Lk Gentle

Microsatellite loci in the crested newt (Triturus cristatus) and their utility in other newt taxa

A.P. Krupa1, R. Jehle1, D.A. Dawson1, L.K. Gentle1, M. Gibbs1, J.W. Arntzen2 & T. Burke1,∗ 1Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK; 2National Museum of Natural History, P.O. Box 9517, 2300 RA Leiden, The Netherlands, and Universidade do Porto, Unidade de Genetica Animal e Conservacao, Campus Agrario de Vairao, Rua de Monte, Crasto, 4480 Vila do Conde, Portugal (∗Corresponding author: E-mail: T.A.Burke@sheffield.ac.uk)

Conditioning pigeons to discriminate naturally lit insect specimens.

Pigeons (Columba livia) were trained on a visual discrimination task using a novel apparatus which enabled pinned specimens of insects, illuminated by natural daylight, to be presented under a pecking key transparent to ultraviolet light. Three birds showed evidence of learning to discriminate between sets of wasp and fly specimens. This response transferred to specimens of four hoverfly species, the strength of the response varying between the different hoverfly species. This conditioning technique offers a promising means of analysing mechanisms of visual processing in birds that are relevant to theories of the evolution of camouflage and mimicry.

Identifying individual wild Eastern grey wolves (Canis lupus lycaon) using fundamental frequency and amplitude of howls

The use of amplitudes to identify individuals has historically been ignored by bioacoustic researchers due to problems of attenuation. However, recent studies have shown that amplitudes encode identity in a variety of mammal species. Previously, individuality has been demonstrated in both fundamental frequency (F0) and amplitude changes of captive Eastern wolf (Canis lupus lycaon) howls with 100% accuracy where attenuation of amplitude due to distance was controlled in a captive environment. In this study, we aim to determine whether both fundamental frequency and amplitude data collected from vocalizations of wild wolves recorded over unknown distances, in variable conditions and with different recording equipment, can still encode identity. We used a bespoke code, developed in Matlab, to extract simple scalar variables from 67 high-quality solo howls from 10 wild individuals and 112 chorus howls from another 109 individuals, including lower quality howls with wind or water noise. Principal component analysis (PCA) was carried out on the fundamental frequency and normalized amplitude of harmonic 1, yielding histogram-derived PCA values on which discriminant function analysis was applied. An accuracy of 100% was achieved when assigning solo howls to individuals, and for the chorus howls a best accuracy of 97.4% was achieved. We suggest that individual recognition using our new extraction and analysis methods involving fundamental frequency and amplitudes together can identify wild wolves with high accuracy, and that this method should be applied to surveys of individuals in capture–mark–recapture and presence–absence studies of canid species.

Improving individual identification in captive Eastern grey wolves (Canis lupus lycaon) using the time course of howl amplitudes

Many bioacoustic studies have been able to identify individual mammals from variations in the fundamental frequency (F0) of their vocalizations. Other characteristics of vocalization which encode individuality, such as amplitude, are less frequently used because of problems with background noise and recording fidelity over distance. In this paper, we investigate whether the inclusion of amplitude variables improves the accuracy of individual howl identification in captive Eastern grey wolves (Canis lupus lycaon). We also explore whether the use of a bespoke code to extract the howl features, combined with histogram-derived principal component analysis (PCA) values, can improve current individual wolf howl identification accuracies. From a total of 89 solo howls from six captive individuals, where distances between wolf and observer were short, we achieved 95.5% (+9.0% improvement) individual identification accuracy of captive wolves using discriminant function analysis (DFA) to classify simple scalar variables of F0 and normalized amplitudes. Moreover, this accuracy was increased by 100% when using histogram-derived PCA values of F0 and amplitudes of the first harmonic. We suggest that individual identification accuracy can be improved by including amplitude changes for species where F0 has only been included so far. Using DFA on PCA values of both F0 and amplitude could optimize vocal identification in a range of mammal bioacoustic studies.

