Home range and landscape use by a marabou stork and the breeding success of Africa's most southerly breeding colony

SummaryThe number of vultures is declining in many parts of the world due to numerous threats, such as poisoning and collisions with power-lines as well as the lack of adequate food sources. Vulture restaurants, i.e. supplementary feeding stations, have become a widespread conservation tool aimed at supporting vulture colonies. However, it is poorly understood how vulture restaurants influence population dynamics and whether they affect breeding success of vulture populations. We used a 12-year dataset from a breeding colony of the Cape Vulture Gyps coprotheres and a nearby vulture restaurant in South Africa to investigate the effect of supplementary food on population dynamics and breeding success. We found a significantly positive effect of supplementary food during the nest-building stage on the number of breeding pairs. However, breeding success, i.e. the proportion of successful nests, did not depend on supplementary food during the incubation and rearing stage. Especially during the critical rearing stage, the amount of food supplied might not have been sufficient to meet food demands of the colony. Still, our results indicate that carefully managed vulture restaurants might stabilise vulture colonies and can therefore aid vulture conservation.

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Inferred predation of Fairy Tern eggs by Ruddy Turnstones at Rottnest Island, Western Australia, an internationally significant shorebird site

10.20938/afo38115117 ◽

2021 ◽

Vol 38 ◽

pp. 115-117

Author(s):

C.N. Greenwell ◽

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Keyword(s):

Biodiversity Conservation ◽

Western Australia ◽

Breeding Success ◽

Behavioural Response ◽

Environment Protection ◽

Egg Predation ◽

Breeding Colony ◽

Wide Range ◽

Collective Group ◽

The Tropics

Ruddy Turnstones Arenaria interpres have been identified as egg-predators at seabird and shorebird colonies, including gull and tern colonies in the tropics and Northern Hemisphere. The Australian Fairy Tern Sternula nereis nereis is a threatened (Environment Protection and Biodiversity Conservation Act 1999: Vulnerable) coastal seabird, whose breeding behaviour and ecology expose it to a wide range of threats. This study describes inferred predation on Fairy Tern eggs at a small breeding colony on Rottnest Island, Western Australia, by Ruddy Turnstones, a previously unsuspected predator for thisspecies. Unlike the behavioural response shown towards Silver Gulls Larus novaehollandiae and Australian Ravens Corvus coronoides, which includes collective group defence and dive-bombing, Fairy Terns showed a lack of aggression towards Turnstones within the colony. The lack of a behavioural response suggests that the Terns did not recognise the Turnstones as predators, which may increase the risk of egg-predation. This study suggests that we should be alert to threats from unsuspected predators, which have the potential to reduce the breeding success of this Vulnerable tern.

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Applying home-range and landscape-use data to design effective feral-cat control programs

Wildlife Research ◽

10.1071/wr11097 ◽

2012 ◽

Vol 39 (3) ◽

pp. 258 ◽

Cited By ~ 24

Author(s):

Andrew J. Bengsen ◽

John A. Butler ◽

Pip Masters

Keyword(s):

Home Range ◽

Habitat Preferences ◽

South Australia ◽

Gps Tracking ◽

Feral Cat ◽

Feral Cats ◽

Small Areas ◽

Control Programs ◽

Spatial Coverage ◽

Landscape Use

Context Effective feral-cat (Felis silvestris catus) management requires a sound understanding of the ways cats use their environment. Key characteristics of landscape use by cats vary widely among different regions and different conditions. Aims The present study aimed to describe the most important characteristics of landscape use by feral cats on a large, human-populated island, and to use this information to guide the development of feral-cat management programs. Methods We used GPS tracking collars to record the movements of 13 feral cats at two sites on Kangaroo Island, South Australia, for between 20 and 106 days. We described home-range extents by using local convex hulls, and derived management suggestions from examination of home-range and movement data. Key results Median feral-cat home range was 5.11 km2, and this did not differ between sexes or sites. Cats at a fragmented pastoral site tended to favour woody vegetation over open paddocks, but habitat preferences were less clear at a bushland site. Cats that preferentially used treelines at the pastoral site were almost twice as likely to be recorded close to a tree-line junction as expected. Conclusions Control programs for feral cats on Kangaroo Island should deploy control devices at a density no less than 1.7 devices km–2. Spatial coverage should be as large as practicable or repeated frequently. Infrequent programs covering small areas can be expected only to provide short-term reductions in cat abundance. Implications The information gained from the present study will contribute to the development of strategic sustained management plans for feral cats on Kangaroo Island. The principles from which we inferred management guidelines are applicable to other regions and species.

