good statistical precision are obtained with high efficiency
particle identification. Systematics of pair production cross sections, and
form factors with respect to the number of strange quarks in the hyperons are
studied, and evidence is presented for effects of diquark correlations in
comparative results for $\Lambda^0$ and $\Sigma^0$, both of which have the same
$uds$ quark content.
