Thursday, June 3, 2021

Newsletter


Chapala Birders Newsletter, June 2, 2021
Five New Species Seen in May
New species for the Lake Chapala Area were:

  • Fan-tailed Warbler sighted by Carlo Cuevas and Ingrid Tello on the main trail up Cerro Viejo. This is an uncommon bird occurring from Mexico to Nicaragua.
  • Spotted Towhee seen by Carlo and Ingrid on the same trail. This is a common bird of the western US and northern Mexico, not normally seen this far south..
  • Masked Tityra seen by Nicola Cendron and two visiting birders from Guadalajara on the Allen Lloyd Trail. This is a common bird in coastal regions of Mexico, but not normally seen at our altitude.
  • Slaty Vireo seen by Nicola and visitors on the Caracol Trail to the Oak Forest. This is a rare endemic bird - see the feature section below.
  • Western Screech Owl identified by Carlo Cuevas after it flew into a house in Jocotepec. This is a tiny owl, strictly nocturnal, common in western US and and Mexico.

This is incredible. How is it possible to suddenly add five new species to a list of 335 species accumulated over a fifty-year period of observations by resident and visiting birders and ornithologists? The answer is that now we have some younger, sharp-eyed birders who are willing to spend more time exploring the hiking trails going up our mountains.

Other interesting sightings last month included:

  • A Spotted Owl photographed by Nicola Cendron on the Caracol Trail. This is only the second sighting of this large night-hunting owl in our mountains.
  • An unusual Boat-billed Flycatcher seen in Chapala by visiting birder John Bruin.

Note that our definition of the "Lake Chapala Area" is all land and water within 15km of the shores of the lake.
Featured Bird: Slaty Vireo
A Slaty Vireo as seen in Chapala in May.
  • The Slaty Vireo is a rare bird found only in Mexico, occurring on the west coast from Jalisco to Oaxaca. We are at the upper edge of its range.

  • It inhabits scrubby pine-oak forests and low dense brush, at higher altitudes above sea level.

  • It forages close to the ground and is known to be skulking - very clever at remaining hidden.

  • It makes a tiny nest of plant materials at low to mid levels in a bush or tree.

  • Food is primarily insects gleaned from leaves or from the ground, supplemented by fruit in season.
Notes on Migration - Part Two
Where do birds get the energy to fly so far?

Last month we noted that some birds migrate locally to lower altitudes, some migrate a few thousand miles to nest in regions in the north that are covered with snow in the winter, and some are super flyers summering in the arctic and wintering in the general area of New Zealand.

Physiological research has been conducted on medium-distance migrators such as Swainson's Thrushes (3,000 miles), super migrators such as Bar-tailed Godwits (7,000 miles) and Hummingbirds (2,000 miles) for whom migration is most stressful because normally they carry no reserves and cannot survive more than a few hours without food.

Now let's look at the physiological adaptations:

  1. Fat build up. At least two weeks before migration birds bulk-up by eating as much food as they can. This food is converted into fat which is deposited in different body cavities. Fat is known to be light-weght and efficient, containing much more energy per gram than carbohydrate or protein. Hummingbirds typically double their weight before starting migration.
  2. Shrinking organs. In order to make room for fat in many parts of the body, Bar-tailed Godwits are able to reduce the size of their liver, kidneys and digestive tract by a quarter.
  3. Emergency muscle reduction. If it becomes necessary with adverse winds or longer than expected flying time to a good feeding stop, birds will consume muscle tissue (but not the flying muscles of course). After migrating, birds will rebuild their muscles and organs back to regular size.
  4. Reduced sleep. Birds normally sleep at night, but in migration most birds will fly all night. Swainson's Thrushes are able to shut down one half of the brain for nine seconds at a time to rest while the other half manages the flying tasks.

While the fall migration is a slower more casual exercise, the spring migration is more stressful for two important reasons. First is the pressure to arrive on time. It is vital that birds arrive at their breeding grounds (usually where they were born) within a two week window. Arriving too early means it's too cold and risks snow and ice and less insects to eat. Too late means other birds will have reserved the best nesting spots. Second, is the combined necessity of eating a a great deal of food to rebuild the internal organs, at the same time as finding a mate and a good nesting spot.
Bird-walks and Trips
We are proposing to gradually get back to normal with larger groups, but masks will be worn in public in compliance with regulations.