The breeding performance of raptors in urban landscapes: a review and meta-analysis

AbstractGlobal urbanisation is rapidly increasing and can have profound impacts on wild flora and fauna. For many species, the impacts are detrimental and irreversible, whereas others are able to colonise and apparently thrive in these novel, human-made environments. Raptors are particularly susceptible to changes in the environment due to their position at the end of the food chain, yet some species are increasingly associated with towns and cities. To explore the impact of urbanisation on raptors, we reviewed the literature and compared breeding performance in urban and rural populations globally. In general, raptors began breeding earlier and had larger brood sizes in urban compared to rural environments. However, some of these raptors also fledged fewer young in urban habitats, apparently caused largely by a lack of prey and, in some cases, increased human disturbance. As such, urban environments may act as ecological traps for some raptor species. Species differed in their response to urbanisation. In particular, specialist bird predators such as Peregrine Falcons (Falco peregrinus) had a higher breeding performance (clutch size, brood size, number to fledge and nest success) and showed a positive response to urbanisation compared to those that predate on small mammals, such as Eurasian Kestrels (F. tinnunculus), which showed a negative response. This suggests that prey availability is one of the most important determinants of the success of urban-nesting raptors. We demonstrate a need for continued research into the breeding performance of raptors that live in urban environments, and stress the importance of focusing on the reasons for any differences in breeding performance between urban and non-urban environments in order to aid conservation and management efforts for this iconic bird group.ZusammenfassungBrutleistung von Greifvögeln in städtischen Landschafen: Überblick und Meta-Analyse Global nimmt die Urbanisierung rapide zu und kann wesentlichen Einfluss haben auf Flora und Fauna. Für viele Arten sind die Auswirkungen schädlich und unumkehrbar, während andere in der Lage sind, sich anzusiedeln und in diesen neuen anthropogenen Umgebungen aufzublühen. Greifvögel sind aufgrund ihrer Position am Ende der Nahrungskette besonders empfindlich für Veränderungen in der Umwelt, und trotzdem sind manche Arten zunehmend typisch für städtische Umgebungen. Um den Einfluss der Urbanisierung auf Greifvögel zu untersuchen, gingen wir die Literatur durch und verglichen die Brutleistung in urbanen und ländlichen Populationen weltweit. Insgesamt begannen Greifvögel früher zu brüten und hatten größere Bruten in städtischen im Vergleich zu ländlichen Umgebungen. Allerdings wurden bei einigen der Greifvögel weniger Jungtiere flügge in urbanen Umgebungen, anscheinend größtenteils aufgrund von Beutemangel und, in manchen Fällen, stärkerer Störung durch Menschen. Insofern könnten städtische Umgebungen als ökologische Falle für manche Greifvogelarten wirken. Die Arten unterschieden sich in ihrer Reaktion auf die Urbanisierung. Insbesondere hatten Arten wie der Wanderfalke (Falco peregrinus), deren Hauptbeute Vögel sind, eine höhere Brutleistung (Gelegegröße, Brutgröße, Anzahl von flüggen Jungvögeln und Bruterfolg) und zeigten eine positive Reaktion auf die Urbanisierung, im Gegensatz zu Arten, die im wesentlich auf Kleinsäuger jagen wie der Turmfalke (F. tinnunculus), die eine negative Reaktion zeigten. Das legt nahe, dass die Verfügbarkeit von Beute eine der wichtigsten Determinanten ist für den Erfolg von stadtbrütenden Greifvögeln. Wir zeigen die Notwendigkeit einer fortgesetzten Erforschung der Brutleistung von Greifvögeln in Städten auf und betonen die Notwendigkeit, sich auf die Gründe für jegliche Unterschiede in der Brutleistung zwischen urbanen und ländlichen Umgebungen zu konzentrieren, um die Bemühungen um Schutz und Management dieser Vogelarten zu unterstützen.

