scholarly journals Assessing multiple threats to seabird populations using flesh-footed shearwaters Ardenna carneipes on Lord Howe Island, Australia as case study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chris Wilcox ◽  
Nicholas Carlile ◽  
Britta Denise Hardesty ◽  
Tim Reid
Keyword(s):  
Breeding Success ◽  
Housing Development ◽  
Road Mortality ◽  
Population Demographics ◽  
Seabird Conservation ◽  
Lord Howe Island ◽  
Demographic Rates ◽  
Weak Evidence ◽  
Additional Equipment ◽  
Conservation And Management

AbstractGlobally, seabird populations have been in decline due to multiple threats throughout their range. Separating simultaneous pressures is challenging and can require significant amounts of data over long periods of time. We use spatial contrasts to investigate the relative importance of several drivers for the purported decline in a species listed as in decline as an example species, the Flesh-footed shearwater (Ardenna carneipes). On Lord Howe Island in the Tasman Sea, Australia, this seabird suffers from habitat loss due to housing development, intensive mortality in fisheries, plastic ingestion, and roadkill due to vehicular traffic on its breeding island. We repeated a quantitative survey of the population to ascertain whether the decline previously reported had continued and to evaluate the purported mortality sources (Reid et al. in PLoS ONE 8(4):e58230, 2013, Lavers et al. in Global Ecol Conserv 17:e00579, 2019). We measured burrow density, area of occurrence, occupancy and breeding success, integrating them with previous surveys using a Bayesian statistical model to generate longer term estimates of demographic rates. We used spatial patterns to test whether mortality on roads or proximity to human habitation was influencing population demographics. In contrast to predictions, we found the population had stabilised or increased. Characteristics such as burrow occupancy and breeding success showed little pattern, with weak evidence for impacts from road mortality and housing development. Such a data-rich approach is substantially more informative and can better support seabird conservation and management efforts does require more field-time and additional equipment than most contemporary surveys, the data is substantially more informative and can better clarify the results of efforts in seabird conservation and management.

scholarly journals Variation among colonies in breeding success and population trajectories of wandering albatrosses Diomedea exulans at South Georgia

Polar Biology ◽  
2021 ◽  
Author(s):  
Carola Rackete ◽  
Sally Poncet ◽  
Stephanie D. Good ◽  
Richard A. Phillips ◽  
Ken Passfield ◽  
...  
Keyword(s):  
Body Condition ◽  
Breeding Success ◽  
Population Trends ◽  
Contributing Factors ◽  
South Georgia ◽  
Vortex Model ◽  
Demographic Rates ◽  
Diomedea Exulans ◽  
Adult Body ◽  
Provisioning Rate

AbstractThe wandering albatross, Diomedea exulans, is a globally threatened species breeding at a number of sites within the Southern Ocean. Across the South Georgia archipelago, there are differences in population trends even at closely located colonies. Between 1999 and 2018 the largest colony, at Bird Island, declined at 3.01% per annum, while in the Bay of Isles, the decline was 1.44% per annum. Using mean demographic rates from a 31-year study at Bird Island and an 11-year study of breeding success at Prion Island in the Bay of Isles in a VORTEX model, we show that differences in breeding success do not fully explain observed differences in population trends. Other potential contributing factors are differential use of foraging areas, with possible knock-on effects on adult body condition, provisioning rate and breeding success, or on bycatch rates of adults or immatures.

scholarly journals The breeding biology of the Critically Endangered Seychelles Scops-owl Otus insularis: consequences for conservation and management

2004 ◽  
Vol 14 (2) ◽  
pp. 123-137 ◽  
Author(s):  
DAVE CURRIE ◽  
RODNEY FANCHETTE ◽  
JAMES MILLETT ◽  
CAMILLE HOAREAU ◽  
NIRMAL J. SHAH
Keyword(s):  
Breeding Success ◽  
Sex Roles ◽  
Montane Forest ◽  
Breeding Biology ◽  
Critically Endangered ◽  
Restricted Range ◽  
Conservation Implications ◽  
Tree Cavities ◽  
Conservation And Management

The endemic Seychelles Scops-owl Otus insularis is a Critically Endangered restricted-range species currently recorded only from the montane forest of Mahé, the largest (152 km2) and highest (903 m) island in the granitic Seychelles. Limited research has been conducted on the species and, in particular, details of its breeding biology are poorly known. Behavioural observations were made on 12 pairs by the systematic monthly use of playback of conspecific calls, in conjunction with frequent non-playback territory visits from April 1999 to May 2001. A total of eight nests, including the first nest record, were found on three territories. All were in tree cavities (7–25 m high) and contained either a single egg or chick. This was consistent with additional observations of solitary fledglings (n = 11, from eight territories). Incubation lasted 3–4 weeks and the fledging period was 4–6 weeks (data from two nests). The timing of copulations, in conjunction with the detection of nests and fledglings, suggests that the scops-owl can breed throughout the year with peaks in nesting occurring around May and October. Sex roles during breeding were similar to those of other Strigidae owls: incubation was performed by the female; males courtship-fed the female prior to and during incubation, and the female and chick for the first 2 weeks post-hatching; and both parents fed older chicks and fledglings. Fledglings remained on territory for at least 3 months. Breeding success of study pairs was low: two of eight nests were successful and 11 fledglings (recorded from eight of 12 study territories) were observed in a 26-month period, equivalent to c. 0.5 fledglings per territory per year. Evidence suggests that alien predators may have been a factor limiting breeding success. We discuss the conservation implications of our findings.

