Demography and decline of the Mentasta caribou herd in Alaska

Jenkins, Kurt J.; Barten, N. L.
September 2005
Canadian Journal of Zoology;Sep2005, Vol. 83 Issue 9, p1174
Academic Journal
We evaluated population trends in the Mentasta caribou (Rangifer tarandus (L., 1758)) herd in Wrangell � St. Elias National Park and Preserve, Alaska, from 1990 to 1997 and determined factors contributing to its decline. We postulated that predation-related mortality of adult females and juveniles was the proximate cause of the decline, and that survival of juvenile caribou reflected interactions with winter severity, calving distribution, timing of births, density of caribou, and physical condition of neonates at birth. The population declined at its greatest rate from 1990 to 1993 (r = �0.32) and at a lower rate from 1994 to 1997 (r = �0.09). Recruitment (number of calves/100 females during September) averaged 4/100 during the rapid population decline from 1990 to 1993 and 13/100 from 1994 to 1997. Parturition rate of adult females ranged from 65% to 97%. Survival of adult females and juveniles ranged from 0.77 to 0.86 and from 0.00 to 0.22, respectively. Approximately 43%, 59%, and 79% of all juvenile mortality occurred by 1, 2, and 4 weeks of age, respectively. We confirmed predation-related mortality as the primary proximate cause of population decline, with gray wolves (Canis lupus L., 1758), bears (species of the genus Ursus L., 1758), and other predators accounting for 57%, 38%, and 5%, respectively, of all juvenile mortality, and bears causing disproportionate mortality among 0- to 1-week-old neonates. We supported the hypotheses that timing of birth and habitat conditions at the birth site, particularly mottled snow patterns, affected vulnerability and survival of neonates, and birth mass affected survival of juveniles through summer. We speculate that the population will continue to decline before reaching a low-density equilibrium that is sustained by density-dependent changes in the functional responses of predators.


Related Articles

  • The influence of lion predation on the population dynamics of common large ungulates in the Kruger National Park. Funston, P. J.; Mills, M. G. L. // South African Journal of Wildlife Research;2006, Vol. 36 Issue 1, p9 

    The impact of lion (Panthera leo) predation on buffalo (Syncerus caffer) and medium-sized ungulates over periods of changing environmental conditions in an area of the Kruger National Park was investigated. Lions were found to prey proportionally most heavily on the resident buffalo and...

  • Continued Gains and Growing Pains: A Look at Texas' Population Change Over the Past Decade.  // Perryman Report & Texas Letter;Apr2011, p1 

    The article examines the population growth in Texas from 1850 to 2010. There is an explosive population growth in the country which makes it the second most populous state in the U.S. as the number of Texans has reached 20.9 million in 2000. Much of the expansion is attributed to the minority...

  • GEODEMOGRAPHIC CHARACTERISTICS REGARDING THE POPULATION FROM THE SOUTHERN OLTENIA. Ceauşescu, Anca // Annals of the University of Craiova. Series Geography / Analele ;2011, Vol. 14, p90 

    The analysed geographic region knew an uninterrupted autochthon dwelling, starting with the Neolithic era and until nowadays. The numeric evolution of the rural population from this region, beginning with the 19th century, was similar to that from the national level. After a continuous ascendant...

  • Population Trends in Malaysia: 1970-2010. Rashid, Saharani Abdul; Ab Ghani, Puzziawati; Daud, Noorizam // AIP Conference Proceedings;2014, Vol. 1635, p875 

    The size of population in Malaysia had reached 28.3 million in 2010 and is expected to increase to 38.6 million in the next 30 years. This demographic milestone that is causing renewed attention to the challenges caused by population growth. This paper looks at the last 40 years of changes in...

  • A conceptual model for migratory tundra caribou to explain and predict why shifts in spatial fidelity of breeding cows to their calving grounds are infrequent. Gunn, Anne; Poole, Kim G.; Nishi, John S. // Rangifer;2012, Vol. 32 Issue 2, p259 

    Calving grounds of migratory tundra caribou (Rangifer tarandus) have two prominent characteristics. Firstly, the cows are gregarious, and secondly, the annual calving grounds spatially overlap in consecutive years (spatial fidelity). The location of consecutive annual calving grounds can...

  • LETTER FROM VIMER.  // Farmers Weekly;1/24/2003, Vol. 138 Issue 4, p78 

    Presents an article on the different activities in a farm during winter. Preparations done for Christmas; Information on the birth of a cow.

  • Calving Season Begins. McDaniel, Jeremiah // BEEF Exclusive Insight;3/8/2011, p7 

    The article discusses the impact of the March calving season on calves born in winter and early spring, such as the possibility of frozen ears, feet and tails.

  • The role of predation in the decline and extirpation of woodland caribou. Wittmer, Heiko U.; Sinclair, Anthony R. E.; McLellan, Bruce N.; Fryxell, John // Oecologia;Jul2005, Vol. 144 Issue 2, p257 

    To select appropriate recovery strategies for endangered populations, we must understand the dynamics of small populations and distinguish between the possible causes that drive such populations to low numbers. It has been suggested that the pattern of population decline may be inversely...

  • Genetic Feedback and Human Population Regulation. Hopfenberg, Russell // Human Ecology: An Interdisciplinary Journal;Oct2009, Vol. 37 Issue 5, p643 

    Human population growth has been identified as a primary cause of ecologically destructive phenomena and, if left unchecked, will threaten the survivability of the human species. It has been demonstrated that genetic feedback is the mechanism by which species achieve ecological balance. The...


Read the Article


Sign out of this library

Other Topics