scholarly journals Breeding biology of the Critically Endangered Galapagos Petrel Pterodroma phaeopygia on San Cristóbal Island: conservation and management implications

2010 ◽  
Vol 20 (3) ◽  
pp. 306-319 ◽  
Author(s):  
FRANCISCO CRUZ-DELGADO ◽  
JOSÉ A. GONZÁLEZ ◽  
DAVID A. WIEDENFELD
Keyword(s):  
Reproductive Success ◽  
Agricultural Land ◽  
Reproductive Period ◽  
Breeding Biology ◽  
Critically Endangered ◽  
Alien Invasive Species ◽  
Island Conservation ◽  
Galapagos Archipelago ◽  
Management Measures ◽  
Causes Of Mortality

SummaryThe Galapagos Petrel Pterodroma phaeopygia is endemic to the Galapagos Archipelago, where it nests on only five islands. The species is considered ‘Critically Endangered’, mostly due to the effects of alien invasive species, which impair its reproductive success. During 2002–2003 we studied the breeding biology of the petrels nesting on San Cristóbal island. The study revealed particular characteristics of the San Cristóbal petrel population and differences compared to those of other islands, mostly related to nesting habitat, phenology, reproductive success and causes of mortality. On San Cristóbal, petrel nests were primarily located along ravines, in areas of dense vegetation cover formed by the endemic shrub Miconia robinsoniana and a wide variety of native ferns. Over 90% of the nests on the island were located on private agricultural land. The petrel population has a prolonged reproductive period covering 10 months. Laying dates occurred mostly from May to October, with a peak during August, although eggs may be occasionally laid between November and March. The incubation period averaged 50.8 days (range: 46–53), and parental care 103.7 days (range: 98–108). Overall reproductive success was 23.6%; 63.8% for eggs and 37.1% for chicks. Predation by rats was the primary cause (72.2%) of nest failure. Rat control campaigns and clearing of exotic plant species in areas of high density of petrel nests, as well as promoting cooperation agreements between conservation authorities and landowners of the properties where nests are located, are suggested among other critical management measures intended to reduce nest mortality and ensure the survival of the San Cristóbal petrel population.

Breeding biology of the Critically Endangered Tahiti MonarchPomarea nigra, a bird with a low productivity

2017 ◽  
Vol 28 (4) ◽  
pp. 606-619 ◽  
Author(s):  
CAROLINE BLANVILLAIN ◽  
THOMAS GHESTEMME ◽  
TEHANI WITHERS ◽  
MARK O’BRIEN
Keyword(s):  
Reproductive Success ◽  
French Polynesia ◽  
Egg Laying ◽  
Breeding Biology ◽  
Critically Endangered ◽  
Tropical Island ◽  
Island Endemics ◽  
Nest Activity ◽  
Considerable Length ◽  
One Year

SummaryWe studied the breeding biology of Tahiti MonarchPomarea nigra, a ‘Critically Endangered’ forest bird endemic to Tahiti (French Polynesia). Nest activity was monitored from 1998 to 2002, and again from 2008 to 2015. During these 12 years, only 2–13 breeding pairs per year produced hatchlings. Egg-laying occurred all year, but usually increased between August and January, peaking around November. Of the 200 nests monitored, 33 (16%) were abandoned shortly after construction, 71 had an egg laid immediately after the nest were completed (34 %) and 96 nests (46 %) had a pre-incubation phase of 18.9 ± 1.9 days (3–62 days;n= 47 nests), during which the birds visited the nest on an irregular basis. Half (49 of 96) of these nests were abandoned before an egg was laid, with incubation subsequently commencing at the remaining nests (n= 47). Although both sexes incubated for an average of 13.6 ± 0.3 days (range 13–15), the female usually spent more time incubating than the male. Only one young per nest was ever observed. The average nestling phase was 15.5 ± 0.7 days (range 13 to 20 days). Parents continue to feed the young after fledging for 74 ± 4.7 days (range 42–174). As with many tropical island endemics, the Tahiti Monarch has low reproductive productivity as indicated by the fact that: 1) only 56% of pairs attempt to lay an egg in any one year, 2) most pairs attempt only one brood per year and 3) the considerable length of the nesting and fledging phases. Because of its low productivity, maximising the reproductive success of the Tahiti Monarch is essential to secure its recovery.

