scholarly journals Is habitat enhancement a viable strategy for conserving New Zealand's endemic lizards?

2021 ◽  
Author(s):  
◽  
Sarah Herbert
Keyword(s):  
New Zealand ◽  
Habitat Loss ◽  
The Other ◽  
Habitat Characteristics ◽  
Lizard Species ◽  
Apparent Survival ◽  
Stage 4 ◽  
Invasive Mammals ◽  
Habitat Enhancement

<p>In our current era, the Anthropocene, species are disappearing at an unprecedented rate due to the impact of humans on Earth’s environments. Of the many causes of these extinctions, habitat loss is thought to be the most severe. Three habitat management strategies are available for halting habitat loss: reservation, restoration and reconciliation. The latter two of these strategies actively seek to improve the ability of degraded or lost habitats to support species. If successful on a large enough scale, use of restoration and reconciliation (hereafter referred to collectively as ‘habitat enhancement’) could reverse the effects of habitat loss.  I evaluated the viability of habitat enhancement for the conservation of New Zealand’s lizard fauna. 83% of New Zealand’s 106+ endemic species are threatened or at risk of extinction. While habitat loss is one key driver of declines, predation by invasive mammals is the other. Neither of these processes are well understood. Habitat enhancement is increasingly being employed in New Zealand by landowners, community groups, conservationists, and businesses as a strategy for mitigating lizard declines, but outcomes are rarely investigated comprehensively. This is concerning because habitat manipulation potentially affects both exotic and native species, which has led to unexpected negative effects on threatened fauna in New Zealand and overseas. I posed four questions to help address this knowledge gap. (1) What habitat enhancement strategies are available for reptiles, and have they produced successful conservation outcomes? (2) How do habitat characteristics affect populations and communities of endemic New Zealand lizards? (3) How does the presence of invasive mammals affect populations and communities of endemic New Zealand lizards over intermediate to long-term time frames? (4) Can habitat enhancement produce positive conservation outcomes in the presence of invasive mammals?  A review of the global literature on habitat enhancement for reptiles identified 75 studies documenting 577 responses of 251 reptile species. For outcome evaluation, I adapted an existing stage-based framework for assessment of translocation success. High levels of success (84-85%) at Stages 1 (use of enhanced habitat) and 2 (evidence of reproduction in enhanced habitat) suggested that enhancement could be useful for creating areas that can be inhabited, and reproduced in, by reptiles. Fewer cases were successful at Stage 3 (30%; improvement of at least one demographic parameter demonstrated in enhanced habitat) or Stage 4 (43%; self-sustaining or source population established in enhanced habitat). Additionally, only 1% of the 577 cases sufficiently examined or modelled long-term population trends to allow evaluation against the Stage 4 criterion. Thus, there was a lack of evidence indicating that enhancement could result in higher population growth rates, or reduced extinction risk, of reptiles.  I conducted field work in the Wellington region to investigate the effects of habitat characteristics and mammals on terrestrial lizards inhabiting coastal environments. Surveys conducted in two mammal-invaded mainland areas and on two mammal-free offshore islands showed that presence or absence of invasive mammals had a stronger effect on lizard community structure than habitat variables. However, occupancy probabilities of northern grass skinks Oligosoma polychroma and Raukawa geckos Woodworthia maculata were positively correlated with increasing cover of divaricating shrubs. O. polychroma were also more likely to occupy patches with increasing cover by non-Muehlenbeckia vines. Mark-recapture studies were conducted at two mammal-invaded mainland sites to investigate the current abundance of lizard species: Turakirae Head and Pukerua Bay. Estimated densities of O. polychroma ranged between 3,980 and 4,078 individuals / ha and W. maculata between 4,067 and 38,372 individuals / ha. Other species known to occur, at least historically, at each site were either not detected or comprised only a small proportion of total lizard captures. Analysis of longitudinal lizard monitoring data available for Pukerua Bay, Turakirae Head, and an additional mammal-invaded site, Baring Head, did not reveal a significant decline in abundance, occupancy, or catch rates of O. polychroma over time periods ranging between six and 34 years, nor of W. maculata over six to 49 years. Habitat information available for Baring Head showed that the probability of local extinction of W. maculata was significantly lower at rocky sites.  Finally, I conducted a before-after-control-impact habitat enhancement experiment on lizard communities inhabiting 100 m2 plots on the mammal-invaded Miramar Peninsula. After a six-month pre-enhancement monitoring period, native plants and gravel piles were added to enhancement plots and lizard monitoring continued for a further nine months. Enhancement did not significantly affect plot use, body condition, or evidence of reproduction in Oligosoma aeneum, O. polychroma or W. maculata, but were considered successful at Stages 1 and 2 due to the absence of a negative effect. Neither the abundance, probability of entry into plots by birth or immigration, nor apparent survival of O. aeneum was significantly affected by enhancement (Stage 3). Apparent survival of O. polychroma increased significantly in response to enhancement, but this did not result in increased abundance.   Adding gravel and native vegetation (especially divaricating shrubs and vines) may be a suitable strategy for creating habitat in invaded coastal landscapes for O. polychroma and W. maculata. However, most of the other lizard species that would have historically occurred in mammal-invaded coastal areas of Wellington appeared to be sensitive to sustained mammal presence, even with low-to-moderate levels of control in operation. Therefore, habitat enhancement without intensive mammal control or eradication is not expected to benefit these species, nor be capable of restoring coastal lizard communities. In invaded landscapes it is, at best, a reconciliation measure that could allow co-existence of an endemic lizard community comprised of common species with invasive mammals. However, habitat enhancement could still be useful for restoring lizard communities in mammal-free sanctuaries.</p>

