In April 1977, I hung up on Faith
McNulty. I don't think I had ever hung up on anybody before. It's
not nice, and it isn't good business. I did apologize later. Still,
in my opinion, she deserved it. She was writing an article on
the condor for "Audubon," and I had given her
and her husband a several-day interview as we toured through condor
country. She also had ample opportunity to talk to others knowledgeable
about condors, and to various condor "personalities."
By the time she got back to Rhode Island and called me with follow-up
questions, it appeared to me that she had lost all her notes except
those from the day she visited with the McMillans.
The subject that caused the phone disconnection was predator and
rodent control. We had discussed poisons in detail while we were
together, and had spent considerable time talking about the McMillans'
concerns. Now she was back on the phone, going over and over the
same ground. She asked me why - since there was (in her mind)
so much evidence that poisons were killing condors - I hadn't
more aggressively researched the subject. After each attempt to
get to the heart of the subject - to clarify what I had done,
and to restate my reasons for not doing other things - she was
back with the same questions over and over again. When her questions
reached the point where I considered they had minimal objectivity,
and where I found them too personal regarding my credentials and
motives, I hung up the phone.
It wasn't my finest hour. In fact, if I was picking the part of
my condor research that I handled most poorly, it would be the
question of animal control and condors. I have no doubt that the
"scientific community" was with me close to 100 per
cent through the years - they told me so - but I don't think I
tried hard enough to present my case to those who were "anti-control"
in principle. I despise most animal control (chemical and otherwise),
but on the question of animal control and condors, I found myself
in a situation similar to the one I was in at the Pine Mountain
phosphate mine (Chapter 20). What I considered my scientific credibility
wouldn't let me "fly the condor by" everything I disliked
that was happening in condor country [see Footnote]. Faith was
not concerned with my particular demons; hers seemed to center
more around personalities and the emotion of the bigger animal
control argument. Roland Clement (Vice-president for National
Audubon Society) put some perspective on it in a letter he wrote
to me:
"Your letter to Faith seems to me extremely well balanced
and will, we may both trust, satisfy her concerns on the matter
of pesticides. She has had trouble keeping all this in
perspective, and feels unsure how to wrap all this up. In short,
the 'story' is now so involved--as in real life--that there are
no longer good guys and bad guys. Faith is a great writer, but
involved reality is difficult to dramatize for lay publics."
To make amends for not handling the subject better in the
past, let me describe my rationale and conclusions on the effects
of animal control on condors. Maybe I can get across to you what
I couldn't get across to Faith. For the few moments it takes to
read the rest of this chapter and the next, please set aside whatever
philosophical opinions you have about "animal control,"
generally, and concentrate only on the question: what impact
did this have on the condors?
In Chapter 4, I explained why the early writers who claimed major losses of condors during predator control were probably wrong. Most of the later investigators, up to and including Carl Koford, agreed that the alleged losses to poisons set out for predators were greatly overstated. But that doesn't give predator control a clean bill of health. California condors have almost certainly been killed and made ill by strychnine poisoning, and at least one condor suffered from an M-44 "coyote getter." Although the number of confirmed cases are few, predator control activities added to a generally hostile environment in which the species attempted to survive.
STRYCHNINE - For
many years, strychnine was the poison of choice to kill coyotes
and (before they were eradicated) California grizzly bears and
wolves. With the exception of one condor death from cyanide poisoning
in 1983 (see below), strychnine is the only animal control poison
that can clearly be linked to condor deaths. Even the three known
cases of strychnine poisoning lack definite "proof,"
but it would be almost impossible to argue for any other cause.
Here are the details of the three cases:
1. Walter Fry, a Sequoia National Park naturalist, gave the first
non-hearsay report of condor deaths from apparent poisoning. He
doesn't name the poison, but it would almost certainly have been
strychnine at that time:
"While I was stopping at Huron, Fresno Co., California,
during January 1890, Mr. Manuel Cardoza, a sheep herder, brought
in two beautiful dead Condors. These birds had died from eating
poison. Coyotes had killed two of his sheep and he had poisoned
the carcasses with the hope of killing the coyotes; but instead
of getting the animals he got the two big birds that had been
feeding on the dead sheep. Cardoza said that he had noticed several
of the Condors around the poisoned sheep the day before and upon
going out in the evening found the dead ones a few yards from
the bait."