scholarly journals Breeding biology and post-fledging dispersal of red-crowned parakeets (Cyanoramphus novaezelandiae) translocated to a fenced mainland sanctuary

2021 ◽  
Author(s):  
◽  
Ellen Irwin
Keyword(s):  
Reproductive Success ◽  
Human Impacts ◽  
Release Site ◽  
Habitat Destruction ◽  
Breeding Biology ◽  
Food Sources ◽  
Lifetime Reproductive Success ◽  
Species Dispersal ◽  
Dispersal Patterns ◽  
Mammalian Predators

<p>With human impacts like habitat destruction and climate change contributing to range contractions in species, translocations stand out as an important tool for conserving species suffering from these effects. However, an understanding of the life history of many threatened species prior to translocation is often lacking, but critical for translocation success. For example, dispersal away from the release site—particularly when a protected release site is surrounded by unmanaged habitat—can result in translocation failure, and therefore successful translocation practice must include an understanding of a species’ dispersal patterns. I conducted a study examining the breeding biology and post-fledging dispersal of a population of red-crowned parakeets Cyanoramphus novaezelandiae), or kakariki, recently translocated to a mainland sanctuary in Wellington, New Zealand. The sanctuary, ZEALANDIA, is fenced to exclude invasive mammalian predators; however, birds can and do leave. Approximately one-third of juveniles that dispersed outside the sanctuary were killed by predators. Kakariki post-fledging dispersal was male-biased, possibly driven by inbreeding avoidance, and distance dispersed decreased with increasing body condition. Parental age may have also influenced offspring dispersal. In addition, I found that kakariki reproductive success may be affected by age, and estimated lifetime reproductive success was >30 fledglings by age five. Conservation initiatives could work on controlling predators in currently unprotected reserves and around food sources that kakariki targeted, particularly in summer and autumn when many plants are fruiting and recently fledged juveniles are more active. Future translocations should consider selecting younger birds to translocate to take advantage of their high lifetime reproductive success and therefore improve viability of populations.</p>

Reproductive success in a reintroduced population of a critically endangered shrub, Symonanthus bancroftii (Solanaceae)

2007 ◽  
Vol 55 (4) ◽  
pp. 425 ◽  
Author(s):  
Qigang Ye ◽  
Eric Bunn ◽  
Siegfried L. Krauss ◽  
Kingsley W. Dixon
Keyword(s):  
Reproductive Success ◽  
Pollen Viability ◽  
Natural Habitat ◽  
Female Parent ◽  
Clonal Plants ◽  
Critically Endangered ◽  
Positive Sign ◽  
Male And Female ◽  
Sterile Culture

Symonanthus bancroftii is a critically endangered dioecious shrub, with only one male and one female plant known in the wild. Micropropagated, clonal plants of the male and female parents were hand-pollinated. Seed was germinated in sterile culture and a subsequent daughter (F1) seedling was multiplied in vitro. Micropropagated plants of the original parents and daughter were reintroduced to a natural habitat site. We detail the first study of pollination biology and reproductive success in this extremely rare species. Floral morphology, flowering phenology, pollen viability, female receptivity and fruit set of reintroduced plants of S. bancroftii were investigated. Flower viability of S. bancroftii shows a 25-day maximum for male flowers, whereas non-pollinated female flowers remain viable for a maximum of 38 days (female parent) and 41 days (daughter), respectively. Flowering of reintroduced male and female plants overlaps from mid-June to early November. Pollen remained viable for at least 8 days after anther dehiscence. Maximum stigma longevity recorded was 28 days (female parent) and 39 days (daughter) and maximum ovule longevity varied from 13 days (female parent) to 28 days (daughter). The mean percentage of flowers setting fruit was 39 ± 13% for female parent plants and 48 ± 4% for daughter plants. Empirical reproductive success measures for male–daughter crosses generally exceeded those of the original parent crosses. The reproductive success of S. bancroftii so soon after reintroduction of plants is a positive sign indicating that rapid accumulation of a soil seedbank is feasible and is thus an important first step towards successful establishment of self-sustaining populations of this critically endangered species.