scholarly journals Is habitat enhancement a viable strategy for conserving New Zealand's endemic lizards?

2021 ◽  
Author(s):  
◽  
Sarah Herbert
Keyword(s):  
New Zealand ◽  
Habitat Loss ◽  
The Other ◽  
Habitat Characteristics ◽  
Lizard Species ◽  
Apparent Survival ◽  
Stage 4 ◽  
Invasive Mammals ◽  
Habitat Enhancement

<p>In our current era, the Anthropocene, species are disappearing at an unprecedented rate due to the impact of humans on Earth’s environments. Of the many causes of these extinctions, habitat loss is thought to be the most severe. Three habitat management strategies are available for halting habitat loss: reservation, restoration and reconciliation. The latter two of these strategies actively seek to improve the ability of degraded or lost habitats to support species. If successful on a large enough scale, use of restoration and reconciliation (hereafter referred to collectively as ‘habitat enhancement’) could reverse the effects of habitat loss.  I evaluated the viability of habitat enhancement for the conservation of New Zealand’s lizard fauna. 83% of New Zealand’s 106+ endemic species are threatened or at risk of extinction. While habitat loss is one key driver of declines, predation by invasive mammals is the other. Neither of these processes are well understood. Habitat enhancement is increasingly being employed in New Zealand by landowners, community groups, conservationists, and businesses as a strategy for mitigating lizard declines, but outcomes are rarely investigated comprehensively. This is concerning because habitat manipulation potentially affects both exotic and native species, which has led to unexpected negative effects on threatened fauna in New Zealand and overseas. I posed four questions to help address this knowledge gap. (1) What habitat enhancement strategies are available for reptiles, and have they produced successful conservation outcomes? (2) How do habitat characteristics affect populations and communities of endemic New Zealand lizards? (3) How does the presence of invasive mammals affect populations and communities of endemic New Zealand lizards over intermediate to long-term time frames? (4) Can habitat enhancement produce positive conservation outcomes in the presence of invasive mammals?  A review of the global literature on habitat enhancement for reptiles identified 75 studies documenting 577 responses of 251 reptile species. For outcome evaluation, I adapted an existing stage-based framework for assessment of translocation success. High levels of success (84-85%) at Stages 1 (use of enhanced habitat) and 2 (evidence of reproduction in enhanced habitat) suggested that enhancement could be useful for creating areas that can be inhabited, and reproduced in, by reptiles. Fewer cases were successful at Stage 3 (30%; improvement of at least one demographic parameter demonstrated in enhanced habitat) or Stage 4 (43%; self-sustaining or source population established in enhanced habitat). Additionally, only 1% of the 577 cases sufficiently examined or modelled long-term population trends to allow evaluation against the Stage 4 criterion. Thus, there was a lack of evidence indicating that enhancement could result in higher population growth rates, or reduced extinction risk, of reptiles.  