Behavior of cougar in Iowa and the Midwest

Background
With the exception of the southern Florida population much of our understanding of cougar behavior is based on studies of mountain lions out west .  Many of the earlier studies were done on mountain lions in wilderness areas where there were larger populations less affected by hunting, which can disrupt the social structure of the cats.  The first one of these studies that elucidated the social structure was done by a capture (tag),  release, and recapture of cougar in a remote wilderness area of Idaho (Hornocker 1970).  This was followed by numerous other studies1 most of which used radio collars to track the individual movements of the cats.  One of these was Anderson's  study of the cougar on the Uncompahgre Plateau in Western Colorado (Anderson 1992).  Anderson's study stands out from many other studies by its well thought out planning, investigation of other parameters that would affect the cougar, and a thorough understanding of other studies. His great summary of the literature was published as a separate special report (Anderson 1983).  A third study that I found really helpful was a long term (ten years - about the life span of an adult wild cougar) study of cougar in an area of the San Andres mountains in New Mexico (Logan and Sweanor 2001).  Their study area was relatively undisturbed by man because it had been a missile testing site.   Finally, Maehr (1997) has written a book summarizing what he and others have learned about the Florida cougar. This is perhaps the most intensively studied population because of its endangered species classification and is the only population in the eastern US.

Social structure of cougar
Cougar are solitary cats  They do not run around in packs like wolves.  The only cats you will see together (other than the short time breeding pairs are together) are mothers with their young.  The young (often two) stay with their mother for a year and a half until they are almost full size.  They are also a very cryptic (secretive) cat. They typically hunt at dawn or dusk and find some cover to bed down in during the daytime.  Because of these solitary and secretive habits it is not unusual for people to be unaware of cougar that are passing through.  For instance, the provincial officials in Saskatchewan  know they have some cougar along their riparian (river) corridors in the prairies and suspect some may be breeding but have little idea of exactly where they are.  Similarly, here in NW Iowa we have wide open farmland and I probably am informed of most of the good sightings. Yet I have little idea (except for one that for now appears to have set up a home territory) exactly where along some of the river corridors other cougar might be, if there are others in the area..

In areas where resident cougar have been studied, the males set up home ranges in good habitat.  The core areas of these ranges show little overlap, at least in the San Andreas mountains (Logan and Sweanor 2001).  Females have a much smaller home range usually within the territory of a male.  Often several related females (matrilines) share adjacent territories.   The size of the territory can vary greatly. Anderson (1983) summarizes data from studies from seven states (table 34, p.38).  Male territories ranged from 48 square miles in Idaho to 398 square miles in Texas. 2   Most were bigger than 70 square miles. The Black Hills males have some of the largest territories known, at 312 square miles (Kintigh 2003).   The female home ranges that Anderson lists ranged from 25 square miles in California to 398 square miles in Texas. 2  Most were in the range of 25 to 50 square miles. The Black Hills again has larger home ranges for females at 70 square miles (Kintigh 2003).  Two factors that influence the size of home ranges are prey abundance (they need enough prey in their home range to sustain them) and number of other cougar.  Males especially avoid neighboring cougar and may constrict their range when another male cougar comes into the area (Logan and Sweanor 2001; Maehr  1997).  In Saskatchewan, where a small population exists along narrow river corridors in the western prairie part of the province no distinct home ranges have been detected (phone conversation of Feb 1, 2005 with Dave Brewster of Saskatchewan's department of Environment).3  Similarly in Minnesota no cougar have been shown to have set up resident populations with fidelity for specific areas for long times, even though a few females have been detected.  I am aware of at least two females, a mother and cub that wandered across the northern part of the state and a female that was killed near Bloomington. However, in the later case wildlife officials suspect this cat had been in the area for some time so it may have had at least a temporary home area.  It is speculative to assume without studies that actually track the cats, that the social structure of cougar in very low densities is different, but the long term fidelity of cougar to defined home areas that is typical of many studies with healthy cougar populations is not obvious in some of these low density areas.