Enough is enough… Can various legislative tools cause ambiguities when applied in a single area? (Case study: Hády Hill, Brno, Czech Republic)

2021 ◽  
Author(s):  
Lucie Kubalíková
Keyword(s):  
Nature Conservation ◽  
Czech Republic ◽  
Protected Areas ◽  
Agricultural Land ◽  
Earth Science ◽  
Legal Protection ◽  
Habitats Directive ◽  
The Czech Republic ◽  
Care Plans ◽  
Management Measures

&lt;p&gt;Establishing legal protection to a geosite (or geodiversity site) is considered one of the key tools of how to conserve its values and how to avoid degradation and devastation. The proper management measures (usually included in care plans or other planning and strategic documentation) then help to balance the conservation needs and sustainable use of the sites and allow to gain public finances for these purposes.&lt;/p&gt;&lt;p&gt;In the Czech Republic, nature conservation is anchored in Act n. 114/1992 Coll. (Nature Conservation Act) which defines several levels of protected areas that can be applied also on geoheritage. However, there are other legislative tools that protect other entities (e.g. agricultural land, water, or forests). The special relationship to geodiversity has Act n. 44/1988 Coll. (Mining Act) which aims to protect the mineral deposits including their deposit areas. Various tools for the protection applied to a single area can cause ambiguities because every protected entity has different management and limitations.&lt;/p&gt;&lt;p&gt;This is the case of H&amp;#225;dy Hill, an area situated in the outskirts of Brno, the second-largest city in the Czech Republic. The area is important from the Earth Science point of view (tectonics, paleontology, geomorphology, stratigraphy, hydrogeology) and has high ecological and cultural values, e.g. occurrence of endangered species linked to the subsoil, remnants of old landscape structures (orchards, pastures), historical mining, use of the building material for Brno monuments. Earth-science and ecological values are protected according to Nature Conservation Act within one National Nature Reserve, two Nature Monuments, and four Important Landscape Elements and partly included in Special Area of Conservation (according to the Habitats Directive - Council Directive 92/43/EEC). Moreover, due to the occurrence of quality limestone, which was extracted from the Middle Ages up to the end of the 20&lt;sup&gt;th&lt;/sup&gt; Century, the part of the study area is declared as a reserved mineral deposit and protected deposit area (according to Mining Act). All these areas mutually overlap.&lt;/p&gt;&lt;p&gt;Concerning geoheritage, some phenomena still have no degree of protection, but they are included in the Database of Geological Localities (kept by the Czech Geological Survey) and proposed for legal protection.&lt;/p&gt;&lt;p&gt;Last but not least, the site undergoes tourist and recreational pressure which is continuously increasing due to the COVID-19 situation (lack of indoor possibilities of how to spend the free time).&lt;/p&gt;&lt;p&gt;To find the balance between the various conservation needs, management measures, limitations, tourist/recreation pressure, and urban development, it was necessary to do a complex analysis of the various types of protected areas and their values. Based on the SWOT analysis and Risk Assessment, the main threats, risks, and possible conflicts of interest were identified and assessed. Then, specific proposals and possible solutions were designed with an emphasis on effective geoconservation (e.g. declaration of the new or enlarging the currently protected areas), development of sustainable forms of tourism, and future rational use of an area (e.g. via volunteer activities or participative planning of management).&lt;/p&gt;

Pollinators necessary for the reproductive success of critically endangered mangrove, Sonneratia griffithii

