Workshop Summary: Developing Northern Bobwhite Management Plans - A Habitat-Based Framework

Successful northern bobwhite (Colinus virginianus) management is a complex and often expensive process that requires careful planning and a well-designed habitat management program. Written management plans are often used by landowners who wish to maximize quail populations on their property. Although management plans are as varied as the individuals who write them, a successful plan should: (1) be chronologically based, (2) contain an associated budget, and; (3) combine the objectives of the landowner with the limitations and potential of the individual property. The goal of a management plan is to insure that habitat modifications proceed in a well-designed, cost-effective, and orderly fashion. Although this paper focuses on developing management plans for northern bobwhite, the concepts presented here can be used to develop management plans for other species of quails in the United States

Survival of Northern Bobwhite Infected with Avian Pox

Avian pox is an enzootic disease among northern bobwhite (Colinus virginianus) in the southeastern United States, but occasionally it occurs as local or regional epizootics. Little information exists concerning survival of wild bobwhite infected with this disease. During the winters of 1985 and 1986, we compared survival of radio-tagged bobwhite with and without pox lesions. Pox lesions were considered wet or dry depending on field evaluations. The incidence of pox was greater in 1985 (x1=\u27 16.536, df= 1, P\u3c 0.005) than in 1986. Bobwhite with wet pox lesions weighed less than those with dry pox (t = 2.550, P = 0.014) or no pox (t = 2.393, P = 0.018). In 1985 6-week survivorship of bobwhite showing signs of wet pox was different compared to those with dry pox (Z = 1. 7 498, P = 0.0402) and no pox (Z = 2.9992, P = 0.0014). Survivorship of birds with dry pox and no pox was not different (Z = 0.6460, P = 0.2611. Bobwhite with wet pox in 1985 had 45.6 and 53.3% overall lower 6-week survival rates than birds with dry and no pox, respectively. No difference in survivorship existed between bobwhite with dry pox and those with no pox in 1986 (Z = 1.1727, P= 0.1210). No difference in predatory agents responsible for mortalities between birds with or without pox occurred (X2 = 0.8851, df= 2, P\u3e 0.05). All mortality of infected birds appeared to be caused by predation and not the disease itself. Implications of these data for inter- and intraspecific disease transmission are discussed

Potential Polygamous Breeding Behavior in Northern Bobwhite

Breeding behavior ofradio-tagged northern bobwhite (Colinus uirginianus) was observed at Fort Bragg Military Reservation (n = 19), North Carolina, in 1985-88, and Tall Timbers Research Station (n = 27), Florida, during 1984-86. We observed apparent polygamous breeding behavior in 95% (18 of 19) of the radio-tagged northern bobwhite at Fort Bragg, and 93% (25 of 27) of the birds at Tall Timbers. We documented 5 cases of double-clutching by radio-tagged females. Twenty-seven percent of Fort Bragg clutches (n = 30), and 20% of Tall Timbers clutches (n = 56) were incubated by radio-tagged males. Northern bobwhite exhibited characteristics of both rapid multiclutch and am bisexual polygamous mating systems. Northern bobwhite are capable of uniparental care, have long breeding seasons, live in an environment with fluctuating resources, suffer high predation pressure during the nesting season, and raise precocial young; all traits that are similar to other bird species which have evolved polygamous mating systems

Reproduction of Relocated and Resident Northern Bobwhites in East Texas

We examined reproduction by relocated and resident northern bobwhites (Colinus virginianus) on an intensively managed 563-ha study area in Trinity County, eastern Texas. During the late winters of 1990-1992, 155 South Texas (84 hens, 71 cocks) and 136 East Texas (64 hens, 72 cocks) bobwhites were captured, radio-tagged, and relocated to the study area; 139 resident birds (73 hens, 66 cocks) were also captured, radio-tagged, and released at the point of capture. For the 3 years combined, the 33 South Texas, 33 East Texas, and 39 resident hens alive at the beginning of the breeding season produced 6, 13, and 22 documented nests (P = 0.004) and 0, 3, and 4 fledged broods. Pooled, the number of nests by East Texas and resident hens was higher than that of South Texas hens (P = 0.003); numbers of nests of East Texas and resident hens were similar (P = 0.150). Our results do not support relocation of South Texas bobwhites into the East Texas Pineywoods

