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Note: when collecting feathers, examine each one quickly to make sure that you have also plucked the feather tip the white part of the feather attached to the skin. Collecting a blood sample from a bird can be more challenging than a collecting feather samples. The samples can be collected by following the below procedure:.
You need to ensure to clip at the right point — clipping too high might cause pain or discomfort. If no blood ensues, try squeezing the nail. For any questions or queries about our bird sexing service, do not hesitate to contact us.
Bird species have a chromosomal designation known as ZW chromosomes which share no genes with the X and Y chromosomes we find in mammals. Females carry the ZW chromosome pairs whilst males have the ZZ chromosome pairs. Unlike what happens in mammals, it is the female who determines the gender and not the male. Note that although many bird species do not have characteristics that help distinguish the sexes such as size, colour of plumage, external appearance characteristics etc , other bird species have very physically distinct males and females.
And new data on more than 60 globally threatened species would be a "crucial toolkit for conservation geneticists". Follow Victoria on Twitter. Image source, Brian K Schmidt. The diversity among bird species intrigued Charles Darwin. The analysis was run with k set at six and replicated five times. Orning [ 20 ] estimated the number of coyotes around sage-grouse leks and genotyped lethally removed coyotes and fecal samples collected along transects. We attempted to obtain genotypes from eggs and carcasses to identify individual coyotes from the area using microsatellite Set B.
We used the genotype match function in genalex v6. A total of 14 depredated nests were discovered and we recovered an average depredated egg count of 4. Using the genetic methods described herein, we successfully amplified mammalian mtDNA from 11 of 14 nests The average number of eggs per nest from which we obtained predator identification was 2.
We also opportunistically collected 7 hen carcasses. The approach of using two mtDNA genes increased our ability to identify predators Table 2. We did encounter problems with human contamination that seemed to primarily source from field collection but there were two instances where it originated in the lab. We successfully obtained complete genotypes with microsatellite Set A from eight eggs obtained from five nests Additional file 1.
The set A allelic dropout rate across loci was 0. These genotypes allowed us to distinguish which canid species were the nest predators where we lacked resolution with mtDNA Table 2. Two of the five nest genotypes N4 and N5 confirmed mtDNA results and identified the predator as coyote.
Microsatellite set A also helped us refine the species identification for one nest N8 , which was a coyote, where the mtDNA could not distinguish between wolf or coyote. Neither the microsatellites nor the mtDNA could resolve whether the nest predator for N7 was a coyote or wolf, thus we classified it as a wild canid.
This was the same nest from where we also extracted and amplified deer mouse mtDNA from one egg. The single canid genotype we obtained from N11 further identified that a coyote was also in contact with this nest. Overall, we identified coyotes from six nests, dogs from three nests, and one we could not distinguish whether wolf or coyote, thus we called it a wild canid likely coyote as wolves are not common in this area [ 33 ].
The set B allelic dropout rate across loci was 0. The genotype error rates for both set A and set B were within the range of 48 h depredation rates as documented by [ 34 ]. Coyotes which were removed and for which genotypes were obtained were on average within Coyotes in Wyoming have large annual home ranges These were compared to 27 tissue genotypes and 28 fecal genotypes from Orning [ 20 ]. We were unable to match any genotypes from eggs and carcasses to captured coyotes or fecal samples collected in the study area.
None of the nest or carcass predator genotypes matched each other. The goal of this study was to test the concept that non-invasive genetic sampling can be used as a forensic tool to identify predators of ground-nesting birds. When we compared the results of the genetic analyses to species identifications made in the field from physical evidence and camera data, the molecular results agreed with identifications made from physical evidence in four cases, all identified as coyote, and also identified the nest predators in four cases where species identification from physical evidence was deemed indeterminate Table 2.
We determined that five mammalian species had contact with 11 depredated nests Table 2. In the majority of the cases the species was a canid, but we encountered two events, one nest and one carcass, where we were unable to resolve the canid species identification e. Both cases were most likely coyote because wolves have not been documented in the study area [ 33 ]. We could not distinguish the canid species because some mtDNA haplotypes found in wolves in eastern North America and coyotes are nearly identical, which is thought to be a result of historic hybridization or incomplete lineage sorting [ 36 ].
The molecular method we employed was successful in supplementing field and camera identifications of nest predators by either confirming or providing identification when other methods proved inconclusive. There were only two disagreements between physical evidence and our results, in one case the field identification suggested bird or bobcat Lynx rufus as the predator but we identified cow, and in the second case the field identification was cow but we identified coyote.
Camera data provided evidence for predator identification in eight out of 14 nests and was not applied to carcasses Table 2. The camera data and the molecular identifications unequivocally agreed in four of the cases and all of these were coyote. In one case the camera captured a close-up of the face of a potential predator but from the photo we could not differentiate whether it was a striped skunk or an American badger Taxidea taxus. In this case the molecular data clarified the camera data by determining that it was a striped skunk.
There was a disagreement in only one case where the molecular data identified domestic dog DNA but the camera captured a photo of a weasel Mustela sp. Possible reasons for disagreements between datasets are likely due to difficulties with predator species identification in the field from nest remains, non-mammalian predators, camera failure, or DNA isolated from a scavenger instead of the nest predator.