I conducted field work in the Wellington region to investigate the effects of habitat characteristics and mammals on terrestrial lizards inhabiting coastal environments. Surveys conducted in two mammal-invaded mainland areas and on two mammal-free offshore islands showed that presence or absence of invasive mammals had a stronger effect on lizard community structure than habitat variables. However, occupancy probabilities of northern grass skinks Oligosoma polychroma and Raukawa geckos Woodworthia maculata were positively correlated with increasing cover of divaricating shrubs. O. polychroma were also more likely to occupy patches with increasing cover by non-Muehlenbeckia vines. Mark-recapture studies were conducted at two mammal-invaded mainland sites to investigate the current abundance of lizard species: Turakirae Head and Pukerua Bay. Estimated densities of O. polychroma ranged between 3,980 and 4,078 individuals / ha and W. maculata between 4,067 and 38,372 individuals / ha. Other species known to occur, at least historically, at each site were either not detected or comprised only a small proportion of total lizard captures. Analysis of longitudinal lizard monitoring data available for Pukerua Bay, Turakirae Head, and an additional mammal-invaded site, Baring Head, did not reveal a significant decline in abundance, occupancy, or catch rates of O. polychroma over time periods ranging between six and 34 years, nor of W. maculata over six to 49 years. Habitat information available for Baring Head showed that the probability of local extinction of W. maculata was significantly lower at rocky sites.  Finally, I conducted a before-after-control-impact habitat enhancement experiment on lizard communities inhabiting 100 m2 plots on the mammal-invaded Miramar Peninsula. After a six-month pre-enhancement monitoring period, native plants and gravel piles were added to enhancement plots and lizard monitoring continued for a further nine months. Enhancement did not significantly affect plot use, body condition, or evidence of reproduction in Oligosoma aeneum, O. polychroma or W. maculata, but were considered successful at Stages 1 and 2 due to the absence of a negative effect. Neither the abundance, probability of entry into plots by birth or immigration, nor apparent survival of O. aeneum was significantly affected by enhancement (Stage 3). Apparent survival of O. polychroma increased significantly in response to enhancement, but this did not result in increased abundance.   Adding gravel and native vegetation (especially divaricating shrubs and vines) may be a suitable strategy for creating habitat in invaded coastal landscapes for O. polychroma and W. maculata. However, most of the other lizard species that would have historically occurred in mammal-invaded coastal areas of Wellington appeared to be sensitive to sustained mammal presence, even with low-to-moderate levels of control in operation. Therefore, habitat enhancement without intensive mammal control or eradication is not expected to benefit these species, nor be capable of restoring coastal lizard communities. In invaded landscapes it is, at best, a reconciliation measure that could allow co-existence of an endemic lizard community comprised of common species with invasive mammals. However, habitat enhancement could still be useful for restoring lizard communities in mammal-free sanctuaries.</p>

scholarly journals Novel Predators and Naïve Prey: How Introduced Mammals Shape Behaviours and Populations of New Zealand Lizards

2021 ◽  
Author(s):  
◽  
Joanne Marie Hoare
Keyword(s):  
New Zealand ◽  
Synergistic Effects ◽  
Activity Patterns ◽  
Major Influence ◽  
Population Declines ◽  
Lizard Species ◽  
Predator Detection ◽  
Term Survival ◽  
Mammalian Predators ◽  
Invasive Mammals

