What good are Ticks?
by Jan Weaver
Sometimes in casual conversation I will mention that I am an
entomologist - a scientist who studies insects and related arthropods. If
I mention it this time of year, someone will seize on that fact and want
to know: "What good are ticks?" Several thoughts flash through my mind
in quick succession - Uh oh, the tick question again . . . Hey, ticks
are
not my fault just because I study insects . . . Do you have any idea how
many species of arthropods there are, I canŐt know about all of them . . .
Well, I did take a Medical/ Veterinary Entomology class . . . Yeah, but
that was 20 years ago . . . Ok, but you have to tell them something . . .
But I don't know anything about the role of ticks . . . Nevermind, wing it
and hope they don't ask for specifics. "Well, ticks are important to
the
bacteria that cause Rocky Mountain Spotted Fever and Lyme disease." Not
surprisingly my questioner usually finds this explanation highly
unsatisfactory.
Anyway, this year, as I was picking ticks off a new puppy (66 Lone
Star ticks - Amblyomma americanum, 52 Amblyoma - unknown
species, 2
American dog ticks - Demacentor variabilis, and 38 seed ticks, for
a total
of 158 ticks) I thought what good are ticks? I decided to
try and give
the question some serious consideration. What role do they play in
nature, and what would happen if there were no ticks? A recent review
article on the role of parasites in animal communities concluded that
parasites do play a role in structuring ecological communities and that
they may serve to maintain biodiversity . So for example, ticks may
rarely kill the animals they feed on, but they certainly weaken them and
make them more vulnerable to predators. In addition, the ticks probably
respond to increases in their host populations by becoming proportionally
more numerous (i. e. more ticks per individual host as the host population
density goes up). Therefore ticks may act as a brake on runaway
population growth in host populations. This is good for the hosts in the
long run because they are less likely to end up consuming all their
available food and then starving. This is also beneficial to the other
species that share the same food as the host. It probably helps predators
too because if the host population exploded and then crashed from
starvation, the predators would be left with nothing to eat and they would
starve as well.
So, ticks, although irritating and able to transmit mortal
infections to humans and domestic animals, may play an important role in
maintaining steady levels of their host populations and therefore of the
plants and animals that interact with the hosts. The good of ticks is
that they help maintain species diversity. If we turn around and apply
that same criterion of usefulness to humans, we clearly lag far behind
ticks. This does not mean that I think ticks are better than people, or
that we should tolerate ticks on ourselves, our families, our pets or our
livestock. But I do think as the only species in 30 million (give or take
a couple million) capable of recognizing the complex interdependency of
nature, that humans should not let narrow concerns decide the fitness of a
species to coexist with us on this planet.
Or, as Aldo Leopold put it: ÓThe outstanding scientific discovery
of the twentieth century is not television, or radio, but rather the
complexity of the land organism. Only those who know the most about it can
appreciate how little we know about it. The last word in ignorance is the
man who says of an animal or plant: "What good is it?" If the land
mechanism as a whole is good, then every part is good, whether we
understand it or not. If the biota, in the course of aeons, has built
something we like but do not understand, then who but a fool would discard
seemingly useless parts? To keep every cog and wheel is the first
precaution of intelligent
tinkering.Ó
To find out more:
Bioregional Quiz: How do ticks find you and what
can you
do about it?
Job of the Month: Naturalists for Raptor Theatre Department - World
Bird
Sanctuary. Positions require hands on work with trained raptors,
psittacines and other bird species. Public speaking experience preferred,
but not required. Able to work in front of large audiences at nature
centers, theme parks and zoological institutions. Biology or related
degree preferred. Students between semesters are welcome. Must want to
travel. Outgoing and self motivated individuals. Responsibilities: 1)
presentation of programs; 2) interacting with public and answering
questions about birds, conservation issues, etc.; 3) daily maintenance
with all birds and related animals in programs; 4) cleaning and management
of housing areas for birds; 5) cleaning and maintenance of stage and back
stage areas. Send cover letter and resume with three references to:
Jeffrey Meshach, Director of Special Events, World Bird Sanctuary, P.O.
Box 270270, St. Louis, Missouri 63127 - (636) 938-6193 fax (636)
938-WING
Information on other Environmental Positions is available from the MU
Environmental Studies Program, 211 Lowry (inside the Honors College),
882-7116, envstudy@showme.missouri.edu or at www.ejobs.org
Special Events/Information:
MU Meetings and Events (call to confirm times and places)
Organization Meetings and Events (call to confirm times and
places)
Answer to BioRegional Quiz: Ticks "quest" for hosts by climbing
grass and brush and waiting for a host animal to come along. They hang on
with the third pair of legs and wave the other pairs in the air hoping to
grab on to whatever passes. You can reduce your chances of picking up
ticks by staying out of brushy or grassy areas (staying on the trail), by
wearing long pants and tucking them into your socks, wearing light colored
clothing so you can see ticks, and doing regular tick checks even on the
trail.