Young males, subadults,  when they leave their mother must disperse out of their natal area or be killed by the dominant tom (their father).  Females, usually disperse shorter distances (half to a third), and often times set up a home ranges adjacent to their mother.  Here in the Midwest we would expect the first cats to appear to be dispersing males and indeed, most of the captured or killed cats in Nebraska and Iowa have been young males..  In at least some populations all young disperse as subadults.  Males usually show longer dispersal than do females who can disperse and set up a close to their mother.  Length of male dispersal is not ended at the first unoccupied area with a good food supply if they are still close to their natal area..  Males usually set up their home range distant enough from the natal area so that inbreeding with their mothers or sisters is not possible.  Dispersal can be frustrated by natural barriers or dense residential areas.  In some cases this has caused some of the dispersers to return to their natal areas although males will usually try to disperse again.  This was seen in a study of 9 (8 male and one female) dispersing cougar in the California Santa Anna mountains surrounded by dense metropolitan areas and only a few corridors for dispersal (Beier 1995).  Several of the males frustrated in dispersal temporarily returned to their natal area before trying to disperse again. The female came back to her mother's home area where she died of unknown causes.  In Florida the subadult males attempt to disperse but are frustrated by metropolitan area of Miami suburbs and the Caloosahatchee River.  Not being able to disperse they occupy marginal habitat on the fringe but then return after a couple months to their natal area and try and take over one of the resident male's territory (Maehr 1997).

Based on other studies Anderson et al. (1992) give the average dispersal distance of  53 miles for 65 north America males (maximum of 170miles). This would not be nearly long enough to get the young adults here from the closest expanding population in the Black Hills.  However, dispersers tend to disperse until they find suitable open habitat and many cougar that are dispersing east are dispersing into areas that we would not normally consider good habitat and into areas presumably devoid of females.  In fact a few very long dispersals are known.  Logan and Sweanor knew of a male that dispersed 300 miles from the Big Horns in northern Wyoming to Colorado, where he was killed by a hunter west of Denver.  And more recently two dispersers from the Black Hills have set records for dispersal as they moved east into areas without cougar.  One in less than a year had moved 660 miles from the Wyoming Black Hills to just south of Kansas and another dispersed north and east about 400 some miles through North Dakota and now is in northern Minnesota (as of Jan 2005 still moving east).

Behavior in this area
The focus on my work has been on tracking where some of the cougar are in NW Iowa.  Since we have a very open agricultural area, I figured a cougar would be apt to be seen by someone and if I developed good contacts with local farmers and hunters, I would probably hear of most good sightings in this area.

I have noticed several patterns of movement in the local area.  Obviously some of them in this area may be still dispersing and only setting up temporary home areas as they disperse through. This is a pattern that would be hardest to detect without collars since cat would be in the area for only a little while and then move out of the area.

Another pattern is for cougar is for cougar to be reported in one area for a week or two in one area along or close to wooded areas along the Big Sioux and Rock Rivers.   These cats appear to not be passing rapidly through but hunting in one area close to the river for a couple of weeks and then moving up or down the river where again you will hear reports for about a week or two.   Most of the sightings north of Sioux City have been  of cougar(s) that I think are moving up and down the wooded areas along the Big Sioux and Rock Rivers The woods provide cover and also have a high density of deer.  In some cases more of the reports come from certain areas.  For instance in 2004 I had a number of reports from the same area of the Rock River (from about Doon to South of Rock Valley) but really don't know how mobile this or these cats are.  Although the  reports would suggest that cougar had not left the area, motion detector cameras that were there for a number of months did not confirm the presence of the cougar and I could find no good prints in the areas that cougar had been reported from.

Another pattern I have noticed is that some cougar are hunting in more open areas.  The cougar killed west of Sioux Center (Ireton cat) was using corn for cover to bed down in the day after feeding on raccoon that dawn or previous evening.

Cougar sign [prints, numerous sightings] suggest that another cat has occupied an open area in the center of Sioux County between the Floyd River and highway 75 to the west for almost a year. The cougar was first detected in winter (of 2004) in an area with little cover, other than farmer's groves and smaller stream beds.  I was first surprised that a presumably male would set up a home range in an area apparently devoid of females.  However, several dispersing males that have crossed the Caloosahatchee River have set up home ranges without evidence of any females (Lotz and Land 2003).  If this is a male as is likely, the cougar may disperse again sometime in search of a female.