<p>Biotas that evolved in isolation from mammalian predators are susceptible to degradation due to recent human-mediated introductions of mammals. However, behavioural, morphological and life historical adaptations of prey to novel mammalian predators can allow prey to persist in mammal-invaded areas. Lizards in New Zealand are an ideal group for exploring the effects of invasive mammals on vertebrate prey because: (1) the ca. 80 endemic species evolved without mammals as a major influence for 80 my, (2) mammalian introductions during the past 2000 y have differentially affected lizard species, and (3) some species coexist with mammals on the mainland as well as occurring on mammal-free offshore islands. I tested three hypotheses: (1) lizard populations that have persisted on New Zealand’s mainland are no longer declining in the presence of introduced mammalian predators, (2) introduced mammals induce behavioural shifts in native lizards, and (3) lizard behavioural patterns and chemosensory predator detection abilities vary according to exposure to introduced mammals. Trends in capture rates of five sympatric native lizard populations over a 23 year (1984-2006) period demonstrate that not all lizard populations that have persisted thus far on New Zealand’s mainland have stabilised in numbers. Large, nocturnal and terrestrial species remain highly vulnerable at mainland sites. Introduced kiore, Rattus exulans, induce behavioural changes in Duvaucel’s geckos, Hoplodactylus duvaucelii. A radio telemetric study demonstrated that geckos start reverting to natural use of habitats within six months of kiore eradication. Activity patterns of common geckos, H. maculatus, and common skinks, Oligosoma nigriplantare polychroma, in laboratory trials are also correlated with their exposure to mammalian predators. Lizard activity (time spent moving) increases relative to freeze behaviour with greater exposure to mammals. However, specific antipredator behaviours are not elicited by chemical cues of either native (tuatara, Sphenodon spp) or introduced (ship rat, R. rattus) predators. Lizard populations may persist by changing their behaviours in the presence of invasive mammals. However, the continued declines of particularly vulnerable mainland lizard taxa suggest that mammal-induced behavioural shifts may only slow population declines rather than enabling long-term survival. Eradicating pest mammals from offshore islands has proven effective at restoring both populations and behaviours of native lizards, but lizard populations on the mainland also deserve conservation priority. Research directed at understanding the synergistic effects of invasive species that are causing continued lizard population declines and mammal-proof fencing to protect the most vulnerable mainland populations from extinction are both urgently required.</p>

scholarly journals Novel Predators and Naïve Prey: How Introduced Mammals Shape Behaviours and Populations of New Zealand Lizards

2021 ◽  
Author(s):  
◽  
Joanne Marie Hoare
Keyword(s):  
New Zealand ◽  
Synergistic Effects ◽  
Activity Patterns ◽  
Major Influence ◽  
Population Declines ◽  
Lizard Species ◽  
Predator Detection ◽  
Term Survival ◽  
Mammalian Predators ◽  
Invasive Mammals

