title: Factors affecting post-release dispersal, mortality, and territory settlement of endangered kokako translocated from two distinct song neighborhoods

authors: Bradley, David William

subjects: Callaeas wilsoni

abstract: Animal translocation success rate is generally low, with the causes of failure poorly understood without comprehensive and protracted monitoring. Here we examine the outcome of a translocation of endangered North Island kokako (Callaeas wilsoni) from two adjacent song neighborhoods in New Zealand, each with individual vocal traditions (c. 75% of phrases unshared) to a single release site. We conducted detailed radio-telemetry to monitor post-release dispersal over 50 days during four serial releases of 20 birds while we broadcast neighborhood-specific song around the release site. The birds moved substantial distances after release, however overall short-term release site dispersal was not as great as predicted by a random walk model, suggesting an attraction to playback and/or a reluctance to explore areas away from the release site. This apparent attraction was not specific to a given song neighborhood, however. Although the post-release mortality rate (22% over 31 days) was relatively high in this translocation, we did not detect an effect of sex, age, source origin, or duration of captivity on mortality. We show that habitat use during this acclimation period was disproportionate to availability – the birds’ preferred habitat was similar to that at the capture site. At least four pairs formed, with two and three confirmed breeding in the first and second seasons post-release respectively. Mate choice was non-assortative with respect to song neighborhood, revealing that reduced phrase sharing rates found in adjoining neighborhoods are not a barrier to pair formation. We compare this example with other kokako translocations and make recommendations for future translocations.

text: Factors affecting post-release dispersal, mortality, and territory settlement of endangered kokako translocated from two distinct song neighborhoods Animal translocation success rate is generally low, with the causes of failure poorly understood without comprehensive and protracted monitoring. Here we examine the outcome of a translocation of endangered North Island kokako (Callaeas wilsoni) from two adjacent song neighborhoods in New Zealand, each with individual vocal traditions (c. 75% of phrases unshared) to a single release site. We conducted detailed radio-telemetry to monitor post-release dispersal over 50 days during four serial releases of 20 birds while we broadcast neighborhood-specific song around the release site. The birds moved substantial distances after release, however overall short-term release site dispersal was not as great as predicted by a random walk model, suggesting an attraction to playback and/or a reluctance to explore areas away from the release site. This apparent attraction was not specific to a given song neighborhood, however. Although the post-release mortality rate (22% over 31 days) was relatively high in this translocation, we did not detect an effect of sex, age, source origin, or duration of captivity on mortality. We show that habitat use during this acclimation period was disproportionate to availability – the birds’ preferred habitat was similar to that at the capture site. At least four pairs formed, with two and three confirmed breeding in the first and second seasons post-release respectively. Mate choice was non-assortative with respect to song neighborhood, revealing that reduced phrase sharing rates found in adjoining neighborhoods are not a barrier to pair formation. We compare this example with other kokako translocations and make recommendations for future translocations.

year: 2012

title: Processing, microstructure and mechanical properties of TiₓAlᵧ/Al₂O₃ and Al₂Ti₄C₂/TiₓAlᵧ/Al₂O₃/TiC composites

authors: Cai, Z.H.

