A MODIFIED PROTOCOL FOR SEX IDENTIFICATION OF IN OVO AVIAN EMBRYOS AND ITS APPLICATION AS A MANAGEMENT TOOL FOR ENDANGERED SPECIES CONSERVATION PROGRAMS

2001 ◽  
Vol 32 (2) ◽  
pp. 176-180 ◽  
2021 ◽  
Vol 24 (2) ◽  
pp. 161-162 ◽  
Author(s):  
Sarah J. Converse ◽  
Hannah A. Sipe

1990 ◽  
Vol 69 (4) ◽  
pp. 1546-1548 ◽  
Author(s):  
H. Rahn ◽  
S. A. Poturalski ◽  
C. V. Paganelli

A method is presented for measuring the heart rate of avian eggs noninvasively during the last half of incubation. The technique involves briefly placing an egg in tightly sealed vessel containing an inexpensive condenser microphone. The amplified output of the microphone, termed the acoustocardiogram (ACG), is nearly sinusoidal in shape and synchronous with the electrocardiogram. The ACG can also be obtained by mounting the microphone directly on the shell with Plasticine. The method offers advantages over previously described techniques in simplicity, low cost, and noninvasiveness.


2001 ◽  
Vol 20 (1) ◽  
pp. 3-12 ◽  
Author(s):  
Brian Czech ◽  
Rena Borkhataria

Species conservation via the Endangered Species Act is highly politicized, yet few data have been gathered to illustrate the relationship of political party affiliation to species conservation perspectives. We conducted a nationwide public opinion survey and found that Democrats value species conservation more highly than do Republicans, and that Democrats are also more strongly supportive of the Endangered Species Act. Republicans place higher value on property rights than do Democrats, but members of both parties value economic growth as highly as wildlife conservation. The results imply that the Democratic propensity to value species conservation reflects a biocentric perspective that does not bode well for practical conservation efforts. Species conservation will depend upon the success of academicians and progressive political leaders in educating students and members of all parties about the fundamental conflict between economic growth and wildlife conservation.


PLoS ONE ◽  
2016 ◽  
Vol 11 (8) ◽  
pp. e0159738 ◽  
Author(s):  
Tian-Pei Guan ◽  
Jacob R. Owens ◽  
Ming-Hao Gong ◽  
Gang Liu ◽  
Zhi-Yun Ouyang ◽  
...  

Author(s):  
Joe Kerkvliet

Economics plays strong roles in the design, implementation, and evaluation of the Endangered Species Act (ESA). First, the ESA’s language allows for economic analysis of critical habitat designations, recovery plan implementations, listing postponements, and the design of habitat-conservation plans. Extensive administrative changes to the ESA in the 1990s were designed to reduce economic costs and to elicit landowners’ cooperation. These reforms were partly motivated and guided by economic analysis. Second, economic analysis plays a role in providing credible estimates of the economic costs of ESA implementation. Cost estimates are highly variable and likely to depend on species’ characteristics and the effectiveness of recovery programs. Emerging evidence suggests that the 1990 reforms are reducing costs and increasing effectiveness. Third, economic science contributes to estimation of benefits. Because of the “public goods” nature of nearly all ecosystem and species conservation efforts, estimates must be based on stated preference methods. This use leads to difficulties in establishing the authenticity of benefits estimates. Also, research suggests that benefits estimates are highly sensitive to the spatial nature of the market (beneficiaries’ geographic locations). Future research needs to tackle both authenticity and spatial issues. Fourth, benefit–cost analysis (BCA) is required by law to inform many resource decisions affecting ecosystem and species conservation. Four illustrative BCAs show that whether benefits exceed costs is highly dependent on the authenticity of benefits based on stated preference methods and assumptions about the spatial nature of the market. Substantial uncertainty accompanies both benefit and cost estimates.


Development ◽  
1983 ◽  
Vol 74 (1) ◽  
pp. 1-14
Author(s):  
Marianne Veini ◽  
Ruth Bellairs

The blastulae of unincubated eggs of the quail, Coturnix coturnix japonica, have been bisected in ovo, using the technique of Lutz (1949). Some embryos were harvested after 24 hand found to possess two primitive streaks. Most were fixed at 48 h or 72 h. Some were found to have regulated to form almost normal single axes, whilst others had developed into duplicitas anterior embryos, separate twins or collided axes. All three types of twinned embryos were smaller than the control embryos. The number of somites was not however reduced in the shorter embryos. This finding corresponds with a similar result obtained by Cooke (1975) who reported that if a Xenopus blastula is reduced in size, it nevertheless develops the correct number of somites. The quail however adjusts the shape of the individual somites so that they fit into the reduced body length, whereas Xenopus reduces the size of somites. No miniaturized somites were ever seen in these quail embryos. As a result of the present experiments, it was concluded that the length of incubation time does not directly control the rate of somite formation, because different numbers of somite were found in twins which possessed identical genomes and had developed in almost the same environment for identical periods. In addition, the size of the area pellucida does not appear to control somite formation. Probably, the most important influence is the regression of the node.


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