From: itannman@dogbert.ucdavis.edu (Ann Mansker)
Subject: Critter of the Week: Nicrophorus americanus
Date: 1999/04/20
Newsgroups: ucd.life


The American Burying Beetle ( http://ifw2es.fws.gov/tulsafo/beetle1.htm )
was once found throughout the eastern and midwestern United States as well
as the southeast edge of Canada.  Over the year its numbers have declined
to the point that it is now considered endangered.  The reasons for the
decline are not fully understood, but it is likely that habitat loss and
increased competition from scavangers are involved.

These handsome, 1.5 inch members of the carrion beetle family seek freshly
dead mice and other small animals and birds at night when flies that might
lay their eggs on the corpse are inactive.  They are able to locate a mouse
within an hour of death from two miles away, via their keen sense of smell.
It is critical for the beetles to sequester the body quickly, before
terrestrial scavengers such as skunks or raccoons take it away.  Carrion
is a valuable, scarce resource and the beetles fight vigorously for it until
one male and one female succeed in driving off their same-sex competitors.
The pair mate under the body and quickly begin digging underneath to bury
their prize.  If the ground isn't suitable, the pair will attempt to push
it to a more convenient site.

Once the corpse is safely underground, the beetles strip off any fur or
feathers and cover the body with a secretions to preserve it.  Next, they
excavate a cavity above it and lay their eggs.  The body represents the
food supply for the entire brood.  Many beetles lay eggs on or in a food
supply and abandon the young to raise themselves, but the burying beetle
pair are excellent parents.  They regurgitate half-digested food into a
depression on top of the carcass until the larvae hatch.  The larvae beg
food from both parents initially, but soon are able to feed themselves.
The parents then occupy themselves by taking care of the carcass until
the larvae are ready to pupate.  At this point the parents fly away to
seek another corpse to begin the cycle again.