Manage one beach or two? Movements and space-use of the threatened hooded plover (Thinornis rubricollis) in south-eastern Australia

2009 ◽  
Vol 36 (4) ◽  
pp. 289 ◽  
Author(s):  
Michael A. Weston ◽  
Glenn C. Ehmke ◽  
Grainne S. Maguire

An understanding of space use and dispersal of a wildlife species is essential for effective management. We examined the movements of a beach-dwelling, threatened population of hooded plover (Thinornis rubricollis) in southern central Victoria, Australia, by analysing sightings of colour-banded birds (4897 sightings; 194 birds tracked for up to 9 years). Most movements were relatively short (5050 ± 305 m), with 61.4% <1 km and 95.3% <20 km; they lacked directional or sexual bias. The extent of coastline used by individual birds was 47.8 ± 58.0 km. Regional differences in average distances moved by adults were apparent. For adults, movement rates (mean distance per day) were higher during the non-breeding season than during the breeding season. Non-breeding adults generally remained close to their partners (non-breeding, 456.3 ± 163.9 m; breeding, 148.2 ± 45.3 m). Largest flock sizes were recorded during the non-breeding period, and flocking was not uniformly distributed along the coast but appeared to be concentrated in particular locations. The frequency of pair cohesion (i.e. when the distance between partners was zero on a given day) was similar during the breeding (69.6%) and non-breeding seasons (67.7%). Breeding territories (kernel analysis) were 36.7 ± 5.7 ha and overlapped from year to year in all cases (23 pairwise comparisons; 47.9 ± 7.1% overlap). The high fidelity and constancy of territories confirms they warrant ongoing management investment, although the species relies on a matrix of breeding and non-breeding sites. The latter appear to occur in specific parts of the coast and warrant enhanced protection and more research attention. Fragmentation of the breeding population might occur where habitat is rendered unsuitable for > ~50 km.

2018 ◽  
Vol 88 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Maurizio Fraissinet ◽  
Lucio Bordignon ◽  
Massimo Brunelli ◽  
Matteo Caldarella ◽  
Enzo Cripezzi ◽  
...  

The Black Stork Ciconia nigra, following an expansion on European scale, started breeding in Italy in 1994 with one pair in the Piedmont Region and one in the Calabria Region. Since then, the breeding pairs established in Italy have progressively increased up to 18 in 2016, and they are currently in Piedmont, Lazio, Campania, Molise, Apulia, Basilicata and Calabria. However, the number of breeding pairs could be higher than 20, as indicated by records and observations of adults and juveniles, during the breeding period in potentially suitable nesting areas. Despite the low population density in Italy, the trend in the breeding population in Northwest and in Southern Central regions seems to show a slight and high increase respectively. Productivity, breeding success and fledging rate have been considered and analysed. A difference between the two macro areas has been found in the choice of nesting sites, which is on trees for Northwest couples, and cliffs for Southern Central couples. It is necessary to further explore the reason why the small Northwest population does not show any increase and range expansion compared to the Southern Central one.


1984 ◽  
Vol 11 (3) ◽  
pp. 579 ◽  
Author(s):  
CJ Limpus ◽  
A Fleay ◽  
V Baker

The Bundaberg coast is the southern limit for reproduction by Chelonia depressa in eastern Australia. Here the species lays 2.84 � 0.78 (mean � SD) clutches per breeding season with a renesting interval of 15.99 � 1.89 days. When successful nesting does not occur on a nesting crawl the female returns after 1.17 � 1.07 d for another attempt. The mean remigration interval is 2.65 � 0.92 years and the average female is estimated to have a reproductive life of between 2.05 and 2.55 breeding seasons. The estimated annual recruitment rate of neonate nesting females into this colony is 27.2 � 10.8% of the population. The females return repetitively with a high degree of accuracy to the same small nesting beach within a single breeding season and in successive breeding seasons. The reproductive strategy of C. depressa compared with that of other sea turtles appears to involve an increase in hatchling size, to reduce predation, achieved by laying relatively large eggs. However, only a few small clutches are laid in a breeding season, so that seasonal fecundity for the species is low relative to that in other sea turtles such as C. mydas. Because its reproductive life is longer, C. depressa has a total fecundity only slightly less than that of C. mydas.


