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Posts Tagged ‘Central America’

Studying the Ridgway’s Osprey of Belize: Part II

Tuesday, March 14th, 2017
Flat calm Caribbean and three young Ridgway’s!

by Ben Wurst, Habitat Program Manager

 

The flat calm beauty of the Caribbean sea.

February 18: Second Survey of nests surrounding Placencia

Our second survey began from Placencia, a small beach resort town on the southern coast of Belize, which is a beautiful place to visit if you’re planning a trip to Belize. It was flat calm that morning, which made for great boating, but it was extremely hot! Life in the tropics was finally setting in… We headed towards the first nest location, which was last surveyed in 2016 by Paul and his team. Paul and Alan have been surveying osprey nests in Belize since 2014, so all known nests have been mapped and surveyed over the past couple years. Through the continued surveys of these nests we should be able to determine if the low productivity of Ridgway’s (around .3-.4 young/active nest) can sustain the population in Belize (the southern most nesting colony of Ridgway’s throughout their range). The work performed as a part of these surveys is critical to their long term survival in Belize. The first nest we visited was very unkept; however a pair was present. This ended up being quite the common sight during this survey.

An unkept nest south of Lark Caye.

An adult female Ridgway’s osprey in flight.

Red mangroves growing in the Caribbean off Placencia.

We then motored to several other small Cayes and surveyed a total of eight nests (only two produced young, photos below). Many were abandoned so it was hard for us to determine their overall fate. Many (good looking) nests Paul thought had failed (once had young or eggs and were lost) since the nests did look like they have been used this year but there were no birds around during our survey. Generally it is hard to determine overall nest success unless you watch a nest throughout the entire nesting season, or find evidence of nest failure when visiting a nest. In New Jersey, I generally can tell when a nest fails or hasn’t by observing the behavior of the adults. If a nest is active (bird present) and it is defending its nest with no young or eggs then it failed. If the nest is active (bird present) and it flies away with no defense of nest/young, then I call that nest active and housekeeping (a term for a bird that starts a nest but does not produce any eggs/young). Lastly, a nest with no birds = not active. Either way – it is very difficult to determine the overall nest success with only one visit/nest/season. If I were to go back to Belize then I would go twice during the nesting season there, which runs from December – March/April (once when birds are incubating and once when they have young). 🙂

Kept or Unkept nest?? You decide.

While we try to determine the cause of failure to an active nest, we think about potential threats to nesting ospreys. A substantial threat to ospreys in coastal Belize should be no surprise to us in New Jersey. Coastal development was a huge contributor to the decline of ospreys throughout coastal New Jersey. In Belize, there are many resorts on the coastal Cayes and the desire for more. Could this be the beginning of the decline of ospreys in Belize?? I hope not, as humans and ospreys can live alongside each other in very close proximity. To develop a Caye, mangroves are first cleared and then sand/coral is dredged onto the island to “fill” it in. Raising the elevation of the island allows buildings to be built and lovely white sand beaches to be manufactured for the enjoyment of humans (and sand flies!). During our survey we saw this in plain view. A nest on Long Coco Caye was still present in a large mangrove tree, however a huge pile of fill dredged into a pile right next to the nest. If this happened during the nesting season then there is no doubt that this nest failed…but, where were the adults?? The more we think about this work and the ospreys of Belize, the more concern we have for their overall safety and stability of their population.

A looming threat to Ridgway’s ospreys is development of coastal Cayes.

While scanning shorelines brown pelicans were a common sight around Placencia.

Kept or Unkept house on a coastal caye? You decide.

Sadly, evidence of humans is all over Belize. Welcome to the anthropocene.

The beauty of a disappearing horizon in coastal Belize. 

A brown pelican thermoregulating atop a red mangrove.

We kept moving along with our survey and ventured outside of the previous survey route to check a small Caye for a nest. Success! We found a nice nest atop a huge almond tree on Moho Caye. Bonus! There were also two large young (5-6 week old young) making this our first productive nest of the day! The island was private and occupied by a friendly caretaker. We talked to him about the ospreys, and he was happy to share the island with them. This just goes to show that ospreys and humans can coexist on the coast of Belize.

