Welcome, Guest. Please login or register.
December 02, 2023, 06:10:53 AM

Login with username, password and session length

Recent Topics

[December 01, 2023, 11:39:30 PM]

[December 01, 2023, 06:22:20 PM]

[December 01, 2023, 01:59:01 PM]

[December 01, 2023, 12:36:54 PM]

[December 01, 2023, 06:13:34 AM]

[November 30, 2023, 03:03:00 PM]

[November 29, 2023, 08:28:34 PM]

[November 28, 2023, 10:24:44 PM]

[November 28, 2023, 09:56:54 PM]

[November 28, 2023, 07:54:47 PM]

[November 28, 2023, 03:34:14 PM]

[November 28, 2023, 11:24:04 AM]

[November 28, 2023, 10:43:45 AM]

[November 28, 2023, 08:08:46 AM]

[November 28, 2023, 07:59:22 AM]

[November 28, 2023, 07:28:22 AM]

[November 27, 2023, 01:33:14 PM]

[November 27, 2023, 11:16:47 AM]

[November 27, 2023, 09:00:55 AM]

[November 27, 2023, 06:33:18 AM]

[November 26, 2023, 07:12:05 PM]

Support NCKA

Support the site by making a donation.

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Topics - Hojoman

Pages: [1] 2 3 ... 214
November 20, 2023

The California Department of Public Health (CDPH) has lifted the shellfish safety notification today related to sport-harvested mussels, scallops, and clams in San Mateo County. The safety notification was issued on July 28, due to dangerous levels of naturally occurring paralytic shellfish poisoning (PSP) toxins that can cause illness or death. Recent testing shows PSP toxins have decreased to safe or undetectable levels for bivalve shellfish in this area.

The notifications do not apply to commercially sold clams, mussels, scallops, or oysters from approved sources. State law permits only state-certified commercial shellfish harvesters or dealers to sell these products. Shellfish sold by certified harvesters and dealers are subject to frequent mandatory testing to monitor for toxins.

PSP toxins affect the nervous system, producing a tingling around the mouth and fingertips within a few minutes to a few hours after eating toxic shellfish. These symptoms are typically followed by loss of balance, lack of muscular coordination, slurred speech and difficulty swallowing. In severe poisonings, complete muscular paralysis and death from asphyxiation can occur.

You can get the most current information on shellfish advisories and quarantines by calling CDPH's toll-free Shellfish Information Line at (800) 553-4133 or viewing the recreational bivalve shellfish advisory interactive map. For additional information, please visit the CDPH Marine Biotoxin Monitoring Web page.

November 17, 2023

The California Department of Fish and Wildlife (CDFW) is continuing the temporary recreational crab trap restriction from the Sonoma/Mendocino county line to Lopez Point (Fishing Zones 3 and 4) and expanding the restriction to the California/Oregon state line to Cape Mendocino (Fishing Zone 1) due to presence of humpback whales and the potential for entanglement from trap gear. The recreational trap restriction for Fishing Zone 1 will go into effect on Sunday, Nov. 26, 2023, at 6 p.m. and continue in Zones 1, 3 and 4 until at least the next risk assessment. This means recreational crabbers must remove all traps in Zone 1 by the time the restriction goes into effect. CDFW reminds recreational crabbers that take of Dungeness crab by other methods, including hoop nets and crab snares, is allowed during a temporary trap restriction. The use of recreational crab traps in Fishing Zones 2 and 5 is still allowed. In addition, the Fleet Advisory issued for all Fishing Zones (1-6) for the recreational fishery remains in effect. CDFW encourages recreational crabbers to implement best practices, as described in the Best Practices Guide.

Pursuant to Fish and Game Code section 8672.2, CDFW Director Charlton H. Bonham delayed the northern California commercial Dungeness crab season, which had been scheduled to open on Dec. 1, 2023, due to poor crab meat quality test results for Mendocino, Humboldt and Del Norte counties (Fishing Zones 1 and 2). The commercial Dungeness crab fishery in this area will be delayed until at least 12:01 a.m. on Saturday, Dec. 16, 2023, pending another round of meat quality testing.

The commercial Dungeness crab fishery in Fishing Zones 3-6 will also remain delayed due to the presence of high numbers of humpback whales and the potential for entanglement with lines and traps in this fishery.

