Ground Squirrels Flashcards
What genera of ground squirrel are used in research?
Urocitellus, Ictodomys, and Spermophilus
Genus and species of Richardson’s ground squirrel.
Urocitellus richardsonii
Genus and species of 13-lined ground squirrel
Ictodomys tridecemlineatus
Genus and species of golden-mantle and Califronia/Beechy/rock ground squirrel
Spermpophilus lateralis and beecheyi
Spermophilus beecheyi - California or Beechey or rock squirrel
Spermophilus elegans - Wyoming ground squirrel
How much do ground squirrels weigh?
85g to 1kg
Describe the appearance of ground squirrels.
Fur is grizzled brownish of gray, often with fine light spots on upper parts and underparts are whitish or yellow
What do ground squirrels have in relation to hamsters?
Large internal cheek pouches to carry food
Generally, where are ground squirrels found? Where are they not found?
Great Plains region of the US and south-central region Canada. Not found in areas with dense forest cover.
Generally, how do ground squirrels live in the wild?
In burrows. Territorial, not highly social.
What are ground squirrels used for in research? How are they adapted?
Hibernation. Cardiac muscle undergoes hypertrophy during hibernation to maintain cardiac output, but has a higher proportion of alpha isoform of cardiac myosin heavy chain which preserves contractile strength.
What do California ground squirrels possess that has inhibitory function against rattlesnake venom?
Serum metalloproteinase inhibitors
Cholesterol-fed Richardson’s ground squirrels are an effective model for what?
Cholesterol gallstone formation.
When are ground squirrels active?
Diurnal. Richardson’s has three daily activity periods at dawn, mid-day, and dusk.
When do ground squirrels hibernate?
Sept/Oct. to April/May
Describe ground squirrel reproduction.
Monestrous, with one litter per year. Mating after emerging from hibernation. Gestation of 23-31 days and 2-15 pups per litter. Pups weaned at 4-6 weeks.
When do juvenile ground squirrels reach sexual maturity?
11 months
What are ground squirrels fed in the lab?
High protein dog chow supplemented with sunflower seeds, carrots, celery, and live mealworms. Supplemented with kitten milk replacer as a behavior modification for observation.
How can hibernation be induced in ground squirrels? What can occur during hibernation that requires intervention?
Unlighted room maintained at 5-10C. Lose considerable weight and die if forced to hibernate beyond the end of the natural season. Remove from hibernation.
What agents have caused dermatitis in ground squirrels?
Corynebacterium ulcerans
Staphylococcus aureus
California ground squirrels can be infected with what zoonotic agent? How and when are animals infected?
Yersinia pestis in southern California and Alaska. Infected via fleas. Infected following hibernation and again when reoccupying colonial burrows.
What occurs when ground squirrels are infected with ground squirrel hepatitis virus (GSHV)?
Mild, nonprogressive persistent hepatitis. Chronic portal LP hepatitis with aggregates of mononuclear cell inflammatory cells.
What ground squirrel can be experimentally infected with Western equine encephalitis? What level of viremia develops?
Richardson’s ground squirrel. Viremia sufficient to provide a source for arthropods.
