In that year he began his career as an assistant professor in zoology at the University of Texas at Austin.

[1] In 2009, Gilbert became professor of biology and director of the Brackenridge Field Laboratory at the University of Texas at Austin.

His research interests include the biological control of fire ants with flies of the Phoridae family,[1] the evolutionary biology and ecology of the tropical genus Psiguria and Gurania (Cucurbitaceae), the moth Eudulaphasia invaria, insect and spider bites, the role of mesquite in the South Texas ecosystem, and the ecological interactions of butterflies of the genus Heliconius with passion flowers.

This involves the plants growing small structures that resemble the eggs of Heliconius butterflies, whose caterpillars feed on Passiflora.

[4] The biologist Georges Pasteur named the rare mimicry system after Gilbert.