Survival and Causes of Mortality of Relocated and Resident Northern Bobwhites in East Texas

We estimated survival of 3 groups of northern bobwhites (Colinus virginianus) on a 563-ha intensively managed study area in eastern Texas. During the 3-year study, 155 bobwhites from South Texas and 136 bobwhites from East Texas were captured, radio-marked, and relocated to the study area; 139 bobwhites that were resident on the study area were also captured, radio-marked, and released at the point of capture. There were no differences (P \u3e 0.05) in survival among the 3 groups of bobwhites. However, survival of bobwhites from South Texas were consistently lower than those of the other 2 groups during each year; both bobwhites from East Texas and resident bobwhites survived better than bobwhites relocated from South Texas. Avian predation claimed 57.6% of 243 known-fate birds, mammalian predation and apparent capture stress each caused 9.1 % mortality, while 1.2% of the birds died of snake predation and 14.0% were lost to unidentifiable causes

Survival and Causes of Mortality of Relocated and Resident Northern Bobwhites in East Texas

We estimated survival of 3 groups of northern bobwhites (Colinus virginianus) on a 563-ha intensively managed study area in eastern Texas. During the 3-year study, 155 bobwhites from South Texas and 136 bobwhites from East Texas were captured, radio-marked, and relocated to the study area; 139 bobwhites that were resident on the study area were also captured, radio-marked, and released at the point of capture. There were no differences (P \u3e 0.05) in survival among the 3 groups of bobwhites. However, survival of bobwhites from South Texas were consistently lower than those of the other 2 groups during each year; both bobwhites from East Texas and resident bobwhites survived better than bobwhites relocated from South Texas. Avian predation claimed 57.6% of 243 known-fate birds, mammalian predation and apparent capture stress each caused 9.1 % mortality, while 1.2% of the birds died of snake predation and 14.0% were lost to unidentifiable causes

Reproduction of Relocated and Resident Northern Bobwhites in East Texas

We examined reproduction by relocated and resident northern bobwhites (Colinus virginianus) on an intensively managed 563-ha study area in Trinity County, eastern Texas. During the late winters of 1990-1992, 155 South Texas (84 hens, 71 cocks) and 136 East Texas (64 hens, 72 cocks) bobwhites were captured, radio-tagged, and relocated to the study area; 139 resident birds (73 hens, 66 cocks) were also captured, radio-tagged, and released at the point of capture. For the 3 years combined, the 33 South Texas, 33 East Texas, and 39 resident hens alive at the beginning of the breeding season produced 6, 13, and 22 documented nests (P = 0.004) and 0, 3, and 4 fledged broods. Pooled, the number of nests by East Texas and resident hens was higher than that of South Texas hens (P = 0.003); numbers of nests of East Texas and resident hens were similar (P = 0.150). Our results do not support relocation of South Texas bobwhites into the East Texas Pineywoods

Locomotor adaptability in persons with unilateral transtibial amputation

Background Locomotor adaptation enables walkers to modify strategies when faced with challenging walking conditions. While a variety of neurological injuries can impair locomotor adaptability, the effect of a lower extremity amputation on adaptability is poorly understood. Objective Determine if locomotor adaptability is impaired in persons with unilateral transtibial amputation (TTA). Methods The locomotor adaptability of 10 persons with a TTA and 8 persons without an amputation was tested while walking on a split-belt treadmill with the parallel belts running at the same (tied) or different (split) speeds. In the split condition, participants walked for 15 minutes with the respective belts moving at 0.5 m/s and 1.5 m/s. Temporal spatial symmetry measures were used to evaluate reactive accommodations to the perturbation, and the adaptive/de-adaptive response. Results Persons with TTA and the reference group of persons without amputation both demonstrated highly symmetric walking at baseline. During the split adaptation and tied post-adaptation walking both groups responded with the expected reactive accommodations. Likewise, adaptive and de-adaptive responses were observed. The magnitude and rate of change in the adaptive and de-adaptive responses were similar for persons with TTA and those without an amputation. Furthermore, adaptability was no different based on belt assignment for the prosthetic limb during split adaptation walking. Conclusions Reactive changes and locomotor adaptation in response to a challenging and novel walking condition were similar in persons with TTA to those without an amputation. Results suggest persons with TTA have the capacity to modify locomotor strategies to meet the demands of most walking conditions despite challenges imposed by an amputation and use of a prosthetic limb