Characterization of 38 microsatellite loci in the European blackbird, Turdus merula (Turdidae, AVES)

We characterized 38 microsatellite loci in the European blackbird, Turdus merula. Thirty‐seven loci were identified by testing 242 loci that had been originally isolated in other avian species. One additional locus was isolated from a European blackbird genomic library. All loci were characterized in 20–29 blackbirds from a population in the Czech Republic and displayed between two and 16 alleles, with observed heterozygosity ranging from 0.04 to 1.00. Thirty‐seven loci could be assigned a chromosome location in the zebra finch (Taeniopygia guttata) genome based on sequence homology.

Evidence of an urban Peregrine Falcon (Falco peregrinus) feeding young at night

Peregrine Falcons (Falco peregrinus) are typically considered diurnal raptors; thus, the majority of studies on the nesting and hunting behavior of the species have been carried out during the day in rural/natural areas (e.g., Carlier 1993, Carlier and Gallo 1994, Palmer et al. 2003). Nevertheless, early morning (Byre 1990) and late night (Sick 1961) hunting has been observed occasionally in urban environments. Furthermore, studies of prey remains indicate that urban Peregrines may feed on nocturnal species, including bats, as well as species that are typically secretive throughout the day and fly mostly at night, including Jack Snipe (Lymnocryptes minimus) and Western Water Rail (Rallus aquaticus; Drewitt and Dixon 2008); although this latter finding may suggest that Peregrines hunt nocturnally, it does not provide conclusive evidence. Following their population recovery, peregrines are frequently found nesting in urban areas. As a result, nests can be accessed with relative ease and many urban nests (e.g., Winnipeg, Canada; New York City, U.S.A.; Brisbane, Australia; Brussels, Belgium; Rome, Italy) now have cameras that stream live footage on the internet day and night, providing an opportunity to study nesting behaviors in detail. Thus, nocturnal behaviors at the nests are increasingly observed. For example, in Derby, U.K., a web camera documented adults bringing in and plucking a live Eurasian Woodcock (Scolopax rusticola), female Greenwinged Teal (Anas crecca) and Eurasian Collared-Dove (Streptopelia decaocto) at around 2300 H on each occasion; these were delivered to the nest in December, March (when there were no nestlings), and May, respectively, and it was thought that the prey items were cached rather than eaten on the night when they were caught (N. Brown pers. comm.). However, the frequency of nocturnal hunting is not entirely clear. More rarely, the nocturnal feeding of young at the nest has been observed. In Warsaw, Poland, Rejt (2004) monitored a single nest for two breeding seasons (2000 and 2002) between 2000 H and 0400 H and found that nocturnal feedings occurred on 59% of the total observed nights in 2000 (n 1⁄4 34) and 76% of the total observed nights in 2002 (n 1⁄4 21). Rejt (2004) suggested that this behavior might result from the pair taking advantage of the city lights, individual fitness, availability of prey, and/ or weather conditions. Video archives from the pair nesting in Derby also showed evidence of nocturnal feeding of young (Derby Cathedral Peregrine Project 2012). However, the extent to which this nocturnal behavior occurs is unknown, likely because many nest observers do not watch the birds during the night. Here, we compare the nocturnal behaviors observed at three nest sites in the U.K. Recordings of streamed web-cameras were made using screen-capture software for later analysis as part of a larger study on the parental care of urban Peregrines. Nests were located in Chichester, Sheffield, and Nottingham in England, U.K. We collected and analyzed 1800 hr of footage, 451 hr of which were recorded between 2200 H and 0400 H (Chichester, n 1⁄4 127; Sheffield, n 1⁄4 208; Nottingham, n 1⁄4 116). We observed nighttime feeding at only one nest (Fig. 1A); in Nottingham, on four occasions the adult male visited the nest (Table 1), bringing with him what appeared to be smallto medium-sized birds (though on one occasion possibly a bat). On average, the male visited the nest for 10 min 36 sec and fed the chicks for 8 min 4 sec (Table 1). During the night feedings, the female remained at the nest; she brooded the nestlings (n1⁄44) for the entire night, only lifting slightly when they were being fed (Fig. 1B). The male did not feed the female on any of the occasions. The nestlings were fed a further eight times during the day on 27 April and nine times during the day on 30 April (recording stopped at 1737 H that day, thus the recording was incomplete), and it is therefore likely that the adults were providing an adequate number of birds during the day, which may suggest that prey availability was not low. The lunar phase was in its third quarter on 27 April and there was a full moon on 30 April; the impact of the lunar phase on nocturnal hunting and feeding warrants further investigation. We observed no nocturnal feeding of young at either Chichester or Sheffield. Both nests produced fewer young 1 Email address: esther.kettel02@ntu.ac.uk

