It has been a good year for the Black-tailed Jackrabbit (Lepus californicus) here in Utah. This has meant plentiful food for the jackrabbit’s main predator: the Golden Eagle (Aquila chrysaetos).
In Utah’s West Desert, Golden Eagle reproduction is closely tied to jackrabbit abundance, which runs in cycles spanning roughly 10 years. Every 10 years or so, jackrabbits peak in abundance for a few years, followed by several years of low abundance.
However, in recent decades HawkWatch International scientists have seen a reduction in peak jackrabbit numbers, and less consistency in when those peak abundance years occur.
Why are jackrabbits declining? With the ever increasing conversion of native shrubs to invasive plants such as cheatgrass (Bromus tectorum), jackrabbits are losing the vital shrub habitat they need as cover from predators. Because jackrabbits do not burrow underground, shrubs provide crucial shelter from the summer heat, and from predators.
While this year has seen an uptick in jackrabbits with a corresponding increase in Golden Eagle breeding occupancy and success, it will be interesting to see what happens in the coming years when rabbit abundance drops into a trough again.
Tags: 52-week project, black-tailed jackrabbit, jackrabbit, Lepus, Lepus californicus, prey