Optimizing reserve expansion for disjunct populations of San Joaquin kit fox

Expanding habitat protection is a common strategy for species conservation. We present a model to optimize the expansion of reserves for disjunct populations of an endangered species. The objective is to maximize the expected number of surviving populations subject to budget and habitat constraints. The model accounts for benefits of reserve expansion in terms of likelihood of persistence of each population and monetary cost. Solving the model with incrementally higher budgets helps prioritize sites for expansion and produces a cost curve showing funds required for incremental increases in the objective. We applied the model to the problem of allocating funds among eight reserves for the endangered San Joaquin kit fox (Vulpes macrotis mutica) in California, USA. The priorities for reserve expansion were related to land cost and amount of already-protected habitat at each site. Western Kern and Ciervo-Panoche sites received highest priority because land costs were low and moderate amounts of already-protected habitat resulted in large reductions in extinction risk for small increments of habitat protection. The sensitivity analysis focused on the impacts of kit fox reproductive success and home range in non-native grassland sites. If grassland habitat is lower quality than brushland habitat resulting in higher annual variation in reproductive success or larger home ranges, then protecting habitat at the best grassland site (Ciervo-Panoche) is not cost-efficient relative to shrubland sites (Western Kern, Antelope Plain, Carrizo Plain). Finally, results suggested that lowest priority should be given to three relatively high-cost grassland sites (Camp Roberts, Contra Costa, and Western Madera) because protecting habitat at those sites would be expensive and have little effect on the expected number of surviving kit fox populations.     

The effectiveness of conservation measures to enhance nest survival in a meadow bird suffering from anthropogenic nest loss

The main reason for meadow bird declines is supposed to be the intensification of grassland management with earlier first harvest dates and more frequent harvests, resulting in high nest destruction rates. To increase productivity of meadow bird populations in intensified grassland areas a delay of mowing date and individual nest protection measures have been proposed. However, for ground-nesting songbirds such as the whinchat (Saxicola rubetra) the effectiveness of such measures remains widely unknown. In particular, if nest predation rate is high, measures to protect nests from agricultural destruction alone might be questionable. Here, we quantify whinchat nest survival of (1) unprotected nests situated in early mown meadows, (2) protected nests situated in early mown meadows, and (3) nests situated in late mown meadows. Analyses considered the fact that successful and unsuccessful nests are not found with equal probabilities. Periods of reduced nest survival were associated with mowing periods in the different types of meadows. In early mown meadows nest survival rates were low (S < 0.1), and both conservation measures, individual nest protection and delayed mowing, resulted in significantly increased nest survival rates (S > 0.7). Individual nest protection cannot avoid changes in habitat quality of intensively managed meadows, and therefore is only suitable as small-scale and short-term measure to increase nest success until a high portion of late mown meadows is established. Thus, we suggest that a combination of the two measures applied to intensified grassland fields should be provided to maintain viable sizes of endangered meadow bird populations.     

Metapopulation dynamics and conservation of the marsh fritillary butterfly: Population viability analysis and management options for a critically endangered species in Western Europe

This study investigates the dynamics and viability of a marsh fritillary butterfly Euphydryas aurinia metapopulation in a Belgian successional landscape. Based on capture-mark-recapture and winter nest census data, we first estimated demography (survival and recruitment rates, population size, density dependence) and dispersal parameters (emigration rate, effect of patch connectivity on dispersal, mortality during dispersal). Then using RAMAS/GIS platform, we parameterised a population viability analysis (PVA) model with these parameters to simulate the future of this metapopulation under different scenarios.The metapopulation does not seem viable even if natural reforestation is controlled by adequate management. In its present state, the patch system is not able to sustain enough individuals: due to the large temporal fluctuations in demographic parameters, a carrying capacity far higher than currently would be necessary to limit extinction risk to 1%, suggesting the existence of an extinction debt for the species in Belgium. The situation of E. aurinia appears much worse compared to two other fritillary species threatened in Belgium, for which similar PVA are available. It is therefore urgent to increase the carrying capacity of the patch system. How and where it is achieved are of secondary importance for the gain in viability: improvement of habitat quality through restoration, or increase of habitat quantity via enlargement of existing patches and/or creation of new habitat in the matrix. A regime of management based on regular re-opening and maintenance of habitat patches may be the only guarantee of long-term persistence for this critically endangered species in Belgium.     