Feedback - Got an opinion? If we have space, we will consider
publishing
it. Submit it by email (envstudy@showme.missouri. edu), snail mail
(Environmental Studies, 211 Lowry Memorial Union, MU, Columbia MO 65211),
or call Jan Weaver to talk about it (882-7116). MU Environmental Network
News is published by MUŐs Environmental Studies Initiative. All opinions
expressed are the responsibility of the editor. Any part of this
newsletter may be copied for distribution but please give us credit.
EARTH DAY COALITION SMALL GRANTS PROGRAM: EDC is offering small (<$500)
grants for non-profit organizations to assist them in environmental
education and awareness. Please call or email for information on how to
apply. 875-0539; email: peacewks@coin.org.
ENVIRONMENTAL AFFAIRS COUNCIL 882-7116 Call for meeting dates and times
over the summer.
ENVIRONMENTAL STUDIES EXEC COM 882-7116 Call for meeting dates and times
over the summer.
RECYCLING COMMITTEE 882-3091 Call for meeting dates and times over the
summer. .
AUDUBON SOCIETY 874-3904 Next regular meeting Wed Sept 19, 7:30 pm Env
Res Ctr, New Haven for more information, check out
http://columbia-audubon.missouri.org/
CENTER FOR SUSTAINABLE LIVING 875-0539 Planning meeting for CSL & PedNet
Coalition Alt. Energy &Transportation Fair - Monday July 2, 6:30 pm Peace
Nook. http://peaceworks.missouri.org/sustainable.html; email:
peacewks@coin.org.
COLUMBIA FOOD CIRCLE Call 882-7463 or e-mail hendricksonm@missouri.edu
for information.
COLUMBIA PUBLIC WORKS VOLUNTEER PROGRAMS 874-6271 Volunteers needed:
Household Haz Waste, 1st/3rd Sats; Composting Wkshops; numerous solid
waste reduction activities; turning compost at demonstration site, huge
worms are yours for the taking. Call for details.
http://www.ci.columbia.mo.us/dept/pubw/
FRIENDS OF ROCK BRIDGE STATE PARK 474-7429 Batty for Ice Cream (ice cream
social and bat viewing), Tuesday July 24, 7 pm, lower (DevilŐs icebox)
lot. http://rockbridge.missouri.org/
GREENBELT COALITION 442-4789 Meeting, Tuesday July 3, 7 pm - Outdoors
Building, 200 Old 63 S.
http://www.coin.org/community/rec-center/greenbelt/green.htm
MISSOURI HEARTWOOD 443-6832 Meetings Tuesdays, 7:30 pm, 1027 E. Walnut.
http://www.heartwood.org/MO/
MISSOURI NATIVE PLANT SOCIETY. Call 445-0321 or
hayden@tranquility.net.
MISSOURI RIVER COMMUNITIES NETWORK. 443-0292 http://mrcn.missouri.org/
for info or to volunteer
NATIVE AMERICAN SUPPORT GROUP 443-5985 Potluck/Ceremony/Music July 8 4
to 8 pm, Douglass Park, tree planting will honor peace and harmony among
all peoples, co-sponsored by the Douglass Coalition. Big Mt Water Crisis
- check http://www.theofficenet.com/~redorman/pagea~1.htm for updates on
the situation.
PEDNET COALITION pednet@pednet.org Volunteers needed for the CityŐs
Bicycle and Pedestrian Commission. Application forms - City Clerk's
Office (701 E. Broadway, 4th floor, downtown Columbia) Completed
application forms must be received at the Clerk's Office, by NOON on
Friday, July 6, 2001.
ROCK BRIDGE MEMORIAL STATE PARK 449-7402 http://rockbridge.missouri.org
Work sessions 2nd Saturdays 9 and 1:30 pm Park Office. Picnic for old and
new volunteers Sat July 14, 11 am to 1 pm, DevilŐs Icebox Parking lot.
Night Vision Hikes, Saturdays July 14 and 288-10 pm, DevilŐs Icebox
Parking Lot, reservations required.
SHOW ME CLEAN STREAMS COALITION Volunteers needed for 12 area watershed
surveys and stream cleanups throughout the summer. Call for information
(573)751-4115 ext 3169 or register on-line at www.mostreamteam.org
SIERRA CLUB 443-4401 Meeting 3rd Tuesday of each month at the Hillel
Foundation, 1107 University Avenue, http://sierra.osage.missouri.org/
SMART GROWTH COALITION Meetings 1st Weds, 7 pm, Boone County Government
Bldg. Contact tomvmoran@yahoo.com for more information.
WILD ONES 499-3749 email beamerl@missouri.edu. Garden Visits July 7th
1:30 pm - meet at 8400 South Route N. August 18th 1:30 pm Site visits of
future potential projects, possibly including a site for Habitat with
Humanity.