A Subset of Latency-Reversing Agents Expose HIV-Infected Resting CD4⁺ T-Cells to Recognition by Cytotoxic T-Lymphocytes

Resting CD4⁺ T-cells harboring inducible HIV proviruses are a critical reservoir in antiretroviral therapy (ART)-treated subjects. These cells express little to no viral protein, and thus neither die by viral cytopathic effects, nor are efficiently cleared by immune effectors. Elimination of this reservoir is theoretically possible by combining latency-reversing agents (LRAs) with immune effectors, such as CD8⁺ T-cells. However, the relative efficacy of different LRAs in sensitizing latently-infected cells for recognition by HIV-specific CD8⁺ T-cells has not been determined. To address this, we developed an assay that utilizes HIV-specific CD8⁺ T-cell clones as biosensors for HIV antigen expression. By testing multiple CD8⁺ T-cell clones against a primary cell model of HIV latency, we identified several single agents that primed latently-infected cells for CD8⁺ T-cell recognition, including IL-2, IL-15, two IL-15 superagonists (IL-15SA and ALT-803), prostratin, and the TLR-2 ligand Pam₃CSK₄. In contrast, we did not observe CD8⁺ T-cell recognition of target cells following treatment with histone deacetylase inhibitors or with hexamethylene bisacetamide (HMBA). In further experiments we demonstrate that a clinically achievable concentration of the IL-15 superagonist ‘ALT-803’, an agent presently in clinical trials for solid and hematological tumors, primes the natural ex vivo reservoir for CD8⁺ T-cell recognition. Thus, our results establish a novel experimental approach for comparative evaluation of LRAs, and highlight ALT-803 as an LRA with the potential to synergize with CD8⁺ T-cells in HIV eradication strategies.United States. National Institutes of Health (AI111860

Histone Deacetylase Inhibitors Impair the Elimination of HIV-Infected Cells by Cytotoxic T-Lymphocytes

Resting memory CD4+ T-cells harboring latent HIV proviruses represent a critical barrier to viral eradication. Histone deacetylase inhibitors (HDACis), such as suberanilohydroxamic acid (SAHA), romidepsin, and panobinostat have been shown to induce HIV expression in these resting cells. Recently, it has been demonstrated that the low levels of viral gene expression induced by a candidate HDACi may be insufficient to cause the death of infected cells by viral cytopathic effects, necessitating their elimination by immune effectors, such as cytotoxic T-lymphocytes (CTL). Here, we study the impact of three HDACis in clinical development on T-cell effector functions. We report two modes of HDACi-induced functional impairment: i) the rapid suppression of cytokine production from viable T-cells induced by all three HDACis ii) the selective death of activated T-cells occurring at later time-points following transient exposures to romidepsin or, to a lesser extent, panobinostat. As a net result of these factors, HDACis impaired CTL-mediated IFN-γ production, as well as the elimination of HIV-infected or peptide-pulsed target cells, both in liquid culture and in collagen matrices. Romidepsin exerted greater inhibition of antiviral function than SAHA or panobinostat over the dose ranges tested. These data suggest that treatment with HDACis to mobilize the latent reservoir could have unintended negative impacts on the effector functions of CTL. This could influence the effectiveness of HDACi-based eradication strategies, by impairing elimination of infected cells, and is a critical consideration for trials where therapeutic interruptions are being contemplated, given the importance of CTL in containing rebound viremia