Long-term persistence of prairie dog towns: insights for designing networks of prairie reserves

We studied the persistence of 281 towns of the black-tailed prairie dog (Cynomys ludovicianus) from surveys conducted in Oklahoma in 1966 and 1967 and again in 1988 and 1989. Town size during initial surveys tended to increase along a northwesterly gradient toward the panhandle of the State, and larger towns tended to occur in clusters while small towns occurred as isolates. Persistence of prairie dog towns from 1967 to 1989 increased significantly with town size and decreased with town isolation, with higher persistence for towns that occurred in landscapes with greater coverage of other towns. Comparisons to our studies of persistence of towns mapped in 1989 and resurveyed in 1997 [Journal of Mammalogy, 82 (2001) 937] indicate that the latter part of this pattern was reversed, with persistence highest for the most isolated towns. The reversal in persistence patterns may be attributed to an outbreak of plague (Yersinia pestis) during the early 1990s, favoring isolated towns. We recommend adaptive management and a mixed strategy for the development of prairie reserves which should include networks (clusters) of relatively large reserves, along with large but isolated reserves across the species’ native range.     

Population viability of Cape mountain zebra in Gamka Mountain Nature Reserve, South Africa: the influence of habitat and fire

The small Cape mountain zebra population in Gamka Mountain Nature Reserve represents a third of the entire gene pool of this endangered species and is thus vital for it’s conservation. Presently, management of this population is largely hands off, with the belief that it will grow to levels which will allow it to form a source for the mixing of mountain zebra stocks in the future. The growth of this population however, has been slow and we investigated the influence of habitat and fire on this growth. Firstly, we used a diffusion model to perform a population viability analysis. This analysis indicated that the population had a low probability of attaining quasi-extinction in the next 50 years (G = 0.0032). However, our findings indicated that less than 30% of the reserve was suitable for mountain zebra and that the preferred habitat would have to be burnt at unnaturally short intervals to sustain the present growth. We therefore argue that the risk of quasi-extinction to this population is greater than predicted and suggest that management options need to be implemented to reduce this risk. These options include; translocation to another protected area; acquisition of adjacent land; burning preferred habitat at unnaturally short intervals; forming a conservancy with adjacent landowners; leasing cultivated land for pasture. We suggest that only the latter two options are likely to stimulate mountain zebra population growth in the short term and that these should receive immediate attention.     

Decline and likely extinction of a northern Australian native rodent, the Brush-tailed Rabbit-rat Conilurus penicillatus

Contemporary fire patterns are considered the most likely cause for regional population decline amongst small to medium mammals in northern tropical Australia. Here we assess the extinction risk faced by a vulnerable north Australian native rodent, the Brush-tailed Rabbit-rat Conilurus penicillatus in relation to fire frequency. This species has recently suffered a significant contraction in range. We provide the first quantitative evidence to demonstrate the immediate threat destructive wildfires and regular annual fire pose to the long-term population persistence of C. penicillatus. We show that late-dry season fires cause a reduction in both juvenile and adult survival probabilities. However, abundance declined at the unburnt as well as a frequently burnt site, suggesting that fire exclusion alone does not guarantee the species’ long-term persistence. Our model projections indicate that the remaining populations of C. penicillatus on the Northern Territory mainland risk extirpation within the next ten years. Conservation requires decisive management action to ameliorate extensive and destructive fires. A multi-faceted management plan needs to focus on restoring a fire management regime which generates a fine-scale mosaic of burnt and unburnt habitat, and the release of captive bred animals into fenced reserves free of exotic predators.     

Complementary conservation strategies for the genus Coffea: A case study of Mascarene Coffea species

No single conservation technique can adequately conserve the full range of genetic diversity of a target species or genepool. To optimize the efficiency of germplasm conservation, a range of conservation techniques needs to be applied simultaneously. In this paper we review the progress made in the application of both in situ and ex situ complementary conservation strategies and techniques to the conservation of the genus Coffea and identify areas where more research work is required. Traditionally, Coffea species have been conserved ex situ as living plants in field genebanks due to their intermediate seed storage behaviour. However, progress made in the field of biotechnology in recent years have made it possible to envisage the use of in vitro, slow growth and cryopreservation for medium- and long-term conservation of Coffea germplasm, respectively. In situ conservation is also an important option for long-term conservation, but there are no genetic reserves specifically set up for conserving Coffea. Protected areas and managed reserves offer the best opportunities for conserving Coffea. A case study for Mascarene Coffea in Mauritius is presented and a strategy for their conservation is discussed.     