abstract: The TiₓAlᵧ/Al₂O₃ metal-ceramic composites materials [TiₓAlᵧ is α-Ti(Al,O), Ti₃Al, or TiAl] and Al₂Ti₄C₂/TiₓAlᵧ/Al₂O₃/TiC ceramic-ceramic composites with different volume fractions of ceramic reinforcement phases were synthesized using a complex combination of high energy mechanical milling, thermal treatment and powder consolidation processes. The thermal treatment process included reactions between carbon and TiO₂, and between Al and TiO₂, TiO₃ or TiOₙC₁₋ₙ, which was produced by reacting TiO₂ and carbon. Heat treating C/TiO₂ composite powder produced pure TiO₃. Pure TiO could not be obtained by only increasing the carbon to TiO₂ ratio in the C/TiO₂ composite powder. Instead, TiOₙC₁₋ₙ solid solution was formed. Reaction kinetic studies showed that higher carbon to TiO₂ ratios accelerated the reaction due to refinement of the C/TiO₂ composite structure. Reactions between Al and TiOₙC₁₋ₙ formed Al₂Ti₄C₂/Al₂O₃ ceramic-ceramic composite. When the aluminum content of the starting Al/TiOₙC₁₋ₙ composite powders was increased, Al₂Ti₄C₂ still formed, but small amounts of Ti₃Al or TiAl also formed. Producing TiC from Al and TiOₙC₁₋ₙ reaction depended on the value of n in the TiOₙC₁₋ₙ phase. When n is small enough, TiC formed; otherwise TiC did not form.

This study found that fully dense matrix phase of TiₓAlᵧ/Al₂O₃ and Al₂Ti₄C2/TiₓAlᵧ/Al₂O₃/TiC formed after sintering at 1550°C. The Al₂O₃ particles became fully sintered when the composites were sintered at 1650°C but not at 1550°C. The Al₂O₃ particles in the α-Ti(Al,O) and Ti₃Al based composites had a high coarsening rate above 1550°C, indicating that the oxygen and Al diffusion rates of α-Ti(Al,O) and Ti₃Al are very high at these temperatures. The Al₂O₃ particles in TiAl based composites also had a high coarsening rate above 1550°C, caused by TiAl being liquid at these temperatures. The Al₂O₃ particles in the Al₂Ti₄C₂/TiₓAlᵧ/Al₂O₃/TiC based composites had a much lower coarsening rate because of the Al₂Ti₄C₂ matrix the lower oxygen content and high melting point decreases oxygen and aluminum mobility.

The size and volume fraction of Al₂O₃ particles in the composites strongly affected the mechanical properties of the TiₓAlᵧ and Al₂Ti₄C₂ based composites. Hardness of α-Ti(Al,O), Ti₃Al, and Al₂Ti₄C₂ based composites was 800-1600 VHN and hardness of TiAl based composites was 150-500 VHN. Bending strength of TiₓAlᵧ/Al₂O₃ composites was 105-230 MPa and bending strength of Al₂Ti₄C₂/TiₓAlᵧ/Al₂O₃/TiC based composites was 250-460 MPa. It appeared that 10 μm might be the critical size of Al₂O₃ particles. Below 10 μm bending strength dramatically improved with deceasing the Al₂O₃ particle size in the composites. The fracture toughness of these composites was 2-4.5MPa•m¹/². Composite hardness increased and bending strength decreased with increasing Al₂O₃ particle size and volume fraction.

text: Processing, microstructure and mechanical properties of TiₓAlᵧ/Al₂O₃ and Al₂Ti₄C₂/TiₓAlᵧ/Al₂O₃/TiC composites The TiₓAlᵧ/Al₂O₃ metal-ceramic composites materials [TiₓAlᵧ is α-Ti(Al,O), Ti₃Al, or TiAl] and Al₂Ti₄C₂/TiₓAlᵧ/Al₂O₃/TiC ceramic-ceramic composites with different volume fractions of ceramic reinforcement phases were synthesized using a complex combination of high energy mechanical milling, thermal treatment and powder consolidation processes. The thermal treatment process included reactions between carbon and TiO₂, and between Al and TiO₂, TiO₃ or TiOₙC₁₋ₙ, which was produced by reacting TiO₂ and carbon. Heat treating C/TiO₂ composite powder produced pure TiO₃. Pure TiO could not be obtained by only increasing the carbon to TiO₂ ratio in the C/TiO₂ composite powder. Instead, TiOₙC₁₋ₙ solid solution was formed. Reaction kinetic studies showed that higher carbon to TiO₂ ratios accelerated the reaction due to refinement of the C/TiO₂ composite structure. Reactions between Al and TiOₙC₁₋ₙ formed Al₂Ti₄C₂/Al₂O₃ ceramic-ceramic composite. When the aluminum content of the starting Al/TiOₙC₁₋ₙ composite powders was increased, Al₂Ti₄C₂ still formed, but small amounts of Ti₃Al or TiAl also formed. Producing TiC from Al and TiOₙC₁₋ₙ reaction depended on the value of n in the TiOₙC₁₋ₙ phase. When n is small enough, TiC formed; otherwise TiC did not form.

