Praying mantises pose a threat to small birds worldwide

A praying mantis kills a hummingbird in San Juan Capistrano.  Photo by Kris Okamoto

Zoologist Martin Nyffeler from the University of Basel, Switzerland contacted me after my story about praying mantises killing hummingbirds ran in the Orange County Register on February 15, 2014.  He was studying this problem and asked to contact the photographer, Kris Okamoto from San Juan Capistrano.  He received permission to use the photo as part of his scientific research published on July 4, 2017 in the Wilson Journal of Ornithology.
 
Original Source: 
Martin Nyffeler, Michael R. Maxwell, J. V. Remsen, Jr.
Bird predation by praying mantises: a global perspective
The Wilson Journal of Ornithology (2017) 129(2): 331-344 | DOI: 10.1676/16-100.1

 A study by zoologists from Switzerland and the United States shows: praying mantises all over the globe also include birds in their diet. The Wilson Journal of Ornithology has just published the results.
 

Praying mantises are carnivorous insects with powerful raptorial front legs that usually depend on arthropods such as insects or spiders as their primary prey. Rather infrequently, they have also been witnessed eating small vertebrates such as frogs, lizards, salamanders or snakes. A new study by the zoologists Martin Nyffeler (University of Basel), Mike Maxwell (National University, La Jolla, California), and James Van Remsen (Louisiana State University) now shows that praying mantises all over the world also kill and eat small birds.

Feeding on birds is a global pattern

The researchers gathered and documented numerous examples of bird-eating mantises. In a systematic review, they were able to show that praying mantises from twelve species and nine genera have been observed preying on small birds in the wild. This remarkable feeding behavior has been documented in 13 different countries, on all continents except Antarctica. There is also great diversity in the victims: birds from 24 different species and 14 families were found to be the prey of mantises. “The fact that eating of birds is so widespread in praying mantises, both taxonomically as well as geographically speaking, is a spectacular discovery," comments Martin Nyffeler from the University of Basel and lead author of the study.

Praying mantises pose a threat to small birds

The researchers assembled 147 documented cases of this feeding behavior from all over the world. However, more than 70 percent were reported in the US, where praying mantises often capture birds at hummingbird feeders or plants pollinated by hummingbirds in house gardens. Consequently, hummingbirds make up the vast majority of birds killed by praying mantises, with the Ruby-throated Hummingbird (Archilochus colubris) being a particularly frequent victim.

Decades ago, several alien species of large mantises (e.g., Mantis religiosa and Tenodera sinensis) were released across North America as biological pest control agents. These imported species now constitute a new potential threat to hummingbirds and small passerine birds. However, there are also large native mantises that prey on birds. “Our study shows the threat mantises pose to some bird populations. Thus, great caution is advised when releasing mantises for pest control,” says Nyffeler.

Further information
PD Dr. Martin Nyffeler, University of Basel, Department of Environmental Sciences, Tel. +41 61 702 07 03, email: martin.nyffeler@unibas.ch

When birds take up residence in your yard

A mourning dove and its nestling on a window ledge in Mission Viejo.  Photo by J.J. Meyer 

Here's my latest column scheduled to run in the Orange County Register on Saturday. 

Summer is a busy time for birds. Many species are still nesting and raising their families.

Certain bird behaviors can be clues of a nest nearby. When birds are in the nest-building phase, you might see them gathering materials, such as twigs and dried grasses. You might witness them flying in and out of a particular spot in a bush or tree, often perching nearby first to watch for predators. The sound of noisy nestlings begging to be fed can also point to a nest.

So now that you’ve spotted it, what should you do?

“Keep your distance, use binoculars,” said Nancy Kenyon, local Sea and Sage Audubon chapter board member and newsletter editor. When birds are nesting near your house, the key is to minimize the disturbance, she said.

“The parents won’t feed the babies if you’re around. You’re keeping them from the nest.”

Being in close proximity to a nest can also tip predators to its location.

“Don’t draw any attention to it,” Kenyon said. “We have problems at the marsh with some photographers. They want to get that close shot of a nest, but when they leave, the crows come in and rob it.”

Depending upon the species, some birds will let you know when you’ve ventured too close. Some parents produce alarm calls, signaling to their young to remain quiet.

Killdeer, a shorebird found at the San Joaquin Wildlife Sanctuary in Irvine, display a broken-wing performance to lead predators away from their nest. “At first you may wonder what’s wrong with that poor bird, but it’s just an act to get a predator to follow it,” Kenyon said.

Other birds take a more direct approach to defending their nests.

“Brewer’s blackbirds are nesting in various shopping centers in Irvine now,” she said. “If you get too close, they will attack you.”

Raptors, such as owls and hawks, are particularly known for displaying aggressive behavior when defending their nests against perceived threats.

A nesting hawk at the Orange Tree Golf Club in Orlando, Florida, prompted course officials to post caution signs earlier this year.  Members carried umbrellas and altered their walking paths to avoid getting struck in the head with sharp talons.

A barred owl with a nasty disposition earned the name of “Owlcapone” for its repeated attacks on joggers in a Salem, Oregon, park two years ago. Several people received cuts and scrapes on their heads from the talons of the large owl.

Even hummingbirds are known to fly directly at the face of a person who gets too close to its nest.

Kenyon suggests keeping dogs and cats indoors during the nesting period and delaying tree trimming until September. Ask gardeners to avoid the area of an active nest. She also recommends leaving nests in place for the duration of the breeding season, since some species will reuse a previous nest.

Many birds return to the same area to nest year after year.

The swallows are slowly returning to San Juan Capistrano

Cliff swallows are nesting in the East Corridor near the Serra Chapel entry, and rough-winged swallows have been spotted nesting in the ruins of the Great Stone Church.

Monday, June 19, 2017

SAN JUAN CAPISTRANO, Calif. (KABC) -- By Rob Hayes

 

Mission San Juan Capistrano is known around the world for the swallows.

The migratory birds are said to return to the area every March 19.

Mission specialist Megan Dukett said even though some of the swallow legend is based in myth, it has stuck around for nearly 100 years.

"Birds don't adhere to a human calendar, but they do tend to come back every spring," she said.

The famous birds are even the subject of the hit 1940s Bing Crosby song "When the Swallows Come Back to Capistrano."

But even though visitors will find painted swallows on signs and buildings throughout the town, the swallow population has dwindled down to zero over the last 30 years.

"They've been in the area, just not nesting here," Dukett said.

So how do you lure the swallows back to the mission? Well you play their favorite song. For the last five years, researchers have been playing swallow songs on speakers to bring them back.

The mission folks have also built fake nests to help the swallows find a home instead of having to spend two to three weeks building a nest out of other materials.

There's been good news with the efforts. Dukett said she was walking the mission grounds and noticed one swallow and then found a mud nest.

The swallows have brought in the attention of tourists and if you listen closely, you can hear the sounds of baby swallows. For each nest, there can be up to four hatchlings.

The hatchlings could kick-start a cycle that can bring hundreds of swallows back to the mission.

See a video at ABC 7.