CDFW anticipates the next risk assessment will take place on or around Dec. 7, 2023, at which time Director Bonham will re-evaluate the temporary recreational crab trap restrictions and commercial fishery delay. That risk assessment is expected to inform the potential for a commercial fishery opener and modification of the recreational trap restriction. For more information related to the risk assessment process, please visit CDFW’s Whale Safe Fisheries page or more information on the Dungeness crab fishery, please visit www.wildlife.ca.gov/crab.

CA Regulations / Emergency White Sturgeon Regulations Now in Effect
« on: November 16, 2023, 06:57:23 PM »
November 16, 2023

The California Department of Fish and Wildlife (CDFW) announced today that emergency regulations enacted by the California Fish and Game Commission (Commission) last month to reduce the harvest of white sturgeon in state waters are now in effect, having been approved by the Office of Administrative Law.

The new regulations reduce the number of fish that can be kept to one per year, reduce the slot limit to 42-48 inches, cap the number of white sturgeon that can be possessed on a vessel at two per day and add seasonal closures to sturgeon fishing in key spawning areas.

The new regulations were enacted by the Commission following a joint recommendation by CDFW and angling groups. The emergency action was taken in response to long-term declines in adult white sturgeon populations as well as impacts of a harmful algal bloom (HAB) in the summer of 2022.

There are two sturgeon species in California: green sturgeon and white sturgeon. Green sturgeon are listed as a threatened species under the Federal Endangered Species Act. White sturgeon are listed in California as a Species of Special Concern.

Sturgeon are one of the oldest fish in existence with fossil records dating back more than 200 million years. Individual white sturgeon can live about 100 years and don’t start spawning until approximately 14 to 19 years old. Scientists estimate that white sturgeon in the Central Valley only spawn successfully every six to seven years. White sturgeon abundance has declined significantly from approximately 200,000 harvestable fish in 1997 to around 33,000 (recent five-year average). Sturgeon fisheries in California have closed multiple times in the past due to overharvest.

During the summer of 2022, a HAB in the San Francisco and San Pablo bays caused the death of tens of thousands of fish including at least 864 sturgeon. Most sturgeon experts believe there were likely thousands more sturgeon killed during the HAB, that sank to the bottom of bay waters and were not counted.

Harvest has been reduced to one white sturgeon for 2023 and 2024. Catch and release fishing for white sturgeon will still be allowed with a valid sturgeon report card after one sturgeon is kept except for closures outlined in California Code of Regulations, Title 14, Sections 5.80 and 27.95. The slot limit has been reduced to 42-48 inches, and a limit of two fish per vessel per day was added. Fishing for white sturgeon will also be closed seasonally upstream of the Highway 50 bridge on the Sacramento River and Interstate 5 bridge on the San Joaquin River from January 1 to May 31, 2024. This upstream area will re-open to catch and release fishing on June 1, 2024, once spawning season is over.

Sturgeon Report Cards ( https://wildlife.ca.gov/Conservation/Fishes/Sturgeon/Report-Card?utm_medium=email&utm_source=govdelivery ) purchased in the 2023 calendar year remain valid for the remainder of 2023. All reporting, tag and report card requirements remain in effect. Only one sturgeon harvest tag will be valid. Any remaining sturgeon harvest tags beyond one still in possession for the 2023 calendar year will be invalid for the remainder of 2023. Anglers that have already harvested one or more fish in 2023 will still be allowed to catch and release sturgeon for the remainder of 2023 with a valid Sturgeon Report Card. The changes to sturgeon harvest regulations may cause a delay in availability of 2024 sturgeon report cards and the single harvest tag.

Report cards for 2024 will be available for sale soon. Sturgeon Report Card requirements will remain in effect for 2024.

CDFW is currently working on a white sturgeon regulation package to allow for limited harvest. The regulation package is scheduled to go through the Commission regulation setting process with a target effective date of January 2025.

For more information visit CDFW’s sturgeon web page at https://wildlife.ca.gov/Conservation/Fishes/Sturgeon?utm_medium=email&utm_source=govdelivery. Questions can be sent to sturgeon@wildlife.ca.gov.

CA Regulations / Free Hunting Days
« on: November 16, 2023, 03:35:18 PM »
November 16, 2023

Question: When are the next California Free Hunting Days?

Answer: Under state law the California Department of Fish and Wildlife (CDFW) Director designates two Free Hunting Days. In this license year, they are Nov. 25, 2023, and April 13, 2024. On these days, eligible California residents may hunt without purchasing a California hunting license, provided other requirements are met.

