This Land Management Plan (LMP) was prepared as a guide for the California Department of Fish and Game (herein referred to as the Department) in the management, maintenance, and restoration of the biological diversity and ecosystem components currently and historically present within the 5,189-acre Hollenbeck Canyon Wildlife Area (HCWA). HCWA is located in south-central San Diego County between the communities of Jamul and Dulzura, approximately
26 miles east-southeast of downtown San Diego (Figure 1). It lies between the Jamul Mountains
to the west, Otay Mountain to the south, and the Cleveland National Forest to the northeast.
Hollenbeck Canyon Wildlife Area (HCWA), a 3,200-acre property historically used as cultivated agriculture and grazing lands, became part of the California Department of Fish and Game (CDFG) reserve system in 2001. Following this acquisition, the U. S. Geological Survey conducted surveys to establish baseline species data. Herpetofauna pitfall arrays and incidental sightings detected 2 amphibian species, 10 lizard species, and eight snake species. Twenty-eight ant species were recorded using ant pitfall traps co-located at the herpetofauna pitfall arrays. Bird point counts and incidental bird sightings recorded 104 bird species present at Hollenbeck Canyon Wildlife Area and the neighboring Rancho Jamul Ecological Reserve (RJER). Sherman live traps, combined with herpetofauna pitfall arrays small mammals captures, documented 14 small mammal species present at Hollenbeck Canyon Wildlife Area. Thus a total of 134 native vertebrate species, 28 native invertebrate species (ants) and four non-native vertebrate species were recorded during these surveys. Of these, one avifauna species is listed as a California Department of Fish and Game endangered species, two herpetofauna species, 14 avifauna species and three small mammal species are listed as California Department of Fish and Game Species of Special Concern, and two herpetofauna species and seven avifauna species are covered under the San Diego Multiple Species Conservation Program.
In 2014, 14 eggs and 11 adults (5 females and 6 males) were released in two different areas at
Hollenbeck Canyon Wildlife Area. Initial plans included releasing more individuals in 2014 as well as
supplementing these releases with similar numbers in 2015. Due to a continuing drought that has
suppressed adult butterfly numbers, the 2014 release numbers were lower than desired and we were
unable to conduct releases in 2015.
In FY 2011, the California Department of Fish and Game (DFG) funded this initial study by a Natural Community Conservation Plan (NCCP) Local Assistance Grant (LAG) to determine if badgers still persist in the western portion of San Diego County. Survey sites were prioritized according to three criteria; 1) areas with historical and/or recent badger records, 2) conserved lands with priority given to MSCP and Multiple Habitat Conservation Plan (MHCP) lands, and 3) areas containing moderate to abundant grassland habitat.
We conducted canine scent surveys for American badger scat using a specially trained canine scent team from Conservation Canines (Heath Smith and Pips; University of Washington) from November 14 to December 14, 2011. We surveyed for badger scat across 32 sites within San Diego County and two sites in southern Riverside County. Pips had positive behavioral responses to scat at 13 sites. Using a badger specific DNA test, we were able to verify the scat collected to be that of the American badger at twelve sites: Marine Corps Base Camp Pendleton (Juliett and Oscar One), Fallbrook Naval Weapons Station, Daley Ranch in Escondido, Ramona Grasslands, Warner Springs Ranch, Whelan Lake, Crestridge Ecological Reserve, Santa Ysabel Ecological Reserve, Hollenbeck Canyon Wildlife Area, Marron Valley, and the Santa Rosa Plateau.
