scholarly journals A 10-year assessment of Asian Houbara Bustard populations: trends in Kazakhstan reveal important regional differences

2010 ◽  
Vol 21 (2) ◽  
pp. 134-141 ◽  
Author(s):  
SAMUEL RIOU ◽  
JACKY JUDAS ◽  
MARK LAWRENCE ◽  
SERGUEI POLE ◽  
OLIVIER COMBREAU
Keyword(s):  
Regional Differences ◽  
Conservation Status ◽  
Breeding Birds ◽  
Population Trends ◽  
Sharp Decline ◽  
Sharp Drop ◽  
North East ◽  
Houbara Bustard ◽  
Steep Decline ◽  
Variable Population

SummaryA sharp decline in the numbers of Asian Houbara Bustard Chlamydotis macqueenii towards the end of the 20th century raised concerns about the conservation status of this species. Yet due to its large breeding range in the remote steppes and deserts of Central Asia and to its cryptic behaviour, it has been difficult to obtain enough comparable data to make reliable estimates of population trends. Here, we present the results of 10 years of extensive biannual surveys throughout southern Kazakhstan, considered to host the majority of the breeding birds in Asia, and we discuss trends in the Kazakh populations for the first decade of this century. The breeding Houbara population has generally declined over the greater part of Kazakhstan between 2000 and 2009 but with important regional differences. A steep decline was observed in north-east Caspian and Karakum, and a sharp drop followed by a stabilisation occurred in Kyzylkum. Over the same period, estimated densities were stable or increased in the area surrounding Lake Balkash, and increased in the Betpak-Dala region of central Kazakhstan. Autumn surveys showed more variability and revealed little decline overall. It was also clear that Betpak-Dala and Balkash regions hosted the largest populations. Our findings suggest that it is a complex undertaking to assign a level of vulnerability for this species as a whole. Highly variable population trends between regions indicate that threats and pressures are to a considerable extent region-specific, and that conservation measures need to be adjusted locally.

scholarly journals Tendencias poblacionales recientes de la avutarda hubara en las Islas Canarias: análisis metodológico y estado de conservación

2012 ◽  
Vol 35 (1) ◽  
pp. 125-139
Author(s):  
C. Schuster ◽  
◽  
J. J. Iglesias-Lebrija ◽  
L. M. Carrascal ◽  
◽  
...  
Keyword(s):  
Canary Islands ◽  
Conservation Status ◽  
Distance Sampling ◽  
Small Variation ◽  
Population Trends ◽  
Line Transect ◽  
Sampling Area ◽  
Average Value ◽  
Houbara Bustard ◽  
Population Sizes

Recent population trends of the houbara bustard in the Canary Islands. Methods and conservation status Determining conservation status requires rigorous and reliable data about population sizes and trends, especially if they have to be applied to islands where the species have small populations. The Canary bustard houbara (Chlamydotis undulata fuertaventurae) is catalogued as ‘in danger’ by the Red Book of the Birds of Spain. This work analyzes the value of previously published information on the species using the method of adjacent linear transects separated by 200 m, as a baseline for establishing robust population trends in 30 important areas (ranging from 1.3 to 12.8 km2) for the houbara in the islands of Lanzarote and Fuerteventura (Canary Islands). Censuses were repeated on the same dates (from November to December) and localities as those carried out in 1994, 2004 and 2006. The detection probability of the houbara was estimated by means of distance sampling, being 0.42 up to 250 m from the observer, and 0.82 in the main census belt of 100 m on either side of the line transect. The method of adjacent linear transects —counting the maximum number of hubaras detected— provides accurate figures of population densities (detection of 95.2% of the birds). The previous estimations of houbara densities can therefore be considered highly trustworthy, with a probable average underestimation of only 5 %. Nevertheless, the confidence intervals of density estimations using only one census were very large. Therefore, with only one census per sampling area and year it is not possible to obtain precise estimates of houbara densities with small variation around the average value. This raises concern when trying to obtain solid evidence about the increases–decreases of houbara populations comparing different dates or study areas. The density of the Canary Island hubara bustard decreased significantly from 2004/2006 to 2011 in eight areas of Fuerteventura (Vega Vieja, Los Alares–Pocetas, Matas Blancas, Lorenzo– Diviso, Corralejo, Lajares and Fimapaire) and in two areas of Lanzarote (Argana and La Santa). Conversely, the density of the houbara significantly increased in three areas of Lanzarote (Zonzamas, Guatiza and Llano de las Maretas). As a whole, average population density did not differ significantly between 2004/2006 and 2011 in Fuerteventura (slight decrease of 29% in 2011), but there was a significant increase in Lanzarote (increase of 60% from 2004/2006 to 2011). The change in density from 2004/2006 to 2011 tended to be an increase in areas further from paved roads, and a decrease in locations predominantly covered by loose sandy soils.