Those requirements include proof of completion of a hunter education course, possession of a valid Free Hunt Days Registration and any required tags, federal entitlements and entry permits. All hunting participants in Free Hunting Days must be accompanied by a hunter at least 21 years of age who possesses a valid California hunting license.

The dates were chosen intentionally to provide the widest variety of hunting opportunities and options for people trying hunting. On Nov. 25, waterfowl seasons and many upland game seasons, from rabbit and squirrel to dove, pheasant, quail and fall wild turkey will be open in various zones throughout the state. April 13, 2024, was chosen with two other popular species in mind, wild pig and wild turkey. More information is available at CDFW’s Free Hunting Days webpage at https://wildlife.ca.gov/Licensing/Hunting/Free-Hunting-Days.

CA Regulations / Best Time to Visit Nimbus Hatchery
« on: November 16, 2023, 03:34:58 PM »
November 16, 2023

Question: Is this the best time of the year to watch salmon spawning at Nimbus Hatchery, east of Sacramento?

Answer: November is the start of a four month stretch when the Nimbus Fish Hatchery is most busy, with Chinook salmon returning up the American River for about two months, and then steelhead trout make that trip in January and February. This hatchery is one of 21 operated by CDFW and it attracts the greatest number of visitors – about 65 thousand people annually in addition to about 10 thousand children on field trips.

CDFW Interpretive Services Supervisor Laura Drath said the hatchery is back to full strength after the pandemic, meaning all tours and public spaces are available. The list of activities includes play areas for children and a preschool story and craft program called Tot Time on Sunday mornings. Visitors can feed fish in the raceways, then walk along the river bluff to see salmon in their natural habitat. Finally, it's also possible to watch as fish filled with eggs make their way up the fish ladder to the processing room where hundreds of thousands of eggs are extracted and then raised on-site until they’re large enough for placement into the river. The Nimbus Hatchery produces about 4.5 million Chinook salmon and 430,000 steelhead trout each year.

This hatchery is widely visited and visitor-friendly because it’s located so close to a populated urban area (about 20 miles east of Sacramento). Drath said this facility is in a great position to represent the important work being done by CDFW.

The Nimbus Fish Hatchery is open to the public every day of the year except Christmas Day (rain or shine).

CA Regulations / Oil Spill Fingerprints
« on: November 16, 2023, 03:34:38 PM »
November 16, 2023

Question: Can CDFW track down the source of a mysterious oil spill?

Answer: Within CDFW is the Office of Spill Prevention and Response (OSPR). That’s where the Petroleum Chemistry Lab (PCL) has a staff of chemists whose primary task is determining where spilled oil came from. Hundreds of oil spills or leaks occur in the state annually, with incidents ranging from tanker truck rollovers to pipeline leaks to natural offshore seeps. When it’s not obvious which company or facility is the source of a spill, the PCL steps in.

Petroleum is a mixture of thousands of individual components that indicate the geographic location, age, thermal characteristics and organisms of a geologic oil reservoir. These factors create unique signatures or fingerprints that help chemists identify one oil sample from another. When oil is collected by CDFW during an investigation, OSPR’s scientists can identify the source of that spill by comparing the fingerprints to samples from the most likely potential sources. That work can lead to the collection of fines and even criminal charges in cases when the responsible party isn’t admitting fault. The PCL is one of just a handful in the country doing this work.

General Talk / Razor Clam Fishery Closed in Del Norte County
« on: November 10, 2023, 09:14:49 PM »
November 9, 2023

The California Department of Fish and Wildlife (CDFW) Director has closed the recreational razor clam fishery in Del Norte County following a recommendation from state health agencies that the consumption of razor clams in the area poses a significant threat for domoic acid exposure.

Domoic acid is a neurotoxin produced by Pseudo-nitzschia, a naturally occurring single-celled, marine alga, under certain ocean conditions. Bivalve shellfish, like clams and mussels, accumulate the toxin without being harmed. Razor clams are known to bioaccumulate domoic acid and it may not clear their system until long after a Pseudo-nitzschia bloom has abated.

Razor clam sampling from Crescent Beach in Del Norte County in early November found clams exceeding the current federal action level for domoic acid of greater than or equal to 20 parts per million.

