Cougar Dispersal Patterns, Metapopulation Dynamics, and Conservation

Abstract: We examined cougar (   Puma concolor ) dispersal, emigration, and immigration in the San Andres Mountains, New Mexico, from 1985 to 1995 to quantify the effects of dispersal on the local population and surrounding subpopulations. We captured, tagged, and radio-collared animals to detect the arrival of new immigrants and dispersal characteristics of progeny. We found that cougars in southern New Mexico exhibited a metapopulation structure in which cougar subpopulations were separated by expanses of noncougar habitat and linked by dispersers. Of 43 progeny (n = 20 males , 23 females ) studied after independence, only 13 females exhibited philopatric behavior. Males dispersed significantly farther than females, were more likely to traverse large expanses of noncougar habitat, and were probably most responsible for nuclear gene flow between habitat patches. We estimated that an average of 8.5 progeny (i.e., cougars born in the study area) successfully emigrated from and 4.3 cougars successfully immigrated to the San Andres Mountains each year. Concurrently, an average of 4.1 progeny were recruited into the San Andres cougar population. Protected cougar subpopulations can contribute to metapopulation persistence by supplying immigrants to surrounding subpopulations that are affected by fragmentation or offtake by humans. Cougar population dynamics and dispersal behavior dictate that cougar management and conservation should be considered on a regional scale.     

Nitrogen removal efficiencies and microbial communities in full-scale IFAS and MBBR municipal wastewater treatment plants at high COD:N ratio

• Two IFAS and two MBBR full-scale systems (high COD:N ratio 8:1) were characterized. • High specific surface area carriers grew and retained slow-growing nitrifiers. • High TN removal is related to high SRT and low DO concentration in anoxic tanks. The relative locations of AOB, NOB, and DNB were examined for three different kinds of carriers in two types of hybrid biofilm process configurations: integrated fixed-film activated sludge (IFAS) and moving bed biofilm reactor (MBBR) processes. IFAS water resource recovery facilities (WRRFs) used Anodkalness^TM K1 carriers (KC) at Broomfield, Colorado, USA and polypropylene resin carriers (RC) at Fukuoka, Japan, while MBBR WRRFs used KC carriers at South Adams County, Colorado, USA and sponge carriers (SC) at Saga, Japan. Influent COD to N ratios ranged from 8:1 to 15:1. The COD and BOD removal efficiencies were high (96%–98%); NH₄⁺-N and TN removal efficiencies were more varied at 72%–98% and 64%–77%, respectively. The extent of TN removal was higher at high SRT, high COD:N ratio and low DO concentration in the anoxic tank. In IFAS, RC with high specific surface area (SSA) maintained higher AOB population than KC. Sponge carriers with high SSA maintained higher overall bacteria population than KC in MBBR systems. However, the DNB were not more abundant in high SSA carriers. The diversity of AOB, NOB, and DNB was fairly similar in different carriers. Nitrosomonas sp. dominated over Nitrosospira sp. while denitrifying bacteria included Rhodobacter sp., Sulfuritalea sp., Rubrivivax sp., Paracoccus sp., and Pseudomonas sp. The results from this work suggest that high SRT, high COD:N ratio, low DO concentration in anoxic tanks, and carriers with greater surface area may be recommended for high COD, BOD and TN removal in WRRFs with IFAS and MBBR systems.     

Work—family conflict: A comparison of dual-career and traditional-career men

This research examines differences in the antecedents and consequences of work—family conflict — a form of interrole conflict that occurs when the demands of work and family are mutually incompatible in some respect — for two groups of career-oriented men: those with a homemaker wife (called traditional-career men) and those with a spouse in a career-oriented job (labelled dual-career men). Using a model built on the work of Kopelman, Greenhaus and Connolly (1983), the responses from 136 dual-career men and 137 traditional-career men were compared. The primary conclusion of this research is that maternal career employment has a significant effect on the antecedents of work — family conflict. Dual-career men appear to experience a significant negative spillover from their work domain. We suggest that this spillover is due to a lack of structural flexibility in the workplace, outdated organizational policies that operate on the myth of separate worlds' and a lack of social support for the male dual-career role which contradicts societal norms.     

