This Saguaro skeleton clearly shows the support ribs and the callous or "boot" made from a Gila Woodpecker nest entrance.
These heavily callused structures areleft behind after a Saguaro has long died and rotted away. They are originally formed by the cactus in defense against the tisue damage done by Gila Woodpeckers when they excavate for a nest cavity.
Also shown are the dead nurse tree - probably a Palo Verde or Mesquite as well as the next generation of Saguaro growing along side it's fallen kin.
Condo Cactus By Lauray Yule
Even when you're on an early-morning or evening hike in Saguaro National Park or anywhere saguaros grow, you can't escape the "condo" scene. Oh, you may think you've retreated from noisy (or nosey!) neighbors and the quiet residents you sometimes wonder about, but you haven't.
They're all around you. Stop for a while and stand quietly near a big saguaro cactus with holes in it, and you may glimpse some local "condo critters" going about their lives.
Flickers and woodpeckers are the ambitious hole drillers in saguaros. They know a good investment when they find it: Home sweet home. Rent for free.
Nest sites drilled into saguaro arms and bodies by these strong-beaked birds generally make a sharp curve downward into the cactus' pulpy flesh. The hollows are sometimes over a foot and a half deep! The saguaro reacts by manufacturing scar tissue or callus around the nest cavity, which soon becomes very hard and resistant. Often this tough shell remains even after a saguaro is dead and fallen. Because of its shape, it's called a "boot."
Nest holes remain throughout the cactus' life – little apartments for future residents even after woodpeckers and flickers leave. Other feathered saguaro residents? Elf and screech owls, house sparrows, ash-throated flycatchers, purple martins, and more. Even cactus wrens (Arizona's state bird) will raise a family in a saguaro boot, though ambitious nest builders themselves. Larger birds (hawks, eagles and big owls like the great-horned or barn varieties) build messy nests of sticks and other desert litter in the crooks between the trunk and a branching saguaro arm. Even bugs and arthropods (spiders and scorpions) occupy the "boots," and some cactus-climbing rodents don't mind overnighting in an empty hole.
Once a saguaro dies and falls, it's still home to many creatures. Grubs, water beetles, and other insect larvae swim or slough their way through soupy, sweet-smelling saguaro rot. Even when only the saguaro's rib skeleton remains, snakes, rodents, lizards, and invertebrates such as scorpions move into the carcass'shelter. Eventually, decomposers completely recycle the remains. Saguaro "boots" are often the last to break down, and may collect enough rainwater for a thirsty critter to have a sip or two as it goes on making its desert living.
With luck and good rains, a saguaro cactus "condo" provides homes and food for desert dwellers that choose to live in its "boots" for many years. It'll probably have lots of tenant turnover: Hey, the rent's free.
This Saguaro skeleton clearly shows the support ribs and the callous or "boot" made from a Gila Woodpecker nest entrance.
These heavily callused structures areleft behind after a Saguaro has long died and rotted away. They are originally formed by the cactus in defense against the tisue damage done by Gila Woodpeckers when they excavate for a nest cavity.
Also shown are the dead nurse tree - probably a Palo Verde or Mesquite as well as the next generation of Saguaro growing along side it's fallen kin.
By Lauray Yule
Even when you're on an early-morning or evening hike in Saguaro National Park or anywhere saguaros grow, you can't escape the "condo" scene. Oh, you may think you've retreated from noisy (or nosey!) neighbors and the quiet residents you sometimes wonder about, but you haven't.
They're all around you. Stop for a while and stand quietly near a big saguaro cactus with holes in it, and you may glimpse some local "condo critters" going about their lives.
Flickers and woodpeckers are the ambitious hole drillers in saguaros. They know a good investment when they find it: Home sweet home. Rent for free.
Nest sites drilled into saguaro arms and bodies by these strong-beaked birds generally make a sharp curve downward into the cactus' pulpy flesh. The hollows are sometimes over a foot and a half deep! The saguaro reacts by manufacturing scar tissue or callus around the nest cavity, which soon becomes very hard and resistant. Often this tough shell remains even after a saguaro is dead and fallen. Because of its shape, it's called a "boot."
Nest holes remain throughout the cactus' life – little apartments for future residents even after woodpeckers and flickers leave. Other feathered saguaro residents? Elf and screech owls, house sparrows, ash-throated flycatchers, purple martins, and more. Even cactus wrens (Arizona's state bird) will raise a family in a saguaro boot, though ambitious nest builders themselves. Larger birds (hawks, eagles and big owls like the great-horned or barn varieties) build messy nests of sticks and other desert litter in the crooks between the trunk and a branching saguaro arm. Even bugs and arthropods (spiders and scorpions) occupy the "boots," and some cactus-climbing rodents don't mind overnighting in an empty hole.
Once a saguaro dies and falls, it's still home to many creatures. Grubs, water beetles, and other insect larvae swim or slough their way through soupy, sweet-smelling saguaro rot. Even when only the saguaro's rib skeleton remains, snakes, rodents, lizards, and invertebrates such as scorpions move into the carcass'shelter. Eventually, decomposers completely recycle the remains. Saguaro "boots" are often the last to break down, and may collect enough rainwater for a thirsty critter to have a sip or two as it goes on making its desert living.
With luck and good rains, a saguaro cactus "condo" provides homes and food for desert dwellers that choose to live in its "boots" for many years. It'll probably have lots of tenant turnover: Hey, the rent's free.
Above info from:
The Friends of Saguaro National Park Newsletter