<p>Biotas that evolved in isolation from mammalian predators are susceptible to degradation due to recent human-mediated introductions of mammals. However, behavioural, morphological and life historical adaptations of prey to novel mammalian predators can allow prey to persist in mammal-invaded areas. Lizards in New Zealand are an ideal group for exploring the effects of invasive mammals on vertebrate prey because: (1) the ca. 80 endemic species evolved without mammals as a major influence for 80 my, (2) mammalian introductions during the past 2000 y have differentially affected lizard species, and (3) some species coexist with mammals on the mainland as well as occurring on mammal-free offshore islands. I tested three hypotheses: (1) lizard populations that have persisted on New Zealand’s mainland are no longer declining in the presence of introduced mammalian predators, (2) introduced mammals induce behavioural shifts in native lizards, and (3) lizard behavioural patterns and chemosensory predator detection abilities vary according to exposure to introduced mammals. Trends in capture rates of five sympatric native lizard populations over a 23 year (1984-2006) period demonstrate that not all lizard populations that have persisted thus far on New Zealand’s mainland have stabilised in numbers. Large, nocturnal and terrestrial species remain highly vulnerable at mainland sites. Introduced kiore, Rattus exulans, induce behavioural changes in Duvaucel’s geckos, Hoplodactylus duvaucelii. A radio telemetric study demonstrated that geckos start reverting to natural use of habitats within six months of kiore eradication. Activity patterns of common geckos, H. maculatus, and common skinks, Oligosoma nigriplantare polychroma, in laboratory trials are also correlated with their exposure to mammalian predators. Lizard activity (time spent moving) increases relative to freeze behaviour with greater exposure to mammals. However, specific antipredator behaviours are not elicited by chemical cues of either native (tuatara, Sphenodon spp) or introduced (ship rat, R. rattus) predators. Lizard populations may persist by changing their behaviours in the presence of invasive mammals. However, the continued declines of particularly vulnerable mainland lizard taxa suggest that mammal-induced behavioural shifts may only slow population declines rather than enabling long-term survival. Eradicating pest mammals from offshore islands has proven effective at restoring both populations and behaviours of native lizards, but lizard populations on the mainland also deserve conservation priority. Research directed at understanding the synergistic effects of invasive species that are causing continued lizard population declines and mammal-proof fencing to protect the most vulnerable mainland populations from extinction are both urgently required.</p>

scholarly journals Captives No Longer, but Servants Still? Contract Parliamentarism and the New Minority Governance in Sweden and New Zealand

2006 ◽  
Vol 41 (3) ◽  
pp. 422-449 ◽  
Author(s):  
Tim Bale ◽  
Torbjörn Bergman
Keyword(s):  
New Zealand ◽  
System Dynamics ◽  
Party System ◽  
The Other ◽  
Institutional Constraints ◽  
Cultural Norms ◽  
Social Democratic

AbstractRecent years have seen the institutionalization of minority governance in Sweden and New Zealand. Large, historic social democratic labour parties enjoy comparative security of tenure thanks to smaller, newer parties with whom they have signed long-term, detailed support agreements covering both policy and process. This trend toward ‘contract parliamentarism’ owes much to party-system dynamics, but also to the accretion of experience, to cultural norms and to institutional constraints – all of which, along with electoral contingency, explain why the trend has gone slightly further in one polity than in the other. While the trend seems to favour the left in general, its implications for the support or ‘servant’ parties, and – more normatively – for democracy itself, may be less favourable.

scholarly journals Dialogue on ‘Dialogic Education’: Has Rupert gone over to ‘the Dark Side’?

2014 ◽  
Vol 2 ◽  
Author(s):  
Eugene Matusov ◽  
Rupert Wegerif
Keyword(s):  
New Zealand ◽  
Personal Responsibility ◽  
The Other ◽  
Dark Side ◽  
Critical Dialogue ◽  
Dialogic Pedagogy ◽  
Individual Agency ◽  
Other Hand ◽  
Full Participation

This email dialogue that we record and report here between Eugene Matusov and Rupert Wegerif, exemplifies Internet mediated dialogic education. When Eugene emailed Rupert with his initial (mis)understanding of Rupert's position about dialogic pedagogy Rupert felt really motivated to reply. Rupert was not simply motivated to refute Eugene and assert his correctness, although Rupert is sure such elements enter into every dialogue, but also to explore and to try to resolve the issues ignited by the talk in New Zealand. Through this extended dialogue Rupert's and Eugene's positions become more nuanced and focussed. Rupert brings out his concern with the long-term and collective nature of some dialogues claiming that the – "dialogue of humanity that education serves is bigger than the interests of particular students and particular teachers.…" – and so he argues that it is often reasonable to induct students into the dialogue so far so that they can participate fully. On the other hand, Eugene's view of dialogue seems more focussed on personal responsibility, particular individual desires, interests and positions, individual agency and answering the final ethical "damned questions" without an alibi-in-being.  Rupert claims that dialogic education is education FOR dialogue and Eugene claims that dialogic education is education AS dialogue. Both believe in education THROUGH dialogue but education through dialogue is not in itself dialogic education. For Rupert dialogic education can include ‘scaffolding’ for full participation in dialogue as long as dialogue is the aim. For Eugene dialogic education has to be a genuine dialogue and this means that a curriculum goal cannot be specified in advance because learning in a dialogue is always emergent and unpredictable. Our dialogue-disagreement is a relational and discursive experiment to develop a new genre of academic critical dialogue. The dialogue itself called to us and motivated us and flowed through us. This dialogue is much bigger than us. It participates in a dialogue that humanity has been having about education for thousands of years. We hope that it also engages you and calls you to respond.