This study found that fully dense matrix phase of TiₓAlᵧ/Al₂O₃ and Al₂Ti₄C2/TiₓAlᵧ/Al₂O₃/TiC formed after sintering at 1550°C. The Al₂O₃ particles became fully sintered when the composites were sintered at 1650°C but not at 1550°C. The Al₂O₃ particles in the α-Ti(Al,O) and Ti₃Al based composites had a high coarsening rate above 1550°C, indicating that the oxygen and Al diffusion rates of α-Ti(Al,O) and Ti₃Al are very high at these temperatures. The Al₂O₃ particles in TiAl based composites also had a high coarsening rate above 1550°C, caused by TiAl being liquid at these temperatures. The Al₂O₃ particles in the Al₂Ti₄C₂/TiₓAlᵧ/Al₂O₃/TiC based composites had a much lower coarsening rate because of the Al₂Ti₄C₂ matrix the lower oxygen content and high melting point decreases oxygen and aluminum mobility.

The size and volume fraction of Al₂O₃ particles in the composites strongly affected the mechanical properties of the TiₓAlᵧ and Al₂Ti₄C₂ based composites. Hardness of α-Ti(Al,O), Ti₃Al, and Al₂Ti₄C₂ based composites was 800-1600 VHN and hardness of TiAl based composites was 150-500 VHN. Bending strength of TiₓAlᵧ/Al₂O₃ composites was 105-230 MPa and bending strength of Al₂Ti₄C₂/TiₓAlᵧ/Al₂O₃/TiC based composites was 250-460 MPa. It appeared that 10 μm might be the critical size of Al₂O₃ particles. Below 10 μm bending strength dramatically improved with deceasing the Al₂O₃ particle size in the composites. The fracture toughness of these composites was 2-4.5MPa•m¹/². Composite hardness increased and bending strength decreased with increasing Al₂O₃ particle size and volume fraction.

year: 2002

title: Research support in New Zealand University Libraries

authors: Howie, Jess

abstract: Researcher-facing librarians in New Zealand are providing guidance across more of the research lifecycle than ever before in response to an increasingly complex scholarly ecosystem. This research explored the development of research support through survey responses from all eight New Zealand University Libraries. From the responses it was possible to ascertain the level of services offered or planned in the four key areas of research impact, Research Data Management, scholarly communication and Kaupapa Māori research. Skills gaps and barriers to service development were also identified. Comparison with an earlier study revealed that research impact and Research Data Management services have developed well over the last 6 years. A good level of maturity was identified in scholarly communication services but support for Kaupapa Māori research was identified as an area for development. Barriers to service development included lack of resourcing and low recognition of library value from the wider institution.

text: Research support in New Zealand University Libraries Researcher-facing librarians in New Zealand are providing guidance across more of the research lifecycle than ever before in response to an increasingly complex scholarly ecosystem. This research explored the development of research support through survey responses from all eight New Zealand University Libraries. From the responses it was possible to ascertain the level of services offered or planned in the four key areas of research impact, Research Data Management, scholarly communication and Kaupapa Māori research. Skills gaps and barriers to service development were also identified. Comparison with an earlier study revealed that research impact and Research Data Management services have developed well over the last 6 years. A good level of maturity was identified in scholarly communication services but support for Kaupapa Māori research was identified as an area for development. Barriers to service development included lack of resourcing and low recognition of library value from the wider institution.

year: 2019-01-01