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    Effects of urban noise on vocalisations of tūī (Prosthemadera novaeseelandiae) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Auckland, New Zealand
    (Massey University, 2015) Ludbrook, Miriam Robin
    The two most important functions of avian acoustic communication are territory defence and mate attraction. As such the effective communication of these signals is critical for individual reproductive success. However if these vocal signals are masked by anthropogenic noise, their signal efficiency is reduced and this may result in direct negative fitness consequences. Therefore knowledge on how urban habitat features including anthropogenic noise affect avian vocal communication is important in understanding the evolution of animal communications in urban ecosystems. Such knowledge is also important for the management of endangered and declining species in urban areas. Little is known about how birds respond to the highly variable levels of urban noise in urban habitats. In this study I investigated spectral and temporal differences in songs between populations of tūī (Prosthemadera novaeseelandiae) in urban habitats with both high noise levels (near motorway) and lower noise levels (distant from motorway). Male long-range tūī songs were collected during the breeding season (October 2012 to February 2013) at three paired sites, with one of each pair situated within 100m of a motorway and the matching site within 2-3 kilometres from the first site and the motorway. Urban noise levels (dB) were measured at all sites. I compared motorway and non-motorway urban songs to determine whether tūī shift the frequency, duration, trill components and output of songs in response to anthropogenic noise. Songs were also recorded at two paired non-urban sites over 50 kilometres from the urban sites (Mahurangi Regional Park and Wenderholm Regional Park) and spectral characteristics were also compared between these non-urban and the urban sites. I compared song rate and singing rate to investigate whether song output varied with noise levels and between urban and non-urban habitats. Through comparison of the degree of syllable sharing and proportion of unique syllables and phrases at these sites, I explored the presence of song dialects at urban and non-urban sites. From 63.5 hours of field sampling, I collected a total of 1017 long-range broadcast songs (627 songs from motorway sites and 390 songs from nonmotorway sites). A significantly higher minimum frequency was found in songs III from the noisier, motorway sites compared with those from non-motorway sites. Motorway songs had shorter song durations and decreased syllable diversity than non-motorway songs. There were also a significantly lower proportion of trills in the songs at sites near to motorway. As predicted a smaller syllable repertoire size was found in the sites near the motorway compared to repertoires at nonmotorway sites. The presence of site-specific syllables and phrases and site-specific clusters in a Ward cluster analysis, as well as a reduced degree of syllable sharing between urban sites indicated the formation of local dialects in these fragmented urban sites. This study has provided data of bird song variation within urban ecosystems of varying noise levels. These findings aid our understanding of modifications to tūī songs to avoid the masking effects of low frequency traffic noise. Song duration, trill proportion and repertoire size have all been demonstrated as being subject to sexual selection. Changes in these aspects at noisy urban sites are considered adaptations to urban effects. Such changes may have further implications for other important behavioural aspects such as mate choice and can have profound effects on tūī population dynamics between urban fragments. Understanding these urban effects on bird songs and other important behavioural aspects are important not only for advances in ecological theory in urban ecology, but also for conservation management of urban habitats. For example, dialects between urban fragments may create a reproductive barrier for dispersing birds, therefore reducing gene flow between sites. Habitat corridors should be considered in urban designs, not only to increase gene flow of species with poor dispersal ability, but may also help to connect populations of highly mobile species such as tūī.