The effects of fire and predators on the long-term persistence of an endangered shrub, Grevillea caleyi

Grevillea caleyi is an endangered plant species with a restricted range lying partly within Ku-ring-gai Chase and Garigal National Parks in NSW, Australia. The principle threatening processes affecting G. caleyi are habitat destruction and adverse fire regimes combined with high levels of seed predation. A stochastic, spatially explicit, individual-based model was constructed to investigate the population dynamics of small populations of the species and to determine the impact of a variety of management strategies. Results of model simulations indicate there is a high risk of population decline and local extinction in remnant sites with small populations under current management regimes. The most effective fire management strategy is to schedule fires that burn 20-100% of sub-populations every 5-15 years, in combination with reduced predation rates. When predation management strategies are employed in conjunction with a structured fire regime, then a 20-30% reduction in predation rates can improve the chance of long-term persistence substantially.     

Hunting habitat selection by hen harriers on moorland: Implications for conservation management

We examine habitat use by hunting hen harriers Circus cyaneus at three study sites in Scotland to evaluate whether foraging patterns differ between sexes, sites, and stages of the breeding period. We modelled time spent hunting in focal plots as a function of habitat and nest proximity. Male hunting intensity (time spent hunting per hour of observation and km²) varied between sites and breeding periods, being lower during the nestling than the incubation period. Habitat use patterns were mostly consistent among study sites, which is important for developing species management recommendations applicable over the species’ range. Males avoided improved grassland, and selected areas of mixed heather and rough grass (with an optimum at ca. 50% heather cover). The effect of nest proximity was small. In contrast, females hunted mainly within 300-500 m of the nest, with a small additive effect of vegetation cover, areas of fragmented heather being preferred. Habitat management to benefit foraging harriers will involve creating (or maintaining) mosaics of heather/grassland around nest areas. Additionally, it might be possible to manipulate habitat to reduce conflict in areas where harrier predation on red grouse is important by segregating areas holding highest grouse densities (with high heather cover) from those favoured for harrier foraging (heather-grass mosaics). However, it would be necessary to test whether these manipulations might also influence harrier nest distribution, an effect which could negate any benefits from this strategy.     

Intensive beach management as an improved sea turtle conservation strategy in Mexico

We evaluate the role of intensive beach management, meaning intense patrolling and nest reburial to a central hatchery, as a strategy for improving the success of sea turtle conservation at nesting sites in Mexico. We report the results of an experimental program at Playa Cuixmala, Jalisco, western Mexico. Sea turtle conservation efforts in Mexico have, in general, poor results because of lack of funds, which leads to insufficient beach protection and severe negative effects of nest removal on hatching success and sex ratios. Alternative strategies are needed to optimize limited resources. We predicted that intensive beach management, which included intense patrolling and careful nest reburial, could be an effective way to maximize nest survival and hatchling release under limited financial and human resources. The results of our 9-year study were very positive. Survival rate increased several fold during the study period. Hatching success and sex ratios were not significantly different between in-situ and removed nests. Survival in removed nests was, however, much higher that in-situ nests, because of predation and beach erosion. In total, the small (3 km length) Playa Cuixmala became the second most productive sea turtle nesting beach in the region because of these concentrated efforts. Intense beach management can be an important technique for sea turtle conservation, and can be properly applied to small beaches or the most productive sections of large beaches.     

