If you have close-focusing binoculars you should also have a great time observing lizards, mammals and an occasional snake. Several monarchs were seen flying through the garden. All of the ones I saw today were moving in a SSE direction. Generally Monarchs from the eastern United States migrate to central Mexico, whereas those west of the Rockies migrate to and spent the winter months on the Monterey Peninsula. Their flight direction would seem to suggest Mexico.
Monarchs are large brownish-orange butterflies with black markings.
A large brown butterfly with yellow spots flutters about nectar source flowers and members of the citrus family, the host plant for its caterpillars. These butterflies probably don't breed at all at the Botanical Garden. They have flown hundreds of miles up from the southeast, perhaps as far as Mexico. A majority of the snout butterflies have also come by the same route. These movements aren't properly called migrations because there is no evidence that the butterflies make a return trip.