Radioimmunotherapy for treatment of acute myeloid leukaemia and myelodysplastic syndrome

2005 ◽  
Vol 44 (03) ◽  
pp. 107-117
Author(s):  
R. G. Meyer ◽  
W. Herr ◽  
A. Helisch ◽  
P. Bartenstein ◽  
I. Buchmann
Keyword(s):  
Acute Myeloid Leukaemia ◽  
Myeloid Leukaemia ◽  
Primary Tumour ◽  
The Other ◽  
Haematopoietic Stem Cell ◽  
Other Hand ◽  
Primary Reduction ◽  
The One ◽  
Acute Myeloid

SummaryThe prognosis of patients with acute myeloid leukaemia (AML) has improved considerably by introduction of aggressive consolidation chemotherapy and haematopoietic stem cell transplantation (SCT). Nevertheless, only 20-30% of patients with AML achieve long-term diseasefree survival after SCT. The most common cause of treatment failure is relapse. Additionally, mortality rates are significantly increased by therapy-related causes such as toxicity of chemotherapy and complications of SCT. Including radioimmunotherapies in the treatment of AML and myelodyplastic syndrome (MDS) allows for the achievement of a pronounced antileukaemic effect for the reduction of relapse rates on the one hand. On the other hand, no increase of acute toxicity and later complications should be induced. These effects are important for the primary reduction of tumour cells as well as for the myeloablative conditioning before SCT.This paper provides a systematic and critical review of the currently used radionuclides and immunoconjugates for the treatment of AML and MDS and summarizes the literature on primary tumour cell reductive radioimmunotherapies on the one hand and conditioning radioimmunotherapies before SCT on the other hand.

Hidden “holes” in the capital of banks and the supply of credit to the real sector of economy

2018 ◽  
pp. 49-68 ◽  
Author(s):  
M. E. Mamonov
Keyword(s):  
Credit Risk ◽  
The Other ◽  
Real Sector ◽  
Capital Management ◽  
Loan Loss ◽  
Short Term ◽  
The Real ◽  
Ex Post ◽  
The One

Our analysis documents that the existence of hidden “holes” in the capital of not yet failed banks - while creating intertemporal pressure on the actual level of capital - leads to changing of maturity of loans supplied rather than to contracting of their volume. Long-term loans decrease, whereas short-term loans rise - and, what is most remarkably, by approximately the same amounts. Standardly, the higher the maturity of loans the higher the credit risk and, thus, the more loan loss reserves (LLP) banks are forced to create, increasing the pressure on capital. Banks that already hide “holes” in the capital, but have not yet faced with license withdrawal, must possess strong incentives to shorten the maturity of supplied loans. On the one hand, it raises the turnovers of LLP and facilitates the flexibility of capital management; on the other hand, it allows increasing the speed of shifting of attracted deposits to loans to related parties in domestic or foreign jurisdictions. This enlarges the potential size of ex post revealed “hole” in the capital and, therefore, allows us to assume that not every loan might be viewed as a good for the economy: excessive short-term and insufficient long-term loans can produce the source for future losses.

Sign in / Sign up

Export Citation Format

Share Document