Climate change might drive the invasive tree Robinia pseudacacia into nature reserves and endangered habitats

Static networks of nature reserves disregard the dynamics of species ranges in changing environments. In fact, climate warming has been shown to potentially drive endangered species out of reserves. Less attention has been paid to the related problem that a warmer climate may also foster the invasion of alien species into reserve networks. Here, we use niche-based predictive modelling to assess to which extent the Austrian Natura 2000 network and a number of habitat types of conservation value outside this network might be prone to climate warming driven changes in invasion risk by Robinia pseudacacia L., one of the most problematic alien plants in Europe.Results suggest that the area potentially invaded by R. pseudacacia will increase considerably under a warmer climate. Interestingly, invasion risk will grow at a higher than average rate for most of the studied habitat types but less than the national average in Natura 2000 sites. This result points to a potential bias in legal protection towards high mountain areas which largely will remain too cold for R. pseudacacia. In contrast, the selected habitat types are more frequent in montane or lower lying regions, where R. pseudacacia invasion risk will increase most pronouncedly.We conclude that management plans of nature reserves should incorporate global warming driven changes in invasion risk in a more explicit manner. In case of R. pseudacacia, reducing propagule pressure by avoiding purposeful plantation in the neighbourhood of reserves and endangered habitats is a simple but crucial measure to prevent further invasion under a warmer climate.     

Spatial variation in anthropic and natural factors regulating the breeding success of the cinereous vulture (Aegypius monachus) in the SW Iberian Peninsula

The management of the cinereous vulture (Aegypius monachus) populations, the largest bird of the Western Palæarctic and considered an umbrella species, requires the understanding of the factors limiting the breeding success. As part of a management program, we studied such factors in seven breeding colonies in Extremadura (SW Iberian Peninsula). Using a Geographic Information System and multivariate models, we analyzed the relationship of breeding success with anthropic and natural factors at the nest site and in the foraging area of the adults. We incorporated into the models density-dependent effects between pairs and the spatial autocorrelation of the environmental variables. The differences in breeding success resulted from spatial variations in natural and anthropic conditions, with present human disturbance to nests and future alteration of climate having an expected negative effect at all the sites. Management measures must set calendar restrictions for the immediate environment of the nests, mainly with respect to forestry and hunting activities. A second key element is the protection of the habitats at the nest sites and in their surrounding area, with the aim of there being both wooded areas available for the location of the nest and open environments for the availability of food. The Special Protection Areas showed a partial effectiveness of conservation measures for the species, and the need for future improvement. Lastly, in a scenario of global warming, management policies with respect to nesting habitats will have to be extended to higher altitude zones, actions that should be guided by the study of the selection of potential nesting habitat.     

Evaluating recovery strategies for an ocelot (Leopardus pardalis) population in the united states

The ocelot Leopardus pardalis population in the United States was listed as endangered in 1982, with only two known isolated breeding populations occurring in southern Texas. Conservation concerns for ocelots include loss of dense thornshrub habitat, mortality from ocelot-vehicle collisions, and genetic erosion. In this study, we used a population viability analysis (PVA) to evaluate four recovery strategies (i.e., supplementation of additional ocelots, reduced road mortality, habitat protection and restoration, and linkage of two breeding populations) for ocelot conservation management. We used the VORTEX (Version 9.42) program to conduct our PVA for an ocelot population located in Cameron County, Texas. Each scenario was simulated 500 times over 100 years. We compared the effectiveness of recovery strategies and combinations thereof with estimates of extinction probability and final population size. Model scenarios with no recovery strategies predicted an extinction probability of 0.65 for the Cameron population of ocelots over 100 years. The protection and restoration of thornshrub habitat was the most effective recovery strategy, followed by population linkage and reduced road mortality, with the supplementation of ocelots being the least effective strategy. Protection and restoration of ocelot habitat cannot be accomplished without the participation of private landowners. Using an adaptive management approach, future actions need to be taken to monitor ocelot populations and habitats and help to reduce the high probability of extinction predicted in our PVA for the ocelot population in Cameron County.     

Disturbance to a foraging seabird by sea-based tourism: Implications for reserve management in marine protected areas

The provision of recreational opportunities is one of the important human goals of marine protected areas. However, as levels of recreational use increase, human disturbance is likely to cause significant detrimental effects upon wildlife. Here we evaluate the best managing options to mitigate the impact of sea-based tourism on the foraging activity of an endangered population of European shags, Phalacrocorax aristotelis, in a coastal marine protected area (Cíes islands, north-western Iberia). Boat disturbance elicited a characteristic avoidance behavior that resulted in a substantial reduction in foraging activity as levels of boat use increased. Moreover, boats excluded shags from the best feeding areas, resulting in higher densities of foragers in areas of little boat traffic. We used a behavioral model to explore the effects of managing strategies aimed at reducing the impact of boats on the foraging activity of shags. Our model suggested that in low boat disturbance scenarios limiting the number of boats using the reserve would be a better management option than habitat protection (i.e. the establishment of set-aside areas free of boat traffic). On the contrary, when boat disturbance levels are high the protection of habitat is recommendable, even if spatial variation in habitat quality is unknown or poorly assessed. Our study stresses the point that management strategies to minimize disturbance to foraging seabirds may depend on the spatial overlap between sea-based recreational activities and foraging seabirds and the spatial variation in marine habitat quality for seabirds.     