Thinking about populations

2019 ◽  
pp. 303-310
Author(s):  
Louis W. Botsford ◽  
J. Wilson White ◽  
Alan Hastings
Keyword(s):  
Population Dynamics ◽  
Environmental Variability ◽  
Spatial Models ◽  
General Role ◽  
State Variable ◽  
Demographic Rates ◽  
Extinction Probabilities ◽  
Age Replacement ◽  
Coherent Body ◽  
Conservation And Management

This chapter describes some general ways of thinking about population dynamics as a coherent body of interrelated advances in understanding, as developed in the first eleven chapters. The first generality is that understanding population dynamics depends on the concept of a state variable. It also underscores that dynamics depend on time delays, thus on age, even though demographic rates may ultimately depend more on size than age. Replacement plays a general role in dynamics, influencing both behavior at equilibrium and the time scales at which populations respond to environmental variability. Replacement even retains its importance in spatial models, where it is related to the same replacement threshold as in non-spatial models. Additionally, the way in which the distribution of reproduction (i.e. replacement) over age “filters” environmental variability influences extinction probabilities. The chapter closes by discussing how lessons from this book will guide conservation and management in a changing climate.

scholarly journals Spatial synchrony of breeding success in the blacklegged kittiwake Rissa tridactyla reflects the spatial dynamics of its sandeel prey

2020 ◽  
Vol 638 ◽  
pp. 177-190
Author(s):  
AB Olin ◽  
NS Banas ◽  
PJ Wright ◽  
MR Heath ◽  
RG Nager
Keyword(s):  
Spatial Patterns ◽  
Breeding Success ◽  
Spatial Dynamics ◽  
Weather Conditions ◽  
Rissa Tridactyla ◽  
Demographic Rates ◽  
Long Term Trends ◽  
Underlying Mechanisms ◽  
The Uk

Synchrony in demographic rates between spatially disjunct populations is a widespread phenomenon, although the underlying mechanisms are often not known. This synchrony and its spatial patterns can have important consequences for the long-term persistence of metapopulations and can also be used to infer drivers of population dynamics. Here, we examined spatial patterns of synchrony in the breeding success of black-legged kittiwakes Rissa tridactyla in the UK, using an extensive dataset on kittiwake breeding success and 2 different ways of measuring synchrony: one reflecting synchrony in inter-annual fluctuations only (rdiff) and one reflecting synchrony in both inter-annual fluctuations and long-term trends (r). We found that between-colony synchrony in breeding success decreased with distance up to just over 200 km but that some colony pairs showed stronger or weaker synchrony than expected based on distance. This was also reflected in the configuration of spatially coherent clusters of kittiwake colonies with synchronous breeding success. Further, we compared the support for different drivers of these spatial patterns, including trophic interactions and weather conditions. We found that the spatial dynamics of the kittiwakes’ main prey in this region, the lesser sandeel Ammodytes marinus, appeared to play some role in generating synchrony in long-term patterns, but their role in generating synchrony in inter-annual fluctuations was less clear. The study shows that examining spatial patterns in synchrony can provide useful information for inferring potential drivers and the spatial scale over which they are acting.

Climate change and breeding success: decline of the capercaillie in Scotland

2001 ◽  
Vol 70 (1) ◽  
pp. 47-61 ◽  
Author(s):  
Robert Moss ◽  
James Oswald ◽  
David Baines
Keyword(s):  
Climate Change ◽  
Breeding Success

A Medieval Burial from Graham Street, Leith, Edinburgh

2003 ◽  
Vol 25 (2) ◽  
pp. 165-169
Author(s):  
Paul R. J. Duffy ◽  
Olivia Lelong
Keyword(s):  
Contextual Information ◽  
Human Remains ◽  
Housing Development ◽  
Archaeological Research ◽  
Archaeological Excavation ◽  
Radiocarbon Dates ◽  
Physical Evidence ◽  
Research Division ◽  
The North ◽  
The Individual

Summary An archaeological excavation was carried out at Graham Street, Leith, Edinburgh by Glasgow University Archaeological Research Division (GUARD) as part of the Historic Scotland Human Remains Call-off Contract following the discovery of human remains during machine excavation of a foundation trench for a new housing development. Excavation demonstrated that the burial was that of a young adult male who had been interred in a supine position with his head orientated towards the north. Radiocarbon dates obtained from a right tibia suggest the individual died between the 15th and 17th centuries AD. Little contextual information exists in documentary or cartographic sources to supplement this scant physical evidence. Accordingly, it is difficult to further refine the context of burial, although a possible link with a historically attested siege or a plague cannot be discounted.

Sign in / Sign up

Export Citation Format

Share Document