2021 ◽  
Vol 169 ◽  
pp. 103340
Author(s):  
Christine Ely Nuevo Diego ◽  
Alyssa B. Stewart ◽  
Sara Bumrungsri
Keyword(s):  
Reproductive Success ◽  
Critically Endangered

Breeding biology of the critically endangered Malherbe's parakeet on Maud Island, New Zealand, following the release of captive-bred individuals

2009 ◽  
Vol 57 (6) ◽  
pp. 433 ◽  
Author(s):  
Luis Ortiz-Catedral ◽  
Jonathan C. Kearvell ◽  
Mark E. Hauber ◽  
Dianne H. Brunton
Keyword(s):  
New Zealand ◽  
Clutch Size ◽  
Captive Breeding ◽  
Breeding Biology ◽  
Critically Endangered ◽  
Limiting Factor ◽  
Early Age ◽  
Small Islands ◽  
Austral Spring ◽  
Nesting Sites

We studied a population of the critically endangered Malherbe’s parakeet (Cyanoramphus malherbi), following the release of 62 captive-bred individuals on Maud Island, New Zealand, to identify and characterise nesting sites in a novel island environment. Previous work on Malherbe’s parakeets consisted of limited observations on remnant mainland populations. The age of breeding pairs on Maud Island was 7.2 ± 4.7 months and included both captive-bred individuals of the first release flock and individuals hatched on Maud Island within a year of the first release. Nests were found in hollows of mamaku (Cyathea medullaris), vacant nests of sacred kingfisher (Todiramphus sanctus), a hole in the ground and a hollow in a kohekohe (Disoxylum spectabile). Active nests were found in the austral spring, summer and autumn. Clutch size was 5 eggs. The fledging of three Malherbe’s parakeets was confirmed for one nest 43 days after hatching. Observations of newly fledged individuals around the island indicate that at least seven successful nesting attempts occurred. Consistent with other studies in Cyanoramphus parakeets, our results suggest that availability of nesting sites on small islands may not be a limiting factor for the establishment of additional populations of Malherbe’s parakeets via captive breeding and translocation. The formation of breeding pairs at an early age, the use of diverse nesting sites in regenerating vegetation, and the evidence of successful breeding shortly after release on an island represent encouraging prospects for the conservation of New Zealand’s rarest parakeet.

scholarly journals Floating rafts as breeding habitats for the Common tern, Sterna hirundo. Colonization patterns, abundance and reproductive success in Venice Lagoon

2018 ◽  
Vol 88 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Francesca Coccon ◽  
Stefano Borella ◽  
Nicola Simeoni ◽  
Stefano Malavasi
Keyword(s):  
Reproductive Success ◽  
Breeding Population ◽  
Venice Lagoon ◽  
Reproductive Period ◽  
Common Tern ◽  
Sterna Hirundo ◽  
Breeding Sites ◽  
Common Terns ◽  
Colonization Patterns ◽  
Floating Rafts

The Venice lagoon hosts the 15% of the entire Italian breeding population of Common terns, Sterna hirundo, highlighting the great value of the area for this species. However, in the last 25 years, a substantial decline of Common terns has been detected in the Lagoon, which culminated in 2008. The main causes of this negative trend were the loss of salt marsh habitats, where terns typically breed in the Venice lagoon. This was due to the increase in the mean sea level and the greater frequency of high tides during the reproductive period with consequent flooding of their breeding sites; competition with yellowlegged gulls (Larus michahellis), predation and human disturbance. As a preliminary experimental approach to counter the depletion of the species and favour its recovery, we performed a habitat loss compensation project by setting up four floating rafts (3x2m), covered by two different types of substrate (sandy and vegetal substrate). This was to function as an artificial nesting site safe from flooding, positioned in a protected internal wetland area of the Venice lagoon, Valle Averto (Sourthern Lagoon). We studied the colonization patterns of the rafts and the reproductive success of Common tern breeding pairs during the 2014 and 2015 breeding seasons. We also investigated those environmental and structural variables that could favour the use of the rafts and the nesting success of the species. In both years, the rafts were successfully colonized and used by terns for nesting. Our results also indicated higher temperature, lower rainfall and greater distance from the shore as the main habitat factors favouring the occurrence and the reproductive success of the breeding pairs, while a windrow of dead plants was indicated as the preferred substrate for covering rafts in order to make them more attractive. The results provided some suggestions for successful restoration plans to be developed in similar lagoon areas.