Can you spot the nest? 

No need to climb this nest. We wouldn’t be able to anyway. Next week we might bring a small drone to help survey tall nests like this one.

Two young visible along with an adult and loads of plastic bags. 🙁

The guardian. We were glad to see humans and ospreys getting along just fine on Moho Caye and hope to see this in the future too.

We continued to head north and back to Sittee River. Navigating along the edges of the mangrove islands would not have been possible with our experienced captain and his mate, Steve. They really made every survey go extremely smooth. Having boated for the majority of my life, I can attest to the fact that anything can go wrong at any time. You definitely do not want to get into trouble when boating offshore in Belize! There is few other boaters who could offer help, no patrolling of Coast Guard boats, no SeaTow/Boat US, and many islands are totally undeveloped and without freshwater. We are lucky to have had such a great crew to be able to get to us to where we needed to go and then back safely!

Navigating through tiny mangrove islands in search of nesting ospreys!

First mate Steve keeps an eye out while approaching the edge of a Caye.

Our experienced guide and captain Horace.

Guiding Horace through a cut along the edge of a Caye.

Fishing resort.

Siesta time!

Osprey siesta time!

The last nest we surveyed on our way back to Sittee River was one on Channel Caye. This nest was remarkable. It was built in a large dead mangrove and had two visible young. After closer inspection with my camera, we believed that their could be three young, so we decided to climb up and use a mirror to get a view into the nest. Jay T. eagerly climbed the short tree and saw three young. The female took off from the nest as the young played dead, as they do in New Jersey. She was not as upset as our ospreys get (Ridgway’s are less disturbed than NJ’s ospreys and hence less aggressive, IMO) and flew over the nest several times and then perched on a nearby branch, which allowed me to get some great photos of her. We were only by the nest for a couple minutes and quickly departed to let her return to the nest. This was the first time that Paul has ever seen three young in a Ridgway’s nest, so very cool for us to see and document! We surely hoped that all three survived to fledge. Usually by the time they reached the age that they were (around 3-4 weeks), then their chances of surviving were much more likely.

All things considered, there are many concerning threats to ospreys in Belize: nest abandonment, coastal development, plastic marine debris, possible persecution?, and the combined threats from the effects of climate change but we can only hope that from our work we can help improve their chances of surviving.

Stay tuned for Part III where we cover the next two surveys out and back from Turneffe Atoll and Calabash Caye!

Channel Caye female perched on her nest.

Jay peers into the nest.

Female looks on as we exit the area.

The third and elusive nesting!

A cut through to Sittee River.

Sunset on Sittee River.

Studying Ridgway’s Osprey of Belize: Part I

Friday, March 10th, 2017
CWF contributes to conservation of Belizean ospreys

by Ben Wurst, Habitat Program Manager

A male Ridgway’s osprey perched near its nest on a snag off Blue Ground Caye. Photo by Ben Wurst

When I first learned of the work being done by Dr. Paul Spitzer and Alan Poole to study the breeding population of Ridgway’s ospreys (Pandion haliaetus ridgwayi) in Belize, I was instantly captivated. I first met Paul at the Raptor Research Foundation Conference in Cape May last October where he explained the study and the need for partners to assist with this years survey. Some of the aspects that immediately drew my attention was the fact that the estimated size of the population there was around 50 pairs, that those pairs nest exclusively on the coastal cayes (mangrove islands), and that their estimated productivity rate was around .3-.4 young/active nest. The coast of Belize is approximately 170 miles long and protected by barrier reefs and these mangrove islands. (more…)

International Migratory Bird Day Series: Golden-Winged Warbler

Monday, May 9th, 2016
CWF is celebrating International Migratory Bird Day all week long

by Kelly Triece, Private Lands Biologist

Kelly Triece’s blog on the Golden-winged Warbler is the first in a series of five to be posted this week in celebration of International Migratory Bird Day (IMBD). IMBD 2016 is Saturday, May 14. This #birdyear, we are honoring 100 years of the Migratory Bird Treaty. This landmark treat has protected nearly all migratory bird species in the U.S. and Canada for the last century. 

