Glenn Aguilar

The house crow (Corvus splendens): a threat to New Zealand?

The house crow (Corvus splendens), a native of the Indian subcontinent, has shown a rapid expansion of habitat range across Eastern Africa, the Arabian Peninsula, Europe and Asia. It is an adaptable, gregarious commensal bird which is regarded globally as an important pest species due to its impacts on livestock, agricultural and horticultural crops and indigenous fauna and as a fecal contaminator of human environments and water resources. Two Maxent (v3.3.3k) models (A) with presence data in Australia and (B) with simulated entry data locations in New Zealand) and a third ArcGIS model (C) with environmental and social layers) are used to determine an overall suitability index and establish a niche-based model of the potential spatial distribution for C. splendens within New Zealand. The results show that New Zealand, particularly the northern regions of North Island, has suitable environments for the establishment of the house crow. In order of suitability Model B showed highest potential land area suitability (31.84%) followed by Model A (13.79%) and Model C (10.89%). The potential for further expansion of this bird’s invasive range is high and, if New Zealand is invaded, impacts are likely to be significant.

A performance based consensus approach for predicting spatial extent of the Chinese windmill palm (Trachycarpus fortunei) in New Zealand under climate change

Abstract The predicted distribution of the Chinese Windmill Palm ( Trachycarpus fortunei ) was modelled using several algorithms with inputs consisting of occurrence information and bioclimatic datasets. A global species distribution model was developed and projected into New Zealand to provide a visualization of suitability for the species in current and future conditions. To ensure model robustness, occurrence data was checked for redundancy, spatial auto-correlation and the environmental variables checked for cross-correlation and collinearity. The final maps predicting suitability resulted from ensembling the predictions of all the algorithms. The resulting ensembled maps were weighted based on the evaluation parameters AUC, Kappa and TSS. When reclassified into low, medium and high suitability categories, results show an expansion of high suitability areas accompanied by a reduction of low suitability areas for the species. The centroids of the high suitability areas also exhibit a general movement towards the Southwest under future climate conditions. The range expansion was proportional with the representative values of emission trajectories RCPs (2.5, 4.5, 6.0 and 8.5) used in projecting into future conditions. The movement magnitude and direction of predicted high suitability area centroids for the palm supports the use of the plant as an indicator of climate change.

Assessment of a Targeted Trap-Neuter-Return Pilot Study in Auckland, New Zealand

Simple Summary It is generally accepted that stray cats need to be managed to minimise the associated negative impacts and there is a need for effective and humane management tools. One such potential tool is trap-neuter-return (TNR), which anecdotally has been used in New Zealand to manage stray cats, but no concerted and targeted implementation of this technique has been reported, nor any formal assessments conducted. A targeted TNR (TTNR) programme for urban stray cats was implemented and assessed in one Auckland suburb. Assessment was based on the number of incoming felines; stray, unsocialised cats euthanased; unsocialised, unowned cats sterilised and returned (independently of the TTNR programme); and neonatal/underage euthanasias. Incoming stray feline, underage euthanasia, and unsocialised stray cat euthanasia numbers all reduced for the targeted suburb when these outcome measures were compared for the years before and after the programme. These outcome measures had a greater reduction in the targeted suburb compared to the other Auckland suburbs not targeted by the TTNR programme, although causation cannot be inferred, as a variety of reasons could have contributed to the changes. This pilot programme suggests that TTNR could be a valuable humane cat management tool in urban New Zealand, and further assessment is warranted. Abstract There is a need for effective and humane management tools to manage urban stray cats and minimise negative impacts associated with stray cats. One such tool is targeted trap-neuter-return (TTNR), but no concerted implementation of this technique or formal assessments have been reported. To address this deficit, a TTNR programme was implemented and assessed in one Auckland suburb from May 2015 to June 2016; the programme sterilised and returned 348 cats (4.2 cats/1000 residents). Assessment was based on the number of incoming felines; stray, unsocialised cats euthanased; unsocialised, unowned cats sterilised and returned (independently of the TTNR programme); and neonatal/underage euthanasias. Incoming stray felines, underage euthanasias, and unsocialised stray cat euthanasias were all reduced for the targeted suburb when compared for the years before and after the programme (the percentage reduction in these parameters was −39, −17, −34, −7, and −47, respectively). These outcome measures had a greater reduction in the targeted suburb compared to the Auckland suburbs not targeted by the TTNR programme (p < 0.01), although causation cannot be inferred, as a variety of reasons could have contributed to the changes. This pilot programme suggests that TTNR could be a valuable, humane cat management tool in urban New Zealand, and further assessment is warranted.

The Philippine Indigenous Outrigger Boat: Scaling Up, Performance and Safety

The traditional indigenous double outrigger crafts, called banca boats, of the Philippines vary in size from the very small 4 meter single crew paddle boats to large 50 meter fishing vessels and passenger ferry boats. Regardless of size, the same construction techniques are used by native boat builders with wood as the main building material. Many hull forms, particularly economically important fishing boats, have been scaled up, resulting in problems related to the availability of wood for construction, safety at sea, and performance. Model experiments on craft performance show the hydrodynamic characteristics of the double outrigger form and describe characteristics important for design, construction, and operation of the crafts. The presence of outriggers has a definite effect on the heave, pitch, and roll motion of the craft as compared to the hull without an outrigger. Data analyses of maritime incident reports show a high percentage of capsizing by these motorized banca boats, highlighting the need for some regulation of their design and construction. Other concerns related to fisheries as being the main area of use of these boats are further discussed. large size outrigger crafts were already in existence. Today, the basic unit of Philippine government, the “barangay” was named after these vessels that were used in the islands before the Spanish came. The Spaniards noted the navigational skill of Filipinos, particularly the Bisaya (from the Visayas Regions) who used a compass found among the Malays and Chinese. Legaspi, an early Spanish explorer, captured a Moro in Butuan and noted that he was “...a most experienced man who had much knowledge, not only of matters concerning these Filipinas Islands, but those of Maluco, Borney, Malaca, Java, India, and China, where he had had much experience in navigation and trade.” (Blair and Robertson, 1903). Such navigational skill would have been developed through a tradition of constant voyaging and exploration where seasonal winds are favorable and literally blow boats and their passengers from one part to another.