2. On 1 March 1950, 3 condors (2 adults, 1 immature) were found
near a Fish and Wildlife Service strychnine drop bait site east
of Bakersfield. Strychnine-laced fat baits had been placed around
a sheep carcass, to kill coyotes. One adult condor was dead near
a coyote carcass, the other two birds were weak and unable to
fly. The living birds were provided with horsemeat and water at
the site from 2 March to 6 March, when the adult was able to fly
away. The immature continued to run around the area, and came
for food and water, but didn't fly for some time. It finally disappeared
on 18 March. The predator control people searched for it, but
couldn't find it. They assumed it flew away.
Analysis of the dead bird was done by the Bureau of Chemistry,
California Department of Agriculture. There was only a trace of
strychnine in its digestive tract. Fish and Wildlife Service concluded
that it probably wasn't strychnine poisoning because of the small
amount of strychnine found, and because the trappers didn't think
the birds exhibited signs of strychnine poisoning. It still looks
to me as if the condors were poisoned, probably by feeding on
a coyote that had eaten a strychnine-laced bait.
3. Quail hunters found a "sick" adult condor 2 January
1966 in Alisos Canyon near Los Alamos, California. They reported
their observation to the Department of Fish and Game, and on 3
January 1966 Game Warden Gene Durney went out to look. He found
the bird "huddled under an oak tree, unable to fly and
seemed to be a very sick bird. Mr. Durney placed the bird in a
burlap sack...and the bird was taken to Griffith Park Zoo... Upon
arrival at the zoo the Condor was examined by a veterinarian and
was found to be suffering from strychnine poisoning. The Condor
was placed in a padded, darkened cage and treated (treatment
unspecified) for several days. On Jan. 12 the Condor was taken
to the locality where it was found and released. It seemed to
have recovered from the effect of the strychnine."
"Mr. Louis Dourdet, owner of the ranch, has stated that he
poisoned these (calf) carcasses in an effort to relieve himself
of a serious predator damage to his livestock and poultry. He
bought 4 ounce of strychnine at a drug store in Solvang, cleaned
the carcasses...and sprinkled 1/8 ounce in each carcass,"
A news release from the Department of Fish and Game said "the
diagnosis of strychnine poisoning as the most probable cause of
the condor's illness was made by Dr. Nathan Gale and Dr. Charles
Sedgwick of the Los Angeles Zoo, who treated the bird, and Eldridge
G. Hunt, leader of the Department's Pesticides Investigations
project." Fecal samples from the condor did not show
any strychnine, but that wouldn't be a very good test. No one
did any other tests, so strychnine is only "probable."
Apparently a number of the ranchers in the area were using strychnine-
laced carcasses at the time.
While it seems unlikely that strychnine was the major decimator of condors that the earliest writers claimed, it seems probable to me that strychnine poisoning accounted for the regular loss of occasional condors through the years. Strychnine was still a "threat" when I came on the job, but the news about it was mostly good. Fish and Wildlife Service animal control people were no longer using strychnine for predator killing, and were discouraging others from using it. [For example, as soon as it was learned that the Los Alamos rancher had been using strychnine, the Fish and Wildlife Service volunteered to remove his "problem" coyotes with steel traps.] It was also good news of a sort that the record showed that exposure to strychnine did not automatically mean death for condors. (Three out of the six condors suspected of being poisoned became ill, but didn't die. Of course, the sick ones had some assistance; we don't know what would have happened if they had been left to recover or die on their own.) The bad news was that strychnine was still readily obtainable (the Los Alamos rancher bought it at the drug store), and was often in the hands of those with the least training in how to reduce its possible impacts on condors. Thankfully, the use of strychnine as a predator poison was prohibited in California in 1972, although I suspect that there were supplies in ranchers' barns that continued to be used for years.
M-44s - The "coyote
getter" is a relatively new animal killer, one not used in
the California condor range until after 1975. It is a hollow metal
tube containing a capsule of cyanide, a spring-loaded ejector,
and a triggering device. The tube is buried to ground level, then
baited with something with a strong odor (like a paste of cheese
and meat). When a coyote or other mammal bites on the bait and
pulls up on the M-44, the trigger ejects cyanide into the animal's
mouth. Death is often instantaneous.