 

Ruth Bennett, studying GWWA in their wintering habitat, with a recently banded Golden-winged Warbler Photo by Mayron Mejia

Ruth Bennett, studying GWWA in their wintering habitat, with a recently banded Golden-winged Warbler Photo by Mayron Mejia

The Golden-winged Warbler (GWWA), Vermivora chrysoptera, is a Nearctic-Neotropical Migrant songbird that spends half its life in Central or South America and the other half in North America. This small songbird is less than 5 inches long with a slim body and short tail. GWWA are most noted by their yellow-patched wings, yellow cap and black-and-white face.

 

Right now, GWWAs are migrating to their breeding habitat in North America. They return every spring to the Upper Mid-west and Appalachians, including New Jersey, where they find a mate, breed and rear their young. The breeding range of the Golden-winged Warbler extends along the Appalachians from the northern portion of Georgia in the south to Vermont in the north.

 

Our latest report from the online observation database, eBird, reported a Golden-winged Warbler sighting in Cameron County, Texas on May 3! They are currently migrating north, and do so mostly at night. GWWA migrate at night to avoid predation from day-time predators such as American crows or Blue jays. The skies are also friendlier at night with less turbulence, allowing the birds to stay the course more readily. In addition, migrating birds need to forage to maintain energy during the long migration and must do so during the day. So flying at night gives the bird’s ample time to chow down! Get ready New Jersey!

Golden-winged Warbler Photo by D. Kenny Golden

Golden-winged Warbler Photo by D. Kenny Golden

In September, after breeding season, Golden-winged Warblers migrate south, mainly through a corridor of states east of the Mississippi River and west of the Appalachians. The winter range for this species is southern Mexico and Central and South America, including Colombia and Venezuela. Migrants are seen most commonly in late April and May, and during September.

 

Recent studies have shown that Golden-winged Warblers can also migrate in response to storm events (Streby et al. 2015). While GWWAs migrate long distances twice a year to occupy their breeding and wintering habitat, they may also “mini-migrate” to avoid large storm systems. Last year, a study in Tennessee found that Golden-winged Warblers evacuated their breeding territories days before a large storm system. After the system they returned to their breeding grounds and continued to defend their territories and breed. This research is important as it may provide future insight into the energetic demands and fitness consequences of these “mini-migrations.” As climate change continues to increase the frequency and severity of large storms along the east coast the “mini-migrations” may impact the overall fitness of the species as the energetic demands of migrations are great (Streby et al. 2015).

 

Golden-winged warblers are threatened due to habitat loss in their breeding range and wintering range. Golden-winged warblers require early successional, young forest habitat to nest and raise their young. Young forest habitat, also known as scrub-shrub habitat, is new or regenerating forest that is less than 20 years old.  In its breeding range in North America, habitat loss has occurred as forests have matured. In the past 30 years, over 11,000 acres of upland shrub and emergent wetland habitat have been lost to succession in New Jersey. In a naturally occurring system, where fire, wind, flooding and other disturbances are not controlled by humans this age class would be more evenly distributed. In addition, loss of quality stopover and wintering habitat may also be contributing to declines. Golden-winged warblers are a federal species of concern and endangered in the state of New Jersey. Through management and proper forestry techniques, more diversity can be created to balance the age of the forest. This type of forestry management can help protect the Golden-winged warbler in its breeding range.

 

Learn More:

 

Kelly Triece is the Private Lands Biologist for Conserve Wildlife Foundation of New Jersey.

 

Reference: Streby, H. M., Kramer, G. R., Peterson, S. M., Lehman, J. A., Buehler, D. A., & Anderson, D. E. (2015). Tornadic Storm Avoidance Behavior in Breeding Songbirds. Current Biology, 25(1), 98-102. doi:doi:10.1016/j.cub.2014.10.079

 

Connecting the Life Cycle of a Golden-winged Warbler

Friday, April 29th, 2016
A Closer Look at Cutting-Edge Research on the Multi-Country, Migratory Life-Cycle of GWWA

by Kelly Triece, Private Lands Biologist

Don Jose Mendoza, Honduran wildlife conservation leader, holding a Golden-winged Warbler captured on his property in Cerro Agua Buena, Olancho, Honduras. Photo by Ruth Bennett.