Because badgers are present within the western portion of the County, they are a suitable species for assessing upland connectivity by means of radio-telemetry. As a priority for research, we recommend follow-up focused surveys to identify target areas for future live-trapping and telemetry and to better define any areas with higher densities of badgers. We recommend development of a microsat
We investigated the role of large-scale wildfires on the relative abundance of carnivores at two study areas within San Diego County of southern California, 1) Santa Ysabel Open Space Preserve and 2) Rancho Jamul Ecological Reserve-Hollenbeck Canyon Wildlife Area. In October and November of 2003, large-scale fires burned approximately 130,000 ha of San Diego County. To assess fire impacts on local carnivore communities, we collected data using two sampling techniques, 1) track surveys with baited scent stations and 2) remotely triggered camera stations. Sampling prior to the fires was conducted between May 2001 and June 2003, while post-burn sampling was conducted between August 2006 and September 2007. We calculated the relative abundance of carnivore species for each track transect and camera station, comparing pre-burn and post-burn abundance indices.
Fifteen medium to large mammal species were detected across Santa Ysabel and Rancho Jamul at track transects and camera stations. We detected 11 native species including mountain lion (Puma concolor), mule deer (Odocoileus hemionus), coyote (Canis latrans), bobcat (Felis rufus), badger (Taxidea taxus), gray fox (Urocyon cinereoargenteus), raccoon (Procyon lotor), striped skunk (Mephitis mephitis), spotted skunk (Spilogale gracilis), opossum (Didelphis virginiana), and
long-tailed weasel (Mustela frenata). We also detected four species typically associated with humans including, domestic cow (Bos taurus), domestic horse (Equus caballus), domestic dog (Canis familiaris), and domestic cat (Felis catus). Ten of the native species (badger excluded) and two human-associated species (domestic horse and domestic dog) were documented within both study sites. Within Santa Ysabel and Rancho Jamul, we found little evidence that the 2003 wildfires affected the relative abundance of the carnivore species for which we gathered sufficient data. Most of the species we studied seemed capable of persisting in the patchwork of unburned and burned
habitats resulting from these wildfires. In addition, the effects of the fires were likely short term for most carnivore species. We did not begin post-burn monitoring until nearly three years after the wildfires of 2003, by which time we likely missed the more dramatic immediate responses to wildfire. Overall, we suspect the indirect effects of wildfires, such as changes in habitat suitability and predator-prey dynamics, were largely responsible for the minor changes we observed
This review prioritizes infrastructure improvements of 35 existing undercrossings inspected by wildlife experts in the field along 14.6 miles of SR-94 where the highway bisects conserved lands—particularly between the San Diego National Wildlife Refuge (SDNWR), where a box culvert has been designed specifically for this undercrossing, between Rancho Jamul Ecological Reserve (RJER) and Hollenbeck Canyon Wildlife Area (HCWA), and between Bureau of Land Management (BLM) lands and the Lawrence and Barbara Daley Preserve (LB Daley). In total, SR-94 crosses >10 miles of conserved lands with only three bridges—at the Sweetwater River, Dulzura Creek, and Campus Grove bridge in Dulzura. Following is a summary of improvements recommended for existing undercrossings and proposed new undercrossings, by segment, presented in this document.
We investigated the role of large-scale wildfires on the community composition and
structure of foraging bats within San Diego County, California. In October and
November of 2003, large–scale wildfires burned nearly 130,000 hectares of San Diego
County. To assess the potential impacts of these fires on the native bat communities, we
conducted surveys at eleven sites within each of our two study areas, Rancho Jamul
Ecological Reserve - Hollenbeck Canyon Wildlife Area and Santa Ysabel Open Space
Preserve. At each study area a subset of these sites was sampled before the fires (2001-
2003) and a subset after the fires (2005-2006). Our pre-fire sampling efforts included
five survey techniques: active-Anabat, mist-netting, roost, visual, and audible. These
same five techniques were employed during the first year of post-fire sampling, 2005. In
2006, we altered our survey methods by discontinuing mist-netting and began using
passive-Anabat monitoring stations instead of an actively monitored station.