Therefore, we recommend combining molecular data and cameras to increase the success in identifying mammalian predators of ground-nesting birds, similar to the approach by Steffens et al. Combining these two techniques provides valuable insight for management decisions to facilitate protection of threatened and endangered species. All of the species we detected have been previously documented as nest predators [ 37 , 38 ].
The literature contains multiple reports of both coyotes and striped skunks feeding upon eggs of ground-nesting birds [ 39 , 40 ]. The high rate of coyote depredation detected in this study was not surprising given that this species is known to be abundant in the study areas and they have been documented eating sage-grouse eggs [ 8 , 20 ].
Even though dogs are not considered a common predator of sage-grouse nests [ 8 , 37 , Orning and Young, in review], we detected DNA evidence of domestic dogs from three depredated nests.
Domestic dogs have been documented disturbing nests of both ground-nesting birds and sea turtles [ 41 , 42 ], but not sage-grouse eggs. These nests were not close to human dwellings, the area is 30—40 miles from a populated area, but human activities that included the presence of dogs, such as oil and gas development, recreation, and livestock, were regularly observed in the area of the nesting sage-grouse E.
Orning; personal observation. However, the small sample size of this study may have artificially amplified the apparent impacts that dogs have on sage-grouse nests. Thus the dog results obtained herein should be interpreted with caution when considering management strategies. One approach that could easily reduce the potential for human-caused losses of this nature would be to increase public awareness of sage-grouse nesting by limiting human and pet access to areas during critical nesting periods.
Deer mice, in particular native Peromyscus spp. We also documented cow DNA from one nest. Cattle are possible ground-nesting bird egg predators [ 44 ]. However, cattle activity and feces were in close proximity to some of the nests and Orning [ 20 ] collected video of cattle investigating sage-grouse nests so whether this event was predation or contamination is unclear. Finally, we detected human DNA from a few of the nests. The sensitivity of the general mammalian primers used for this study must be taken into account when conducting a molecular forensic study.
Wildlife genetics laboratories should also apply the same stringent protocols of sample collection and processing required in the human forensics field [ 45 ].
Further, approaches can be applied in the laboratory to prevent amplification of human DNA such as species-specific PCR primers [ 5 ], human-blocking PCR primers [ 46 ], and metabarcoding with high-throughput sequencing technology. The most likely explanation is that the DNA had degraded beyond our detection ability.
If the eggs were collected too long after the depredation event, and depending on weather conditions, the DNA could degrade quickly [ 47 ]. Increasing the number of visitations to nests to shorten the time intervals between predation and discovery is unlikely to be a feasible approach to limit DNA degradation. Intensified human disturbance can increase the chances of nest abandonment or predation which would be counterproductive to conservation goals [ 7 , 48 ].
One way to increase the success rate of detecting degraded DNA would be to target a smaller fragment. However, this approach has drawbacks because resolution can be lost for differentiating recently derived species when using shorter fragments of DNA but this shortcoming could be addressed by using genes with higher mutation rates. For example, we increased the number of PCR cycles to 52 for microsatellite Set B which allowed us to obtain a higher percentage of full genotypes.
However this high number of cycles could increase the chance of false alleles. In fact, any optimization strategy could increase non-specific amplification which could decrease the accuracy of species identification. Another explanation for failure to detect the predator species might be that the nest predator was avian.
The primers we used were mammal-specific, thus we were not able to amplify avian DNA. We did have one case where field reports suggested the nest predator was a raven Corvus corvax or a snake and another where the camera identified a raven around the nest, but could we did not obtain molecular species identification from either nest. Using this method to determine if the predator was a reptile i. We foresee multiple continuations of this study to increase the thoroughness and robustness of predator species identification.
The first and most obvious is to increase the sample size. We acknowledge that the sample size in this study is quite small, but our goal was to prove the concept rather than thoroughly quantify the diversity of predators on sage-grouse eggs and adults.
To rigorously estimate nest predation rates, and provide a control for identifying predators of sage-grouse adults, which was lacking from this study, there would need to be a larger study with more cameras placed around leks and on more leks throughout the range of the species. Another follow-up study would be to test DNA degradation rates by having captive predators deposit saliva on eggshells and carcasses.
This would allow one to establish a reasonable time since depredation and evaluate the accuracy of predator species identification from adult carcasses as these are usually opportunistic samples and filming these depredation events is unlikely. To increase the breadth of predator taxa identified from nest remains and carcasses one could apply primers that amplify avian DNA.
Avian predator DNA has been successfully sampled from black-fronted tern Chlidonias albostriatus eggshells [ 13 ], so this approach may also be feasible for sage-grouse. The challenge of this approach is that DNA from the prey species could also be amplified which would obscure predator identification as seen in Steffens et al. Thus employing nesting species blocking primers may be an approach to decrease the chances of avian predator and prey co-amplification [ 46 ].
The ultimate goals of conservation plans are to halt decline and facilitate recovery of species at risk.
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