Don Jose Mendoza, Honduran wildlife conservation leader, holding a Golden-winged Warbler captured on his property in Cerro Agua Buena, Olancho, Honduras. Photo by Ruth Bennett.

While in Honduras this February 2016, I had the opportunity to meet researchers studying the Golden-winged Warbler (GWWA) in their wintering habitat. The GWWA is Neotropical Migrant songbird that breeds in New Jersey, but migrates south for the winter. Golden-winged Warblers migrate south in September, mainly through a corridor of states east of the Mississippi River and west of the Appalachians. Their peak return migration to the Upper Mid-west and Appalachians, including New Jersey, occurs in late April where they find a mate, breed and rear their young.

 

This neo-tropical songbird is a species of special conservation concern in the U.S. and endangered in New Jersey, experiencing population declines due to loss of young forest habitat on their breeding grounds, habitat loss on their wintering grounds and hybridization with the Blue-winged Warbler (BWWA). The GWWA has experienced one of the steepest population declines of any songbird species in North America. The population size of the GWWA has decreased by an average of 2.6% every year, according to the USGS Breeding Bird Survey, since the survey began in 1966.  In particular, the Appalachian populations are now approaching a rate of -9% per year. Due to the difficulty of tracking birds over large distances, the effects of their multi-country, migratory life-cycle are poorly understood.

Ruth Bennett and Miguel Ramirez attaching a geolocator to a GWWA in Rio Dulce, Guatemala. Photo by Liam Berigan.

Ruth Bennett and Miguel Ramirez attaching a geolocator to a GWWA in Rio Dulce, Guatemala. Photo by Liam Berigan.

 

While many songbirds, migrate thousands of miles every winter, most research has focused on their breeding habitat in North America. Recently, researchers have begun exploring and understanding the importance of conserving the entire life-cycle of migratory birds or any wildlife species. Ruth Bennett, a Ph.D student at Cornell University is one such scientist. Ruth and collaborators at the American Bird Conservancy and Indiana University of Pennsylvania are linking breeding and non-breeding Golden-winged Warbler populations through geolocator technology. Ruth is also studying how changes in land use that lead to habitat loss on the wintering grounds of the GWWA are linked to population declines, with support from the US Fish and Wildlife Service Region 3.

Miguel Ramirez releases a Golden-winged Warbler with a geolocator in Rio Dulce. Photo by Ruth Bennett.

Miguel Ramirez releases a Golden-winged Warbler with a geolocator in Rio Dulce. Photo by Ruth Bennett.

 

Ruth Bennett, P.h.D. student, aims to connect the wintering habitat of the GWWA and its breeding habitat through her research in Central America. Between November 1, 2015 and March 15, 2016, Ruth and collaborators deployed geolocators on 145 GWWA and 35 BWWA at 9 sites from Belize through Panama, including Honduras. She will then recapture the individuals next winter, 2016-2017. These geolocators supply location data for up to 12 months, giving insight into the full life-cycle of the Golden-winged Warbler and closely-related Blue-winged warblers (BWWA). Through this research she will be able to establish the migratory pathways for all recaptured individuals. She will be able to compare how habitat loss on their wintering grounds and land use changes correlate with population trends described on the breeding grounds.

 

This will be one of the first geolocator studies to establish the connectivity of a migratory species from a winter grounds origin.  This research is important, because it creates a connection between non-profit, local and state governments in the United States and those in Latin America. This may increase funding opportunities and increase the efficiency of conservation action taken on the winter grounds. This research is especially important, as it forms one of the core informational components of the Golden-winged Warbler Non-breeding Season Conservation Plan (currently in review, soon to be available at gwwa.org). The conservation plan provides a regional strategy for conserving Golden-winged Warbler wintering habitat based on the wintering ecology of this species. The plan furthermore outlines conservation projects and budgets within high priority wintering focal areas that have been developed by Latin American partners. Ongoing research will be critical to ensure that these conservation actions effectively conserve the non-breeding habitat of this declining species.