2013 ◽  
Vol 24 (1) ◽  
pp. 72-87 ◽  
Author(s):  
STEFANIE M. H. ISMAR ◽  
TOM TRNSKI ◽  
TONY BEAUCHAMP ◽  
SARAH J. BURY ◽  
DAVID WILSON ◽  
...  

SummaryNo published information is available on the foraging ecology and choice of feeding habitat of New Zealand’s rarest breeding bird: the New Zealand Fairy Tern (NZFT) Sternula nereis davisae. To address this gap, we conducted an assessment of the largest remaining breeding population at Mangawhai Harbour, Northland, New Zealand, during the chick-rearing period of the 2010/2011 breeding season. We combined visual tracking of birds with prey surveys and stable isotope analyses, and we present the first quantitative assessment of NZFT foraging. We recorded 405 foraging dives that show NZFT foraging habitat includes the water edges, shallow channels, and pools on the tidal flats of mangrove-lined (Avicennia marina var. resinifera) parts of the estuary; tidal pools on mud- and sandflats in the mid-estuary and lower harbour; the shallow margins of the dredged main channel in the lower harbour; the oxbow lagoons on the sand spit; and coastal shallows. Our study identifies the mangrove-lined highly tidal and shallow mid-estuary and the lagoon on the sand spit as foraging hotspots for the Mangawhai breeding population of the NZFT. The prey survey employed a seine-net sampling method at identified NZFT foraging sites and yielded 4,367 prey-sized fish of 11 species, two of which had not previously been reported in Mangawhai Harbour, as well as numerous shrimps. The most abundant fish were gobies of the genus Favonigobius. Our stable isotope results highlight gobies as the most important prey for NZFT chick rearing, also indicating that flounder Rhombosolea sp. contribute to NZFT diet. We raise the possibility that shrimps may also constitute a substantial diet component for NZFT, potentially providing up to 21% of diet mass for adult birds. While our results provide a first basis to understanding the feeding ecology of NZFT during their breeding season in order to facilitate conservation planning, further research is required to address inter-annual variation and to identify key foraging grounds for this Critically Endangered bird at other breeding sites.


1991 ◽  
Vol 21 (6) ◽  
pp. 813-820 ◽  
Author(s):  
Donald L. Copes ◽  
Richard A. Sniezko

Reproductive bud phenology from 1983 through 1989 limited potential outcross efficiency to a maximum of 58 to 87%, in a Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) clonal orchard near Monmouth, Oregon. Potential outcross efficiency was calculated for 20 clones from dates of male and female bud opening and pollination mechanism information. Cool weather before bud opening of the earliest clones delayed and compressed the breeding period and resulted in a greater percentage of trees having synchronous periods of pollen release and receptive seed strobili. Length of breeding season among years averaged 20 days and ranged from 16 to 27 days. Differences in phenology significantly impacted the breeding system because the overall breeding period of the orchard clones exceeded the 8-day receptive period of individual clones by two or three times and often prohibited or limited potential outcrossing between the earliest and latest clones. Outcrossing was greatest in clones with intermediate phenology and least in the earliest clones. The breeding system appears to be an almost continuous series of overlapping breeding subpopulations. Each year's breeding subpopulations were different from those of other years because of large shifts in rank order of bud opening by 10 to 20% of the clones and because of great differences in the length of breeding season. Average temperature during March was linearly associated with time of floral bud opening. Geneticists may be able to use average temperature of the 4-week periods prior to opening of the earliest floral buds as a tool to identify seed crops formed during years with compressed breeding seasons. Such seed crops have potential of being more diverse than do seed crops produced during years with extended breeding seasons. Use of procedures in this report will allow tree-improvement workers to calculate the maximum outcross efficiency of each seed crop produced by their orchards.


2019 ◽  
Vol 36 ◽  
pp. 1-8 ◽  
Author(s):  
Rodrigo Morais ◽  
Luiz Carlos Araújo ◽  
Gleidson Ramos Silva ◽  
Charles Duca