While certainly not a "nice" weapon, neither I nor anybody
else considered the M-44 as a problem for condors. M-44s are buried
in the ground, and aren't baited with anything that a condor would
consider "food." (The attractant is a "scent bait,"
and condors don't have much, if any, sense of smell.) During widespread
field tests during 1974 and 1975, only one bird - a raven - died
from an M-44. Cyanide gas is so volatile it is highly unlikely
that any residue would remain that could poison a condor that
fed on a poisoned coyote. Regulations adopted when the M-44 was
registered by the Environmental Protection Agency in 1976 further
reduced the risk to condors:
"They cannot be used 'where threatened or endangered animal
species might be adversely affected.' None can be placed within
30 feet of a livestock carcass used as a draw station (to attract
the target animals to the trap site); no more than three draw
stations can be operated within any square mile area; and no more
than four M-44s can be placed at a draw station."
Considering all the safety features built into M-44 use in
condor habitat, it came as a considerable surprise when, in November
1983, a condor was found dead of what was later shown to be cyanide
poisoning. The condor, only a year old, was found approximately
three-quarters of a mile from an M-44 that had been detonated
by something, presumably the condor. Speculation is that the condor
"played with" the M-44 and set it off, then was able
to glide some distance down the canyon before it died. Why it
fiddled with the device is an unanswerable question. Condors,
particularly young ones, often pull at grass and toss sticks,
which could explain why this one pulled on an M-44, but there
was no particular reason for it to be attracted to the site in
the first place. Whatever the reason, I think this qualifies as
a "freak accident," and not as a serious safety problem
for condors. Following this mishap, Fish and Wildlife Service
further reduced the potential for harm to condors by making sure
that the M-44 tubes were countersunk below ground level, were
covered so that no part of the devices were visible, and were
placed singly, rather than in clusters (so that a condor coming
to feed on a coyote killed by one M-44, would not inadvertently
set off another one nearby).
STEEL TRAPS - Carl Koford's monograph records five incidences of condors being caught in steel leg-hold traps. Three times the birds were released with minimal injury; the other two times, the condors died. Although I don't know of any such occurrences after 1950, I wouldn't be surprised to learn that this happened rather regularly through the years. The potential for such mishaps would have dropped considerably after California State law and Fish and Wildlife Services procedures were modified to prohibit setting traps near animal carcasses. (Formerly, birds attracted by the carcasses might inadvertently set off a trap.) The practice of setting steel traps in clusters was also curtailed (reducing the chance of a condor setting off one trap while feeding on a dead animal in a nearby one), and traps were more often "baited" with scent, rather than meat (so that the sight of food was no longer an attraction). The State of California also requires that steel traps have offset jaws, which reduce the chances of serious leg injuries (although they can still occur).
Each year for many years, hundreds of thousands of acres of central California rangeland have been regularly poisoned to kill ground squirrels and kangaroo rats. Some of this ongoing campaign has been done in the name of bubonic plague control (which squirrels do sometimes carry), but mostly to keep down the number of mammals building burrows in pasture and farm lands. The technique used is to strew poisoned grain in areas of high rodent density. The predominant poisons used in the condor range have been strychnine, thallium sulfate, Compound 1080, and (in more recent times) zinc phosphide. No condor is known to have died or been made ill by any rodent poisoning, although strychnine and thallium sulfate are certainly toxic enough to have caused harm on occasion. Thallium has been banned for use as a rodenticide in California for many years, and strychnine has largely been replaced by Compound 1080 and zinc phosphide. Zinc phosphide is highly volatile, changing to phosphine gas when consumed, so the chances of a bird eating poisoned squirrels and being poisoned in turn are very low. That leaves Compound 1080 to consider.
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Footnote: "Flying the condor by" was my term for what seemed to happen in central and southern California any time anybody wanted to stop anything - from a strip mine to a shopping mall. The condor was also "flown by" attempts to acquire land or to set aside wilderness areas, whether or not the proposed action had anything to do with condors.