Bird Conservation Success Stories

For the final blog for conservation biology class I thought it would be nice to highlight some conservation success stories, just to come out of this with a good feeling that we are able to turn things around if we need to. So I searched for some success stories and found some on BIRDS!!! that I would like to summarize here.

First, I’m going to talk about the Wood Duck. Its populations decreased drastically in the late 1800’s due to over-hunting and the loss of its wetland habitat. The Wood Duck was almost brought to the brink of extinction. But, simply by closing the hunting seasons for the Wood Duck for several decades, the numbers of this good-looking duck have increased dramatically, and it now actually occurs over a wider range in North America than it ever did before. This was helped by the duck’s high reproductive rate; Wood Ducks typically lay 10-14 eggs. Also, the construction of nest boxes has been important in bringing them back. So now we’re allowed to hunt Wood Ducks again. The Wood Duck is one of my favourite ducks – they’re so cool looking and are like the North American equivalent of the Mandarin Duck in Asia, which is I think supposed to be a symbol of fidelity.

Next, let’s look at the famous success story of the Whooping Crane. This bird, like the Wood Duck, declined due to over-hunting and loss of its prairie marsh habitat. At one point only 16 individuals returned to a regular wintering area on the Texas coast. With the protection of breeding and nesting grounds, and stopover sites, and with captive breeding and release programs, the numbers of Whooping Crane have increased to a more stable population size. They’re future is not set in stone yet, though. Time is still required for population numbers to reach a totally safe level.

And now, a success story from one of the coolest birds around: the Peregrine Falcon. For over 3 decades this raptor was classified as an endangered species. The biggest cause of population declines was DDT, which caused reproductive failure by causing thin egg shells. With the banning of DDT in 1972 and intensive conservation efforts including artificial insemination, incubation, and fostering young peregrines to other raptor species, the species has made a great recovery. It is no longer endangered, but its number are still being monitored closely.

And last but not least, the California Condor. This species had suffered a century-long collapse until only 21 individuals remained in the wild. All of these super-critically endangered animals were captured in the 1980s, and had to be treated for lead poisoning. Captive breeding programs were established at zoos in the United States, and today the population has reached over 150 birds, and efforts are still underway to ensure the maximum amount of outbreeding occurs. California Condors are still vulnerable to environmental poisoning like lead poisoning, and collisions with power lines can be fatal. The captive-breeding programs are still vital to the survival of the population.

So I guess I didn’t leave off on as positive a note as I would of liked, but these conservation success stories still show us that conservation efforts can be very successful. These are only a few examples of success stories, which can be found all over the world. These stories show us that even in the most desperate situations, our efforts can, literally, bring species back to life.


Bird Predators for Controlling Pest Birds in Vineyards

Vineyards and other fruit orchards are important to the southern interior region of BC; people like their wine and fresh fruit. But vineyards and orchards often have a plethora of pests, which can cause the fruit growers to lose significant amounts of dough. Some of the most annoying pests are birds, especially starlings. There are some ways to keep the birds away; some of the conventional methods include propane cannons for making loud noises, netting to catch the little buggers, and shotguns to kill the little buggers, which all help somewhat, but do not make much of an impact in bird flocks that can number in the tens of thousands. Speakers have also been used to broadcast alarm and distress calls of the pest birds, and this has been shown to be quite effective when combined with conventional methods (Berge et al. 2007). But to really save your fruit crops, probably the most effective way of keeping the birds away is the use of bird predators.

On a side note, predators, being at the top levels of the food chain, often are more vulnerable to threats such as habitat loss because they require relatively large territories to find enough to eat. Agricultural producers, however, are often not very excited to support the presence of predators for some pretty obvious reasons (they’ll eat their livestock). Also, having predators around does not always benefit farmers economically. But for vineyards, having a predator around can have a large economic benefit. Bird predators such as falcons can do a great job in keeping the birds away and can save much of a fruit grower’s crop.

