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Axel Moehrenschlager

Publications and source records attributed to Axel Moehrenschlager.

6 recordsLinked to original sources

Public support for puma reintroduction in the eastern United States

Pumas ( Puma concolor ) are among the species identified as having the potential to enhance ecosystem function. Previous research highlights sufficient ecological habitat to support pumas in the eastern United States; however, their reintroduction requires social and institutional support as well. To this end, we conducted research to assess attitudes about puma reintroduction among key constituencies like hunters, rural residents, and young people. We sampled 2756 respondents across seven states (Massachusetts, Maine, New Hampshire, New York, Pennsylvania, Vermont, and West Virginia). Ratios of strong support (for puma reintroduction) to strong opposition across states ranged from 4:1 to 13:1, and support outweighed opposition in every state. Our results contrasted with common assumptions that hunters, rural residents, and people who identify as politically conservative oppose carnivore conservation and reintroduction. We found marginal differences among categories of people, but overall little variation in support exhibited by different groups. People who identified very strongly as hunters were more supportive of reintroduction than those who did not identify as hunters at all. Taken together, the presence of quality habitat and support for puma restoration warrant further exploration. However, federal funding for state-based restoration efforts likely requires the inclusion of pumas in State Wildlife Action Plans (SWAPs), which are currently under a 10-year revision due to be published this year (2025).

Maine, Massachusetts, New Hampshire, New York, Pen

Self‐sustaining populations are a conservation vision, not an operational objective

It is common for species conservation plans to identify the establishment or maintenance of a “self-sustaining population” as an objective. However, this statement vaguely conflates different formulations and interpretations of population viability, management costs, and cultural preferences for non-invasive population management. Hidden value judgments and assumptions about these components can create disagreement and conflict among partners. Thus, although a simple statement about “achieving self-sustaining populations” can be a powerful strategic vision, evoking important shared values, it will not be effective as an operational objective for conservation decision making. Best practices in decision making emphasize the importance of fundamental objectives that are clear, unambiguous, and operational. Conservation planners may be better served by replacing the self-sustaining concept with better-defined fundamental objectives using quantitative statements about viability and clearly laying out ecological, economic, and cultural values.

Conservation Science and Practice

Using decision analysis to determine the feasibility of a conservation translocation

Conservation translocations, intentional movements of species to protect against extinction, have become widespread in recent decades and are projected to increase further as biodiversity loss continues worldwide. The literature abounds with analyses to inform translocations and assess whether they are successful, but the fundamental question of whether they should be initiated at all is rarely addressed formally. We used decision analysis to assess northern leopard frog reintroduction in northern Idaho, with success defined as a population that persists for at least 50 years. The Idaho Department of Fish and Game was the decision maker (i.e., the agency that will use this assessment to inform their decisions). Stakeholders from government, indigenous groups, academia, land management agencies, and conservation organizations also participated. We built an age-structured population model to predict how management alternatives would affect probability of success. In the model, we explicitly represented epistemic uncertainty around a success criterion (probability of persistence) characterized by aleatory uncertainty. For the leading alternative, the mean probability of persistence was 40%. The distribution of the modelling results was bimodal, with most parameter combinations resulting in either very low (<5%) or relatively high (>95%) probabilities of success. Along with other considerations, including cost, the Idaho Department of Fish and Game will use this assessment to inform a decision regarding reintroduction of northern leopard frogs. Conservation translocations may benefit greatly from more widespread use of decision analysis to counter the complexity and uncertainty inherent in these decisions.