Our bird-walks are open to all those interested in birds, both beginners and experienced birders. Just bring binoculars. We always have knowledgeable birders on hand to identify the species.You must reserve a place by email (chapalabirders@yahoo.com) at least 2 days ahead of each bird-walk or bird trip. Please note that we will try to limit car trips to four vehicles because larger convoys are hard to manage when trying to stop on country roads to look at the birds. If you are being given a ride, we suggest you make a contribution to your driver for gas and tolls (perhaps $50-100 pesos for a half day outing, $150-200 pesos for a day trip).

On Wednesday June 9, we will leave at 8.15 for the Rosa Amarilla Loop (60 minutes drive) from Donas Donuts. Expect to see a variety of grassland birds and possibly a White-tailed Hawk. Bring refreshments for the morning and sandwiches for the 12.30 lunch stop. We will be back about 3.00 pm. You must reserve - email John at chapalabirders@yahoo.com at least 2 days ahead saying if you can bring a vehicle or whether you are looking for a ride.

On Tuesday June 15, we will meet at 8.15 at the trail head to hike a mile or more up the Allen Lloyd Trail which has lots of underbrush in which birds love to hide. Expect to see Western Wood-Pewee and hear the Happy Wren - if we are lucky.
How to get to the trail head: Drive up the Libramiento a half mile from the traffic light at Walmart, and park on the north side of the road next to the new hospital.across from the Radisson Blu / El Dorado Condominium towers.

On Thursday June 24, we will leave at 8.15 for the Lake Cajititlan Marsh (30 minutes drive) from the gas station on the Chapala-Guadalajara highway at the intersection of the Ajijic Libramiento. We expect to see a variety of marsh and lake birds such as Black-necked Stilt, Snowy Egret, and perhaps American Avocet. You must reserve - email John at chapalabirders@yahoo.com at least 2 days ahead saying if you can bring a vehicle or whether you are looking for a ride.
Birdwalk & Trip Reports
On May 6, a group of six of us went to Villa Corona to see birds at Lake Atotonilco. We saw American Avocet, Red-winged Blackbird, American Pipit, Wood Stork, as well as Black-bellied, Collared and Snowy Plovers, and 120 Roseate Spoonbills scared up by a low-flying ultra-light. The day's total was 70 species.

On May 16 we had eight keen birders out to explore the Lakeshore east of Chapala including the Pumping Station. We saw 42 species including White-tailed Kite, Western Wood Pewee, Lesser Yellowlegs, Black-necked Stilt and Black-bellied Whistling Duck.

On May 26 we went further afield to Tapalpa with just three birders. The road across the Sierra goes up to 8,000 feet. We identified 30 species including Loggerhead Shrike, Striped Sparrow, Mountain Trogon, Acorn Woodpecker, Red-tailed Hawk, Eastern Bluebird and Buff-breasted Flycatcher.
Monthly Sightings List
Here are the 132 species sighted around Lake Chapala in May:

