Cognition in a changing world: Red-headed Gouldian finches enter spatially unfamiliar habitats more readily than do black-headed birds

Human activities are increasingly confronting animals with unfamiliar environmental conditions. For example, habitat change and loss often lead to habitat fragmentation, which can create barriers of unsuitable and unfamiliar habitat affecting animal movements and survival. When confronted with habitat changes, animals’ cognitive abilities play an important, but often neglected part in dealing with such change. Animals must decide whether to approach and investigate novel habitats (spatial neophilia) or whether to avoid them (spatial neophobia) due to potential danger. For species with strict habitat preferences, such as the Gouldian finch (Erythrura gouldiae), which is an open habitat specialist, understanding these novelty responses may be especially important for predicting responses to habitat changes. The Gouldian finch is a polymorphic species, with primarily red or black head colors, which are linked to differing behavioral phenotypes, including novelty reactions. Here we investigate responses to novel habitats (open, dense) in the Gouldian finch, manipulating the color composition of same-sex pairs. Two experiments, each consisting of novel open and novel dense habitat, tested birds in opposite head color combinations in the two experiments. We measured the number of approaches birds made (demonstrating conflict between approach and avoidance), and their entry latency to novel habitats. Gouldian finches showed more approach attempts (stronger approach-avoidance conflict) towards the dense as compared to the open habitat, confirming their open habitat preferences. Black-headed birds also hesitated longer to enter the dense habitat as compared to the open habitat, particularly in experiment 1, appearing less neophilic than red-headed birds, which showed similar entry latencies into both habitat types. This is surprising as black-headed birds were more neophilic in other contexts. Moreover, there was some indication that pairings including at least one black-headed bird had a stronger approach-avoidance conflict than pairings of pure red-headed birds. Results suggest that the black-headed birds use a cognitive strategy typical for residents, whereas red-headed birds use a cognitive strategy known for migrants/nomads, which may cognitively complement each other. However, as 70% of the population in the wild are black-headed, the spatial wariness we document could be widespread, which may negatively affect population persistence as habitats change

Preliminary analysis of NT AUSRIVAS data. Technical A + D Memorandum 99/5

Made available by the Northern Territory Library via the Publications (Legal Deposit) Act 2004 (NT).Date:1999-0

A survey of the fish fauna of the Roper River near Jude's Crossing in the late dry season 2013

The objective of the study was to assess appropriate sampling methods for quantitative description of fish communities within different stream habitats. Trials were conducted of the efficacy of bankside observation, gill-netting, and baited underwater video stations. The work is a recursor to the establishment of an environmental monitoring program linked to potential reductions in dry season flow.' - Executive sumaryIntroduction -- Methods -- Results -- Discussion -- Acknowledgements -- References -- Appendices 1-6.Made available via the Publications (Legal Deposit) Act 2004 (NT

Patterns in Macroinvertebrate Community Composition & Recommendations for Monitoring in the Daly River System.

Made available by the Northern Territory Library via the Publications (Legal Deposit) Act 2004 (NT).Date:200

A predictive model for assessment of stream health in the Darwin-Daly region of the Northern Territory using mostly genus level data

