Threats and Limiting Factors. Survival and Recovery Needs Conservation and Recovery Efforts to Date Covered Lands
Threats and Limiting Factors. Though they are no longer threatened by direct overexploitation from hunting or trapping, ocelots in Texas still face a variety of threats. Habitat loss from rapid development around the Rio Grande Valley of South Texas threatens remaining ocelot habitat (Xxxxxxxx et al. 2020). Habitat loss has caused isolation of the two Texas ocelot populations, which has led to low genetic diversity in Texas ocelots that could ultimately cause a loss of adaptive capacity and/or inbreeding depression (Xxxxxxx et al. 2011, 2014, 2016). Vehicle collisions are the largest known source of mortality for ocelots in Texas (Xxxxxxxxx et al. 2020, 2021, 2022; Xxxxxxx et al. 2021). Given the small population size and the range of threats that it faces, Xxxxxx et al. (2005b) projected that the Refuge Population has a 65% probability of going extinct within 100 years without effective recovery actions to support the population. These recovery actions include habitat expansion, genetic augmentation via translocations of ocelots, and measures to reduce road mortality (Xxxxxx et al. 2005b). Stochastic, catastrophic natural events such as severe droughts, wildfire, zoonotic disease outbreaks, sea-level rise, and major hurricanes - all of which may be exacerbated by future climate change - may also pose direct threats to the small coastal Texas ocelot populations. A large portion of the known ocelot populations exists in low elevation habitat (< 5 m above sea level). This is a concern for the persistence of Texas ocelots; due to climate change, sea levels are expected to rise by at least 1 foot in coastal areas by 2100 (Sweet et al. 2022) and tropical cyclone intensities and associated storm surges are expected to increase (Xxxxxxx et al. 2020). Further, recent natural disasters have emphasized the need to create an additional ocelot population that is geographically distinct from existing populations and any possible catastrophes they may face. These recent disasters include the Texas Drought of 2011, Hurricane Xxxxxx in 2017, Hurricane Xxxxx in 2020, and the Hayfield South and Oak Motte Wildfires in Willacy and Kenedy Counties in Spring 2022. Establishment of an additional ocelot population may provide a safeguard for the species’ persistence in Texas even in the face of climate change. Ocelots’ survival is dependent on sufficient availability of preferred cover, reproductive access, and availability of prey. Across their geographic range in the Americas, ocelots have been linked to a ...
Threats and Limiting Factors. The primary threats to NSO identified in the Revised Recovery Plan include competition from barred owls; ongoing loss of habitat as a result of timber harvest, wildfire, and other disturbances; and historical loss of habitat from past activities (USDI FWS 2011). The range- wide NSO population is estimated to have declined by 3.8 percent per year since 1985 and annual rates of decline have been accelerating in specific parts of the range (Xxxxxx et al. 2016). The decline of in the historic portion of its range is attributed to timber harvest and fragmentation of older forest stands across the landscape. Historical timber harvest and land- conversion caused an estimated 60-88 percent decline in NSO habitat from the 1800s until the time it was listed in 1990 (USDI FWS 2011). Forest fragmentation increased dramatically from the 1930s and 1940s through 2005 (Xxxxx and Lint 2005) as timber harvesting outpaced the development of structurally complex forests. The most recent assessment of range-wide trends in NSO habitat was based on the NWFP 20- year monitoring report that calculated changes on federal and non-federal lands from 1993 through 2012 (Xxxxx et al. 2015). The report concluded that the rate of habitat loss due to timber harvest on federal lands has declined since the listing of the species in 1990 and the implementation of the NWFP in 1994. This trend is significant because much of the high-quality habitat NSO use for nesting and roosting occurs on federal lands. However, large and severe wildfires continue to pose a risk. On federal lands, most of the nesting and roosting habitat loss (73 percent) was due to wildfire (Xxxxx et al. 2015). Although habitat loss due to timber harvesting has declined on federal lands under the NWFP, net habitat loss is still occurring, particularly from timber harvest on non-federal lands. Timber harvest accounted for 63 percent of the nesting and roosting habitat loss range-wide from 1993 through 2012 (Xxxxx et al. 2015). The barred owl also represents a significant threat to the NSO. With its recent expansion to as far south as Marin County, California along the Coast Range and Kings Canyon National Park in the southern Sierra Nevada, the barred owl’s range now completely overlaps that of the NSO (Xxxxxxxxx et al. 2004). Barred owls affect NSO through competition for resources, direct harm through aggressive behavior, and hybridization. Barred owls have severely reduced NSO site occupancy, reproduction, and survival b...
Threats and Limiting Factors. Though the xxxx xxxx population in the United States is expanding, habitat fragmentation, reduction of prey populations, and direct human contact remain threats to the species (CDFG 2011). The California Wolf Management Plan describes the main threats and limiting factors for the xxxx xxxx in California (Xxxxxx et al. 2016). Wolves are found only where conditions support an adequate prey base comprised primarily of ungulates, such as deer and elk. One of the primary limiting factors for wolf populations in California is the limited availability of large areas of habitat that are relatively undeveloped and have less chance for contact and conflict with humans. Most wolf packs appear particularly sensitive to human disturbance near den sites and may, depending upon the extent of the disturbance, abandon the den. The primary threats to wolves in California include human/livestock interaction that results in persecution of wolves and poaching.