The only study I could find where the effectiveness of falcons was tested was done in New Zealand. Sarah Kross and colleagues (2011) studied the effects of introducing the threatened New Zealand Falcon (Falco novaeseelandiae), a native predator, on the abundance of vineyard pest birds and bird damage to grapes. Starlings (Sturnus vulgaris), Blackbirds (Terdus merula), and Song Thrushes (Terdus philomelos), which are all introduced species, remove whole grapes, while the native Silvereye (Zosterops lateralis) pecks holes in the grapes. The New Zealand Falcon was found to significantly decrease the abundances of the introduced species (not the Silvereye) and cause a 95% reduction in the number of grapes removed and a 55% reduction in the number of grapes with holes pecked in them as compared to vineyards with no falcons introduced. It was calculated that the presence of falcons in vineyards can potentially save US$234/ha for the Sauvignon Blanc variety of grape and US$326/ha for the Pinot Noir variety. So, the introduction of bird predators like this can potentially help in their conservation as well as save some money!

New Zealand Falcon (google images)

Silvereye (googel images)

I know of a cherry orchard in Kelowna where they use falcons and hawks together to control starlings. From what I’ve heard, the red-tailed hawk flys far above a flock of starlings in the orchard, which descend into the orchard to hide from the threat above, and then the falcon comes in and flushes the starlings out of the orchard and back into the open where the hawk can reach them. So the starlings are stuck between the falcon in the orchard and the hawk above, and are effectivley outsmarted. I think the owner of the orchard hires falconers and “hawkers” with trained birds to coordinate this. Pretty cool.

Word count: 558 (oops!)

Kross, Sarah M. and Jason M. Tylianakis and Ximena J. Nelson. 2011. Effects of introducing threatened falcons into vineyards on abundance of passeriformes and bird damage to grapes. Conservation Biology 26: 142-149

Berge, Andrew et al. 2007. Bird control in vineyards using alarm and distress calls. American Journal of Enology and Viticulture 58: 135-143

Wetlands: how close is too close?

Semlitsch, Raymond D. and J. Russel Bodie. 2003. Biological criteria for buffer zones around wetlands and riparian habitats for amphibians and reptiles. Conservation Biology 17: 1219-1228

I’ve said before that wetlands are one of the most biologically important habitats and contain many of BC’s species at risk, and it is critical that they are conserved. Wetlands, and riparian habitats, are important water resources for many organisms including people, and can serve important ecological functions. However, not only  is the protection of the water resource itself critical, the surrounding terrestrial habitat is also important for many species that use aquatic habitats at some point in their life cycle. This surrounding habitat can be considered core habitat for many semiaquatic species, including many reptiles and amphibians (herptiles). So, when we’re conserving wetlands and riparian habitats, how much of the surrounding land should be protected as well?

In this study by Semlitsch and Bodie, the authors reviewed the existing literature and accumulated data from previous studies on the use of terrestrial habitat by herptiles that are associated with wetlands and riparian habitats. The objective of this study was to create a biologically meaningful estimate of the size of these core habitats for the creation of buffer zones around wetlands and riparian areas. For amphibians, they found that core terrestrial habitat ranged from 159m to 290m from the edge of an aquatic site; for reptiles the range was similar, with core terrestrial habitat ranging from 127m to 289m from the edge. The authors also point out that the data indicated the importance of the terrestrial habitat for feeding, overwintering, and nesting. So, to really maintain biodiversity in wetland and riparian habitats, quite a large area of the surrounding land should also protected because there is a biological interdependence between aquatic and terrestrial habitats that has been shown to be essential for the persistence of amphibian and reptile populations. 

Below: the pond (I think it’s called Python Lake) in Pineview in Kamloops, which provides nesting and breeding habitat for a good number of birds every year (and muskrats!). There probably were some herptiles around too, but it looks like a lot of the surrounding terrestrial habitat has been lost or changed too much (houses, trails, and a lot of the land appears to have been dug up). Not much of a buffer zone here. (Photo by me) 

