The monsoon is in full swing and one of the interesting creatures who makes an appearance during this season is the Sonoran Desert Toad.. If you live in the Sonoran Desert, you may be hearing them, especially on rainy nights. The Sonoran Desert toad is
Arizona’s largest toad, growing to 7.5” or more in length and is a common,
nocturnal visitor to yards near water or natural desert vegetation. They
emerge after the summer rains to feed and breed in large, temporary rain
pools. During the rest of the year, the toads hibernate underground.
Sonoran Desert Toads are olive green to brown in color and have
lumpy skin, large glandular lumps on their hind legs, golden eyes with
horizontally elliptical pupils, large, poison-filled parotoid glands behind
their eye and tympanum, and one or more distinctive white tubercles at the
corners of their mouth. The diet consists of just about anything that
moves and will fit into their mouths, including insects, centipedes, spiders,
lizards, mice and other amphibians.
Occurring across southern Arizona, this toad is absent from the
higher mountains and from the arid, western desert valleys. Although also
known as the Colorado River Toad, its populations are declining around the
Colorado River, and it is believed that they no longer exist on the California
side of the river. The habitat of the Sonoran Desert toad includes
semi-desert grasslands, oak woodlands, creosote bush desertscrub, valley
bottoms and lower elevations hills. In the western portion of its range,
the species becomes increasingly tied to permanent water, such as rivers or the
edges of agriculture.
Most Sonoran Desert toads are found at night during the monsoon
season, but they may emerge a month or more before the summer rains begin,
particularly in areas of permanent water (such as the mountain lion
enclosure!). Breeding generally occurs on one night within a couple of
days of a rainfall event of more than one inch. At permanent water areas,
breeding may be independent of rainfall. They may breed in cattle tanks,
reservoirs, backwaters and ponds. Males may call for females from the
water or actively search for females. Sonoran
Desert Toad (Incilius alvarius) Call Females deposit
long stringers of up to 8000 eggs in shallow water. Tadpoles typically
metamorphose in a month or two. The toads live at least 10
years, and possibly as long as 20 years.
The defensive toxins released from several glands in the skin are
extremely potent. Animals that harass the toad are intoxicated
through the mouth, nose or eyes. The toxin is strong enough to kill
full-grown dogs that pick or mouth the toads. Symptoms include excessive
salivation, head shaking, irregular heartbeat and gait, and pawing at the
mouth. The toxins are also hallucinogenic and poisonous to humans.
References
One of the coolest toads around! They are rather large:) And no matter what....they are exciting to see during our summer rain season.
ReplyDeleteI wish I could see the desert at this time of the year!
ReplyDeleteThanks for taking the time to tell us about this interesting animal.
ReplyDeleteI wonder if that's what I heard along the Colorado River at night. I was too tired to go looking for them but liked to fall asleep to their sound.
ReplyDeleteI was amazed to find them active in my back yard in early June this year. They seem to learn that lights, especially, uv lights, are attracting their insect prey even long before the monsoon humidity arrives. In our area they may not produce any offspring for years now - there is no water that lasts long enough for their development - the smaller red-spotted ones just barely make it. So becoming older and wiser - and bigger - they keep the population going. I have a blog in preparation about our dogs and the big toads....dramatic but not tragic in our case
ReplyDeleteI love these guys :) It still amazes me that these massive amphibians make the desert their home.
ReplyDelete