Food
Deer are often a major staple in cougar diet along with some smaller prey.  We have some evidence in the area of deer depredation.  Travis Pollema, did and independent study with me and analyzed the puncture marks in a skull found in Sioux County.   The large puncture marks did not penetrate through the skull and Pollema was able to fit the punctures to the dentition of  young adult cougar skull (Pollema 2004).  I also have one visual report of a cougar leaving a deer carcass by a rural road.  I initiated a necroscopy on the cougar that was shot in rural Sioux County, which had the right front paw of a raccoon in its stomach. There have been almost no depredation of livestock in the area over the years that I have been following the cougar.  Click here for more information generally on livestock depredation. What is sometimes thought to be cougar attacks on livestock turns out on investigation to be something else.  In at least one case, scratches on a horse were more likely caused by barbed wire fence.  I have several credible reports of dead pigs (laid out for the rendering truck) being eaten by cougar.   There have been some wild turkey kills that were attributed to cougar by local land owners, but since I have not seen the evidence - this is only a possibility although turkey are part of the diet elsewhere.  The literature suggests that cougar generally eat about a deer a week and need some smaller prey item in their diet.  With the abundance of white tailed deer in the area and raccoons, I suspect these are both important local prey items and may be supplemented with other rodents and rabbits. 

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1K.C. Lamb (2001) has compiled an extensive (over 780 entries) annotated bibliography  (unfortunately no longer maintained) of many of these studies including a number that are reports to the funding organization. Because the annotation include a full abstract or K.C. Lamb's own summary one can get a good feel of what sort of work has been done before 2000.

2 I used the next to smallest home ranges from Anderson's  listing for minimum home ranges.  The smallest ranges that Anderson lists are for both male (25 square miles) and females (12.3 square miles) were both from Hornocker's Idaho study and had home range determined by a different technique  (tagging, marking and recapturing ) which may not give equivalent results to telemetric studies.

3 Brewster says that they think they have low numbers of cougar in both the boreal forest and along the riparian corridors.  Some of them are likely dispersers from Alberta but they suspect that some are resident.

References:

Anderson, A.E. 1983. A critical review of literature of Puma (Felis Anderson, A.E. 1983. A critical review of literature of Puma (Felis concolor). Special report Number 54. Colorado Division of Wildlife

Anderson, A.E., Bowden, D.C., Kattner, D.M., 1992. The Puma on Uncompahgre Plateau, Colorado (Technical Bulletin 40). Colorado. Division of Wildlife, Fort Collins (p. 116).

Beier, P. 1995 Dispersal of juvenile cougar in fragmented habitat. Journal of Wildlife Management 59(2):228-237

Fecske, D.M. 2003. Distribution and abundance of American martens and cougars in the Black Hills of South Dakota and Wyoming. Unpulbished PhD (South Dakota State University) 194 pages.

Hornocker, M.G. 1970. An Analysis of Mountain Lion Predation upon Mule Deer and Elk in the Idaho Primitive Area. Wild. Monograph #21. 39pp.

Kintigh, M. 2003. State of South Dakota Mountain Lion Status report pages 43-48 in Becker, S.A., Bjornlie, D.D, Lindzey, F.G., and Moody, D.S. eds. 2003 Proceedings of the Seventh Mountain Lion Workshop. Lander, Wyoming. 186.pp [the data was based on Dorothy Fecske 2003 PhD thesis research]

Lamb, K.C. 2007 [last update] Mountainlion.net: An annotated bibliography. Found at http://www.mountainlion.net/ and accessed on January 1, 2007.

Logan, K.A. and Sweanor, L.L., 2001. Desert Puma: Evolutionary Ecology and Conservation of an Enduring Carnivore. Island Press, Washington D.C. 463.

Lotz, M. and Land, E. 2003. Florida Fish and Wildlife Conservation Commission Status Report. In Becker, S.A., Bjornlie, D.D, Lindzey, F.g., and Moody, D.S. eds. Proceedings of the Seventh Mountain Lion Workshop. Lander, Wyoming. P.18-24.

Pollema, Travis 2004. Report 36 [report on this skull and part of his senior individual studies project]. Available from James F. Mahaffy

Maehr, D. 1997. The Florida Panther: Life and death of a vanishing carnivore. Island Press, Washington, D.C. 262 p.

Sweanor, Linda L.; Logan, Kenneth A.; Hornocker, Maurice G.. 2000. Cougar Dispersal Patterns, Metapopulation Dynamics, and Conservation. Conservation Biology 14(3):1523-1739.



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Page created by James Mahaffy in December of 2004
File updated on:  January 1, 2008 (10:11 PM)