kamloops sept. 2012 011

word count: 386

The effects of partial harvesting of forests on birds – article summary

This is a summary of the article from the journal Conservation Biology: A Meta-Analysis of Bird Responses to Uniform Partial Harvesting Across North America, by Vanderwal et al.
Clearcut harvesting of forests typically leads to a great change in habitat characteristics, replacing mature growth forests with early successional habitats. Birds that are associated with old growth forests are replaced with birds that favour more open habitats. To help conserve structural characteristics of mature forests, and in turn habitat for associated birds, different harvesting systems that incorporate partial harvesting (the retention of live trees) have been used to retain more of the structure of mature forests within stands selected for harvest. The aim is to maintain the abundance of birds associated with late successional forests. However, at the same time the conservation of bird species associated with early successional and more open habitats has become a concern in many areas. The change in forest harvesting methods and land use is believed to be responsible for long-term declines in the abundance of birds associated with recently disturbed habitats. Again, partial harvesting has been proposed as a means of creating early successional habitat for these bird species as well as maintain some degree of mature forest structure for those birds associated with late successional stages. But different bird species respond differently to different intensities of the partial harvesting method, and quantitative assessments of species responses to live tree retention are needed for a better understanding of the effects of partial harvesting on birds.
In this study by Vanerwal et al., the authors performed a meta-analysis of 42 studies that examined the effects of uniform partial harvesting on bird abundances across North America. They found enough data that they were able to model bird responses to varying levels of live tree retention for 34 species of birds. 14 species showed evidence for a negative response (decrease in abundance) to partial harvesting. These species included the brown creeper, ovenbird, american redstart, golden-crowned kinglet, and hermit thrush. Six species showed evidence for a positive response to partial harvesting; examples of these species include the robin, dark-eyed junco, brown-headed cowbird, chipping sparrow, and indigo bunting. The effects of partial harvesting were found to be relatively consistent across three main forest regions in North America, probably because there is a general lack of significant variation between the forest regions.
So it is sort of a trade-off: uniform partial harvesting is expected to cause large decreases in the abundance of bird species associated with late successional stages of forests, but it can also greatly increase the abundance of bird species that favour more open habitats. The authors state that probably the best strategy the manage both late-successional and early-successional bird species’ abundances at the forest stand level is to use moderate-intensity uniform partial harvesting, in which 50-70% of live trees are retained.
Vanderwel, Mark C., Jay R. Maicolm, and Stephen C. Mills. 2007. A meta-analysis of bird responses to uniform partial harvesting across North America. Conservation Biology 21: 1230-1240.
Word count: 495

Restoring Wetlands/Freshwater Habitats

Wetlands in BC are one of the most important habitats, providing critical habitat for many species at risk. Most wildlife in BC use wetlands at some point in their life cycle. About 5.5% of the 5.28 million hectares of BC is wetlands. In the Thompson region wetlands are provided by rivers, lakes, and ponds. Many of the species at risk in this region are contained in these habitats, including the painted turtle, sharp-tailed snake, rubber boa, western toad, great basin spadefoot, westslope cutthroat trout, monarch, dun skipper, and the mexico mosquito-fern. 

The main threat to freshwater habitats is the loss of riparian vegetation, which leads to higher water temperatures, higher input of sediments and toxins, loss of habitat complexity, and increased erosion. Wetlands need enough riparian vegetation to protect aquatic habitats from impacts of adjacent land uses. To conserve these habitats, native riparian vegetation can be established. Conservation projects can involve pulling unwanted and invasive weeds and planting native riparian plants.

Here are some pictures I took from Inks Lake, which is an example of wetland habitat that can be conserved. Inks Lake may be turned into a tailings pond for the Ajax mine if it goes in, which would mean the elimination of important habitat for many species including waterfowl, shorebirds, insects, and aquatic invertebrates.     

P1020608dad's camera 085

inks lake 058inks lake 062


Pearson, Mike and Healey, M.C.2012. Species at Risk and Local Government: a Primer for BC. Stewardship Centre of British Columbia, Courtenay BC.

October 11, 2012

The species I saw today were Northern Pintail, Northern Shoveler, Common Goldeneye, Lesser Scaup, Ring-necked Duck, Mallard, Common Raven, and muskrat. I counted a total of 43 ducks on the water. I saw some interesting muskrat behaviour today; once in a while a muskrat would raise its tail above the water at approximately 45 degrees to the surface and hold it there for several seconds. After this, the muskrat would dive underwater. There were also many deer tracks on the shore.

Today I managed to get a water sample to test its pH. Turns out the water has a pH of 8.6, slightly alkaline.

October 4, 2012

Today at the lake I saw Lesser Scaup, Ruddy Duck, Barrow’s Goldeneye, Bufflehead, Northern Pintail, Northern Shoveler, American Widgeon, Green-winged Teal, Mallard, Long-billed Dowitcher, and muskrat. I saw a total of 82 ducks on the water. This time of year, the ducks are very spooky and it is hard to approach them. The muskrats seem to be burrowing into the bank on the south side of the lake.