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Impact of a major forest blowdown event on breeding of Ancient Murrelets, Synthliboramphus antiquus, at a colony in Haida Gwaii, British Columbia

The Canadian Field-Naturalist ◽

10.22621/cfn.v129i3.1730 ◽

2015 ◽

Vol 129 (3) ◽

pp. 285

Author(s):

Anthony J. Gaston ◽

Jake Pattison ◽

Ainsley Brown

Keyword(s):

British Columbia ◽

Breeding Success ◽

Sharp Decrease ◽

Haida Gwaii ◽

Breeding Colony

In the winter of 2010–2011 a large storm blew down an area of about 18 ha of mature coastal rainforest on East Limestone Island, Haida Gwaii, British Columbia. The area supported part of a breeding colony of Ancient Murrelets (Synthliboramphus antiquus). Observations of the timing of chick departures from this section of the colony in 2012 and 2013 suggested that daily timing of chick departures were delayed, on average, by about 30 min, compared with earlier years. This delay may have been caused by debris from the blowdown impeding the progress of chicks over the ground. A sharp decrease in the number of chicks leaving the blowdown area in 2014 may signify that some breeding pairs left the area following reduced breeding success.

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Ecstatic display calls of the Adélie penguin honestly predict male condition and breeding success

Behaviour ◽

10.1163/000579509x12512863752751 ◽

2010 ◽

Vol 147 (2) ◽

pp. 165-184 ◽

Cited By ~ 8

Author(s):

Dianne Brunton ◽

Allen Rodrigo ◽

Emma Marks

Keyword(s):

Frequency Modulation ◽

Breeding Success ◽

Female Mate Choice ◽

Adélie Penguin ◽

Honest Signal ◽

Pygoscelis Adeliae ◽

Breeding Colony ◽

Adelie Penguin ◽

Territory Defence ◽

Male Condition

AbstractThe Adélie penguin (Pygoscelis adeliae) breeds in large, noisy Antarctic colonies and has evolved a communication system of complex intra- and inter-sexual visual and vocal behaviours. The Ecstatic Display Call (EDC) given by males whilst at the breeding colony is composed of introductory beats, short repeated syllables and a climactic long syllable. Here, we show that spectral qualities of the short syllables of the EDC can predict body condition and breeding success and suggest that in addition to its role in territory defence, the EDC may function as an honest signal of male quality for female mate choice. In the short repeated syllables frequency modulation, mean frequency, and pitch were all significantly lower in birds of better condition, with frequency modulation changing concomitantly with changing condition during the breeding season. Furthermore, during the period of mate attraction, a male's frequency modulation predicted both his latency to pair and likelihood of successfully breeding. Due to the long incubation fasts in this species we propose that female Adélie penguins may reliably use frequency modulation of the EDC as a potentially honest signal of early season male condition and the likelihood of a successful breeding outcome.

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Home Range and Landscape Use of Coyotes in a Metropolitan Landscape: Conflict or Coexistence?

Journal of Mammalogy ◽

10.1644/08-mamm-a-277.1 ◽

2009 ◽

Vol 90 (5) ◽

pp. 1045-1057 ◽

Cited By ~ 126

Author(s):

Stanley D. Gehrt ◽

Chris Anchor ◽

Lynsey A. White

Keyword(s):

Home Range ◽

Landscape Use

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Density, movements, and breeding success of female blue grouse in an area of reduced male density

Canadian Journal of Zoology ◽

10.1139/z84-227 ◽

1984 ◽

Vol 62 (8) ◽

pp. 1556-1560 ◽

Cited By ~ 1

Author(s):

Richard A. Lewis

Keyword(s):

Home Range ◽

Breeding Success ◽

Control Area ◽

Home Ranges ◽

Low Density ◽

Timing Of Breeding ◽

Apparent Effect ◽

Adult Females ◽

Male Density ◽

Dendragapus Obscurus

The density of male blue grouse (Dendragapus obscurus) on a 95-ha area was reduced artificially by approximately 75% in 1982. Density, movements, and breeding success of females on this area in that year were compared with those of females on the same area in 1981 (when density of males was undisturbed) and of females on an unmanipulated control area in 1981 and 1982. A reduction in male density had no apparent effect on the density of either yearling (potential recruits) or adult females, or the daily movements, timing of breeding, and breeding success of females. Home ranges of females were largest when male density was artificially reduced, but not significantly so. The larger home range sizes of females residing in an area with a very low density of males did not seem to result entirely from females searching for males with which to breed. Results of this study suggest that densities of male blue grouse have no apparent effect on densities of females or production of young, and support the hypothesis that densities of females in this species are regulated independently of males.

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