Charles D. Hathcock

DEVELOPMENT OF A PREDICTIVE MODEL FOR HABITAT OF THE MEXICAN SPOTTED OWL IN NORTHERN NEW MEXICO

Abstract The Mexican spotted owl (Strix occidentalis lucida) was listed as a threatened species under the Endangered Species Act in 1993. We developed a predictive, vegetation-based model for habitat of the species in the Jemez Mountains, New Mexico, using logistic-regression modeling techniques and analyzed seven habitat variables with six of the variables included in the final model. A plot analysis using Receiver Operating Characteristics indicated a high performance of the model, and validation of the model confirmed proper function. Compared with random unoccupied sites, the model indicates that owls in the Jemez Mountains prefer habitat with greater diversity, density, and height of trees, canopy cover, and shrub density, which is in agreement with much of the literature on biology of the Mexican spotted owl. This model can be used with fine-scale assessments of habitat for land-management agencies that have a priority to accurately delineate habitat of the Mexican spotted owl. Los Alamos National Laboratory will use this model to re-delineate habitat of owls to reduce assessment costs and to better protect appropriate habitat.

Hazards to Birds from Open Metal Pipes

Abstract. There are reports of open polyvinyl chloride (PVC) pipes causing bird deaths in the western United States (Brattstrom 1995). Here, we document cases of open bollards and open pipes on gates causing bird deaths in northern New Mexico. At Los Alamos National Laboratory (LANL), a 10,240-ha site, over 100 uncapped 10.16 cm diameter protective bollard posts were examined, and 27% of the open bollards contained dead birds. A total of 88 open pipes used as gate posts, with diameters of 8.89 cm or 10.16 cm, were examined, and 11% contained dead birds. We conducted a preliminary assessment of open pipes on gates along a highway on federal land north of LANL, and 14% of the open pipes contained dead birds. This gate configuration, with open pipes anchoring the gate on either side, is very common in the western United States. In all cases, Western Bluebirds (Sialia mexicana) composed the majority of the identifiable birds we discovered. Based on these preliminary findings, the number of bird deaths from this source is potentially very large and should be a concern in bird conservation and management.

Organic Chemical Concentrations in Eggs and Nestlings of Cavity Nesting Birds at and around Los Alamos National Laboratory

In 1943, Los Alamos National Laboratory (LANL) was established as part of the Manhattan project to design atomic weapons. LANL now operates as a multidisciplinary research institution. As part of an ongoing assessment of siterelated ecological risk, organochlorine pesticides, their metabolites, polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), and 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) were evaluated in western bluebird (Sialia mexicana) and ash-throated flycatcher (Myiarchus cinerascens) eggs relative to a developed but non-industrial reference area; PCBs and TEQs were also evaluated in nestlings. Chemicals were below detection limits in the majority of samples. Western bluebird eggs collected from the study area had significantly lower concentrations of dieldrin, oxychlordane, and trans-nonachlor when compared with eggs from the reference area. No differences were observed in concentrations of dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyltrichloroethane (DDT), and heptachlor epoxide. Ash-throated flycatcher eggs contained higher total TEQ concentrations when compared with western bluebird eggs; however, no differences in concentrations of DDE, DDT, dieldrin, or total PCBs were observed. No differences were observed in total PCBs or TEQs in nestlings between the two species. Western bluebird eggs contained higher levels of total PCBs and TEQs when compared with nestlings; no differences were observed in total PCBs or TEQs between ash-throated flycatcher eggs and nestlings. Chemical concentrations detected in eggs of both species were below levels that are associated with adverse effects reported in the scientific literature, suggesting that concentrations of organic chemicals observed here appear to be at levels causing negligible risks to local bird populations.

Morphology and sexual dimorphism of the many-lined skink in north central New Mexico

Abstract. In 2001 and 2002, a study of many-lined skinks (Plestiodon multivirgatus) was conducted by Los Alamos National Laboratory biologists in north-central New Mexico to determine means and ranges for several morphological characters and to test for sexual dimorphism. Over both years, there were 539 new captures of many-lined skinks, which included 131 Hatchlings. The earliest hatchling capture was on 19 June and the latest capture was on 31 August. Hatchling captures peaked on 1 August in 2001 and 6 August in 2002. The age class, sex, snout—vent length (SVL), tail length (TL), mass, head length (HL), and head width (HW) were recorded and individuals were released at the point of capture. Our results indicate that the SVL, mass, HL, and HW did not exhibit sexual dimorphism. The sex ratio was skewed toward females in this study. It is not known whether the many-lined skink has sexual determination based on environmental factors, but the data here suggest that more research is needed. From these observations, we supplement the limited existing knowledge on the morphology of this species.

Threatened and Endangered Species Habitat Management Plan for Los Alamos National Laboratory

Los Alamos National Laboratory’s (LANL) Threatened and Endangered Species Habitat Management Plan (HMP) fulfills a commitment made to the U.S. Department of Energy (DOE) in the “Final Environmental Impact Statement for the Dual-Axis Radiographic Hydrodynamic Test Facility Mitigation Action Plan” (DOE 1996). The HMP received concurrence from the U.S. Fish and Wildlife Service (USFWS) in 1999 (USFWS consultation numbers 2-22-98-I-336 and 2-22-95-I-108). This 2015 update retains the management guidelines from the 1999 HMP for listed species, updates some descriptive information, and adds the New Mexico Meadow Jumping Mouse (Zapus hudsonius luteus) and Yellow-billed Cuckoo (Coccyzus americanus) which were federally listed in 2014 (Keller 2015: USFWS consultation number 02ENNM00- 2015-I-0538).