Domoic acid poisoning in humans may occur within minutes to hours after consumption of affected seafood and can result in signs and symptoms ranging from vomiting and diarrhea to permanent loss of short-term memory (Amnesic Shellfish Poisoning), coma or death. There is no way to prepare clams that will remove the toxin – cooking and freezing have no effect.

CDFW will continue to work with the California Department of Public Health (CDPH) and Office of Environmental Health Hazard Assessment to collect, monitor and analyze razor clams to determine when the recreational clam fishery in Del Norte County can reopen safely.

While the recreational fishery in Humboldt County is currently open, razor clam sampling is ongoing. If domoic acid levels exceed federal action levels, the fishery will be closed. CDFW reminds clammers that the daily bag limit for razor clams is 20 and the first 20 clams dug must be retained regardless of size or condition. Each person is required to keep a separate container for their clams and is not allowed to commingle their take with another person when digging and transporting clams to shore.

For more information, please refer to Title 14, California Code of Regulations sections 29.20 and 29.45 for razor clam regulations that can be accessed on CDFW’s website.

For more information on any fishery closure or health advisories, please visit CDFW’s ocean health advisories website.

To get the latest information on current fishing season closures related to domoic acid, please call CDFW’s Domoic Acid Fishery Closure Information Line at (831) 649-2883.

For the latest consumption warnings, please call the California Department of Public Health’s Biotoxin Information Line at (510) 412-4643 or toll-free at (800) 553-4133.

CA Regulations / Rattlesnakes at High Elevation
« on: November 03, 2023, 08:03:29 AM »
November 2, 2023

Question: I was surprised on a recent hike in the Tahoe National Forest to see a rattlesnake since we were at about 7,500 feet in elevation. Is that unusual?

Answer: Based on the picture provided, that’s a western rattlesnake and it’s not unusual to see them at high elevations. There are seven species of rattlesnakes found in California and western rattlesnakes are the most widespread, found throughout the state (except in desert regions) from sea level to 11,000 feet, although they are much rarer above 7,000 feet.

Rattlesnakes use rock mounds, dense vegetation and mammal burrows for thermoregulation, cover from predators and overwintering. Rattlesnakes, like all reptiles, are ectotherms, meaning their metabolic rate and bodily functions are controlled by the temperature in the environment around them. When temperatures consistently drop below approximately 60 degrees Fahrenheit, rattlesnakes go into a hibernation-like state called brumation which can last several months. Rattlesnakes living at higher elevations where it’s colder are typically smaller, due to a shortened time when they can be active and grow.

CA Regulations / Fish Trucked to Bays
« on: November 03, 2023, 08:03:10 AM »
November 2, 2023

Question: Is trucking fish still necessary if the drought is over?

Answer: Drought conditions have played a major role in the decision to use trucks to distribute millions of hatchery-raised salmon to San Pablo and San Francisco bays. During the last multi-year drought, CDFW transported young salmon to more suitable locations due to low river flows and elevated water temperatures, which can be a lethal mixture for the fish.

CDFW salmon hatcheries have traditionally taken a diverse approach in planning strategies used to release fall-run Chinook salmon smolts. Even on the wettest of years the department will incorporate components of releases not just into the rivers next to our hatcheries, but at downstream locations like the San Pablo and San Francisco bays. Releases have also occurred into the ocean, specifically supporting our ocean harvest enhancement programs for anglers. The different tactics help reduce the risk for the overall population, if one of the groups happens to experience losses.

CDFW can track groups of hatchery origin fish as juveniles on their seaward migration and as adults in angler catch reports and when they return to their place of origin to spawn, by retrieving coded wire tags implanted at the hatchery. This data helps inform discussions on the performance of each release strategy and guide decision making on changes to release plans employed each year.

CA Regulations / Wildlife Incident Reporting
« on: November 03, 2023, 08:02:53 AM »
November 2, 2023

Question: Why is it helpful to CDFW to have people fill out wildlife incident reports?

Answer: The Wildlife Incident Reporting (WIR) system ( https://apps.wildlife.ca.gov/wir )is helpful to CDFW as the department continues to learn about the behavior and location of wildlife through reported sightings and encounters. People reporting a wildlife incident are asked for their contact information, the date and location of the incident, the species involved and if they considered it a rare sighting. The information provided to CDFW assists the department in its mission of managing California’s diverse wildlife populations.