The Shetland Bird Survey: population trends for widespread breeding birds 2002–2019

Bird Study ◽  
2021 ◽  
pp. 1-10
Author(s):  
R. Hughes ◽  
N.J. O’Hanlon ◽  
J. Calladine ◽  
P.V. Harvey
Keyword(s):  
Breeding Birds ◽  
Population Trends ◽  
Bird Survey ◽  
Survey Population

scholarly journals Determining population trends and conservation status of the common quail (Coturnix coturnix) in Western Europe

2012 ◽  
Vol 35 (2) ◽  
pp. 343-352
Author(s):  
M. Puigcerver ◽  
◽  
F. Sardà–Palomera ◽  
J. D. Rodriguez-Teijeiro ◽  
◽  
...  
Keyword(s):  
Western Europe ◽  
Conservation Status ◽  
Population Trends ◽  
Distribution Model ◽  
Breeding Period ◽  
Distribution Models ◽  
Winter Cereal ◽  
Coturnix Coturnix ◽  
The Common ◽  
Common Quail

In this paper we review the conservation status and population trends of the common quail (Coturnix coturnix) from 1900 to the present. Data are sometimes contradictory with regard to the status of this species as it has some features that make it difficult to produce reliable population estimates. Recent data clearly suggest, either at a local scale or at a trans–national scale, that the Atlantic common quail populations have remained stable in the last two decades, and that restocking practices with farm–reared quails (hybrids with the Japanese quail, Coturnix japonica) do not affect our estimates. The complex movement patterns showed by this species require special attention. Analysis of ring recoveries can give important information, especially about the nomadic movement of quails in search of suitable habitats after the destruction of winter cereal crops due to harvesting. Thus, when developing a breeding distribution model for this species, continuously updated information on seasonal habitat and weather must be included for optimal prediction. Including fortnightly data of vegetation indices in distribution models, for example, has shown good results. Obtaining reliable predictions about changes in species distribution and movements during the breeding period could provide useful knowledge about the conservation status and population trends and would help in the design of future management measures.

Rediscovery of Euphorbia carissoides (Euphorbiaceae)

1993 ◽  
Vol 6 (3) ◽  
pp. 269
Author(s):  
PI Forster
Keyword(s):  
Conservation Status ◽  
Threatened Plant ◽  
North East ◽  
Made In

This paper documents the rediscovery of Euphorbia carissoides F.M. Bailey from four localities in north-east Queensland. E. carissoides was previously known from two collections made in 1905 and 1908 and listed as Presumed Extinct in Rare or Threatened Plant listings. The species is described in detail, illustrated, its distribution and habitat described and conservation status revised to 3V.

scholarly journals Population trends and conservation status of the Northern Rockhopper PenguinEudyptes moseleyiat Tristan da Cunha and Gough Island

2009 ◽  
Vol 19 (1) ◽  
pp. 109-120 ◽  
Author(s):  
RICHARD CUTHBERT ◽  
JOHN COOPER ◽  
MARIE-HELENE BURLE ◽  
CONRAD J. GLASS ◽  
JAMES P. GLASS ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Conservation Status ◽  
Sharp Decrease ◽  
Population Trends ◽  
Tristan Da Cunha ◽  
Fur Seals ◽  
Introduced Predators ◽  
Gough Island ◽  
The Indian Ocean ◽  
The Impact

SummaryPopulations of the recently split Northern Rockhopper PenguinEudyptes moseleyiare restricted to Tristan da Cunha and Gough Island in the South Atlantic, and Amsterdam and St Paul in the Indian Ocean. The majority of the population is in the Atlantic (> 80%), but population trends at Tristan da Cunha and Gough are uncertain. Early records indicate “millions” of penguins used to occur at Tristan da Cunha and Gough Island. The most recent estimates indicate declines in excess of 90% for both Gough and the main island of Tristan that have occurred over at least 45 and 130 years, respectively. Numbers breeding at Inaccessible and Nightingale islands (TDC) also may have declined since the 1970s, albeit modestly, whereas numbers on Tristan appear stable over the last few decades. Current population estimates are 32,000–65,000 pairs at Gough, 18–27,000 at Inaccessible, 19,500 at Nightingale, and 3,200–4,500 at Tristan. Numbers and trends at Middle Island (TDC) are unknown. Middle Island supported an estimated 100,000 pairs in 1973, and recent observations suggest this colony is being impacted by competition for space with recently recolonising Subantarctic Fur SealsArctocephalus tropicalis. Past human exploitation and the impact of introduced predators may be responsible for the historical decline in numbers at Tristan, but these factors cannot explain the sharp decrease (since the 1950s) at Gough Island. Overall, declines at Gough, Tristan, Nightingale and Inaccessible islands indicate a three-generation decline of > 50%. Taken in combination with recent decreases in Indian Ocean populations, the Northern Rockhopper Penguins is now categorised as globally ‘Endangered’. Determining the causal factors responsible for these recent declines is an urgent priority.

Census of Breeding Birds and Population Trends of the Dupont's LarkChersophilus dupontiin Eastern Spain

Ardeola ◽  
2013 ◽  
Vol 60 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Cristian Pérez-Granados ◽  
Germán M. López-Iborra
Keyword(s):  
Breeding Birds ◽  
Population Trends
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