The County of San Diego owns or is in the process of acquiring key lands within the Multiple Species Conservation Program (MSCP) preserve area. The MSCP Biological Monitoring Plan requires monitoring of covered plant species. The County of San Diego was awarded two Natural Communities Conservation Planning (NCCP) Program Local Assistance Grants to accomplish the first phase of the monitoring program, i.e., collecting baseline data for covered plant species. The study area of this grant was amended to include lands in San Vicente (Boys and Girl?s Club) Ecological Reserve that were originally included in the statement of work for the NCCP Local Assistance grant No. P0050008. The lands in the total amended study area, from north to south are open space areas in Santa Fe Valley, County-owned portions of Lusardi Creek, open space areas conveyed to the County of San Diego in 4S Ranch, San Vicente Open Space Preserve, McGinty Mountain preserve lands, Hollenbeck Canyon Wildlife Area, and lands north and south of the eastern arm of Otay Lakes. Portions of Rancho Jamul Ecological Reserve were also surveyed.
This report summarizes our butterfly survey efforts of 2022. Additional analysis of habitat and
vegetation data for this project/task are planned for 2023. Based on these surveys in 2021, a subset of sites was selected to perform a mark-recapture
study and more accurately estimate population sites. Selected sites included Barrett Lake, Skye
Valley, Hollenbeck Canyon Wildlife Area, and Beaver Hollow (San Diego National Wildlife
Refuge). Not surprisingly, the number of marked individuals demonstrated larger populations
compared to the daily maximum count, but the number of adults were still low. Only a limited
number of individuals were recaptured, limiting our ability to accurately estimate population
sizes. Additionally, habitat sampling was conducted at several sites during the 2022 flight
season. These data, as well as GIS derived data, will be analyzed in 2023.
Overall, transect counts (visual observations) continue to describe small populations when
skippers are present. However, the large size and uneven terrain of some riparian oak
woodlands, patchy distribution of adult skippers, and shifting locations of San Diego sedge
present challenges to accurately categorizing presence/absence and relative population sizes.
We investigated the role of large-scale wildfires on the relative abundance of carnivores at
two study areas within San Diego County of southern California, 1) Santa Ysabel Open Space
Preserve and 2) Rancho Jamul Ecological Reserve-Hollenbeck Canyon Wildlife Area. In October
and November of 2003, large-scale fires burned approximately 130,000 ha of San Diego County. To
assess fire impacts on local carnivore communities, we collected data using two sampling
techniques, 1) track surveys with baited scent stations and 2) remotely triggered camera stations.
Sampling prior to the fires was conducted between May 2001 and June 2003, while post-burn
sampling was conducted between August 2006 and September 2007. We calculated the relative
abundance of carnivore species for each track transect and camera station, comparing pre-burn and
post-burn abundance indices.
Fifteen medium to large mammal species were detected across Santa Ysabel and Rancho
Jamul at track transects and camera stations. We detected 11 native species including mountain lion
(Puma concolor), mule deer (Odocoileus hemionus), coyote (Canis latrans), bobcat (Felis rufus),
badger (Taxidea taxus), gray fox (Urocyon cinereoargenteus), raccoon (Procyon lotor), striped
skunk (Mephitis mephitis), spotted skunk (Spilogale gracilis), opossum (Didelphis virginiana), and
long-tailed weasel (Mustela frenata). We also detected four species typically associated with humans
including, domestic cow (Bos taurus), domestic horse (Equus caballus), domestic dog (Canis
familiaris), and domestic cat (Felis catus). Ten of the native species (badger excluded) and two
human-associated species (domestic horse and domestic dog) were documented within both study
sites.
Within Santa Ysabel and Rancho Jamul, we found little evidence that the 2003 wildfires
affected the relative abundance of the carnivore species for which we gathered sufficient data. Most
of the species we studied seemed capable of persisting in the patchwork of unburned and burned
habitats resulting from these wildfires. In addition, the effects of the fires were likely short term for
most carnivore species. We did not begin post-burn monitoring until nearly three years after the
wildfires of 2003, by which time we likely missed the more dramatic immediate responses to
wildfire. Overall, we suspect the indirect effects of wildfires, such as changes in habitat suitability
and predator-prey dynamics, were largely responsible for the mi