Alligators in natural areas: Choosing conservation policies consistent with local objectives

In parks and reserves, the conservation and management of large animals, particularly dangerous ones, has always been of concern with respect to human safety. In some areas, protective management for crocodilians, some species of which are known to attack humans, is appropriate despite prevailing national or regional management trends emphasising commercial utilisation. Management of problem alligators in Everglades National Park provides an example of protection management. We found that incidents involving conflict between visitors and alligators were not frequent in the Park despite a large resident alligator population and the annual passage of 400 000 people through the area. Furthermore, responses to alligator incidents were not time-consuming, requiring an average of four personnel-days per year. Visitor management was an effective tool in this park, emphasising a balance between visitor safety and alligator protection by focusing on reducing the potential for conflict. Because objectives differ in various reserves, there is a need for locally sensitive planning for crocodilian management. Three criteria to be evaluated at a local level are potential threats to human safety, economic necessity, and the ecological values of the species. Although ethical and philosophical arguments can be raised, in the United States nonconsumptive management appears to be most effectively argued on the value of crocodilians to the ecosystems they inhabit.     

Development of best practices for ex situ conservation of radish germplasm in the context of the crop genebank knowledge base

Information about crop-specific best practices for ex situ conservation of plant genetic resources has been difficult to find until recently. The CGIAR, together with national and regional partners, started to fill that gap by publishing best practices on the crop genebank knowledge base (CGKB -http://cropgenebank.sgrp.cgiar.org/), a website specifically developed and officially launched in 2010 to provide easy access to knowledge about all aspects of ex situ conservation of specific crops to genebank managers and ex situ conservation researchers. A collaborative study, undertaken by Bioversity International with eight national and international genebanks, utilized the framework provided by the CGKB to develop and publish radish conservation best practices. This paper focuses on two aspects of this study: (1) Differences in procedures and practices in radish conservation currently applied in five key genebank activities, namely, acquisition of germplasm, viability testing and monitoring, seed drying, seed storage, and regeneration. While in a few cases genebanks agreed on a specific best practice to recommend, in others it was not desirable to identify one practice as superior to another, therefore a range of existing practices is described as a variety of equivalent options. The results highlight the importance of proactive genebank management aimed at meeting the standards within the specific context in which a genebank operates. (2) The framework and template provided by the CGKB in guiding the development of genebank best practices, and the CGKB as an excellent resource to widely and freely share best practices with the global community to support the effective management of crop genebanks.     

Tallgrass prairie management and bird nest success along roadsides

The attributes of roadside vegetation, an important bird habitat in grassland ecosystems, have been shown to affect bird abundance, distribution composition, and diversity, yet there are relatively few works on reproductive success of birds nesting along roadsides. Because roadsides are linear habitats, management at the landscape scale can affect nest success in roadsides through bottom-up and top-down effects. In northeastern Oklahoma tallgrass prairie is subjected annually to prescribed spring fires. In the short term fires can alter both arthropod abundance and predator access to nests. We explored effects of burning on bird nest success with a five-year study along roads that traversed tallgrass prairie habitat. Using data from ∼1400 nests of 23 species, we generated nest survival curves for groups of altricial species defined by nest substrate (ground, shrub, tree, or culvert). We then determined if these curves were affected by management practice (spring burning), food abundance (arthropod biomass), and habitat attributes (tree density and height). Nest substrate had a large effect on nest success: despite their shorter nest exposure period, ground nests were least successful and culvert nests were most successful. An increase in arthropod biomass following burning was possibly the cause for the increased nest success in burned plots, regardless of substrate, suggesting bottom-up control. Tree height and nest height were correlated positively with nest success, whereas tree density had no effect. Conversely, nest predation rates were correlated negatively with nest success, with ground nests experiencing the highest predation, culvert nests the lowest. Our results suggest that burning may increase nest success through bottom-up processes, but some species may not benefit from the increase in food abundance as a result of a concomitant increase in predation.     