This study describes aspects of the life history of the Tropical MockingbirdMimusgilvus(Vieillot, 1808), including the breeding period, clutch size, nestlings and a list of plants used for nesting. Nests were monitored in an area of Restinga (sand-coastal plain) habitat in a protected area in southeastern Brazil. The data from 181 nests during five breeding seasons (2010-2014) showed that the Tropical Mockingbird has a long breeding season (26.1 ± 2.6 weeks) with up to two peaks of active nests from August to March. The breeding pairs made up to four nesting attempts in the same breeding season. The mean (± SD) clutch size was 2.4 ± 0.6 eggs (n = 169). The mean (± SD) incubation period was 14 ± 0.6 days, and the nestling remained in the nest for 14.5 ± 2.2 days. The nests were built on thirty plant species, andProtiumicicariba(DC.) Marchand. was the plant species most commonly used for nesting. The breeding parameters of the Tropical Mockingbird are similar to those of other Mimidae species. The knowledge gained from this study makes the Tropical Mockingbird a good choice for future studies, particularly for testing ecological and evolutionary hypotheses regarding life history attributes, habitat selection and parental investment.


2002 ◽  
Vol 12 (3) ◽  
pp. 255-268 ◽  
Author(s):  
Rafael A. Dias ◽  
Giovanni N. Maurício

Saffron-cowled Blackbird Xanthopsar flavus is a globally threatened icterid of open areas of south-eastern South America. Several sources suggest that the species is declining throughout its range, mainly due to habitat destruction. Between December 1997 and December 1999 we studied a breeding population of X. flavus at the Banhado do Vinte-e-Cinco and Banhado da Mulata area, Rio Grande municipality, Rio Grande do Sul state, Brazil. This population, previously unreported for the state's coastal plain, numbers at least 60 individuals and seems confined to an area of c. 35 km2. The area is characterized by Cyperacaea-dominated peat marshes in comparatively higher terrain, covered with sandy, rolling fields. The species was recorded in all months (not necessarily of the same year) except March, and a marked irregularity in flock size was detected. During the non-breeding period, flock size averaged 12.7 individuals (S.D. = 11.7; range = 2-37; n = 11). During the 1997-1998 breeding season (December to January), mean flock size was 25.3 individuals (S.D. = 16.2; range = 16-60; n = 7), while in the 1998-1999 and 1999-2000 breeding seasons, 33 and 4 individuals were recorded respectively. No pronounced discrepancy was found in the size of the largest flocks recorded per season (from 20 to 37 individuals), suggesting that the population is sedentary and that it undertakes only local movements. A nesting colony occupying the same part of the marsh in two successive breeding seasons was composed of six breeding pairs in 1997-1998, with an estimated nesting success of 31.8-36.3% at fledgling time. The species is highly gregarious and sociable, foraging flocks frequently following individuals of Black-and-White Monjita Heteroxolmis dominicana and, to a lesser extent, Yellow-rumped Marshbird Pseudoleistes guirahuro and Brown-and-yellow Marshbird P. virescens. Although habitat loss has been indicated as the main factor for the species' decline, we suggest that habitat perturbation and modification may affect negatively recruitment rates in the species and, theoretically, its overall population size. Furthermore, the conservation of Rio Grande's peat marshes should be regarded a regional priority, in order to preserve threatened birds and a very unusual wetland type.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8785
Author(s):  
Tao Liu ◽  
Yongtao Xu ◽  
Bai Mo ◽  
Jinze Shi ◽  
Yachang Cheng ◽  
...  

The home range size and habitat use of the blue-crowned laughingthrush (Garrulax courtoisi, hereafter BCLT), a critically endangered, subtropical, cooperative-breeding bird species in southeast China, were studied during its breeding period using radio telemetry at different sites during 3 consecutive years (2016–18, from May to June of each year). A total of 17 birds (12 males, four females, and one of unknown sex) were tagged, and a total 1515 locations (mean ± se = 89.12 ± 11.42) were obtained over 54 days of tracking. The average 100% minimum convex polygon (MCP) home range size was 10.05 ± 1.17 ha, and the estimated KDE core area (fiexed kernel density estimator, KDE) size was 7.84 ± 1.18 ha. According to the Wilcoxon rank sum tests, both the 100% MCP and KDE core area size of males did not significantly differ from those of females. There were no significant differences in the 100% MCP or KDE core area sizes of the three breeding sites. The available habitats in the breeding sites included water areas, shrubs, grass plots, woodland, residential areas, vegetable field, farmland, and sandy beaches; among them, only woodland was significantly preferred by BCLTs. Woodland (average use ratio was 45.86 ± 1.74%) was strongly preferred by BCLTs for nesting, foraging and roosting. Shrubs/grass plots (24.72 ± 3.39%) and vegetable plots (11.80 ± 1.83%) were used relatively more often than the other habitats, except woodland, since shrubs were always used as perches, and vegetable plots were rich in food resources. Vertically, the canopy layer was used most often from April to June, but it was used most in May when the birds were hatching and brooding. This result indicates that BCLT is predominantly active in the upper strata during the breeding season. In addition, broadleaved trees within or adjacent to villages were important activity areas for the breeding birds; protection and management measures should be increased in these areas.