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    Vocalisations of the New Zealand morepork (Ninox novaeseelandiae) on Ponui Island : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Zoology at Massey University, Palmerston North, New Zealand
    (Massey University, 2015) Brighten, Alex
    Vocalisations provide an effective way to overcome the challenge of studying the behaviour of cryptic or nocturnal species. Knowledge of vocalisations can be applied to management strategies such as population census, monitoring, and territory mapping. The New Zealand Morepork (Ninox novaeseelandiae) is a nocturnal raptor and, to date, there has been little research into their vocalisations even though this offers a key method for monitoring morepork populations. Although not at risk, population monitoring of morepork will help detect population size changes in this avian predator which may prey on native endangered fauna and may suffer secondary poisoning. This study investigated the vocal ecology of morepork on Ponui Island, Hauraki Gulf, New Zealand from April 2013 to April 2014. The initial goal was to develop a monitoring method for morepork. However, due to a lack of detailed basic knowledge of their vocalisations, the primary objective shifted to filling that knowledge gap and providing baseline data for future research. The aims of this study were thus to characterise all of the calls given by the morepork on the island; to investigate spectral and temporal parameters of three main calls; to plot the amount of calling across a night and a year; and to study the responses of morepork to playback calls. Eight morepork were caught using mist-nets and subsequently tracked by radio-telemetry. Vocalisations were recorded using manual and automatic digital sound recorders and calls were analysed with manual and automated sound analysis software. I described eleven distinct calls, referred to as more-pork, trill, rororo, more-more-pork, weow, low trill, copulation squeal, single hoot, distress squeak, chicketting and juvenile begging trill and I further analysed the spectral and temporal characteristics of three main calls, more-pork, trill and rororo. I found variation between individual morepork in acoustic parameters of these call types. I found no evidence of sexual variation in the fundamental frequency, fundamental duration nor inter-syllable duration of the three call types. However, sample sizes were small (2 males to 7 females) and a larger sample size would be needed to confirm these results. The average number of all morepork call types showed temporal variation both nightly and monthly. A low amount of calling in winter months compared to summer appeared to coincide with the morepork breeding cycle. The highest numbers of call were heard from November to January, with the numbers of calls during this period being significantly higher than in all other months. The number of calls per hour showed two peaks: one around the middle of the night and the other during the last hour of darkness. The number of calls heard in the first two hours after sunset were significantly lower than during the rest of the night. Playbacks were effective in eliciting responses from morepork, but the proportion of responses to playback was lower than to natural calls. Response rates did not seem to be affected by season. Session time and order of playback had an effect on proportional responses as well as playback call-type whereby rororo elicited the most responses and trill elicited the fewest. This project broadened our knowledge of morepork vocal ecology and therefore contributes to our knowledge of raptor vocal communication. The study also presents information and recommendations that will be useful to future research and also in management of morepork. In particular, this project provides background information needed to help develop protocols for acoustic monitoring of morepork. The techniques used in this study and the general results can be used or applied to studies of other nocturnal species.
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    The effect of nutrition and body condition of triplet-bearing ewes during late pregnancy on the behaviour of ewes and lambs
    (Asian-Australasian Journal of Animal Sciences, 2018-12) Gronqvist GV; Corner-Thomas RA; Kenyon PR; Stafford KJ; Morris ST; Hickson RE
    OBJECTIVE: Triplet-born lambs are less likely to survive to weaning than twin-born or single-born lambs. Appropriate ewe-lamb bonding behaviours and lamb vigour behaviours are necessary for survival of lambs. The aim of this experiment was to determine whether maternal nutrition during late pregnancy influenced behaviour of the ewe and her lambs soon after birth, and to determine whether mid-pregnancy body condition score (BCS) influenced any behavioural response. METHODS: The experiments included ewes that were in BCS 2.0, 2.5, or 3.0 in mid-pregnancy and were fed either ad libitum or to pregnancy-maintenance requirements in late-pregnancy (day 115 until 136 in experiment one, and day 128 until 141 in experiment two). The time taken for lambs to stand, contact dam, suck from dam and follow dam was recorded three to 18 h after birth. The number of high- and low-pitched bleats emitted by the ewe and lambs was recorded, along with maternal behaviour score (MBS) of the ewe. Lambs in experiment two underwent a maternal-recognition test at 12 or 24 h. RESULTS: There were significant effects of feeding treatment on bleating behaviour of ewes and lambs, but these were inconsistent among BCS groups and between experiments. Lamb vigour behaviours were not affected by feeding treatment. In experiment one, there was no effect of feeding treatment or BCS on MBS, but in experiment two, ewes in BCS3 in mid-pregnancy had greater MBS than ewes in BCS2 in mid-pregnancy (MBS 3.1/5 vs MBS 2.1/5; p<0.05). CONCLUSION: Given there were no repeatable effects on behaviour of ewes and lambs, ad libitum feeding rather than feeding for pregnancy-maintenance requirements cannot be used to improve behaviours soon after birth of triplet-bearing ewes in BCS 2-3 and their lambs in extensive pastoral conditions.