More state-of-the-art tracking associated with GPS technology has revealed larger home ranges than that which we saw using radio tracking. Fine-scale movement data has revealed that most daily movements are short and within habitat patch; they infrequently move long distances to access new habitat patches; and they avoid steep slopes. Disturbances associated with human activities may have disproportionately-large effects on pandas and other species that move conservatively.
It is no surprise that loss- and fragmentation of suitable habitat is the leading threat, and cause of declines, for giant panda populations. These habitat losses were the result of rapid development in China, especially agricultural- and deforestation activities. The panda's range is subdivided into approximately 33 small populations separated by mountains, rivers, roads, forest clearings, and human settlements. Thus, panda populations are genetically vulnerable, and restoring habitat connectivity is critical for maintaining the species' evolutionary potential. Much attention has been directed to determine the extent, quality, and fragmentation, of the remaining panda habitat. Though the chinese government has established 67 protected areas, approximately 46% of the remaining habitat (harbouring one-third of the total panda population) remains unprotected.
Increased understanding of panda habitat and foraging requirements has allowed scientists to develop models predicting the impacts that climate change may have on pandas. These models all predict substantial habitat loss (up to 60% in some models), a decrease in food supplies, increased habitat fragmentation, and population movements to higher latitudes and altitudes. These models, however, hsave not addressed the panda's history. Prior to the excessive human encroachment onto panda habitat, pandas were distributed at much lower elevations in warmer climates, and consumed different species of bamboo (i.e. bamboo species that grow in warmer climates). It is reasonable to predict that, with a warming climate, more habitat will become available at elevations above the current range. Additionally, current panda habitat may become suitable for bamboo species currently thriving in lower latitudes and elevations. These bamboo species had sustained panda populations before pandas were displaced due to human activities. However, it is difficult to predict how human populations will respond to climate changes, and how these human responses will affect panda populations. Agriculture in China is currently limited by climate, and pandas have been allowed to thrive only at elevations above those suitable for productive agriculture. Climate change models predict that the agricultural value within current panda habitat will increase. Thus, it will be critical to increase protection in low-elevation panda habitat.
Giant pandas have a complex and sophisticated chemical communication system that conveys information about the identity, sex, age, reproductive condition, and competitive ability of the individual. Applying this knowledge has led to greatly-improved mating success for conservation breeding programs for pandas. Recent field research has revealed that pandas use a different habitat type (open-forest ridges) for communication than for foraging and other activities. If these open-forest ridges are not preserved, pandas may have difficulty coming together for mating.
Adequate dens are important for the survival of panda cubs. Pandas give birth every 2 or 3 years, rearing their offspring in a cave or tree den for the first few months. Recent evidence suggests that panda populations may be limited by the number of suitable den sites available in old-growth forests. Tree dens can only be found in these old-growth forests, where there exist trees large enough to contain a cavity of sufficient size. Tree dens may also provide better protection than cave dens, and a more-suitable microclimate for rearing cubs. Unfortunately, many panda reserves are dominated by second-growth forest, the old-growth having been logged. Artificial dens may be a practical way to address this problem in the short-term, and articial dens have begun being tested at the Foping Nature Reserve.
Additionally, new methods of genetic sampling from feces has provided a more accurate way to identify and count pandas. In one reserve, this has led to a population estimate more than two times greater than the previous estimate. Accurate population estimations allow for more-effective protection and management actions.
Of the 33 isolated subpopulations, only 6 contain more than 100 pandas. Anthropogenic threats that continue to damage and fragment panda habitat include roads, hydroelectric dams, mining, and tourism. Conservation efforts to increase habitat connectivity are currently in development. Additional necessities for effective conservation include experimental manipulations of bamboo forage, potential dens, and other limiting resources for giant panda populations.
LINK to Wei et al.'s 2015 article in Conservation Biology.