Integrating forage,wildlife, water,and fish projections with timber projections at the regional level: A case study in southern United States

The impact of timber management and land-use change on forage production, turkey and deer abundance, red-cockaded woodpecker colonies, water yield, and trout abundance was projected as part of a policy study focusing on the southern United States. The multiresource modeling framework used in this study linked extant timber management and land-area policy models with newly developed models for forage, wildlife, fish, and water. Resource production was integrated through a commonly defined land base that could be geographically partitioned according to individual resource needs. Resources were responsive to changes in land use, particularly human-related, and timber management, particularly the harvest of older stands, and the conversion to planted pine.     

Maternal serum human chorionic gonadotropin levels in twin pregnancies

Introduction of combined screening with maternal serum alpha-fetoprotein and human chorionic gonadotropin (MShCG) assays for fetal chromosome defects requires establishment of the normal range for twins. This report documents that the normal range for MShCG between 15 and 19 weeks in twin gestations was 1.84–2.41 multiples of the singleton median. Of the 192 twin pregnancies studied, 31.7 and 47.9 per cent had MShCG values ≥2.5 and ≥ 2.0 multiples of the singleton median, respectively.     

First-trimester maternal serum alpha-fetoprotein and human chorionic gonadotropin screening for chromosome defects

The aim of this study was to determine the efficacy of combined maternal serum alpha-fetoprotein (MSAFP) and maternal serum human chorionic gonadotropin (MShCG) screening in detecting chromosome defects in the first trimester of pregnancy. Sera of 492 women (previously assayed for MSAFP) were analysed for MShCG under code without knowledge of cytogenetic results. Overall, 48 of 492 patients (9·8 per cent) had either an MSAFP multiple of the median ⩽0·5 or an MShCG β/a z ratio multiple of the median ⩽ 0·25, eight of whom had a fetus with a serious chromosome defect. A third of fetuses with Down' s syndrome and 83 per cent with trisomy 18 were detected at a potential‘cost’ of providing chorionic villus sampling or amniocentesis in 8·6 percent of women screened.     

Long-term movements of tiger sharks satellite-tagged in Shark Bay,Western Australia

Tiger sharks are important predators in the seagrass ecosystem of Shark Bay, Australia. Although sharks appear to return to a long-term study site within the Eastern Gulf periodically, the extent of their long-term movements is not known. Five sharks fitted with satellite transmitters showed variable movement patterns. Three sharks remained within the Shark Bay region and another made a 500 km round-trip excursion to oceanic waters northwest of the bay. These four sharks showed relatively low displacement rates relative to sharks tracked over shorter time periods, suggesting that sharks move through large home ranges that include Shark Bay. Although no reliable position fixes were obtained for the fifth shark, we were able to use the timing of satellite uplinks and the position of the satellite to determine that it had moved at least 8,000 km to the coastal waters of southeast Africa in 99 days—the longest recorded movement by a tiger shark. This movement and previously documented trans-Atlantic movements suggest that tiger shark populations may mix across ocean basins and that tiger sharks are subject to anthropogenic effects at great distances from protected waters. Finally, our method for using single satellite uplinks may be useful in estimating movements for wide-ranging species that rarely provide high quality location estimates.     

Subordinate males are more likely to help if unrelated to the breeding female in cooperatively breeding white-browed scrubwrens

Subordinates in communally breeding groups of birds usually help to provision nestlings, but in some species helping-at-the-nest is facultative. In species in which groups usually contain relatives, subordinates either always feed young or are more likely to do so when breeding dominants are close relatives, suggesting that benefits of helping collateral kin are important. In other species, adult group members are unrelated to each other and males may only feed young if they have gained paternity, showing that cooperation is related to the mating system. The white-browed scrubwren, Sericornis frontalis, is a communally breeding species in which most groups consist of a simple pair or a dominant pair with a subordinate male. Subordinate males either fed nestlings in a given nest at a rate comparable to the dominants, or did not feed them at all. Breeding groups usually formed through natal philopatry of males, so that about 80% of subordinates were closely related to one or both members of the dominant pair. However, because of death and dispersal, 54% of subordinates were unrelated to the resident female. Although subordinates with their mother fed nestlings in 48% of cases, they fed offspring in 75% of cases if their mother had been replaced by an unrelated female, suggesting that their decision to help is influenced by the opportunity to mate with the female. Supporting this conclusion, relatedness to the dominant male did not affect subordinate behaviour, and genetic studies showed that subordinates often gained paternity if unrelated to the female. Thus, paradoxically, provisioning nestlings is related to the opportunity for mating in a society in which there is natal philopatry and subordinates are usually related to one or both members of the dominant pair. Received: 25 January 1997 / Accepted after revision: 1 May 1997