When reports are made about conflict with wildlife, the local biologist or human-wildlife-conflict specialist is automatically alerted so they can contact the reporting party to learn more about the incident and offer helpful solutions to preventing additional conflicts. The highest rate of incident reporting happens in late summer and early fall, but it’s not clear to CDFW if that’s when wildlife is most active or when people are more likely to be outdoors experiencing these encounters. The WIR system receives between four and six thousand reports a year with bear, coyote and mountain lion incidents being the most common.

The public is encouraged to report all their wildlife encounters via the WIR. The more people that use the reporting tool, the better and more helpful the data is. The goal of data collection is to assist the department in helping the public respond to wildlife issues. Please see the WIR page.

October 27, 2023

The California Department of Public Health (CDPH) announced today that the statewide annual quarantine on mussels taken for human consumption by sport-harvesters from California's ocean waters ends at midnight on Tuesday October 31, 2023, for all coastal counties except San Mateo and San Luis Obispo. 
CDPH warns against eating sport-harvested bivalve shellfish (including mussels, clams, and scallops) from San Mateo and San Luis Obispo counties, due to elevated levels of PSP toxins detected in mussels from these counties and/or absence of recent data to lift the advisory. The naturally occurring PSP toxins can cause illness or death in humans. Cooking does not destroy the toxin.

On October 27, 2023, CDPH also lifted the September 7, 2023, shellfish safety notification related to sport-harvested mussels, scallops, and clams in Mendocino County. The safety notification was issued due to dangerous levels of PSP toxins. Recent testing shows PSP toxins have decreased to safe or undetectable levels for bivalve shellfish in this area.

Domoic acid and paralytic shellfish poisoning (PSP) toxins remain at low or undetectable levels along all other portions of the California coast. Concentrated levels of PSP toxins and domoic acid can develop in mussels and other bivalve shellfish when they feed on certain naturally occurring marine plankton that can increase during favorable environmental conditions.

The annual quarantine on sport-harvested mussels for human consumption, which typically runs May 1 through October 31, is intended to protect the public from shellfish poisoning caused by marine biotoxins. There have been no reports of shellfish related poisonings in California during this quarantine period.

PSP toxins affect the central nervous system, producing a tingling around the mouth and fingertips within a few minutes to a few hours after eating toxic shellfish. These symptoms are typically followed by loss of balance, lack of muscular coordination, slurred speech, and difficulty swallowing. In severe poisonings, complete muscular paralysis and death from asphyxiation can occur.

Domoic acid toxin can cause amnesic shellfish poisoning. Symptoms of amnesic shellfish poisoning can occur within 30 minutes to 24 hours after eating toxic seafood. In mild cases, symptoms may include vomiting, diarrhea, abdominal cramps, headache, and dizziness. These symptoms disappear within several days. Severe cases may experience trouble breathing, confusion, disorientation, cardiovascular instability, seizures, excessive bronchial secretions, permanent loss of short-term memory, coma or death.

CDPH's shellfish sampling and testing programs issue warnings or quarantines when needed. Local health departments, various state, federal and tribal agencies, community groups and others participate in the monitoring program. Residents and community groups interested in volunteering to assist with the testing program should email redtide@cdph.ca.gov or call (800) 553-4133.

Updated information about current conditions is available by calling the Shellfish Information Line at (800) 553-4133 or viewing the recreational bivalve shellfish advisory interactive map, which includes the recent sample results. More information can be found on the CDPH Marine Biotoxin Monitoring web page or the CDPH Annual Mussel Quarantine - Frequently Asked Questions (FAQ) web

October 27, 2023

The recreational take of Dungeness crab using crab traps will be temporarily restricted between the Sonoma/Mendocino county line and Lopez Point, Monterey County (Fishing Zones 3 and 4) when the season opens on Saturday, Nov. 4 due to presence of humpback whales and potential for entanglement from trap gear. Recreational take of Dungeness crab by other methods, including hoop nets and crab snares, is not affected by the temporary trap restriction and is allowed statewide beginning Nov. 4, 2023. The use of recreational crab traps in Fishing Zones 1, 2, 5 and 6 is also allowed. In addition, a Fleet Advisory has been issued for all Fishing Zones (1-6) for the recreational fishery. The commercial Dungeness crab fishery south of the Sonoma/Mendocino county line was scheduled to open on Nov. 15, 2023 in Fishing Zones 3, 4, 5 and 6. However, the season opener has been delayed in those zones due to presence of high numbers of humpback whales.

