For part of their final grade in Conservation Biology, my students are writing blogs about their final papers. Always on point, Allison Roth has handed hers in early. I hope you enjoy her essay on the importance of understanding territoriality in conservation -JAD
In 1965, it was predicted that animal behavior would become a critical part of wildlife management in the following quarter century (Stokes & Balph, 1965). Indeed, by the 1970s and 1980s, behavioral ecologists had begun to leave their mark on the way management decisions were being made (see Butzler, 1972; Halls, 1984; Hutchins & Geist, 1987; Kurt, 1970; Schafer, 1973; Wallmo, 1981), and in recent years, behavioral studies have continued to impact such decisions (Festa-Bianchet & Apollonio, 2003). Territoriality is an important aspect of animal behavior that may need to be taken into consideration when developing plans for conservation management.
Territoriality is generally defined in one of two ways. There are some scientists that argue that territoriality requires individuals or groups to hold exclusive use over an area (Pitelka, 1959). Others believe that the term territoriality entails the defense of a specific area from other animals (Howard, 1920; Low, 1971; Murray 1971; Noble, 1939; Orians & Willson, 1964; Reed, 1982; Tynkkynen et al., 2006). Regardless of which definition is used, territoriality allows individuals or groups to monopolize vital resources in a given location (Stamps, 1994).
Human activity can force animals into areas that they are unfamiliar with, and this may increase the probability of an individual’s demise since these unfamiliar locations may not contain the resources animals need to survive and reproduce (Young & Isbell, 1994). Additionally, an animal’s unfamiliarity with a new environment may lead to its death simply because the animal does not know where to find food, water, or shelter in their new environment (Hutchins & Geist, 1987; Isbell, 1990; O’Bryan & McCullough, 1985; Smith & Raedeke, 1982). In territorial species, displacement may also increase the number of territorial disputes seen in a population as individuals or groups may be forced to try to usurp part of a neighboring territory to compensate for human incursion into their own land. Similarly, if human activities such as harvesting of forest products reduce resource levels within territories below those required for a resident’s survival and reproduction, territory holders may be forced to attempt to expand their territories.
Let’s examine two cases where information about the territorial or home range behavior of a species could help scientists develop more effective management strategies.
1. Heermann’s gulls
On Isla Rasa in the Gulf of California, breeding pairs of Heermann’s gulls form territories in close proximity to one another (Anderson & Keith, 1980). Tourists and local recreationists commonly walk through or near these bird’s territories, temporarily forcing individuals into neighboring territories (Anderson & Keith, 1980). Heermann’s gulls are extremely territorial, and chicks that are driven into neighboring territories are often killed (Anderson & Keith, 1980). In this case, even brief displacement creates irreversible consequences.
As of 1980, this species had already been declining for 9 years (Anderson & Keith, 1980). If conservation managers would have taken the territorial behavior of these birds into consideration, it is possible that this population decline would have been mitigated. Although I cannot find any updates with regards to this situation, I believe that if the situation has not yet been remedied, further deterioration is easily preventable by the addition of paved paths that avoid the breeding territories of these gulls.
2) Banded mongoose
In Queen Elizabeth National Park in Uganda, garbage dumps provide groups of banded mongoose with additional access to food. Gilchrist and Otali (2002) found that the spatial use patterns of mongoose groups that fed at garbage dumps were different from those that did not feed at garbage dumps (Gilchrist and Otali, 2002). Additionally, Gilchrist and Otali (2002) found that intergroup encounter rates were significantly higher in groups that shared a garbage dump than those that did not (Gilchrist and Otali, 2002). Because maintaining the natural balance of ecosystems is generally a primary goal of national parks, in this case, park managers should strive to eliminate dump sites as they result in behavioral changes in mongoose groups (Gilchrist & Otali, 2002).
Animal behavior has become an important consideration in conservation management, and I believe that territoriality is one facet of animal behavior that warrants our attention as conservation biologists.
Anderson, D. W., & Keith, J. O. (1980). The human influence on seabird nesting success: conservation implications. Biological Conservation, 18(1), 65-80.
Butzler, W., 1972: Rotwild. BLV Verlagsgesellschaft, Munich.
Festa-Bianchet, M., & Apollonio, M. (2003). Animal behavior and wildlife conservation. Island Press.
Gilchrist, J. S., & Otali, E. (2002). REGULAR ARTICLES/ARTICLES RÉGULIERS The effects of refuse-feeding on home-range use, group size, and intergroup encounters in the banded mongoose. Canadian journal of zoology, 80(10), 1795-1802.
Halls, L. K. (1984). White-tailed Deer. Stackpole Books, Harrisburg, Pennsylvania.
Howard, H. E. (1920). Territory in Bird Life. London: John Murray.
Hutchins, M., & Geist, V. (1987). Behavioural considerations in the management of mountain-dwelling ungulates. Mountain Research and Development, 135-144.
Isbell, L. A. (1990). Sudden short‐term increase in mortality of vervet monkeys (Cercopithecus aethiops) due to leopard predation in Amboseli National Park, Kenya. American Journal of Primatology, 21(1), 41-52.
Kurt, F., 1970: Rewild. BLV Verlagsgeschaft, Munich.
Low, R. M. (1971). Interspecific territoriality in a pomacentrid reef fish, Pomacentrus flavicauda Whitley. Ecology, 648-654.
Murray Jr, B. G. (1971). The ecological consequences of interspecific territorial behavior in birds. Ecology, 414-423.
Noble, G. K. (1939). The role of dominance in the social life of birds. The Auk, 56(3), 263-273.
O’bryan, M. K., & McCullough, D. R. (1985). Survival of black-tailed deer following relocation in California. The Journal of wildlife management, 49(1), 115-119.
Orians, G. H., & Willson, M. F. (1964). Interspecific territories of birds. Ecology, 736-745.
Pitelka, F. A. (1959). Numbers, breeding schedule, and territoriality in Pectoral Sandpipers of northern Alaska. The Condor, 61(4), 233-264.
Reed, T. M. (1982). Interspecific territoriality in the chaffinch and great tit on islands and the mainland of Scotland: playback and removal experiments. Animal behaviour, 30(1), 171-181.
Schaefer, E., 1973: Hagen und Ansprechen von Rewild. BLV Verlag, Munich.
Smith, C. A., & Raedeke, K. J. (1982). Group size and movements of a dispersed, low density goat population with comments on inbreeding and human impact. In Proceedings of the Biennial Symposium of the Northern Wild Sheep and Goat Council (Vol. 3, pp. 54-67).
Stamps, J. (1994). Territorial behavior: testing the assumptions. Advances in the Study of Behavior, 23, 173-232.
Stokes, A. W. and Balph, D. F. (1965). The relation of animal behavior to wildlife management. North American Wildlife Conference Transactions, 30: 401-410.
Tynkkynen, K., Kotiaho, J. S., Luojumäki, M., & Suhonen, J. (2006). Interspecific territoriality in Calopteryx damselflies: the role of secondary sexual characters. Animal behaviour, 71(2), 299-306.
Wallmo, O. C. (1981). Mule and Black-tailed Deer of North America. University of Nebraska Press, Lincoln, Nebraska.
Young, T. P., & Isbell, L. A. (1994). Minimum group size and other conservation lessons exemplified by a declining primate population. Biological Conservation, 68(2), 129-134.