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.

scholarly journals Nesting Success and Nesting Height in the Critically Endangered Medium Tree Finch (Camarhynchus pauper)

Birds ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 427-444
Author(s):  
Sonia Kleindorfer ◽  
Lauren K. Common ◽  
Petra Sumasgutner
Keyword(s):  
Rattus Rattus ◽  
Nesting Success ◽  
Trophic Levels ◽  
Critically Endangered ◽  
Fledging Success ◽  
Island Endemic ◽  
Galapagos Archipelago ◽  
Black Rat ◽  
Avian Predators ◽  
Fly Larvae

When different introduced species across trophic levels (parasite, predator) invade island systems, they may pose significant threats to nesting birds. In this study, we measure nesting height and infer causes of offspring mortality in the critically endangered Medium Tree Finch (Camarhynchus pauper), an island endemic restricted to Floreana Island on the Galápagos Archipelago. Considering all nests at which a male built a nest, sang and attempted to attract a female (n = 222 nests), only 10.4% of nests produced fledglings (5% of nests had total fledging success, 5.4% of nests had partial fledging success). Of the 123 nests chosen by a female, 18.7% produced fledglings and of 337 eggs laid, 13.4% produced fledglings. Pairing success was higher for older males, but male age did not predict nesting success. All nests with chicks were infested with avian vampire fly larvae (Philornis downsi). We attributed the cause of death to avian vampire fly if chicks were found dead in the nest with fly larvae or pupae (45%) present. We inferred avian (either Asio flammeus galapagoensis or Crotophaga ani) predation (24%) if the nest was empty but dishevelled; and black rat (Rattus rattus) predation (20%) if the nest was empty but undamaged. According to these criteria, the highest nests were depredated by avian predators, the lowest nests by rats, and intermediate nests failed because of avian vampire fly larvae. In conclusion, there is no safe nesting height on Floreana Island under current conditions of threats from two trophic levels (introduced parasitic dipteran, introduced mammalian/avian predators; with Galápagos Short-Eared Owls being the only native predator in the system).

scholarly journals Spiders (Araneae) of selected sinkholes of Moravský kras Protected Landscape Area (Czech Republic)

2012 ◽  
Vol 60 (1) ◽  
pp. 57-70 ◽  
Author(s):  
Vladimír Hula ◽  
Ondřej Košulič ◽  
Pavla Šťastná
Keyword(s):  
Czech Republic ◽  
Agricultural Land ◽  
Point Of View ◽  
Critically Endangered ◽  
Class I ◽  
Bioindicator Species ◽  
Natural Habitats ◽  
Evaluation Point ◽  
Disturbed Habitats ◽  
Time Of Collection

In this study, we present faunistic data about spiders in selected sinkholes of northern part of Moravský kras Protected Landscape Area. Time of collection was established in the following terms: 24 March 2010 – 22 September 2010. We collected altogether 5742 adult specimens which were determined to 59 species of 14 families. We found two very rare spiders (critically endangered Porrhomma errans and endangered Walckenaeria monoceros) and several interesting, rarely collected bioindicator species (Alopecosa trabalis, Mecopisthes silus, Zelotes longipes). From the bioindicative evaluation point of view, 44% of found species belong to species with connection to natural habitats, 37% belong to species preferring semi-natural habitats, and 19% belong to species of disturbed habitats. From the relictness point of view, majority of species was of the expansive category (53%), 40% of class II relicts, and only 7% of class I relicts. Sink holes did not increase total biodiversity of agricultural land too much because of their relative small size.

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