Decision Analysis

Trading off hatching success and cost in the captive breeding of Whooping Cranes

Captive breeding is an increasingly used conservation strategy for species with a high risk of extinction in the wild, but managing a captive breeding programme can be challenging if there is a deficiency in knowledge about the species’ breeding biology. A knowledge gap can make it difficult to evaluate different management options. For avian species, egg hatching success is a key demographic parameter, and data-logging egg technology can provide important information on optimal species-specific incubation conditions, which can help inform captive breeding practises and identify efficient captive management options. In the context of a captive breeding programme for endangered Whooping Cranes Grus americana , we investigated associations between hatching success and incubation conditions, including environmental parameters (temperature, relative humidity and egg turning rate), and incubation type (artificial incubation; foster incubation by Sandhill Cranes, Grus canadensis ; and Whooping Crane incubation). Finally, we considered both cost and breeding output in an analysis of incubation practises. We found that daily mean temperatures were negatively associated with hatching success, and that hatching success was highest with incubation under Sandhill Cranes. However, incubation by artificial incubators, rather than Sandhill Cranes, provided a trade-off between cost and breeding output that is likely to be acceptable to many captive programme managers. We encourage other captive breeding programmes to use innovations that help to increase potential release numbers for conservation translocations by considering biological and financial constraints.

Animal Conservation

Archive eggs: a research and management tool for avian conservation breeding

Worldwide, approximately 168 bird species are captive-bred for reintroduction into the wild. Programs tend to be initiated for species with a high level of endangerment. Depressed hatching success can be a problem for such programs and has been linked to artificial incubation. The need for artificial incubation is driven by the practice of multiclutching to increase egg production or by uncertainty over the incubation abilities of captive birds. There has been little attempt to determine how artificial incubation differs from bird-contact incubation. We describe a novel archive (data-logger) egg and use it to compare temperature, humidity, and egg-turning in 5 whooping crane (Grus americana) nests, 4 sandhill crane (G. canadensis) nests, and 3 models of artificial incubator; each of which are used to incubate eggs in whooping crane captive-breeding programs. Mean incubation temperature was 31.7&deg; C for whooping cranes and 32.83&deg; C for sandhill cranes. This is well below that of the artificial incubators (which were set based on a protocol of 37.6&deg; C). Humidity in crane nests varied considerably, but median humidity in all 3 artificial incubators was substantially different from that in the crane nests. Two artificial incubators failed to turn the eggs in a way that mimicked crane egg-turning. Archive eggs are an effective tool for guiding the management of avian conservation breeding programs, and can be custom-made for other species. They also have potential to be applied to research on wild populations.

Wildlife Society Bulletin

Decision analysis for conservation breeding: Maximizing production for reintroduction of whooping cranes

Captive breeding is key to management of severely endangered species, but maximizing captive production can be challenging because of poor knowledge of species breeding biology and the complexity of evaluating different management options. In the face of uncertainty and complexity, decision-analytic approaches can be used to identify optimal management options for maximizing captive production. Building decision-analytic models requires iterations of model conception, data analysis, model building and evaluation, identification of remaining uncertainty, further research and monitoring to reduce uncertainty, and integration of new data into the model. We initiated such a process to maximize captive production of the whooping crane ( Grus americana ), the world's most endangered crane, which is managed through captive breeding and reintroduction. We collected 15 years of captive breeding data from 3 institutions and used Bayesian analysis and model selection to identify predictors of whooping crane hatching success. The strongest predictor, and that with clear management relevance, was incubation environment. The incubation period of whooping crane eggs is split across two environments: crane nests and artificial incubators. Although artificial incubators are useful for allowing breeding pairs to produce multiple clutches, our results indicate that crane incubation is most effective at promoting hatching success. Hatching probability increased the longer an egg spent in a crane nest, from 40% hatching probability for eggs receiving 1 day of crane incubation to 95% for those receiving 30 days (time incubated in each environment varied independently of total incubation period). Because birds will lay fewer eggs when they are incubating longer, a tradeoff exists between the number of clutches produced and egg hatching probability. We developed a decision-analytic model that estimated 16 to be the optimal number of days of crane incubation needed to maximize the number of offspring produced. These results show that using decision-analytic tools to account for uncertainty in captive breeding can improve the rate at which such programs contribute to wildlife reintroductions.

Journal of Wildlife Management