This is the first report in a series that will document the location and status of selected faunal assemblages on the Northern Territory coastline, offshore islands and Top End floodplains. It addresses colonial waterbird breeding sites and includes species of egrets, herons, cormorants and ibises, and the Australian Pelican, Darter and Royal Spoonbill. Little information existed on the location and status of waterbird breeding colonies in the Top End (north of latitude 16 o 35'S) of the Northern Territory prior to 1990. Information gathered during aerial and ground surveys primarily between 1990 and 1999 have subsequently shown that the coast and major floodplains of the Top End have nationally and globally significant numbers of colonial nesting waterbirds, particularly Intermediate, Great, Little and Cattle Egrets. Seventy-six colonies, confirmed active during the survey period, are here documented. The majority of these colonies were located during surveys by the author, while a few were listed from evidence provided by reliable informants during the survey period. Colonies were distributed around most of the coast and larger coastal floodplains, extending inland for no further than about 40 kilometres. The most important areas for colonial waterbird breeding were the floodplains between the Moyle and Finniss Rivers and between the Adelaide River and Murgenella Creek. The least important areas were the Tiwi Islands, Cobourg Peninsular, Groote Eylandt and most of the northern part of the Gulf of Carpentaria. Apart from two small colonies on Low Rock and Haul Round Island, no islands supported colonial waterbird breeding (their importance was for seabird breeding and will be discussed in a subsequent report). The vast majority of the colonies were located on either Aboriginal land or pastoral leasehold land. Only 5% of colonies occurred on conservation reserves. This is an issue in need of consideration in the future. Stands of mangrove or paperbark trees were strongly preferred as breeding sites, with some species of waterbird preferring one or the other for nesting sites, while others were found breeding equally in both types. Fifteen species of waterbird breed at these sites, with individual sites having between 1 and 11 species. Colony sizes varied from the low tens to 15000+ adults. As well as having nationally significant numbers of colonies and numbers of birds within them, Top End colonies are important because most are active every year, unlike many colonies in southern Australia. Breeding begins as early as November when Cattle Egrets commence nesting, and continues through to October when the later-breeding Darter, Australian White Ibis and Royal Spoonbill are finishing. The longest duration of any single colony was from November to August. A further 52 colonies, which are not discussed in the main body of the report, have been listed as confirmed breeding colonies in the past, or possible breeding colonies at present. These mostly include colonies that were located from the air but require further investigation for confirmation, and sites appearing in historical records (ie prior to 1990) that may no longer be used, or were unable to be located from the information available. All confirmed colonies are individually detailed in Appendix B and possible colonies in Appendix C. The fauna of the Top End of the Northern Territory is in a very unique position. Not only is there an immense amount of habitat which holds large populations of many species, but most of the area is very remote and has not been subject to many of the pressures associated with large human populations. Although this is likely to remain the case for at least the short term, it is equally likely that the pressures of human expansion within Australia will see some of this area targeted for development at some stage in the more distant future. It is for this eventuality that we must be prepared. We must ensure the security of the more significant of these colonies before problems arise.Summary -- Reference site selection procedures -- Timing of sample collection -- Laboratory analyses of macroinvertebrate samples -- Model construction methods -- Model assessment -- Conclusions -- References -- Appendices.Date:2004Made available via the Publications (Legal Deposit) Act 2004 (NT

Phytoplankton communities of East Arm in Darwin Harbour

Phytoplankton communities of East Arm of Darwin Harbour were described to provide reference data for the assessment of potential future impacts on water quality. A total of ninety six samples were collected and analysed from four sites in East Arm on 24 occasions from June 2010 to June 2012. Two hundred and thirty five phytoplankton taxa were identified from nine major taxonomic groups including Bacillariophyceae, Chlorophyceae, Chrysophyceae, Euglenophyceae, Dictyochophyceae, Prasinophyceae, Dinophyceae and Cyanobacteria.Introduction -- Methods -- Results and Discussion -- Acknowledgements -- References -- Appendices.Made available via the Publications (Legal Deposit) Act 2004 (NT

Evidence from a survey of macroinvertebrate communities and water quality in the early dry season 2001

Made available by the Northern Territory Library via the Publications (Legal Deposit) Act 2004 (NT).The focus of this assessment is benthic macroinvertebrate community structure and the measurement of complementary water quality variables. This study aims to develop this capacity and to provide preliminary assessment of the ecological health of stream systems in the Darwin area. The study area includes the Darwin Harbour catchment and the catchments of creeks and rivers eastward to the Howard River which enter Shoal Bay to the north-east of Darwin.Executive summary -- Introduction -- Methods -- Results -- Discussion -- Acknowledgements -- References -- Appendice

Dry season water quality and macroinvertebrate assemblages in Rapid Creek: an urban stream in the monsoonal tropics of northern Australia

This report presents results of an assessment of ecological condition based on data from 2012 and 2013, and the comparison of test site data in Rapid Creek with a large dataset from reference sites in the Darwin-Daly region. The report describes intra-seasonal variation in water quality parameters but does not attempt to identify or quantify potential contaminants in either run-off waters or within the stream.' - IntroductionIntroduction -- Methods -- Results and discussion -- Acknowledgements -- ReferencesMade available via the Publications (Legal Deposit) Act 2004 (NT