2005 ◽  
Vol 53 (4) ◽  
pp. 213 ◽  
Author(s):  
Wouter F. D. van Dongen ◽  
Larissa L. Yocom

The breeding biology of Australian passerines is characterised by long breeding seasons and the potential to produce multiple broods within a single season. However, many species undergo a yearly migration from their breeding sites to climatically milder wintering grounds. This migratory behaviour may impose constraints on the breeding biology of these species. We studied a migratory population of golden whistlers (Pachycephala pectoralis) at Toolangi State Forest, Victoria. Individuals typically arrived in early September, attempted to produce a single successful brood over a 3-month period and departed again in late April. Both site- and pair-fidelity were high, with an average of 66% of males returning to the same site, re-pairing with the same female in up to 100% of cases. Nest predation was common, with 45% of nesting attempts failing due to predation. Each pair initiated an average of 1.7 nests per season, resulting in an average of 1.2 fledglings per pair each season. The short breeding season and single-broodedness of the golden whistlers at Toolangi is atypical amongst Australian passerines and suggests that constraints may be imposed on species undergoing annual migration. In this regard, golden whistlers show more similarities to Northern Hemisphere migratory passerines than to the sedentary passerines of the Southern Hemisphere.


2009 ◽  
Vol 21 (3) ◽  
pp. 237-241 ◽  
Author(s):  
John van den Hoff ◽  
Clive R. McMahon ◽  
Iain Field

AbstractDuring the late 19th and early 20th centuries, when blubber oil fuelled house lamps, the king penguin population at Macquarie Island was reduced from two very large (perhaps hundreds of thousands of birds) colonies to about 3000 birds. One colony, located on the isthmus when the island was discovered in 1810, was extinct by 1894 and it took about 100 years for king penguins to re-establish a viable breeding population there. Here we document this recovery. The first eggs laid at Gadget Gully on the isthmus were recorded in late February 1995 but in subsequent years egg laying took place earlier between November and February (this temporal discontinuity is a consequence of king penguin breeding behaviour). The first chick was hatched in April 1995 but the first fledging was not raised until the following breeding season in October 1996. The colony increased on average 66% per annum in the five years between 1995 and 2000. King penguins appear resilient to catastrophic population reductions, and as the island's population increases, it is likely that other previously abandoned breeding sites will be reoccupied.


2020 ◽  
Author(s):  
Joseph M. Eisaguirre ◽  
Travis L. Booms ◽  
Christopher P. Barger ◽  
Stephen B. Lewis ◽  
Greg A. Breed

AbstractIn populations of many taxa, a large fraction of sexually mature individuals do not breed but are attempting to enter the breeding population. Such individuals, often referred to as “floaters” play critical roles in determining dynamics and stability of these populations. Floaters are difficult to study, however, so we lack data on the roles they play in population ecology and conservation status of many species. Here, we paired satellite telemetry and a new mechanistic space use model based on an Ornstein-Uhlenbeck process to study the differential habitat selection and space use of floater and territorial golden eagles Aquila chrysaetos. Our sample consisted of 49 individuals tracked over complete breeding seasons across four years, totalling 104 eagle breeding seasons. Modeling these data with the new mechanistic approach was required to parse key differences in movement and separate aspects of resource selection from central place behavior. We found that floaters generally had more expansive space use patterns and larger home ranges, partitioning space with territorial individuals seemingly on fine scales through differential habitat and resource selection. Floater and territorial eagle home ranges overlapped markedly, suggesting floaters use the interstices between territories. Further, floater and territorial eagles differed in how they selected for uplift variables, key components of soaring birds’ energy landscape, with territorial eagles apparently better able to find and use thermal uplift. We also found relatively low individual heterogeneity in resource selection, especially among territorial individuals, suggesting a narrow realized niche for breeding individuals. This work furthers our understanding of floaters’ potential roles in population ecology of territorial species, as well as suggests that conserving landscapes occupied by territorial eagles also protects floaters.


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