Ani, groove-billed
Becard, rose-throated (Ac)
Bobwhite, northern (Ch)
Brushfinch, rufous-capped (Ch)
Bunting, lazuli (Sa)
Bunting, painted (Sa)
Bunting, varied
Bushtit
Caracara, crested
Coot, American
Cormorant, neotropic
Cowbird, bronzed
Cowbird, brown-headed
Cuckoo, squirrel
Dove, common ground
Dove, Eurasian collared
Dove, Inca
Dove, mourning
Dove, white-tipped
Dove, white-winged
Duck, black-bellied whistling (Ps)
Duck, Mexican
Egret, cattle
Egret, great
Egret, snowy
Elaenia, greenish
Euphonia, elegant (Sa)
Finch, house
Flycatcher, ash-throated
Flycatcher, boat-billed (Ch)
Flycatcher, buff-breasted (Ch)
Flycatcher, cordilleran
Flycatcher, dusky-capped
Flycatcher, gray silky
Flycatcher, social
Flycatcher, vermilion
Gallinule, common
Goldfinch, lesser
Grackle, great-tailed
Grebe, pied-billed
Grosbeak, black-headed
Grosbeak, blue
Gull, ring-billed
Hawk, Cooper's
Hawk, red-tailed
Heron, black-crowned night
Heron, little blue
Heron, tri-colored
Hummingbird, berylline
Hummingbird, broad-billed
Hummingbird, Rivoli's (Sc)
Hummingbird, sparkling-tailed
Hummingbird, violet-crowned
Hummingbird, white-eared (Ch)
Ibis, white-faced
Jacana, northern
Killdeer
Kingbird, Cassin's
Kingbird, thick-billed
Kingbird, tropical
Kiskadee, great
Kite, white-tailed (Ps)
Mockingbird, blue
Mockingbird, northern (Pz)
Motmot, russet-crowned
Nighthawk, lesser
Nightjar, buff-collared (Pz)
Oriole, black-backed
Oriole, black-vented
Oriole, streak-backed
Osprey
Owl, ferruginous pygmy
Owl, great horned
Owl, spotted (Ch)
Owl, western screech (Jo)
Parakeet, monk
parrow, rusty-crowned ground
Pelican, American white
Pewee, greater
Pewee, western wood
Phoebe, black
Pigeon, rock
Raven, common
Robin, American (Ch)
Robin, rufous-backed
Sandpiper, spotted (Av)
Seedeater, cinnamon-rumped
Shrike, loggerhead
Siskin, pine (Ch)
Solitaire, brown-backed
Sparrow, chipping
Sparrow, house
Sparrow, rufous-crowned (Sa)
Sparrow, rusty (Ch)
Sparrow, stripe-headed
Stilt, black-necked
Swallow, barn
Swallow, cliff
Swallow, northern rough-winged
Tanager, flame-colored
Tanager, hepatic
Tanager, western
Teal, cinnamon
Tern, Forster's
Thrasher, curve-billed
Thrush, orange-billed nightingale
Tityra, masked (Sa)
Towhee, canyon
Towhee, spotted (Ch)
Tyrannulet, northern beardless
Vireo, golden
Vireo, plumbeous (Ch)
Vireo, slaty (Ch)
Vireo, warbling
Vulture, black
Vulture, turkey
Warbler, fan-tailed (Cv)
Warbler, rufous-capped
Warbler, Wilson's (Ch)
Warbler, yellow
Waxwing, cedar (Sa)
Woodcreeper, white striped (Ch)
Woodpecker, acorn
Woodpecker, golden-fronted
Woodpecker, ladder-backed
Wren, Bewick's
Wren, canyon
Wren, happy
Wren, spotted
Yellowlegs, lesser
Yellowthroat, common
Yellowthroat, gray-crowned (Sa)
Sighting Location codes:

Ac - Ajijic: La Cristina / El Bajio
At - Trails above Ajijic
Av - Ajijic village
Ca - Lake Cajititlan & marsh
Ch - Chapala
Ct - Caracol Trail / Int'l School
Cv - Cerro Viejo
Dm - Dike: Jamay to Malteraña
Dp - Dike: Maltaraña to La Palma
Hv - Hidden Valley oak forest
Ja - Jamay
La - La Cañada-Hidden Valley
Jo - Jocotepec
Ld - Lerma & Duero rivers
Oc - Ocotlan
Pe - Petatan area
Ps - Pumping Station/Santa Cruz
Pt - San Pedro Tesistan area
Pz - San Pedro Itzican area
Ra - Rosa Amarilla loop
Rc - Santa Rosa/Carnero dam
Rp - Riberas del Pilar & canyon
Sa - San Antonio/Allen Lloyd Trail
Sc - San Juan Cosala
Sn - San Nicholas/Golf Club
Tz - Tizapan canyon
Te - San Juan Tecomatlan / Mezcala
Tr - Las Trojes / oak forest
Tu - Tuxcueca / San Luis Soyatlan
Xt - Ixtlahuacan / Las Campanillas
Lake Chapala Birders is an informal group of bird observers led by John and Rosemary Keeling.

We like to hear of bird sightings at: chapalabirders@yahoo.com.

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