Forestry and the boreal forest: Maintaining inherent landscape patterns

The forestry industry in Canada has become sensitive to its image through pressure from environmentalists and the European markets and along with Natural Resource Departments across the country, is working hard to change its image by developing environmentally sound management. The dilemma is how to continue resource extraction from the forest yet ensure that wildlife populations do not become endangered. An important ecosystem process in the boreal forest is forest fire and the forestry industry has traditionally argued that clear cutting simulates forest fire by creating large areas devoid of vegetation that can then grow back either through natural regeneration or by planting. What is neglected in present forestry is the landscape pattern created through cutting which is often large continuous expanses of recently clear-cut land. In ecology we often talk about process and pattern. I will argue that we should emulate the pattern across the landscape. Wildlife (including all life) have evolved in landscapes with inherent patterns. If we can maintain the inherent pattern in a landscape I argue that we can maintain the wildlife. Here I outline a method for describing landscape patterns and maintaining these patterns through forest management.     

The abundance of a threatened arboreal marsupial in relation to anthropogenic disturbances at local and landscape scales in Mediterranean-type forests in south-western Australia

This study investigated associations between the relative abundance of the threatened ngwayir (western ringtail possum, Pseudocheirus occidentalis) and anthropogenic disturbances at local and landscape scales within the publicly-managed jarrah (Eucalyptus marginata) forests of south-western Australia. Logging, fire, fox (Vulpes vulpes) control and forest fragmentation were investigated in relation to the relative abundance of ngwayir at 90 sites within an area of 285,000 ha east of Manjimup; the location of the last remaining substantial population of ngwayir in jarrah forest. Overall, ngwayir abundance was greatest in areas with limited anthropogenic disturbance. At the local-scale, ngwayir abundance was negatively associated with greater fire intensity. At the landscape-scale, it was positively associated with fox control and negatively associated with forest fragmentation and distance from non-remnant vegetation (i.e., agriculture and tree plantations). Abundance was also greatest in predominantly unlogged landscapes and in forests that had been regrowing for an average of 40 years since the landscape was most recently logged, in other words, where logging was historically least intense. Interactions between fox control efforts and forest fragmentation were also important. This study emphasises the importance of conducting research at appropriate spatial scales and to account for the synergistic effects of the causes of decline. An adaptive management approach to the mitigation of the agents of decline is recommended.Indirect evidence indicates that high value habitat for ngwayir has in all likelihood been selectively cleared for agriculture, owing to its fertile and productive nature. Habitat loss is, therefore, also likely to be a major cause of the modern decline of the species. While many jarrah forest areas that support remaining high abundances of the ngwayir have been incorporated into reserves, conservation of ngwayir habitat and populations outside reserves also will be essential for the recovery and long-term viability of the species.     

Reproductive success of the black-backed woodpecker (Picoides arcticus) in burned boreal forests: Are burns source habitats?

The black-backed woodpecker (Picoides arcticus) is considered a fire specialist throughout its breeding range. Given its high abundance in recent burns, it has been hypothesized that post-fire forests are source habitats for this species. We conducted a 3-year post-fire study to evaluate the temporal occupancy and reproductive success of black-backed woodpeckers in high-severity burned black spruce forests of central Quebec, Canada. We examined how reproductive success varied temporally and spatially within a burned landscape and investigated the potential source or sink status of this woodpecker population over time. Woodpecker nest density was high in the year after fire but declined significantly over the 3-year period. Based on 106 nests, nest success declined from 84% the first year after fire to 73% and 25%, respectively, for the second and third years after fire. Nest density and reproductive success were higher in areas with high proportions of burned mature forests than in areas dominated by burned young forests. Reproductive success was also higher in proximity to unburned forests. Comparison of annual productivity with a range of survival estimates indicated that these burned forests likely functioned as source habitats for the first 2 years following fire, although this status varied as a function of pre-fire forest age. Our results suggest that post-fire forests may contribute significantly to population levels in fire-prone ecosystems. Forest management practices that reduce the amount of mature and over-mature forests can affect the quality of post-fire habitats important to the black-backed woodpecker and other fire-associated species.