The animals here are clearly takeoffs on the very early Doria Pamphili Paradise Landscape. Since that was definitely done in Rome and the present painting was definitely done in Antwerp/Brussels, this indicates that Jan had drawings of those animals --particularly, for instance, the lion-- that he brought home with him from Italy.
De Clerck was a court painter in Brussels; this work was presumably done in that context.

Related: a version of Munich Paradise with Scenes from Genesis and Four Elements by De Clerck and Alsloot was sold Sotheby's London 5.xii.2007 #16; it's a large copper and is signed and dated 1613. Catalog points out that other versions are usually dated around 1607-12 but this new work argues for a later dating. This painting is signed by both artists, which is interesting; it also has an old collection number on it, 1148, suggesting it was once part of a big collection, probably (say Sotheby's) in Spain.
The mythical horned ass at the left originally had no horns and was in profile; this was changed at some later stage of painting. Version in French private collection shows how it originally looked; see Munich 2013 p. 154.

Variant in the Cremer collection, Dortmund. Photo: Witt.