“Large aggregations of humpback whales continue to forage between Bodega Bay and Monterey and allowing the use of crab traps would increase the risk of an entanglement in those fishing zones,” said California Department of Fish and Wildlife (CDFW) Director Charlton H. Bonham. “We will continue to work with both the recreational and commercial Dungeness crab fisheries to protect whales while working to maximize fishing opportunity. We appreciate the ongoing commitment by both the recreational and commercial fleets and the California Dungeness Crab Fishing Gear Working Group to manage entanglement risk in this iconic fishery."

CDFW reminds anglers that the deployment and use of crab traps in any recreational crab fishery (including rock crab) is temporarily restricted in Fishing Zones 3 and 4 until lifted by the CDFW Director. Recreational crabbers should also implement best practices, as described in the Best Practices Guide. In addition, if adopted, proposed regulations for recreational groundfish will allow the deployment of Dungeness crab traps shoreward of the 50-fathom Rockfish Conservation Area (RCA) boundary line (50 CFR Part 660, Subpart G) when groundfish are onboard. Until the emergency regulations are in place, no fishing gear of any type may be deployed shoreward of the 50-fathom RCA line when shelf rockfish, slope rockfish or lingcod are onboard.

CDFW anticipates the next risk assessment will take place on or before Nov. 17, 2023, at which time the Director will re-evaluate risk for the Dungeness crab fisheries. That risk assessment is expected to inform the potential for a statewide commercial fishery opener on Dec. 1 and the potential to modify the recreational trap restriction.

For more information related to the risk assessment process, please visit CDFW’s Whale Safe Fisheries page or more information on the Dungeness crab fishery, please visit www.wildlife.ca.gov/crab.

CA Regulations / Collaring Wildlife
« on: October 26, 2023, 10:05:04 AM »
October 19, 2023

Question: How do wildlife collars work and what factors are taken into consideration before the California Department of Fish and Wildlife (CDFW) attaches them?

Answer: CDFW attaches collars to animals to study their behaviors, movements and habitat use as a population or as an individual. Collars can also be used to track and manage animals that have the potential of becoming involved in conflict with humans.

Age, health and the weight of the animal are major factors in the decision to attach collars. Collars can appear bulky, but CDFW ensures it does not put anything on an animal that is more than five percent of its body weight. More often collars are between one and three percent of the animal’s weight. Collars are specifically designed for the species, age, weight and purpose of the data collection needs. Generally, younger animals are equipped with lighter collars that are worn for a shorter duration. Adult animals may wear collars for up to two years. Most collars are programmed to drop off after they’ve gathered and sent enough data and prior to battery failure. If an animal begins to outgrow the collar it’s wearing, CDFW can trigger a drop-off mechanism that frees the animal from the device. Cotton spacers integrated into the belting are commonly used as a failsafe in the event of collar failure.

CDFW currently has hundreds of collars on a wide variety of wildlife including desert bighorn sheep, bears, deer, elk, mountain lions, bobcats, gray wolves, Sierra Nevada red fox and others. CDFW partners with the Fresno Chaffee Zoo in a project that even has collars on blunt-nosed leopard lizards.

Wildlife collars communicate with CDFW scientists in two ways. Some use VHF radio signals, which require researchers to be relatively close to detect the signal. More advanced collars that use GPS can send data via satellite to computers hundreds of miles away. Those collars also receive signals if CDFW would like to alter settings or have the collar drop off the animal. When collars fall off or are removed in the wild, CDFW retrieves those devices for later use.

CA Regulations / Crows in Sacramento (and other cities)
« on: October 26, 2023, 10:04:42 AM »
October 19, 2023

Question: Why does it seem there are so many crows in urban Sacramento?

Answer: Many cities around the U.S. have experienced an increase in urban American crow populations in recent years. Crows are social and often sleep or roost in groups overnight. Urban areas can be favorable for roost sites, providing sizeable and numerous trees for sleeping. Also, an urban environment with lots of concrete, asphalt and buildings can trap the heat during the day, providing a warmer environment than the surrounding open areas. There also may be fewer predators in urban areas versus more natural settings. Another reason is that cities often have abundant food that provides food waste, which crows can use as a part of their diet. Lastly, the larger the group the more likely a predator or other threat can be detected by an individual in the group and alert other crows in the roost.

Pages: [1] 2 3 ... 214