This Golden-winged Warbler is fitted with a geolocator in Honduras. Photo by Ian Gardner.

This Golden-winged Warbler is fitted with a geolocator in Honduras. Photo by Ian Gardner.

 

Ruth has a small crew of local biologists who assist in her research in Latin America. Through her research in Honduras and Central America, Ruth has been able to connect with many local biologists and conservationists. It was great to meet Ruth in Honduras and learn about her research, which so important to New Jersey, but taking place so far away.

 

Our next Honduras blog, will feature our time with Ruth at the Feria de Aves Migratorias (Migratory Bird Festival) at the Universidad de las Agricultureal (Agriculture University) in Olancho, Honduras!

 

Learn More:

 

Kelly Triece is the Private Lands Biologist for Conserve Wildlife Foundation of New Jersey.

CWF Headed to Honduras to Study Golden-winged Warbler

Thursday, February 11th, 2016
CWF biologist Kelly Triece to visit Honduras to observe Golden-winged Warblers in their Wintering Habitat

by Kelly Triece, Private Lands Biologist

Golden-winged Warbler. Photo by D. Kenny Golden.

Golden-winged Warbler. Photo by D. Kenny Golden.

CWF is headed down to Central America to see one of New Jersey’s native songbirds! This time of year the Golden-winged Warbler (GWWA) is in Central and South America. The GWWA is Neotropical Migrant songbird that breeds in New Jersey, but migrates south for the winter. This songbird is a species of special conservation concern in the U.S. and endangered in New Jersey, experiencing population declines due to loss of young forest habitat.

 

Conserve Wildlife Foundation biologist Kelly Triece will be traveling to Honduras next week to observe the GWWA in its wintering habitat. While she is there, she will be learning more about the wintering habitat requirements of the Golden-winged Warbler as well as the current threats and challenges facing the species in this part of the world.

Young forest habitat managed for Golden-winged Warbler. Photo by Kelly Triece.

Young forest habitat managed for Golden-winged Warbler. Photo by Kelly Triece.

The management of early successional habitat, or young forest habitat, is important in New Jersey because it provides breeding habitat and post-fledging habitat for the Golden-winged Warbler. In the past 30 years, over 11,000 acres of upland shrub and emergent wetland habitat have been lost to succession in New Jersey.

 

Today, 80% of New Jersey forests are between 60-99 years old, while only 5% of the forests are between 0-19 years old. In a naturally occurring system, where fire, wind, flooding and other disturbances are not controlled by humans, this age class would be more evenly distributed. Through management and proper forestry techniques, more diversity can be created to balance the age of the forest.

 

The Golden-winged Warbler is not the only scrub-shrub dependent bird species considered to be at-risk. About 85% of shrub obligate birds and 35% of forest birds are on the decline in North America. Some of the declining species are Prairie Warbler, Field Sparrow, Northern Bobwhite and American Woodcock. Additionally, woodland breeding birds are also at risk because many rely on young forest habitat for post-fledging. Therefore, the management of young forest habitat is not only specific to the Golden-winged Warbler, it is also important for many other avian species. Furthermore, other wildlife such as insects, reptiles and mammals will benefit from increased flowering plants and foraging habitat.

 

CWF and our partners Natural Resources Conservation Service, New Jersey Division of Fish and Wildlife and New Jersey Audubon Society have worked with private landowners to create or restore over 225 acres of Golden-winged Warbler habitat since 2012 in New Jersey. Our managed forests have a statistically significant higher diversity of birds than unmanaged sites!

 

Stay tuned for Photos from the Field next week as Kelly travels to Central America!

 

Learn More:

 

Kelly Triece is the Private Lands Biologist for Conserve Wildlife Foundation of New Jersey.

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