Eliciting a predatory response in the eastern corn snake (Pantherophis guttatus) using live and inanimate sensory stimuli: implications for managing invasive populations

North Americas eastern corn snake (Pantherophis guttatus) has been introduced to several islands throughout the Caribbean and Australasia where it poses a significant threat to native wildlife. Invasive snake control programmes often involve trapping with live bait, a practice that, as well as being costly and labour intensive, raises welfare and ethical concerns. This study assessed corn snake response to live and inanimate sensory stimuli in an attempt to inform possible future trapping of the species and the development of alternative trap lures. We exposed nine individuals to sensory cues in the form of odour, visual, vibration and combined stimuli and measured the response as rate of tongue-flick (RTF). The RTF was significantly higher in odour and combined cues treatments, and there was no significant difference in RTF between live and inanimate cues during odour treatments. Our findings suggest chemical cues are of primary importance in initiating investigatory behaviours and that an inanimate odour stimulus, absent of simultaneous visual and vibratory cues, is potentially a low-cost alternative trap lure for the control of invasive corn snake populations.

Breeding performance of an apex predator, the peregrine falcon, across urban and rural landscapes

Urban environments present wildlife with major challenges and yet surprising numbers of species have colonised towns and cities globally. Despite the growing realisation that urban centres can be important habitats for wildlife, why some species do better than others in urban environments remains poorly understood. Here, we compare the breeding performance of an apex predator, the peregrine falcon (Falco peregrinus), in urban and rural environments, and test whether variation in reproductive success between and within environments is driven by prey. Historical breeding data were collected from raptor study groups across Great Britain between 2006 and 2016, from 22 urban and 58 rural nest sites, involving 101 and 326 nesting attempts, respectively. Prey density, biomass and diversity around the individual nests was estimated using modelled estimates from a national bird census. Urban peregrines produced more fledglings and had a higher overall nesting success (i.e. whether a nesting attempt was successful or unsuccessful) than rural peregrines. Prey density and biomass were significantly higher, and diversity significantly lower, in the urban sites, and explained the variation in reproductive success within both the urban and rural environments. Therefore, urban environments in Great Britain appear to provide peregrine falcons with superior habitats in terms of prey availability compared to rural habitats. We conclude that some apex predators can benefit from urban environments and that urban planning has the potential to benefit biodiversity across many trophic levels.

Ghost crab burrow density at Watamu Marine National Park: an indicator of the impact of urbanisation and associated disturbance?

Ghost crab (Ocypode species) burrow densities have previously been used as an indicator of anthropogenic impact. This study aimed to assess the burrow density of Ocypode species (O. ryderi and O. cordimanus) at four sites across Watamu Marine National Park, Kenya. Two sites were in front of hotel complexes (denoting a high degree of urbanisation), and two were in front of residential housing among coastal scrub (denoting a low degree of urbanisation). The findings reveal significantly higher burrow densities at sites in front of residential housing, which was the less developed area. This provides further evidence that Ocypode burrow densities can be used, where other methods would be impractical, to estimate the impact of some human activities along beach fronts, such as at Watamu Marine National Park.